WO2025223565A1 - Charger and charging system - Google Patents

Abstract

Disclosed in the present application are a charger and a charging system. The charger comprises a power supply plug and a temperature control switch, the power supply plug being connected to a charging cable, and the temperature control switch being connected to the charging cable. By providing the temperature control switch and controlling the temperature control switch to be turned off in the case of over-temperature, the charger stops charging, reducing the safety risk of the charger.

Description

Charger and charging system

This application claims priority to the following Chinese patent application, the entire contents of which are incorporated herein by reference.

1. A Chinese patent application filed with the Chinese Patent Office on April 26, 2024, with application number 202410518009.5 and invention title "Charger and Charging System";

2. A Chinese patent application filed with the Chinese Patent Office on May 31, 2024, with application number 202410702465.5 and invention title "Charger and Charging System Having the Same";

3. A Chinese patent application filed with the Chinese Patent Office on May 31, 2024, with application number 202410704309.2 and invention title "Charger and Charging System";

4. A Chinese patent application filed with the Chinese Patent Office on May 31, 2024, with application number 202410702550.1 and invention title "Charger and Charging System".

Technical Field

This invention relates to the field of electronic circuit technology, and more specifically to a charger and charging system.

Background Technology

If a charger malfunctions during charging and cannot stop charging in time, there is a safety risk.

Summary of the Invention

One objective of this application is to provide a new technical solution for a charger and charging system.

According to a first aspect of this application, a charger is provided, comprising a power plug and a temperature control switch. The power plug is connected to a charging cable, and the temperature control switch is connected to the charging cable. The charger stops charging when the temperature control switch disconnects due to over-temperature conditions.

Optionally, in some embodiments, the temperature control switch is disposed in the power supply plug, and the power supply plug includes a first segment of a first phase wire, a second phase wire, and a ground wire; the charger further includes a function box, which includes a first voltage detection circuit, a first controller, and a second segment of the first phase wire. When the power supply plug is inserted into a mains socket, the first voltage detection circuit is used to detect the voltage between the second end of the first phase wire and the second phase wire, or the voltage between the second end of the first phase wire and the ground wire; the first controller is used to determine whether the temperature control switch is open based on the voltage, and when the temperature control switch is open, the first controller is also used to determine a protection strategy based on the cumulative number of times the temperature control switch has been opened after the power supply plug is inserted into the mains socket; the temperature control switch is connected between the first segment of the first phase wire and the second segment of the first phase wire.

Optionally, in some embodiments, the temperature control switch includes a temperature spring.

Optionally, in some embodiments, the functional box further includes a first power supply for supplying power to the first controller.

Optionally, in some embodiments, the first input terminal of the first power supply is connected to the first segment of the first phase line, the second input terminal of the first power supply is connected to the second phase line, and the output terminal of the first power supply is connected to the power supply terminal of the first controller.

Optionally, in some embodiments, when the power supply plug is inserted into the AC socket, the first power source powers the first controller, and the first controller stores a cumulative disconnection count of 0; after the power supply plug is inserted into the AC socket, each time the temperature control switch is detected to be disconnected, the first controller increments the cumulative disconnection count by 1; when the power supply plug is disconnected from the AC socket, the first power source stops powering the first controller, and the first controller stores a cumulative disconnection count of zero.

Optionally, in some embodiments, the power supply plug further includes a temperature sensor; the functional box further includes a temperature detector, a first output terminal of the temperature sensor is connected to a first input terminal of the temperature detector, a second output terminal of the temperature sensor is connected to a second input terminal of the temperature detector, and the output terminal of the temperature detector is connected to a first input terminal of the first controller; the temperature detector is used to determine the temperature of the temperature sensor based on the voltage at the first input terminal and the second input terminal of the temperature detector.

Optionally, in some embodiments, the first controller is further configured to determine whether the temperature control switch is functioning properly based on the temperature of the temperature sensor and the state of the temperature control switch.

Optionally, in some embodiments, the first controller is further configured to: when the temperature of the temperature sensor exceeds the temperature control switch If the upper limit temperature is disconnected and the temperature control switch is closed, the first controller determines that the temperature control switch is malfunctioning; if the temperature of the temperature sensor is lower than the lower limit temperature for closing the temperature control switch and the temperature control switch is open, the first controller determines that the temperature control switch is malfunctioning; if the temperature of the temperature sensor is lower than the lower limit temperature for closing the temperature control switch and the temperature control switch is closed, the first controller determines that the temperature control switch is normal; if the temperature of the temperature sensor exceeds the upper limit temperature for disconnecting the temperature control switch and the temperature control switch is open, the first controller determines that the temperature control switch is normal.

Optionally, in some embodiments, the first controller is also configured to issue an alarm when the temperature control switch malfunctions.

Optionally, in some embodiments, the first controller is used to determine whether the temperature control switch is open based on the voltage, including: when the voltage is less than a second threshold, the first controller determines that the temperature control switch is open; when the voltage is greater than a third threshold, the first controller determines that the temperature control switch is closed, wherein the third threshold is greater than the second threshold.

Optionally, in some embodiments, the charger further includes a function box, the power plug and the function box are connected via a charging cable, a portion of which is located inside the function box. The function box includes a second power source and a relay, the input terminal of the second power source is connected to the charging cable; the relay is connected to the charging cable, and the output terminal of the second power source is connected to the coil of the relay via the temperature control switch to control the relay to open or close.

Optionally, in some embodiments, the function box further includes a first switch, the output terminal of the second power supply is connected to a first terminal of the temperature control switch through the first switch, and the second terminal of the temperature control switch is connected to the coil of the relay.

Optionally, in some embodiments, the functional box further includes a second voltage detection circuit for detecting the voltage on the charging cable.

Optionally, in some embodiments, the functional box further includes a third voltage detection circuit for detecting the voltage at the second terminal of the temperature control switch.

Optionally, in some embodiments, the functional box further includes a second controller, and the second power supply is also used to power the second controller; the second controller is used to determine whether the power supply plug is inserted into the mains socket based on the voltage detected by the second voltage detection circuit; the second controller is also used to control the first switch to close when the power supply plug is inserted into the mains socket and charging is ready, and to determine whether the temperature control switch is opened based on the voltage detected by the third voltage detection circuit.

Optionally, in some embodiments, the second controller is further configured to determine a protection strategy based on the cumulative number of times the temperature control switch has disconnected after the power supply plug is inserted into the mains socket when the temperature control switch is disconnected; or the second controller is configured to determine a protection strategy based on the continuous charging time of the charger; or the second controller is configured to determine a protection strategy based on the cumulative number of times the temperature control switch has disconnected after the power supply plug is inserted into the mains socket and the continuous charging time of the charger.

Optionally, in some embodiments, the second controller is configured to determine a protection strategy based on the continuous charging duration of the charger, including: if the continuous charging duration of the charger is greater than a fourth threshold, determining that the continuous charging duration of the charger falls within a target duration interval, and determining a target charging current corresponding to the target duration interval; wherein the target charging current is positively correlated with the target duration interval; if the continuous charging duration of the charger is less than or equal to the fourth threshold, the second controller determines a stop charging strategy.

Optionally, in some embodiments, the functional box further includes a first leakage current detection circuit; wherein the second controller is further configured to control the first switch to disconnect when the first leakage current detection circuit detects leakage current in the charger.

Optionally, in some embodiments, the functional box further includes a first current sampling circuit. The second controller is further configured to control the first switch to open when the first current sampling circuit detects that the current on the charging line is greater than a fifth threshold.

Optionally, in some embodiments, the charger further includes a function box, the power plug and the function box are connected by a charging cable, a portion of the charging cable is located inside the function box; the function box includes a third power supply and a relay, the input terminal of the third power supply is connected to the charging cable through the temperature control switch; the relay is connected to the charging cable, and the first output terminal of the third power supply is connected to the coil of the relay to control the opening or closing of the relay.

Optionally, in some embodiments, the temperature control switch is disposed in the power supply plug.

Optionally, in some embodiments, the temperature control switch includes a temperature switch.

Optionally, in some embodiments, the functional box further includes a fourth switch; the first output terminal of the third power supply is connected to the coil of the relay via the fourth switch.

Optionally, in some embodiments, the functional box further includes a fourth power source, the first input terminal of which is connected to the charging cable, and the first output terminal of which is connected to the coil of the relay.

Optionally, in some embodiments, the functional box further includes a fifth switch, and the first output terminal of the fourth power supply is connected to the coil of the relay through the fifth switch.

Optionally, in some embodiments, the functional box further includes a third controller; the second output terminal of the fourth power supply is connected to the power supply terminal of the third controller.

Optionally, in some embodiments, the functional box further includes a fourth voltage detection circuit for detecting the voltage on the charging cable; the third controller is used to determine whether the power supply plug is inserted into the AC socket based on the voltage detected by the fourth voltage detection circuit; the third controller is also used to control the fourth switch to close and the fifth switch to open when the power supply plug is inserted into the AC socket and charging is ready.

Optionally, in some embodiments, the functional box further includes a fifth voltage detection circuit for detecting the voltage at the input terminal of the third power supply; the third controller is further configured to determine that the temperature control switch is open based on the voltage detected by the fifth voltage detection circuit.

Optionally, in some embodiments, the functional box further includes a sixth voltage detection circuit for detecting the voltage at the second terminal of the fourth switch; the third controller is further configured to determine that the third power supply has failed based on the voltage detected by the sixth voltage detection circuit when the temperature control switch is not disconnected; the third controller is further configured to control the fourth switch to open and the fifth switch to close when the third power supply fails.

Optionally, in some embodiments, the third controller is further configured to determine a protection strategy based on the cumulative number of times the temperature control switch has been disconnected since the power supply plug was inserted into the mains socket when the temperature control switch is disconnected.

Optionally, in some embodiments, the third controller is further configured to determine a protection strategy based on the cumulative number of times the temperature control switch disconnects after the power supply plug is inserted into the mains socket, including: if the cumulative number of times the temperature control switch disconnects is less than a first threshold, the third controller determines a target current reduction strategy based on the cumulative number of times the temperature control switch disconnects; wherein the current reduction degree of the target current reduction strategy is positively correlated with the cumulative number of times the temperature control switch disconnects; if the cumulative number of times the temperature control switch disconnects is greater than or equal to the first threshold, the third controller determines a charging stop strategy.

Optionally, in some embodiments, the function box further includes a control guide; wherein the third controller is further configured to determine the target duty cycle corresponding to the target current reduction strategy based on the cumulative number of times the temperature control switch is disconnected, and send a target CP signal to the vehicle's on-board charger through the control guide, wherein the duty cycle of the target CP signal is the target duty cycle.

Optionally, in some embodiments, the third controller is further configured to determine a protection strategy based on the cumulative number of times the temperature control switch disconnects after the power supply plug is inserted into the mains socket, including: if the cumulative number of times the temperature control switch disconnects is greater than or equal to 1, the third controller sends a stop charging message to the vehicle.

Optionally, in some embodiments, the function box further includes a prompter; wherein, when the temperature control switch is off, the function box is used to issue a prompt message through the prompter, the prompt message being used to indicate that the power supply plug has an over-temperature fault.

Optionally, in some embodiments, when the power supply plug is inserted into the mains socket, the cumulative number of disconnections stored by the third controller is 0; after the power supply plug is inserted into the mains socket, each time the temperature control switch is detected to be disconnected, the third controller increments the cumulative number of disconnections by 1; when the power supply plug is disconnected from the mains socket, the cumulative number of disconnections stored by the third controller is cleared to zero.

Optionally, in some embodiments, the third controller is further configured to stop charging when the fourth power supply is determined to be faulty based on the voltage detected by the sixth voltage detection circuit, provided that the third controller controls the fourth switch to be open and the fifth switch to be closed.

Optionally, in some embodiments, the functional box further includes a reverse current blocking device, through which the second output terminal of the third power supply is connected to the second input terminal of the fourth power supply; the reverse current blocking device is used to prevent the fourth power supply from supplying power to the third power supply.

Optionally, in some embodiments, the functional box further includes a second leakage detection circuit; the third controller is also used to control the fourth switch and the fifth switch to disconnect when the second leakage detection circuit detects leakage in the charger.

Optionally, in some embodiments, the functional box further includes a second current sampling circuit; the third controller is further configured to control the fourth switch and the fifth switch to disconnect when the second current sampling circuit detects that the current of the charging cable is greater than a ninth threshold.

Optionally, in some embodiments, the charger further includes a vehicle plug, which, when inserted into a vehicle socket, establishes a charging circuit with the vehicle.

Optionally, in some embodiments, the power plug is used for detachable connection to a power supply; the charger further includes a charging plug and a temperature control branch. The charging plug is used for detachable connection to the device to be charged, and the charging plug is connected to the power plug via a charging cable. The input terminal of the temperature control branch is connected to the charging cable; the temperature control branch includes the temperature control switch and a fifth power supply connected in series with the temperature control switch, the potential difference across the fifth power supply being greater than a preset threshold.

Optionally, in some embodiments, the charger further includes a function box through which the charging cable passes, and the function box includes the fifth power source.

Optionally, in some embodiments, the functional box further includes an electronically controlled switch, which includes a control terminal and a switch assembly. The switch assembly is disposed on the charging cable, the input terminal of the temperature control branch is connected to the charging cable between the power supply plug and the switch assembly, and the output terminal is connected to the control terminal.

Optionally, in some embodiments, the temperature control switch is located on the power supply plug; the temperature control switch is used to activate the temperature control branch when the temperature of the power supply plug is less than a temperature threshold, so as to energize the control terminal; the control terminal is used to control the switch assembly to close when energized, so as to energize the charging cable;

The temperature control switch is also used to disconnect the temperature control branch when the temperature of the power supply plug is greater than the temperature threshold, so as to de-energize the control terminal; the control terminal is also used to control the switch assembly to open in the power-off state, so as to de-energize the charging cable.

Optionally, in some embodiments, the input terminal of the temperature control branch is connected to the charging cable inside the function box.

Optionally, in some embodiments, the functional box further includes a fourth controller, one end of which is connected to the input terminal of the fifth power supply and the other end of which is connected to the charging plug. The fourth controller is used to determine the conduction state of the temperature control switch based on the voltage at the input terminal of the fifth power supply, and to adjust the charging current output by the charging cable based on the conduction state of the temperature control switch.

Optionally, in some embodiments, the fourth controller includes a processor and a seventh voltage detection circuit, one end of which is connected to the input terminal of the fifth power supply and the other end of which is connected to the processor. The seventh voltage detection circuit is used to detect the voltage at the input terminal of the fifth power supply and send the voltage at the input terminal of the fifth power supply to the processor.

Optionally, in some embodiments, the fourth controller further includes a current detection circuit, one end of which is connected to the charging cable and the other end of which is connected to the processor. The current detection circuit is used to detect the charging current output by the charging cable and send the charging current output by the charging cable to the processor.

Optionally, in some embodiments, the fourth controller further includes a control circuit, one end of which is connected to the processor and the other end of which is connected to the charging plug; the control circuit is used to adjust the duty cycle when the voltage at the fifth power input terminal is 0, so as to adjust the charging current output by the charging cable.

Optionally, in some embodiments, an eighth switch is provided on the line between the control circuit and the charging plug, the eighth switch being used to connect or disconnect the line between the control circuit and the charging plug.

Optionally, in some embodiments, the output of the fifth power supply is connected to the fourth controller to supply power to the processor, and a reverse current isolation device is provided between the output of the fifth power supply and the processor.

Optionally, in some embodiments, a ninth switch is provided on the line between the fifth power source and the control terminal of the electronic control switch, the ninth switch being used to energize or de-energize the charging cable.

Optionally, in some embodiments, the charger further includes a sixth power source, one end of which is connected to the charging cable and the other end of which is connected to the fourth controller.

According to a second aspect of this application, a charging system is provided, comprising any of the aforementioned chargers and a device to be charged.

Optionally, in some embodiments, the charging system further includes a power supply, the power plug is detachably electrically connected to the power supply, and the charging plug is detachably electrically connected to the device to be charged.

Optionally, in some embodiments, the device to be charged includes a vehicle.

Beneficial effects

In this embodiment of the application, a temperature control switch is set to control the temperature control switch to open when the temperature is too high, so that the charger stops charging.

Other features and advantages of this application will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings.

Attached Figure Description

The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the present application and, together with their description, serve to explain the principles of the present application.

Figure 1 is a schematic diagram of the structure of a charger provided in an embodiment of this application;

Figure 2 is a schematic diagram of another charger provided in an embodiment of this application;

Figure 3 is a schematic diagram of another charger provided in an embodiment of this application;

Figure 4 is a schematic diagram of another charger provided in an embodiment of this application;

Figure 5 is a schematic diagram of another charger provided in an embodiment of this application;

Figure 6 is a schematic diagram of another charger provided in an embodiment of this application;

Figure 7 is a schematic diagram of the specific structure of a charger provided in an embodiment of this application;

Figure 8 is a flowchart illustrating an over-temperature protection judgment method for a charger provided in an embodiment of this application.

Figure 9 is a schematic diagram of the structure of a charger provided in an embodiment of this application;

Figure 10 is a schematic diagram of another charger provided in an embodiment of this application;

Figure 11 is a schematic diagram of another charger provided in an embodiment of this application;

Figure 12 is a schematic diagram of another charger provided in an embodiment of this application;

Figure 13 is a schematic diagram of another charger provided in an embodiment of this application;

Figure 14 is a schematic flowchart of a method for detecting the disconnection of a temperature control switch provided in an embodiment of this application.

Figure 15 is a schematic diagram of the structure of a charger provided in an embodiment of this application;

Figure 16 is a schematic diagram of another charger provided in an embodiment of this application;

Figure 17 is a schematic diagram of another charger provided in an embodiment of this application;

Figure 18 is a schematic diagram of another charger provided in an embodiment of this application;

Figure 19 is a schematic diagram of another charger provided in an embodiment of this application;

Figure 20 is a schematic diagram of another charger provided in an embodiment of this application;

Figure 21 is a schematic diagram of another charger provided in an embodiment of this application;

Figure 22 is a schematic flowchart of a voltage detection method provided in an embodiment of this application.

Figure 23 is a circuit diagram of a charger according to an embodiment of the present invention;

Figure 24 is a circuit diagram of a charging system according to an embodiment of the present invention.

Explanation of reference numerals in the attached figures:
10: Power plug; 11: Temperature control switch; 20: Function box; 21: First voltage detection circuit; 211: Second voltage detection circuit;
212: Third voltage detection circuit; 213: Sixth voltage detection circuit; 22: Control module (first controller, second controller, and third controller); 23: Power module (first power supply, second power supply); 231: Power module 1 (third power supply); 232: Power module 2 (fourth power supply); 24: CP module (control guide); 25: Indicator module (indicator); 26: Temperature detection module (temperature detector); 27: Leakage detection circuit (first leakage detection circuit, second leakage detection circuit); 28: Current sampling circuit (first current sampling circuit, second current sampling circuit); 30: Vehicle 40: Vehicle socket; 42: Fifth power supply; 50: Charging plug; 51: Electronic switch; 511: Control terminal; 512: Switch assembly; 52: Fourth controller; 521: Processor; 522: Seventh voltage detection circuit; 523: Current detection circuit; 524: Regulation circuit; 53: Eighth switch; 54: Ninth switch; 55: Eighth voltage detection circuit; 56: Ninth voltage detection circuit; 57: Sixth power supply; 58: Leakage detection circuit; 59: Display; 100: Charger; 1000: Charging system; 60: Device to be charged; 70: Power supply; 80: Temperature control branch.

Implementation methods of this application

Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values of the components and steps set forth in these embodiments do not limit the scope of the present application.

The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

In all the examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in a figure... The meaning of this will not be discussed further in the accompanying figures.

According to a first aspect of this application, a charger is provided, comprising a power plug and a temperature control switch. The power plug is connected to a charging cable, and the temperature control switch is connected to the charging cable. The charger stops charging when the temperature control switch disconnects due to over-temperature conditions.

In this embodiment of the application, a temperature control switch is set to control the switch to disconnect when the temperature is too high, so that the charger stops charging, thereby reducing the safety risk of the charger.

Electric vehicles primarily use two charging methods: DC charging and AC charging. During AC charging, the charger draws power from a mains outlet via a power plug. If a malfunction occurs during AC charging, a large current will flow through the power plug, causing its temperature to rise rapidly. To ensure charging safety, a temperature detection unit is typically installed in the power plug to monitor its temperature. When the temperature exceeds a set threshold, the controller stops charging via software. However, if the software or controller malfunctions, it may be impossible to stop charging in a timely manner, posing a safety risk.

This application provides a charger and charging system that can reduce the safety risks of the charger.

The charger in this embodiment includes a power plug and a function box. The power plug includes a first segment of a first phase wire, a second phase wire, a temperature control switch, and a ground wire. The function box includes a first voltage detection circuit, a first controller, a second segment of the first phase wire, and a temperature control switch connected in series between the first and second segments of the first phase wire. When the power plug is inserted into a mains socket, the first voltage detection circuit detects the voltage difference between the second end of the first phase wire and the second phase wire, or the voltage between the second end of the first phase wire and the ground wire. The first controller determines whether the temperature control switch should be disconnected based on the voltage. If the temperature control switch is disconnected, the first controller also determines a protection strategy based on the cumulative number of times the temperature control switch has disconnected since the power plug was inserted into the mains socket. In this embodiment, the temperature control switch is connected in series between the first and second segments of the first phase wire. When the temperature control switch disconnects due to overheating, it can automatically disconnect the first phase wire, thereby stopping the charger from charging. Compared with software control, this reduces the safety risk of the charger. The temperature control switch is directly connected in series in the phase wire. Because the temperature control switch has a fast thermal conductivity, it can disconnect the phase wire circuit more quickly when there is a large current in the phase wire.

Please refer to Figure 1, which is a schematic diagram of a charger provided in an embodiment of this application. As shown in Figure 1, the charger may include a power plug 10 and a function box 20. The power plug 10 includes a first segment of a first phase wire, a second phase wire, a temperature control switch 11, and a ground wire PE. The function box 20 includes a first voltage detection circuit (i.e., the voltage detection module 21 in Figures 1 to 7), a first controller, and a second segment of the first phase wire. The temperature control switch 11 is connected between the first segment of the first phase wire and the second segment of the first phase wire. The voltage detection module in Figure 1 corresponds to the first voltage detection circuit 21, and the control module 22 in Figure 1 corresponds to the first controller.

When the power supply plug 10 is inserted into the mains socket, the first voltage detection circuit 21 is used to detect the voltage between the second end of the first phase line and the second phase line or the voltage between the second end of the first phase line and the ground line.

The first controller is used to determine whether the temperature control switch 11 is open based on the voltage. When the temperature control switch 11 is open, the first controller is also used to determine a protection strategy based on the cumulative number of times the temperature control switch 11 is opened after the power supply plug 10 is inserted into the mains socket.

In this embodiment, the first voltage detection circuit 21 may include a voltage acquisition circuit, or a voltage acquisition circuit and a voltage processing circuit. The voltage acquisition circuit is used to acquire voltage, and the voltage processing circuit is used to process the voltage acquired by the voltage acquisition circuit; at the same time, the voltage acquisition circuit can be a sensor, and the voltage processing circuit can be set in the sensor or in the back-end controller.

In some embodiments, the temperature control switch includes a temperature spring.

In this embodiment, the first phase line can be any one of L1, L2, and N, and the second phase line can be any one of L1, L2, and N. The first phase line and the second phase line are different, and at least one of the first phase line and the second phase line is L1. In Figure 1, the first phase line is L1, and the second phase line is L2 or N (neutral line). In one possible embodiment, the first phase line is L2 or N (neutral line), and the second phase line is L1.

In this embodiment, L1 and L2 are two different phases of a two-phase electrical system. The voltage between L1 and L2 is generally around 200V, the voltage between L1 and N is generally around 100V, the voltage between N and PE is generally around 100V, the voltage between L1 and PE is generally around 220V, and the voltage between L2 and PE is generally around 220V.

The cumulative number of times the temperature control switch 11 disconnects refers to the cumulative number of times the temperature control switch 11 disconnects during the continuous period that the power plug 10 is inserted into the mains socket. The higher the cumulative number of times the temperature control switch 11 disconnects, the stronger the protection strategy.

Optionally, the first controller is used to determine whether the temperature control switch 11 is open based on the voltage, including:

If the voltage is less than the second threshold, the first controller determines that the temperature control switch 11 is open;

When the voltage is greater than the third threshold, the first controller determines that the temperature control switch 11 is closed, and the third threshold is greater than the second threshold.

In this embodiment of the application, the second threshold can be set to a value less than 50. For example, the second threshold can be set to 30V.

If the voltage is the voltage between the second terminal of the first phase line L1 and the second phase line L2, and the first phase line L1 is L1 and the second phase line L2 is L2, the third threshold can be set to a value greater than 150V and less than 200V. For example, the third threshold can be set to 180V. If the first phase line L1 is L1 and the second phase line L2 is N, the third threshold can be set to a value greater than 50V and less than 100V. For example, the third threshold can be set to 80V.

If the voltage is the voltage between the second terminal of the first phase line L1 and the ground line, the third threshold can be set to a value greater than 150V and less than 200V. For example, the third threshold can be set to 180V.

In this embodiment, the second threshold and the third threshold can be preset. The first controller can accurately determine whether the temperature control switch 11 is open based on the second threshold and the third threshold.

The charger in Figure 1 can charge a vehicle. For example, the second segment of the first phase line L1 and the second phase line L2 can be connected to the vehicle socket via the vehicle plug. The vehicle socket 40 can be connected to the vehicle's on-board charger, which charges the vehicle's power battery, thus enabling the charger to charge the vehicle.

As shown in Figure 1, the first phase line L1 is divided into two segments: the first segment of the first phase line L1 and the second segment of the first phase line L1. The first segment of the first phase line L1 and the second segment of the first phase line L1 are connected by a temperature control switch 11. If the temperature control switch 11 is turned off, the first phase line L1 is disconnected and the charger cannot charge.

When the power plug 10 is first inserted into the mains socket, the temperature control switch 11 is closed. After the charger starts working, there is a voltage difference between the first phase line L1 and the second phase line L2. If the voltage difference between the first phase line L1 and the second phase line L2 is very small, it indicates that the temperature control switch 11 is open. If the voltage difference between the first phase line L1 and the second phase line L2 is large, it indicates that the temperature control switch 11 is closed.

The temperature control switch 11 is connected in series with the first phase line L1. If the temperature of the coupling area between the power plug 10 and the mains socket is abnormal, it will be conducted to the temperature control switch 11 through the wire. When the temperature of the temperature control switch 11 exceeds the material heat deformation temperature, the temperature control switch 11 will automatically disconnect physically. When the temperature of the temperature control switch 11 is lower than the upper limit of the normal operating temperature of the charger, the temperature control switch 11 will automatically close physically.

Please refer to Figure 2, which is a schematic diagram of another charger provided in an embodiment of this application. As shown in Figure 2, based on Figure 1, the functional box 20 in Figure 2 further includes a first power supply, which is used to power the first controller. The power module 23 in Figure 2 corresponds to the first power supply.

The first power supply in this embodiment may or may not rely on a mains power outlet. When the first power supply does not rely on a mains power outlet, the first power supply may be a replaceable power source (e.g., a replaceable battery).

The first power supply in Figure 2 relies on an AC outlet. The first input terminal of the first power supply is connected to the first segment of the first phase line L1, the second input terminal is connected to the second phase line L2, and the output terminal is connected to the power supply terminal of the first controller. The first power supply can draw power from the first phase line L1 and the second phase line L2, and can convert the AC power from the first phase line L1 and the second phase line L2 into DC voltage (e.g., 3.3V, 5V, or 12V DC voltage) to power the first controller.

The first power supply in Figure 2 powers the first controller when the power plug 10 is inserted into the mains socket. The first power supply will not be cut off due to the temperature control switch 11 being disconnected, thereby ensuring that the operation of the first controller is not affected by the temperature control switch 11 and improving the stability of the operation of the first controller.

In this embodiment, the temperature control switch 11 is connected in series between the first segment and the second segment of the first phase line L1. When the temperature control switch 11 disconnects due to overheating, it can automatically disconnect the first phase line L1, thereby stopping the charger from charging. Compared with software control, this reduces the safety risk of the charger. Since the temperature control switch is directly connected in series in the phase line, compared with software control based on temperature sensor readings, the temperature control switch has a faster thermal conductivity than the thermistor of the temperature sensor. Therefore, it can disconnect the phase line circuit more quickly when there is a large current in the phase line, thus protecting the charger more rapidly.

Optionally, when the power plug 10 is inserted into the mains socket, the first power supply powers the first controller, and the first controller stores a cumulative number of disconnections of 0.

After the power plug 10 is inserted into the mains socket, each time the temperature control switch 11 is detected to be disconnected, the first controller increments the cumulative disconnection count by 1.

When the power supply plug 10 is disconnected from the mains socket, the first power supply stops powering the first controller, and the cumulative number of disconnections stored in the first controller is cleared to zero.

In this embodiment, the first controller can store a cumulative number of disconnections. When the power plug 10 is inserted into the mains socket, that is, when the first controller is first powered on, the cumulative number of disconnections is 0.

When the first controller is powered (when the power plug 10 is inserted into the mains socket), the cumulative disconnection count is incremented by 1 each time the temperature control switch 11 is detected to be disconnected. When the first controller is not powered (when the power plug 10 is disconnected from the mains socket), i.e., when the first controller is de-energized, the cumulative disconnection count is cleared to zero.

In this embodiment, the cumulative disconnection count is guaranteed to be the cumulative disconnection count of the temperature control switch 11 after the power plug 10 is inserted into the mains socket. If this cumulative disconnection count continuously increases (i.e., it is not reset to zero), then after the power plug 10 is inserted into the mains socket, the charging current of the charger to the vehicle will be limited, or even the charger will stop charging the vehicle (for example, when the cumulative disconnection count is greater than or equal to the first threshold), which does not conform to actual usage scenarios. By resetting the cumulative disconnection count to zero when the first controller is powered off, it can be ensured that the cumulative disconnection count is recalculated from 0 every time the power plug 10 is inserted into the mains socket, which can improve the user experience.

The first voltage detection circuit 21 can periodically detect whether the temperature control switch 11 is open. Each time the temperature control switch 11 is detected to be open, it means that each time the temperature detector detects the temperature control switch 11 going from closed to open.

The cumulative number of disconnections refers to the number of times the temperature control switch 11 is detected to have gone from closed to open after the power plug 10 is inserted into the mains socket. For example, the first controller determines whether the temperature control switch 11 is open based on the voltage difference detected by the first voltage detection circuit 21. For instance, if the first voltage detection circuit 21 measures the voltage difference 10 times (during these 10 measurements, the first controller is continuously powered, i.e., the power plug 10 is continuously coupled to the mains socket), the corresponding states of the temperature control switch 11 are: closed, closed, open, open, open, closed, closed, closed, open, open. Then the cumulative number of disconnections is 2.

In this embodiment, when the temperature control switch 11 is open, the first controller determines the protection strategy based on the cumulative number of times the temperature control switch 11 has been opened since the power plug 10 was inserted into the mains socket. Generally, the greater the cumulative number of times the temperature control switch 11 has been opened since the power plug 10 was inserted into the mains socket, the stronger the protection. For example, each time the temperature control switch 11 is opened, as the cumulative number increases, the next time the temperature control switch 11 is closed, the charger's operating current will decrease compared to the previous time the temperature control switch 11 was closed, and may even decrease to 0. The opening of the temperature control switch 11 may be due to the high operating current of the charger (a high operating current of the charger may cause the temperature to rise). By reducing the operating current of the charger, the temperature control switch 11 is less likely to open, thereby extending the charger's operating time and allowing the charger to charge the vehicle as much power as possible in the event of a charger failure.

Optionally, the first controller is further configured to determine a protection strategy based on the cumulative number of times the temperature control switch 11 disconnects after the power supply plug 10 is inserted into the mains socket, including:

If the cumulative number of times the temperature control switch 11 is disconnected is less than a first threshold, the first controller determines a target current reduction strategy based on the cumulative number of times the temperature control switch 11 is disconnected; wherein, the degree of current reduction of the target current reduction strategy is positively correlated with the cumulative number of times the temperature control switch 11 is disconnected.

If the cumulative number of times the temperature control switch 11 is disconnected is greater than or equal to the first threshold, the first controller determines a stop charging strategy.

In this embodiment, the first threshold can be preset. The first threshold can be an integer greater than or equal to 2. The target current reduction strategy refers to the strategy of reducing the operating current of the charger. Each time the temperature control switch 11 is opened, if the cumulative number of times the temperature control switch 11 is opened is less than the first threshold, the operating current of the charger will be lower when the temperature control switch 11 is closed next time compared with the previous time the temperature control switch 11 was closed.

The charging stop strategy refers to the strategy by which the charger stops charging. When the cumulative number of times the temperature control switch 11 is disconnected is greater than or equal to a first threshold, the first controller can control the charger to stop working, that is, stop charging the vehicle.

For example, if the first threshold is 3, after the power plug 10 is inserted into the mains socket, if the charger's operating current is the rated current (e.g., 15A), the temperature control switch 11 will open for the first time, and the cumulative number of times the temperature control switch 11 has opened is 1. When the temperature control switch 11 closes again, the charger's operating current can be controlled to 12A. If the temperature control switch 11 opens for the second time, the cumulative number of times the temperature control switch 11 has opened is 2. When the temperature control switch 11 closes again, the charger's operating current can be controlled to 10A. If the temperature control switch 11 opens for the third time, the cumulative number of times the temperature control switch 11 has opened is 3. When the temperature control switch 11 closes again, the charger can be controlled to stop working, that is, stop charging the vehicle.

Optionally, please refer to Figure 3, which is a schematic diagram of another charger provided in an embodiment of this application. Figure 3 is derived from Figure 2. As shown in Figure 3, based on Figure 2, the functional box 20 of the charger further includes: a control guide 24; the first controller is also used to determine the target duty cycle corresponding to the target current reduction strategy according to the cumulative number of times the temperature control switch 11 is disconnected, and send a target CP signal to the vehicle's on-board charger through the control guide 24, wherein the duty cycle of the target CP signal is the target duty cycle. The CP module in Figure 3 corresponds to the control guide 24.

The CP signal is a signal sent by the first controller to the vehicle's onboard charger. The CP signal can be controlled by a control pilot (CP). The CP signal generated by the CP controller 24 can control the duty cycle of the CP signal generated by the CP controller 24.

When the vehicle's on-board charger receives the CP signal, if the on-board charger detects a change in the duty cycle of the CP signal (the duty cycle of the currently received CP signal is different from the duty cycle of the previously received CP signal), the on-board charger will automatically adjust the load, thereby adjusting the charger's operating current.

In this embodiment of the application, the first controller can send a target CP signal to the vehicle's on-board charger (OBC) through the control guide 24, thereby controlling the operating current of the charger.

The greater the cumulative number of times the temperature control switch 11 is disconnected, the lower the target duty cycle corresponding to the target current reduction strategy, which means the lower the operating current of the charger.

For example, if the first threshold is 3, after the power plug 10 is inserted into the mains socket, if the charger's operating current is the rated current (e.g., 15A), the duty cycle of the CP signal sent by the first controller to the vehicle's on-board charger is 25%. When the temperature control switch 11 is opened for the first time, the cumulative number of times the temperature control switch 11 has been opened is 1. When the temperature control switch 11 is closed again, the charger's operating current can be controlled to 12A, and the duty cycle of the CP signal sent by the first controller to the vehicle's on-board charger is 20%. When the temperature control switch 11 is opened for the second time, the cumulative number of times the temperature control switch 11 has been opened is 2. When the temperature control switch 11 is closed again, the charger's operating current can be controlled to 10A, and the duty cycle of the CP signal sent by the first controller to the vehicle's on-board charger is 16.67%. When the temperature control switch 11 is disconnected for the third time, the cumulative number of disconnections of the temperature control switch 11 is 3. When the temperature control switch 11 is closed again, it can control the charger to stop working. At this time, the duty cycle of the CP signal sent by the first controller to the vehicle's on-board charger is 0% or 100%, that is, it stops charging the vehicle.

Optionally, the first controller is further configured to determine a protection strategy based on the cumulative number of times the temperature control switch 11 disconnects after the power supply plug 10 is inserted into the mains socket, including: if the cumulative number of disconnections of the temperature control switch 11 is greater than or equal to 1, the first controller sends a stop charging message to the vehicle.

In this embodiment, as soon as the temperature control switch 11 is detected to be open, a stop charging message is sent to the vehicle to stop the charger from charging the vehicle. When the temperature control switch 11 is detected to be open, the charger stops charging the vehicle. After the over-temperature protection of the temperature control switch 11 is tripped, the charger stops working, preventing the charger from experiencing over-temperature conditions again. This protects the charger, avoids repeated opening and closing of the over-temperature contact spring, and improves the service life of the temperature control switch 11.

Specifically, the first controller sends a stop charging message to the vehicle so that the charger stops charging the vehicle. Specifically, the first controller sends a specific CP signal to the vehicle's on-board charger through the control guide 24.

Optionally, the specific CP signal can be the CP signal specified in the national standard: for example, a CP signal with a duty cycle of 100% or 0%.

Optionally, the specific CP signal can be a CP signal agreed upon by the charger and the vehicle: for example, a CP signal with alternating duty cycles of 100% and 20%. For example, the first half of the CP signal has a 100% duty cycle, and the second half has a 20% duty cycle.

Optionally, when the first controller sends a stop charging message to the vehicle, the vehicle sends a notification message to the user terminal, the notification message being used to notify the user terminal that the charger has experienced a charging failure.

In this embodiment, the first controller sends a stop charging message to the vehicle, causing the vehicle to adjust its load, thereby stopping the charger from charging the vehicle. The vehicle can establish communication with the user terminal. For example, the vehicle can notify the user via a cloud platform or APP (displaying the notification message on the user terminal), and can also display the notification message on the vehicle's instrument panel or display screen the next time the vehicle is started.

The embodiments of this application can promptly notify the user when the charger experiences an overheating fault, thereby improving the user experience.

Please refer to Figure 4, which is a schematic diagram of another charger provided in an embodiment of this application. Figure 4 is derived from Figure 3. As shown in Figure 4, based on Figure 3, the function box 20 of this charger further includes an indicator 25. When the temperature control switch 11 is off, the function box 20 issues an indicator message through the indicator 25. The indicator message is used to indicate that the power supply plug 10 has an over-temperature fault. The indicator module in Figure 4 corresponds to the indicator 25.

The prompter 25 can be at least one of a voice module and a display module. The prompter 25 can issue at least one of voice prompts and text prompts. The prompts can include at least one of voice prompts and text prompts, and can indicate that the power plug 10 has an overheating fault. The prompter 25 on the function box 20 can promptly alert the user.

Please refer to Figure 5, which is a schematic diagram of another charger provided in an embodiment of this application. Figure 5 is derived from Figure 4. As shown in Figure 5, the power plug 10 of this charger further includes a temperature sensor 12, and the functional box 20 further includes a temperature detector 26. The first output terminal of the temperature sensor 12 is connected to the first input terminal of the temperature detector 26, and the second output terminal of the temperature sensor 12 is connected to the second input terminal of the temperature detector 26. The output terminal of the temperature detector 26 is connected to the first input terminal of the first controller. The temperature detection module in Figure 5 corresponds to the temperature detector 26.

The temperature detector 26 is used to determine the temperature of the temperature sensor 12 based on the voltage at the first input terminal and the second input terminal of the temperature detector 26.

In this embodiment, the temperature sensor 12 may include a thermistor, the resistance of which changes with temperature. The temperature detector 26 can obtain the temperature of the temperature sensor 12 by detecting the change in voltage across the thermistor.

In one possible embodiment, a correspondence table between the voltage across the thermistor and the temperature of the temperature sensor can be established in advance. After detecting the voltage at the first input terminal and the second input terminal of the temperature detector 26, the temperature of the temperature sensor 12 can be obtained according to the correspondence table.

In another possible embodiment, a correspondence table between the resistance value of the thermistor and the temperature of the temperature sensor can be established in advance. After detecting the voltage at the first input terminal and the second input terminal of the temperature detector 26, the resistance value of the thermistor of the temperature sensor 12 is determined according to the voltage at the first input terminal and the second input terminal of the temperature detector 26, and the temperature of the temperature sensor 12 is obtained according to the correspondence table.

For example, temperature sensor 12 can be a negative temperature coefficient sensor (NTC).

The voltage at the first and second input terminals of temperature detector 26 is the voltage across the thermistor of temperature sensor 12. Temperature detector 26 may include a voltage divider circuit. For example, Rt is the resistance of the thermistor, and Rf is the resistance of a common resistor, where the resistance Rf does not change with temperature. The power supply voltage is U, and a loop is formed between the power supply, the thermistor, the common resistor, and ground. The voltage across the thermistor is Ut = Rt * U / (Rt + Rf). Since U and Rf are known parameters, and Ut is the voltage detected by temperature detector 26, the resistance Rt of the thermistor can be calculated. The temperature of temperature sensor 12 can be determined according to the correspondence table between the thermistor resistance Rt and temperature.

In some embodiments of this application, the temperature detector 26 may include a temperature acquisition circuit, or a temperature acquisition circuit and a temperature processing circuit. The temperature acquisition circuit is used to acquire voltage, and the temperature processing circuit is used to process the voltage acquired by the temperature acquisition circuit; meanwhile, the temperature acquisition circuit can be a sensor, and the temperature processing circuit can be set in the sensor or in the back-end controller.

Optionally, the first controller is further configured to determine whether the temperature control switch 11 is functioning properly based on the temperature of the temperature sensor 12 and the state of the temperature control switch 11.

In this embodiment of the application, when the temperature of the temperature sensor 12 matches the state of the temperature control switch 11, the temperature control switch 11 is considered to be normal; when the temperature of the temperature sensor 12 does not match the state of the temperature control switch 11, the temperature control switch 11 is considered to be abnormal.

Optionally, the first controller is further configured to:

If the temperature of the temperature sensor 12 exceeds the upper limit temperature for the temperature control switch 11 to disconnect, and the temperature control switch 11 is closed, the first controller determines that the temperature control switch 11 is abnormal.

If the temperature of the temperature sensor 12 is lower than the lower closing limit temperature of the temperature control switch 11 and the temperature control switch 11 is open, the first controller determines that the temperature control switch 11 is abnormal.

If the temperature of the temperature sensor 12 is lower than the lower closing limit temperature of the temperature control switch 11, and the temperature control switch 11 is closed, the first controller determines that the temperature control switch 11 is normal.

If the temperature of the temperature sensor 12 exceeds the upper limit temperature for the temperature control switch 11 to disconnect, and the temperature control switch 11 is disconnected, the first controller determines that the temperature control switch 11 is normal.

In this embodiment, the temperature control switch 11 corresponds to a disconnection temperature range. Under normal conditions, the temperature control switch 11 will disconnect within this disconnection temperature range. For example, if the disconnection temperature range is 100-130°C and the upper limit of the disconnection temperature is 130°C, when the temperature of the temperature sensor 12 exceeds 130°C, if the temperature control switch 11 disconnects, it is considered that the temperature control switch 11 is normal; if the temperature control switch 11 closes, it is considered that the temperature control switch 11 is abnormal (for example, the temperature control switch 11 has stuck or has other faults that prevent it from disconnecting).

The temperature control switch 11 corresponds to a closed temperature range. Under normal conditions, the temperature control switch 11 will close within this closed temperature range. For example, if the closed temperature range is 100～60℃ and the lower limit temperature is 60℃, if the temperature sensor 12 is below 60℃, and the temperature control switch 11 is closed, then the temperature control switch 11 is considered to be normal; if the temperature control switch 11 is open, then the temperature control switch 11 is considered to be abnormal.

In this embodiment, the temperature of the temperature sensor 12 and the state (closed or open) of the temperature control switch 11 can be used to determine whether the temperature control switch 11 is abnormal, thereby accurately detecting whether the temperature control switch 11 has malfunctioned.

Optionally, the first controller is also configured to issue an alarm prompt in the event of an abnormality in the temperature control switch 11.

In this embodiment of the application, when the first controller determines that the temperature control switch 11 is abnormal, the function box 20 issues an alarm message through the indicator 25, the alarm message being used to indicate that the temperature control switch 11 has malfunctioned.

Please refer to Figure 6, which is a schematic diagram of another charger provided in an embodiment of this application. Figure 6 is derived from Figure 5. As shown in Figure 6, the charger further includes a vehicle plug 30. When the vehicle plug 30 is inserted into the vehicle socket 40, the charger establishes a charging circuit with the vehicle.

Among them, the vehicle socket 40 can be connected to the vehicle's on-board charger (OBC), enabling the charger to establish a charging circuit with the vehicle. This charging system can establish a charging circuit between the mains socket, power plug 10, function box 20, vehicle plug 30, vehicle socket 40, vehicle's OBC, and power battery, thereby enabling the charging of the power battery.

Please refer to Figure 7, which is a schematic diagram of the specific structure of a charger provided in an embodiment of this application. Figure 7 is derived from Figure 6. As shown in Figure 7, based on Figure 6, the functional box 20 of the charger further includes a first relay K1, a second relay K2, a leakage current detection circuit 27, and a current sampling circuit 28.

The first relay K1 is connected in series on the second segment of the first phase line L1, and the second relay K2 is connected in series on the second phase line L2.

The first controller can control the first relay K1 and the second relay K2 to disconnect when the temperature sensor 12 detects that the temperature exceeds the disconnection limit temperature of the temperature control switch 11.

The leakage current detection circuit 27 is used to detect whether leakage current occurs in the first phase line L1 and the second phase line L2. The current sampling circuit 28 is used to detect the current in the first phase line L1, thereby detecting the state (closed or open) of the temperature control switch 11.

In Figure 7, the charger includes: a power plug 10, a function box 20, and a vehicle plug 30, wherein the power plug 10 and the function box 20 are connected by a power cord, and the function box 20 and the vehicle plug 30 are connected by a charging cable.

The power plug 10 is coupled to the mains socket. The power plug 10 includes: L1 phase wire, L2/N phase wire, PE, power cord, and temperature control switch 11; wherein the temperature control switch 11 is connected in series with the phase wires (L1, L2, N). For example, the temperature control switch 11 can be fixed in the power plug 10 by potting or encapsulation. The power cord is connected to the input terminal of the temperature control switch 11.

The power plug 10 or the function box 20 also has a temperature sensor 12, which can detect the temperature and confirm whether the temperature control switch 11 is working properly.

The functional box 20 includes: a first power supply, a first voltage detection circuit 21, a first controller, a control guide 24, a leakage current detection circuit 27, and relays (first relay K1 and second relay K2 as shown in Figure 7).

The vehicle plug 30 is coupled with the vehicle socket 40 to conduct electrical energy from the mains socket to the vehicle's power battery, thereby realizing the charging function.

Based on the charger shown in Figure 7, an over-temperature protection determination method for a charger is provided. Please refer to Figure 8, which is a flowchart illustrating an over-temperature protection determination method for a charger according to an embodiment of this application. As shown in Figure 8, the method may include the following steps.

801. After the power plug is inserted into the AC socket, the charger supplies power to the function box.

The charger's power plug and the mains socket are coupled together to form an electrical connection. At this time, the temperature control switch is in the normally closed state, the relay in the function box is in the open state, and the mains voltage is applied between the power plug and the relay in the function box.

The first input terminal of the first power supply is connected to the first segment of the first phase line, the second input terminal of the first power supply is connected to the second phase line, and the output terminal of the first power supply is connected to the power supply terminal of the first controller.

The first input terminal of the first power supply draws power from the first segment of the first phase line (i.e., the input terminal of the temperature control switch). The temperature control switch can be connected electrically by means of welding, crimping, screwing, etc. As long as the power plug is effectively inserted into the mains socket, the first power supply can draw power from the first segment of the first phase line and the second phase line. The first power supply can handle the power consumption of low-voltage components such as electronic components, control circuits, and detection circuits in the functional box.

When there is voltage input at the power supply terminal of the first controller, the power supply plug and the mains socket are effectively coupled by default. When the input voltage at the power supply terminal of the first controller is 0, the function box is powered off, and the power supply plug and the mains socket are completely disconnected by default.

802, the temperature control switch is detected to be in a closed state by the first voltage detection circuit, and the cumulative number of disconnections stored in the first controller is 0.

One end of the voltage detection circuit is connected to the phase line and then connected in series with the temperature control switch. The voltage detection circuit of the charger's function box determines whether the power supply plug is effectively connected to the mains power by detecting the voltage between the phase lines (L1 and L2, L1 and N) or between the phase lines (L1, L2, N) and PE, thereby detecting that the temperature control switch is in the closed state.

When the power plug is inserted into the mains socket, the temperature control switch is in the normally closed state. When the function box is powered on for the first time, the voltage detection circuit detects the phase line voltage. If the phase line voltage indicates that the temperature control switch is in the closed state, the cumulative number of disconnections stored in the first controller is 0, and the data is stored.

803. Determine if the temperature control switch has tripped due to overheating. If yes, proceed to steps 804 and 805; otherwise, proceed to step 808.

The temperature control switch trips when overheated. The temperature control switch is connected in series with the phase line. When the temperature at the coupling area between the power plug and the mains socket is abnormal, this abnormality is conducted to the temperature control switch via the wire. When the temperature of the temperature control switch exceeds the material's heat distortion temperature, the contact spring will automatically and physically disconnect.

804, the function box indicates an over-temperature fault via an indicator.

The first controller of the function box can control the light indicator of the function box to display an over-temperature warning. For example, the function box displays text prompts related to over-temperature via a display screen or other means, and maintains this state until the charger is completely powered off and restarted.

805, the relay state of the function box remains unchanged, the temperature control switch is detected to be in the open state by the first voltage detection circuit, and the first controller controls the cumulative number of disconnections to increment by 1.

When the temperature control switch is at its heat distortion temperature, it automatically disconnects the phase line circuit (because the first power supply of the function box is directly drawn from the input terminal of the temperature control switch, the function box can be used for detection and control at this time). At this point, the voltage detection circuit detects that the phase line voltage is 0V or ≤30V AC (the charging system has capacitors and inductors, so the voltage detection circuit has a detection cycle, which can be no less than 100ms to prevent false detections). The first controller stores a cumulative disconnection count of 1, indicating that the power supply plug has experienced one over-temperature event, and the temperature control switch has disconnected.

After executing step 805, step 806 can be executed.

806. When the cumulative number of disconnections meets the preset control strategy, the first controller controls the CP module to adjust the duty cycle of the CP signal to notify the vehicle's on-board charger (OBC) to reduce the charging current or stop charging through the vehicle.

The first controller can determine the protection strategy based on the cumulative number of disconnections. The CP module here is the control bootloader.

When the voltage detection circuit detects that the temperature control switch is in the open state, and the cumulative number of open cycles N meets the preset control strategy, the first controller controls the CP module to adjust the duty cycle of the CP signal. The function box notifies the vehicle's OBC via the CP signal. The vehicle's OBC reduces the charging current requirement according to the duty cycle, thereby reducing the charger's current carrying capacity and mitigating the risk of overheating of the power supply plug. The protection strategy can be defined by the charger manufacturer, and can be referenced as ① and ② below, where ① and ② are OR relationships. Here, the CP module is the control initiator.

① When N=1, the charger sends a CP signal with a 100% or 0% duty cycle. When the vehicle's OBC detects a CP signal with a 100% or 0% duty cycle, it will stop charging.

② When N=1, if the charger's rated current carrying capacity is 15A and the CP signal duty cycle is 25%, the current can be reduced to 12A, and the CP signal duty cycle to 20%. When N=2, the current can be reduced to 10A, and the CP signal duty cycle to 16.67%. When N=3, the charger sends a CP signal with a 100% or 0% duty cycle, and the vehicle's OBC will stop charging when it detects a 100% or 0% duty cycle CP signal. This process continues, adjusting the CP duty cycle to control the charging current.

It should be noted that after the temperature control switch is turned off, the vehicle OBC will detect that there is no voltage on the phase line and will actively disconnect the relay at the OBC end. The relays at the function box end (the first relay K1 and the second relay K2 as shown in Figure 7) can remain in the closed state.

If the vehicle detects an abnormal duty cycle of the CP signal (such as a 100% or 0% duty cycle when charging is stopped), the vehicle can proactively communicate with the user (e.g., via a mobile app, instrument panel, or vehicle display screen) to issue a charging fault warning and remind the user to proactively check the charging system (e.g., power plug, AC socket) and perform maintenance on the charging device and power socket.

807. When the power plug and mains socket are detected to be disconnected, the cumulative disconnection count is reset to zero and the program restarts.

After the power plug and the mains socket are disconnected, the first power source stops supplying power to the first controller. At this time, the first controller is de-energized, and the cumulative number of disconnections stored in the first controller is cleared to zero due to the power outage.

When the power plug is detected to be disconnected, the cumulative disconnection count of the function box is reset to zero. After the function box of the charger is powered on again, all programs of the charger are restarted and the charging current is restored to the factory default current state.

Step 807 can be performed after step 805, step 806 or step 808.

808, continue charging.

Optionally, if an abnormal duty cycle of the CP signal is detected at the vehicle end (such as a 100% duty cycle), the vehicle can proactively communicate with the user to issue a charging fault warning and remind the user to proactively check the charging system (such as the power plug and AC socket).

Optionally, the temperature sensor can be used to confirm whether the temperature control switch is working properly.

A temperature range can be set. When the temperature sensor temperature is within this range, the first controller records an over-temperature protection event, and then considers the temperature control switch to be working normally.

If the temperature sensor detects a broken phase wire when the temperature is below the lower limit of the specified temperature range, an abnormal wire breakage is considered to have occurred. An alarm may be issued, and the fault may even be stored, preventing charging upon the next restart (manufacturer-defined).

When the temperature sensor reading exceeds the upper limit of the temperature range, if the phase wire is not detected to be disconnected, it is considered that the temperature control switch has malfunctioned due to sticking or other failure to disconnect. An alarm can be issued, and the fault can even be stored, preventing charging upon the next restart (manufacturer-defined). righteous).

When charging stops, the temperature control switch on the overheated phase line will quickly reduce the temperature and automatically reset (i.e., close). At this time, the voltage detection circuit will detect that there is an input voltage on the phase line with the temperature control switch, proving that the circuit is conducting.

The following factors can be considered when setting the temperature range of the temperature control switch:

① The operating temperature T0 of the charger;

② The power plug material of the charger has a temperature resistance of T1;

③ The power plug of the charger is matched with the AC socket material with a temperature resistance of T2;

④ The maximum long-term current carrying temperature rise Tk of the charger;

The thermal distortion temperature Tb of the temperature control switch: T2 and T1 > Tb > T0 + Tk.

The above temperature range can then be set as (T0+Tk, T1).

This application also provides a charging system, which may include the charger and the vehicle described above. The charger can charge the vehicle's power battery.

Electric vehicles primarily use two charging methods: DC charging and AC charging. During AC charging, the charging unit draws power from a mains outlet via a power plug. After power is supplied, the controller within the unit uses software to control whether a relay is activated, thereby controlling whether charging is initiated. To ensure charging safety, a temperature detection unit is typically installed in the power plug to monitor its temperature. When the plug temperature exceeds a set threshold, the controller stops charging via software. However, in cases of software or controller malfunction, timely stopping of charging may be impossible, posing a safety risk.

This application provides a charger and charging system that can reduce the safety risks of the charger.

The charger in this embodiment includes a power plug, a temperature control switch, and a function box. The power plug and the function box are connected by a charging cable, a portion of which is located inside the function box. The function box includes a second power source and a relay. The relay is connected to the charging cable. The input terminal of the second power source is connected to the charging cable, and the output terminal is connected to the relay coil via the temperature control switch to control the relay's opening or closing. In this embodiment, the temperature control switch is connected between the second power source and the relay coil, and the second power source supplies power to the relay coil through the temperature control switch. When the temperature control switch disconnects due to overheating, the second power source cannot supply power to the relay coil, causing the relay to open and automatically disconnecting the charging cable, thus stopping the charger from charging. Compared to software control, this reduces the safety risks of the charger.

Please refer to Figure 9, which is a schematic diagram of a charger provided in an embodiment of this application. As shown in Figure 9, the charger may include a power plug 10, a temperature control switch 11, and a function box 20. The power plug 10 and the function box 20 are connected by a charging cable. A portion of the charging cable is located inside the function box 20. The function box 20 includes a second power source and a relay. The relay is connected to the charging cable. The input terminal of the second power source is connected to the charging cable, and the output terminal of the second power source is connected to the coil of the relay through the temperature control switch 11 to control the opening or closing of the relay. When the relay is closed, the charger can start charging; when the relay is open, the charger stops charging. The relay divides the charging cable into a first segment and a second segment. The first segment of the charging cable is located in the power plug 10 and the function box 20, and the second segment of the charging cable is located in the function box 20. When the relay is closed, the first and second segments of the charging cable are connected; when the relay is open, the first and second segments of the charging cable are disconnected. The second segment of the charging cable can be connected to a load. The input terminal of the second power source is connected to the first segment of the charging cable. In Figure 9, the power module 23 corresponds to the second power supply, and the temperature switch 11 in Figures 9 to 13 corresponds to the temperature control switch.

When the temperature control switch 11 is not open, the second power source can draw power from the charging cable and output voltage to the relay coil to energize the relay coil, thereby controlling the relay to close. When the temperature control switch 11 is opened due to over-temperature, the second power source cannot output voltage to the relay coil to de-energize the relay coil, thereby controlling the relay to open.

The temperature control switch 11 can be located outside the power supply plug 10 (e.g., inside the function box 20) or inside the power supply plug 10. The temperature control switch 11 may include a temperature switch.

In some embodiments of this application, the temperature control switch 11 may include a switching device that can perform the action of turning on or off based on a physical change in temperature. The temperature control switch 11 may also include a switching device, a temperature sensing device, and a processor, wherein the processor can control the switching device to turn on or off based on the temperature signal detected by the temperature sensing device.

In this embodiment, the temperature control switch 11 is connected between the second power supply and the relay coil. The second power supply powers the relay coil through the temperature control switch 11. When the temperature control switch 11 disconnects due to overheating, the second power supply cannot power the relay coil, causing the relay to disconnect and automatically disconnect the charging cable, thus stopping the charger from charging. Compared with software control, this reduces the safety risks of the charger.

The charging cable can be an AC charging cable or a DC charging cable, and can provide AC power or DC power.

The number of relays can be one or at least two.

The charging cable in Figure 9 is shown as an example with a thick wire.

Optionally, the charging cable may include a first phase wire, a second phase wire, and a ground wire. The number of relays may be two.

Please refer to Figure 10, which is a schematic diagram of another charger provided in an embodiment of this application. The charging cable in Figure 10 includes a first phase wire (L1 as shown in Figure 10), a second phase wire (L2/N as shown in Figure 10), and a ground wire PE. The number of relays in Figure 10 is two, namely a first relay K1 and a second relay K2. As shown in Figure 10, the charger includes a power plug 10, a temperature control switch 11, and a function box 20. The power plug 10 and the function box 20 are connected through the first phase wire, the second phase wire, and the ground wire PE. The function box 20 includes a second power supply, a first relay K1, and a second relay K2. The first relay K1 is connected in series with the first phase wire, and the second relay K2 is connected in series with the second phase wire. The input terminal of the second power supply is connected to the charging cable, and the output terminal of the second power supply is connected to the coil 1 of the first relay K1 and the coil 2 of the second relay K2 through the temperature control switch 11 to control the opening or closing of the first relay K1 and the second relay K2. The first segment of the first phase wire is located in the power supply plug 10 and the function box 20, and the second segment of the first phase wire is located in the function box 20. The first segment of the first phase wire is connected to the second segment of the first phase wire through the first relay K1. The first segment of the second phase wire is located in the power supply plug 10 and the function box 20, and the second segment of the second phase wire is located in the function box 20. The first segment of the second phase wire is connected to the second segment of the second phase wire through the second relay K2. The ground wire PE is located in the power supply plug 10 and the function box 20. The first relay K1 is connected in series between the first segment of the first phase wire and the second segment of the first phase wire, and the second relay K2 is connected in series between the first segment of the second phase wire and the second segment of the second phase wire. The second power supply is used to draw power from the first segment of the first phase wire and the first segment of the second phase wire (as shown in Figure 10, the input terminals of the second power supply include the first input terminal and the second input terminal of the second power supply, the first input terminal of the second power supply is connected to the first segment of the first phase wire, and the second input terminal of the second power supply is connected to the first segment of the second phase wire), and to supply power to the coil 1 of the first relay K1 and the coil 2 of the second relay K2 through the temperature control switch 11.

In this embodiment, the temperature control switch 11 is connected in series between the second power supply and the relay coil. If an abnormal temperature occurs in the coupling area between the power plug 10 and the mains socket, heat is conducted to the temperature control switch 11. When the temperature of the temperature control switch 11 exceeds the material's heat distortion temperature, the temperature control switch 11 will automatically physically disconnect; when the temperature of the temperature control switch 11 is below the material's heat distortion temperature, the temperature control switch 11 will automatically physically close. The upper temperature limit of the charger during normal operation is less than the heat distortion temperature.

The following factors can be considered when setting the heat distortion temperature of the temperature control switch 11:

① The operating temperature T0 of the charger;

② The power plug of the charger is made of material with a temperature resistance of T1;

③ The power plug 10 of the charger is matched with a mains socket material with a temperature resistance of T2;

④ The maximum long-term current carrying temperature rise Tk of the charger;

The heat distortion temperature Tb of temperature control switch 11: the maximum value between T2 and T1 > Tb > T0 + Tk.

If the temperature of the temperature control switch 11 is greater than T0+Tk, thermal deformation will occur.

The temperature control switch 11 is disposed inside the power supply plug 10 and connected in series in the second power supply circuit. For example, the temperature control switch 11 can be installed adjacent to the first phase wire. The temperature control switch 11 automatically disconnects after overheating. In the event of software or second controller malfunction, it can also disconnect the first relay K1 and the second relay K2, preventing the power supply plug 10 from burning out, thus enhancing safety. Since the temperature control switch 11 is not connected in series in the main power circuit, the current carrying capacity and durability requirements for the temperature control switch 11 are lower, resulting in higher stability in use. For example, the temperature control switch 11 may include at least one temperature spring. In this embodiment, the temperature control switch 11 can be a single temperature spring or multiple temperature springs connected in series. For example, the temperature control switch 11 is fixed in the power supply plug 10 using processes such as potting or encapsulation.

The coil 1 of the first relay K1 can also be called the control coil or low-voltage coil of the first relay K1. The coil 2 of the second relay K2 can also be called the control coil or low-voltage coil of the second relay K2. When current flows through the coil 1 of the first relay K1, the first relay K1 is closed (closing can also be called energizing); when no current flows through the coil 1 of the first relay K1, the first relay K1 is open. When current flows through the coil 2 of the second relay K2, the second relay K2 is closed; when no current flows through the coil 2 of the second relay K2, the second relay K2 is open. The temperature control switch 11, the second power supply, and the coils 2 of the first relay K1 and the second relay K2 are connected in series in a circuit. When the temperature control switch 11 is open, the first relay K1 and the second relay K2 are also open. The position of the lead wire at the first end of the temperature control switch 11 is not fixed; it can be placed in the function box 20 or in the power plug 10. In Figure 10, the lead wire at the first end of the temperature control switch 11 is located in the function box 20 for easy wiring. The power plug 10 only houses one temperature control switch 11, resulting in a simpler size and manufacturing process, and lower cost. The lead wire at the first end of the temperature control switch 11 can be connected to the temperature control switch via soldering, crimping, screwing, or other methods. 11. Form an effective electrical connection.

It should be noted that the coil 1 of the first relay K1 and the coil 2 of the second relay K2 can be different coils or the same coil. Figure 10 illustrates an example where the coil 1 of the first relay K1 and the coil 2 of the second relay K2 are different coils. When the first relay K1 and the second relay K2 share the same coil, one coil controls the opening and closing of both relays (the first relay K1 and the second relay K2), meaning that the first relay K1 and the second relay K2 are simultaneously turned off and simultaneously closed.

The first phase line can be any one of L1, L2, and N, and the second phase line can be any one of L1, L2, and N. The first phase line and the second phase line are different, and at least one of the first phase line and the second phase line is L1. In Figure 10, the first phase line is L1, and the second phase line is either L2 or N (neutral line). In one possible embodiment, the first phase line is either L2 or N (neutral line), and the second phase line is L1.

In this embodiment, L1 and L2 are two different phases of a two-phase power supply. When the power plug 10 is inserted into the mains socket, the voltage difference between L1 and L2 is generally around 200V, the voltage difference between L1 and N is generally around 100V, the voltage between L1 and PE is generally around 220V, and the voltage between L2 and PE is generally around 220V.

In this embodiment, the temperature control switch 11 is connected between the second power supply and the relay coil. The second power supply powers the relay coil through the temperature control switch 11. When the temperature control switch 11 disconnects due to overheating, the second power supply cannot power the relay coil, causing the relay to disconnect and automatically disconnect the charging cable, thus stopping the charger from charging. Compared with software control, this reduces the safety risks of the charger.

Optionally, the temperature control switch 11 is disposed in the power supply plug 10. With the temperature control switch 11 accurately sensing the heating of the power supply plug 10, when the power supply plug 10 heats up, the temperature control switch 11 can disconnect the power supply to the relay coil, thereby disconnecting the relay.

Please refer to Figure 11, which is a schematic diagram of another charger provided in this application embodiment. Figure 11 is derived from Figure 10. As shown in Figure 11, based on Figure 10, the functional box 20 further includes a first switch S1. The output terminal of the second power supply is connected to the first terminal of the temperature control switch 11 through the first switch S1. The second terminal of the temperature control switch 11 is connected to the first terminal of the coil of the relay, and the second terminal of the coil of the relay is grounded. (As shown in Figure 11, the second terminal of the temperature control switch 11 is connected to the first terminal of the coil 1 of the first relay K1 and the first terminal of the coil 2 of the second relay K2, and the second terminal of the coil 1 of the first relay K1 and the second terminal of the coil 2 of the second relay K2 are grounded.)

Optionally, the charger's functional box 20 further includes a second voltage detection circuit 211 (i.e., voltage detection 1 in FIG. 11); voltage detection 1 is used to detect the voltage on the charging line. As shown in FIG. 11, voltage detection 1 is used to detect the voltage between the first segment of the first phase line (L1 as shown in FIG. 11) and the first segment of the second phase line (L2 or N as shown in FIG. 11).

Optionally, the charger's functional box 20 also includes a third voltage detection circuit 212 (i.e., voltage detection 2 in FIG11), which is used to detect the voltage at the second terminal of the temperature control switch 11.

In this embodiment, both the second voltage detection circuit 211 and the third voltage detection circuit 212 may include a voltage acquisition circuit, or a voltage acquisition circuit and a voltage processing circuit. The voltage acquisition circuit is used to acquire voltage, and the voltage processing circuit is used to process the voltage acquired by the voltage acquisition circuit. Simultaneously, the voltage acquisition circuit can be a sensor, and the voltage processing circuit can be located within the sensor or within the back-end controller.

Optionally, the function box 20 also includes a second controller, and the second power supply is also used to power the second controller; as shown in Figure 11, the first output terminal of the second power supply is connected to the power supply terminal of the second controller, the second output terminal of the second power supply is connected to the first terminal of the first switch, the second terminal of the first switch is connected to the first terminal of the temperature control switch 11, and the second terminal of the temperature control switch 11 is connected to the coil of the first relay and the coil of the second relay. The control module 22 in Figure 11 corresponds to the second controller.

The second controller is used to determine whether the power supply plug 10 is inserted into the mains socket based on the voltage detected by the second voltage detection circuit 211.

The second controller is also used to control the first switch to close when the power plug 10 is inserted into the mains socket and charging is ready, and to determine the temperature control switch 11 to open based on the voltage detected by the third voltage detection circuit 212.

The second controller is the module in function box 20 that plays a control role; the second controller can also be called a control unit. For example, the second controller can be a microcontroller unit (MCU).

The second controller can determine whether the power plug 10 is inserted into the mains socket based on the voltage detected by voltage detector 1. Specifically, it can determine whether the power plug 10 is inserted into the mains socket based on the voltage between the first segment of the first phase line and the first segment of the second phase line detected by voltage detector 1. The voltage between the first segment of the first phase line and the first segment of the second phase line can be the voltage difference between the first segment of the first phase line and the first segment of the second phase line, or the voltage difference between the first phase line and the ground line, or the voltage difference between the second phase line and the ground line.

"Charging ready" is the standard for a charger to be ready for charging as specified in the charging protocol.

Optionally, the second controller determines whether the power plug 10 is inserted into the mains socket based on the pressure difference, including:

If the voltage between the first phase line and the second phase line is less than the sixth threshold, the second controller determines that the power supply plug 10 is not inserted into the mains socket.

If the voltage between the first phase line and the second phase line is greater than the seventh threshold, the second controller determines that the power supply plug 10 has been inserted into the mains socket and the seventh threshold is greater than the sixth threshold.

In this embodiment, the sixth threshold can be set to a value less than 50. For example, the sixth threshold can be set to 30V.

When the first phase line is L1 and the second phase line is L2, the seventh threshold can be set to a value greater than 150V and less than 200V. For example, the seventh threshold can be set to 180V. When the first phase line is L1 and the second phase line is N, the seventh threshold can be set to a value greater than 50V and less than 100V. For example, the seventh threshold can be set to 80V.

If the voltage between the first and second phase lines is the voltage difference between L1 and ground, the seventh threshold can be set to a value greater than 150V and less than 200V. For example, the seventh threshold can be set to 180V.

In this embodiment, the sixth and seventh thresholds can be preset. The second controller can accurately determine whether the power plug 10 is inserted into the mains socket using the sixth and seventh thresholds.

Optionally, the second controller determines whether the temperature control switch 11 is open based on the voltage detected by the third voltage detection circuit 212, including:

If the voltage detected by the third voltage detection circuit 212 is less than the eighth threshold, the second controller determines that the temperature control switch 11 is open.

If the voltage detected by the third voltage detection circuit 212 is greater than the eighth threshold, the second controller determines that the temperature control switch 11 is not disconnected.

In this embodiment, the second controller determines whether the temperature control switch 11 is open based on the voltage detected by the voltage detector 2. The voltage detector 2 detects the voltage at the first input terminal of the second power supply. The voltage signal is V1 when the temperature control switch 11 is on, and V2 when the temperature control switch 11 is off. If the voltage detected by the voltage detector 2 is less than the eighth threshold, the temperature control switch 11 is confirmed to be open; if the voltage detected by the voltage detector 2 is greater than the eighth threshold, the temperature control switch 11 is confirmed to be on.

For example, if the first phase line is L1 in a two-phase circuit, when the temperature control switch 11 is on, the voltage V1 detected by the voltage detector 2 is around 220V, and the voltage V2 detected by the voltage detector 2 is around 0V. The eighth threshold can be set to any value between 20-220V. For example, the eighth threshold can be set to 100V.

In this embodiment, the temperature control switch 11 is connected in series between the second power supply and the coil of the relay. The second power supply supplies power to the coil 1 of the first relay K1 and the coil 2 of the second relay K2 through the first switch S1. When the temperature control switch 11 disconnects due to overheating, the second power supply cannot supply power to the coil 1 of the first relay K1 and the coil 2 of the second relay K2, thereby automatically disconnecting the first phase line and the second phase line, causing the charger to stop charging. Compared with software control, this reduces the safety risk of the charger.

Optionally, the second controller is used to determine a protection strategy based on the cumulative number of times the temperature control switch 11 has been disconnected after the power plug 10 has been inserted into the mains socket when the temperature control switch 11 is disconnected; or the second controller is used to determine a protection strategy based on the continuous charging time of the charger; or the second controller is used to determine a protection strategy based on the cumulative number of times the temperature control switch 11 has been disconnected after the power plug 10 has been inserted into the mains socket and the continuous charging time of the charger.

In this embodiment, when the temperature control switch 11 is open, the second controller can determine the protection strategy based on the cumulative number of times the temperature control switch 11 has been opened since the power plug 10 was inserted into the mains socket. Generally, the greater the cumulative number of times the temperature control switch 11 has been opened since the power plug 10 was inserted into the mains socket, the stronger the protection. For example, each time the temperature control switch 11 is opened, as the cumulative number increases, the next time the temperature control switch 11 is closed, the charger's operating current will decrease compared to the previous time the temperature control switch 11 was closed, and may even decrease to 0. The opening of the temperature control switch 11 may be caused by the high operating current of the charger (a high operating current of the charger may cause the temperature to rise). By reducing the operating current of the charger, the temperature control switch 11 is less likely to open, thereby extending the charger's operating time and allowing the charger to charge the vehicle as much power as possible in the event of a charger failure.

When the temperature control switch 11 is open, the second controller can also determine the protection strategy based on the charger's continuous charging duration. The charger's continuous charging duration refers to the duration of continuous charging before the temperature control switch 11 is opened again. Generally, the shorter the charger's continuous charging duration, the stronger the protection. For example, the lower the charger's operating current, the greater the reduction in operating current when the temperature control switch 11 closes next time, potentially even dropping to zero. A shorter continuous charging duration indicates that the temperature control switch 11 is more likely to open, possibly due to a higher charger operating current (a higher charger operating current may lead to increased temperature). By reducing the charger's operating current, the temperature control switch 11 is less likely to open, thus extending the charger's operating time and allowing it to charge the vehicle as much as possible in the event of a charger malfunction.

Optionally, when the power plug 10 is inserted into the mains socket, the cumulative number of disconnections stored in the second controller is 0;

After the power plug 10 is inserted into the mains socket, the second controller will increment the cumulative disconnection count by 1 each time the temperature control switch 11 is detected to be disconnected.

When the power plug 10 is disconnected from the mains socket, the cumulative number of disconnections stored in the second controller is cleared to zero.

In this embodiment, the second controller can store a cumulative number of disconnections. When the power plug 10 is inserted into the mains socket, that is, when the second controller is first powered on, the cumulative number of disconnections is 0.

When the second controller is powered (when the power plug 10 is inserted into the mains socket), the cumulative disconnection count is incremented by 1 each time the temperature control switch 11 is detected to be disconnected. When the second controller is not powered (when the power plug 10 is disconnected from the mains socket), i.e., when the second controller is de-energized, the cumulative disconnection count is cleared to zero.

In this embodiment, the cumulative disconnection count is guaranteed to be the cumulative disconnection count of the temperature control switch 11 after the power plug 10 is inserted into the mains socket. If this cumulative disconnection count continuously increases (i.e., it is not reset to zero), then after the power plug 10 is inserted into the mains socket, the charging current of the charger to the vehicle will be limited, or even the charger will stop charging the vehicle (for example, when the cumulative disconnection count is greater than or equal to the first threshold), which does not conform to actual usage scenarios. By resetting the cumulative disconnection count to zero when the second controller is powered off, it can be ensured that the cumulative disconnection count is recalculated from 0 every time the power plug 10 is inserted into the mains socket, which can improve the user experience.

Voltage detector 2 can periodically detect the voltage at the second terminal of temperature control switch 11. The second controller can determine whether temperature control switch 11 is open based on the voltage detected by voltage detector 2. Each time temperature control switch 11 is detected to be open, it means each time temperature control switch 11 is detected to have changed from closed to open.

The cumulative disconnection count refers to the number of times the temperature control switch 11 is detected to have gone from closed to open after the power plug 10 is inserted into the mains socket. For example, the second controller determines whether the temperature control switch 11 is open based on the voltage detected by the voltage detector 2. For instance, if the voltage detector 2 measures the voltage difference 10 times (during these 10 measurements, the second controller is continuously powered, i.e., the power plug 10 is continuously coupled to the mains socket), the corresponding states of the temperature control switch 11 are: closed, closed, open, open, open, closed, closed, closed, open, open. Then the cumulative disconnection count is 2 times.

Optionally, the second controller is used to determine a protection strategy based on the cumulative number of times the temperature control switch 11 disconnects after the power plug 10 is inserted into the mains socket, including:

If the cumulative number of times the temperature control switch 11 is disconnected is less than the first threshold, the second controller determines the target current reduction strategy based on the cumulative number of times the temperature control switch 11 is disconnected; wherein, the degree of current reduction of the target current reduction strategy is positively correlated with the cumulative number of times the temperature control switch 11 is disconnected.

If the cumulative number of disconnections of the temperature control switch 11 is greater than or equal to the first threshold, the second controller determines a stop charging strategy.

In this embodiment, the first threshold can be preset. The first threshold can be an integer greater than or equal to 2. The target current reduction strategy refers to the strategy of reducing the operating current of the charger. Each time the temperature control switch 11 is opened, if the cumulative number of times the temperature control switch 11 is opened is less than the first threshold, the operating current of the charger will be lower when the temperature control switch 11 is closed next time compared with the previous time the temperature control switch 11 was closed.

The charging stop strategy refers to the strategy by which the charger stops charging. When the cumulative number of times the temperature control switch 11 is disconnected is greater than or equal to a first threshold, the second controller can control the charger to stop working, that is, stop charging the vehicle.

For example, if the first threshold is 3, after the power plug 10 is inserted into the mains socket, if the charger's operating current is the rated current (e.g., 15A), the temperature control switch 11 will open for the first time, and the cumulative number of times the temperature control switch 11 has opened is 1. When the temperature control switch 11 closes again, the charger's operating current can be controlled to 12A. If the temperature control switch 11 opens for the second time, the cumulative number of times the temperature control switch 11 has opened is 2. When the temperature control switch 11 closes again, the charger's operating current can be controlled to 10A. If the temperature control switch 11 opens for the third time, the cumulative number of times the temperature control switch 11 has opened is 3. When the temperature control switch 11 closes again, the charger can be controlled to stop working, that is, stop charging the vehicle.

Optionally, please refer to Figure 12, which is a schematic diagram of another charger provided in an embodiment of this application. Figure 12 is derived from Figure 11. As shown in Figure 12, based on Figure 11, the functional box 20 of the charger further includes: a control guide; the second controller is also used to determine the target duty cycle corresponding to the target current reduction strategy according to the cumulative number of times the temperature control switch 11 is disconnected, and send a target CP signal to the vehicle's on-board charger through the control guide, wherein the duty cycle of the target CP signal is the target duty cycle. Among them, the CP module 24 in Figure 12 corresponds to the control guide.

The CP signal is a signal sent by the second controller to the vehicle's on-board charger. The CP signal can be generated by the control pilot (CP) module, and the control signal can control the duty cycle of the CP signal generated by the CP module.

When the vehicle's onboard charger receives the CP signal, if the onboard charger detects a change in the duty cycle of the CP signal (currently connected), it will... If the duty cycle of the received CP signal is different from that of the previously received CP signal, the on-board charger will automatically adjust the load, thereby adjusting the charger's operating current.

In this embodiment of the application, the second controller can send a target CP signal to the vehicle's on-board charger (OBC) through the CP module, thereby controlling the charger's operating current.

The greater the cumulative number of times the temperature control switch 11 disconnects, the lower the target duty cycle corresponding to the target current reduction strategy, meaning a lower operating current for the charger. The operating current of the charger after the temperature control switch 11 closes next can be determined based on the cumulative number of disconnections. A higher cumulative number of disconnections means more frequent over-temperature protection triggers by the temperature control switch 11, resulting in a lower operating current for the charger after the next closure. By reducing the charger's operating current, the temperature control switch 11 is less likely to disconnect, thus extending the charger's operating time and maximizing the amount of electricity the charger can deliver to the vehicle in the event of a charger malfunction.

For example, if the first threshold is 3, after the power plug 10 is inserted into the mains socket, if the charger's operating current is the rated current (e.g., 15A), the duty cycle of the CP signal sent by the second controller to the vehicle's on-board charger via the CP module is 25%. When the temperature control switch 11 is opened for the first time, the cumulative number of times the temperature control switch 11 has been opened is 1. When the temperature control switch 11 is closed again, the charger's operating current can be controlled to 12A, and the duty cycle of the CP signal sent by the second controller to the vehicle's on-board charger via the CP module is 20%. When the temperature control switch 11 is opened for the second time, the cumulative number of times the temperature control switch 11 has been opened is 2. When the temperature control switch 11 is closed again, the charger's operating current can be controlled to 10A, and the duty cycle of the CP signal sent by the second controller to the vehicle's on-board charger via the CP module is 16.67%. When the temperature control switch 11 is disconnected for the third time, the cumulative number of disconnections of the temperature control switch 11 is 3. When the temperature control switch 11 is closed again, it can control the charger to stop working. At this time, the duty cycle of the CP signal sent by the second controller to the vehicle's on-board charger through the CP module is 0% or 100%, that is, it stops charging the vehicle.

Optionally, as shown in Figure 12, the function box 20 further includes a first leakage current detection circuit; the second controller is also used to control the first switch to disconnect when the first leakage current detection circuit detects leakage current in the charger. The leakage current detection circuit 27 in Figure 12 corresponds to the first leakage current detection circuit.

Optionally, as shown in Figure 12, the function box 20 further includes a first current sampling circuit; the second controller is also used to control the first switch S1 to open when the first current sampling circuit detects that the current on the charging line (e.g., the first phase line or the second phase line) is greater than a fifth threshold. The current sampling circuit 28 in Figure 12 corresponds to the first current sampling circuit.

The first leakage current detection circuit is used to detect whether leakage occurs in the first phase line and the second phase line. The first current sampling circuit is used to detect the current in the first phase line, thereby detecting whether the charging current is abnormal.

The second controller is also used to control the first switch S1 to open when the first leakage detection circuit detects that the charger is leaking current. This can achieve the purpose of controlling the first relay K1 and the second relay K2 to open when the charger is leaking current, thereby improving the charging safety of the charger.

Optionally, as shown in Figure 12, the charger also includes a vehicle plug 30, which establishes a charging circuit with the vehicle when the vehicle plug 30 is inserted into the vehicle socket 40.

Among them, the vehicle socket 40 can be connected to the vehicle's on-board charger (OBC), enabling the charger to establish a charging circuit with the vehicle. This charging system can establish a charging circuit between the mains socket, power plug 10, function box 20, vehicle plug 30, vehicle socket 40, vehicle's OBC, and power battery, thereby enabling the charging of the power battery.

The vehicle plug 30 is coupled with the vehicle socket 40 to conduct electrical energy from the mains socket to the vehicle's power battery and storage battery, thereby realizing the charging function.

Function box 20 and power plug 10, and function box 20 and vehicle plug 30 can all be integrated structures, or function box 20 as shown in Figure 12 can be located between power plug 10 and vehicle plug 30. This application does not limit the specific embodiment.

The charger includes a power plug 10, a function box 20, and a vehicle plug 30. The power plug 10 and the function box 20 are connected by a power cord (the power cord L1, L2/N in Figure 12 that is connected to the second power supply and the second power supply), and the function box 20 and the vehicle plug 30 are connected by a charging cable (the cable in Figure 12 that is connected to L1, L2/N, PE, and CP of the vehicle plug 30).

Optionally, as shown in Figure 12, the CP module includes a CP detection and control circuit, a second switch S2, a first resistor R1, and a third switch S3; the first output terminal of the CP detection and control circuit is connected to the first terminal of the second switch S2, the second output terminal of the CP detection and control circuit is connected to the second terminal of the second switch S2, the third terminal of the second switch S2 is connected to the first terminal of the first resistor R1, the second terminal of the first resistor R1 is connected to the first terminal of the third switch S3, and the second terminal of the third switch S3 is connected to the CP port of the vehicle plug 30.

In this embodiment, the first output terminal of the CP detection and control circuit can output a 12V voltage, and the second output terminal of the CP detection and control circuit can output a pulse width modulation (PWM) signal.

The charger's power plug 10 and the mains socket are coupled together to form an electrical connection. At this time, the temperature control switch 11 is in a normally closed state. The first switch S1 can be in a normally open or normally closed state. When the first switch S1 is in the normally open state and the power plug 10 is connected to the mains socket, the coil 1 of the first relay K1 and the coil 2 of the second relay K2 are not powered. When charging is ready, the second controller controls the first switch S1 to close, and the second power supply powers the coil 1 of the first relay K1 and the coil 2 of the second relay K2, causing the first relay K1 and the second relay K2 to engage. When the first switch S1 is in the normally closed state, the voltage at the first detection point of the CP can be used to determine whether the vehicle plug 30 is connected to the vehicle socket 40. If the connection fails, the first switch S1 can be immediately disconnected.

The first detection point of the CP is located at the connection point of the second switch S2 and the first resistor R1 in Figure 12. After the vehicle plug 30 and the vehicle socket 40 are connected, the voltage at the first detection point of the CP will change. The second controller can determine whether the vehicle plug 30 and the vehicle socket 40 are coupled by detecting the voltage at the first detection point of the CP. If they are coupled, the first switch S1 is kept in the normally closed state; if they are not coupled, the first switch S1 is opened to reduce the risk of electric shock.

Optionally, if the cumulative number of times the temperature control switch 11 is disconnected is greater than or equal to 1, the second controller sends a stop charging message to the vehicle so that the charger stops charging the vehicle.

In this embodiment, as soon as the temperature control switch 11 is detected to be open, a stop charging message is sent to the vehicle to stop the charger from charging the vehicle. When the temperature control switch 11 is detected to be open, the charger stops charging the vehicle. After the over-temperature protection of the temperature control switch 11 is tripped, the charger stops working, preventing the charger from experiencing over-temperature conditions again. This protects the charger, avoids repeated opening and closing of the temperature control switch 11, and improves its service life.

Specifically, the second controller sends a stop charging message to the vehicle so that the charger stops charging the vehicle. Specifically, the second controller sends a specific CP signal to the vehicle's on-board charger through the CP module.

Optionally, the specific CP signal can be the CP signal specified in the national standard: for example, a CP signal with a duty cycle of 100% or 0%.

Optionally, the specific CP signal can be a CP signal agreed upon by the charger and the vehicle: for example, a CP signal with alternating duty cycles of 100% and 20%. For example, the first half of the CP signal has a 100% duty cycle, and the second half has a 20% duty cycle.

Optionally, the second controller determines a protection strategy based on the continuous charging duration of the charger, including:

If the continuous charging time of the charger exceeds the fourth threshold, determine the target duration interval into which the continuous charging time of the charger falls, and determine the target charging current corresponding to the target duration interval; wherein, the target charging current is positively correlated with the target duration interval.

If the continuous charging time of the charger is less than or equal to the fourth threshold, the second controller determines a charging stop strategy.

In this embodiment of the application, the second controller has a timing function, which can count the continuous charging time of the charger.

For example, N different duration values can be set. Taking N=3 as an example: T1 = 60 minutes, T2 = 180 minutes, T3 = 480 minutes. Different duration values can correspond to different charging currents. T1 duration: 8A; T2 duration: 12A; T3 duration: 15A. It should be noted that N and each duration value TN can be defined according to the manufacturer's over-temperature protection strategy.

During a single charging cycle, voltage is continuously monitored, and the continuous charging time t is recorded. The continuous charging time t is the charging time during the process of the temperature control switch 11 closing and opening.

During continuous charging, if the temperature control switch 11 is disconnected due to overheating, and if the continuous charging time of the charger is t = 100 min, this time is compared with the preset time value. At this time, T1 < t ≤ T2 (the continuous charging time t of the charger is in the range of T1 to T2), the control unit adjusts the duty cycle of the CP signal, and waits for the plug temperature to drop until the temperature control switch 11 closes again before charging according to the charging current of 8A corresponding to T1.

If the continuous charging time of the charger is t = 240 min, this time is compared with the preset time value. At this time, T2 < t ≤ T3 (the continuous charging time t of the charger is in the range of T2 to T3). Then the control unit adjusts the duty cycle of the CP signal and waits for the plug temperature to drop to the temperature control switch 11 and close again before charging according to the charging current of 12A corresponding to T2.

If the continuous charging time of the charger is t = 500 min, this time is compared with the preset time value. At this time, T3 < t (the continuous charging time t of the charger is in the range greater than T3), the control unit adjusts the duty cycle of the CP signal, and waits for the plug temperature to drop to the temperature control switch 11 and close again before charging according to the charging current of 15A corresponding to T3.

If the continuous charging time of the charger is t = 40 minutes, compare this time with the preset time value. At this time, t ≤ T1 (the continuous charging time t of the charger is in the range of less than or equal to T1). At this time, the control unit can control the duty cycle of the CP signal and wait for the plug temperature to drop to the temperature control switch 11 and close again before charging at the set minimum current (<8A). Alternatively, the duty cycle of the CP signal can be adjusted to 100% or 0% to stop charging.

In this embodiment of the application, before the temperature control switch 11 is turned off, if the continuous charging time of the charger is shorter, it indicates that the temperature control switch 11 has a lower tolerance. If overheating protection is likely to occur, the operating current of the charger will be reduced after the temperature control switch 11 closes for the next time. By reducing the operating current of the charger, the temperature control switch 11 is less likely to disconnect, thereby extending the working time of the charger. In the event of a charger failure, the charger can charge the vehicle as much power as possible.

Optionally, the second controller determines a protection strategy based on the cumulative number of times the temperature control switch 11 disconnects after the power plug 10 is inserted into the mains socket and the continuous charging duration of the charger, including:

The charging current after the temperature control switch 11 closes again is determined based on the cumulative number of times the temperature control switch 11 is disconnected and the continuous charging time of the charger. The charging current after the temperature control switch 11 closes again is negatively correlated with the cumulative number of disconnections, and positively correlated with the continuous charging time.

For example, N different duration values can be set. Taking N=3 as an example: T1 = 60 minutes, T2 = 180 minutes, T3 = 480 minutes. Different duration values can correspond to different charging currents. T1 duration: 8~10A; T2 duration: 12~14A; T3 duration: 15~17A. It should be noted that N and each duration value TN can be defined according to the manufacturer's over-temperature protection strategy.

During a single charging cycle, voltage is continuously monitored, and the continuous charging time t is recorded. The continuous charging time t is the charging time during the process of the temperature control switch 11 closing and opening.

During continuous charging, if the temperature control switch 11 disconnects due to overheating, and the cumulative number of disconnections of the temperature control switch 11 is 1, the continuous charging time t = 100 min is compared with the preset time value. If T1 < t ≤ T2 (the continuous charging time t of the charger is within the range of T1 to T2), the control unit adjusts the duty cycle of the CP signal, waiting for the plug temperature to drop until the temperature control switch 11 closes again before charging at the maximum charging current of 10A corresponding to T1. If the cumulative number of disconnections of the temperature control switch 11 is 2, and the continuous charging time t = 100 min, the charging unit waits for the plug temperature to drop until the temperature control switch 11 closes again before charging at the medium charging current of 9A corresponding to T1. If the cumulative number of disconnections of the temperature control switch 11 is 3, and the continuous charging time t = 100 min, the charging unit waits for the plug temperature to drop until the temperature control switch 11 closes again before charging at the minimum charging current of 8A corresponding to T1. If the cumulative number of times the temperature control switch 11 is disconnected is 4, and the continuous charging time of the charger is t = 100 min, then wait for the plug temperature to drop until the charging current is 0 after the temperature control switch 11 is closed again (i.e., stop charging).

If the cumulative number of times the temperature control switch 11 has been disconnected is 1, and the continuous charging time of the charger is t = 240 minutes, this time is compared with the preset time value. In this case, T2 < t ≤ T3 (the continuous charging time t of the charger is within the range of T2 to T3). The control unit adjusts the duty cycle of the CP signal and waits for the plug temperature to drop until the temperature control switch 11 closes again before charging at the maximum charging current of 14A corresponding to T2. If the cumulative number of times the temperature control switch 11 has been disconnected is 2, and the continuous charging time of the charger is t = 240 minutes, the charger waits for the plug temperature to drop until the temperature control switch 11 closes again before charging at the medium charging current of 13A corresponding to T2. If the cumulative number of times the temperature control switch 11 has been disconnected is 3, and the continuous charging time of the charger is t = 240 minutes, the charger waits for the plug temperature to drop until the temperature control switch 11 closes again before charging at the minimum charging current of 12A corresponding to T2. If the cumulative number of times the temperature control switch 11 is disconnected is 4, and the continuous charging time of the charger is t = 240 min, then wait for the plug temperature to drop until the charging current is 0 after the temperature control switch 11 is closed again (i.e., stop charging).

If the cumulative number of times the temperature control switch 11 has been disconnected is 1, and the continuous charging time of the charger is t = 500 min, this time is compared with the preset time value. If T3 < t (the continuous charging time t is greater than T3), the control unit adjusts the duty cycle of the CP signal and waits for the plug temperature to drop until the temperature control switch 11 closes again before charging at the maximum charging current of 17A corresponding to T3. If the cumulative number of times the temperature control switch 11 has been disconnected is 2, and the continuous charging time of the charger is t = 500 min, then the charging continues until the plug temperature drops until the temperature control switch 11 closes again before charging at the medium charging current of 16A corresponding to T3. If the cumulative number of times the temperature control switch 11 has been disconnected is 3, and the continuous charging time of the charger is t = 500 min, then the charging continues until the plug temperature drops until the temperature control switch 11 closes again before charging at the minimum charging current of 15A corresponding to T3. If the cumulative number of times the temperature control switch 11 is disconnected is 4, and the continuous charging time of the charger is t = 500 min, then wait for the plug temperature to drop until the charging current is 0 after the temperature control switch 11 is closed again (i.e., stop charging).

For the i-th continuous charging duration ti, charging or stopping is performed according to the interval where the value of ti is located, based on the maximum current, medium current, or minimum current corresponding to the interval.

In this embodiment, before the temperature control switch 11 is disconnected, given the same continuous charging time, the greater the cumulative number of times the temperature control switch 11 is disconnected, the lower the operating current of the charger after the next time the temperature control switch 11 is closed. By considering both the cumulative number of times the temperature control switch 11 is disconnected and the continuous charging time of the charger, the operating current of the charger is reduced, making it less likely for the temperature control switch 11 to disconnect, thereby extending the charger's operating time and maximizing the amount of electricity the charger can deliver to the vehicle in the event of a charger malfunction.

Optionally, if the second controller sends a stop charging message to the vehicle, the vehicle sends a notification message to the user terminal to inform the user terminal that the charger has failed to charge.

In this embodiment, the second controller sends a stop charging message to the vehicle, causing the vehicle to adjust its load, thereby stopping the charger from charging the vehicle. The vehicle can establish communication with the user terminal. For example, the vehicle can notify the user via a cloud platform or APP (displaying the notification message on the user terminal), and can also display the notification message on the vehicle's instrument panel or display screen the next time the vehicle is started.

When the vehicle detects an abnormal duty cycle of the CP signal (such as a 100% or 0% duty cycle when charging stops), it can proactively communicate with the user (e.g., via a mobile app, instrument panel, or vehicle display screen) to issue a charging fault warning and remind the user to proactively check the charging system (e.g., power plug 10, AC socket) and perform maintenance on the charging device and power socket.

The embodiments of this application can promptly notify the user when the charger experiences an overheating fault, thereby improving the user experience.

Please refer to Figure 13, which is a schematic diagram of another charger provided in an embodiment of this application. Figure 13 is based on Figure 12. As shown in Figure 13, based on Figure 12, the function box 20 of the charger further includes an indicator. When the temperature control switch 11 is off, the function box 20 is used to issue a prompt message through the indicator, which is used to indicate that the power plug 10 has an over-temperature fault.

The prompter can be at least one of a voice module and a display module. The prompter can issue at least one of voice prompts, text prompts, and optical prompts. The prompts can include at least one of voice prompts and text prompts, and can indicate that the power plug 10 has an overheating fault. The prompter on the function box 20 can promptly alert the user. For example, the prompter can include a display module that can issue audio-visual prompts.

Please refer to Figure 14, which is a schematic flowchart of a method for detecting the disconnection of a temperature control switch according to an embodiment of this application. The method in Figure 14 can be based on the charger shown in Figure 13. As shown in Figure 14, the method includes the following steps.

601, Begin.

602. Is charging ready? If yes, proceed to step 603; otherwise, proceed to step 607.

603, the second controller closes the first switch S1.

604. The second controller detects whether there is voltage at the second terminal of the temperature control switch through the third voltage detection circuit. If yes, proceed to step 605; otherwise, proceed to step 606.

605, the temperature control switch is closed, charging is normally connected, until charging is complete.

606. The second controller confirms that the temperature control switch is off, issues an over-temperature warning, controls the CP module to adjust the duty cycle of the CP signal, and counts the cumulative number of disconnections.

607, End.

In this embodiment, when the temperature control switch is detected to be open, an over-temperature warning can be issued. The CP module is then controlled to adjust the duty cycle of the CP signal and count the cumulative number of disconnections, thereby reducing the charger's operating current before the next closing of the temperature control switch. By reducing the charger's operating current, the temperature control switch is less likely to disconnect, thus extending the charger's operating time and maximizing the amount of electricity the charger can deliver to the vehicle in the event of a charger malfunction.

This application also provides a charging system, which may include the charger and the vehicle described above. The charger can charge the vehicle's power battery.

Electric vehicle charging methods mainly include DC charging and AC charging. During AC charging, the charging unit draws power from a mains outlet via a power plug. After the charging unit is powered on, the controller within the unit uses software to control whether a relay is activated, thereby controlling whether charging is initiated. In the event of a software or controller malfunction, charging cannot be stopped in a timely manner, posing a safety risk.

This application provides a charger and charging system that can reduce the safety risks of the charger.

The charger in this embodiment includes a power plug, a temperature control switch, and a function box. The power plug and the function box are connected by a charging cable, a portion of which is located inside the function box. The function box includes a third power source and a relay. The relay is connected to the charging cable. The input terminal of the third power source is connected to the charging cable via the temperature control switch, and the first output terminal of the third power source is connected to the coil of the relay to control the relay's opening or closing. In this embodiment, the temperature control switch is connected between the charging cable and the third power source, which supplies power to the relay coil. When the temperature control switch disconnects due to overheating, the third power source is disconnected from the charging cable. The third power source cannot supply power to the relay coil, causing the relay to open, thus automatically disconnecting the charging cable and stopping the charger from charging. Compared to software control, this reduces the safety risks of the charger.

Please refer to Figure 15, which is a schematic diagram of a charger provided in an embodiment of this application. As shown in Figure 15, the charger may include a power plug 10, a temperature control switch, and a function box 20. The power plug 10 and the function box 20 are connected by a charging cable, a portion of which is located inside the function box 20. The function box 20 includes a third power source and a relay. The relay is connected to the charging cable. The input terminal of the third power source (power module 1 as shown in Figure 15) is connected to the charging cable via the temperature control switch, and the first output terminal of the power module 1 is connected to the coil of the relay. The relay controls the opening and closing of the charging cable. When the relay is closed, the charger can start charging; when the relay is open, the charger stops charging. The relay divides the charging cable into a first segment and a second segment. The first segment of the charging cable is located in the power plug 10 and the function box 20, and the second segment of the charging cable is located in the function box 20. When the relay is closed, the first and second segments of the charging cable are connected; when the relay is open, the first and second segments of the charging cable are disconnected. The second segment of the charging cable can be connected to a load. The first end of the temperature control switch is connected to the first segment of the charging cable. The power module 1, labeled 231 in Figure 15, corresponds to the third power supply. The temperature control switch 11 in Figures 15 to 21 corresponds to the temperature control switch.

When the temperature control switch is not open, power module 1 can draw power from the charging cable and output voltage to energize the relay coil, thereby controlling the relay to close. When the temperature control switch is opened due to over-temperature, power module 1 cannot draw power from the charging cable, and power module 1 cannot output voltage to de-energize the relay coil, thereby controlling the relay to open.

The temperature control switch can be located outside the power plug 10 (e.g., inside the function box 20) or inside the power plug 10. The temperature control switch 11 may include a temperature switch.

In this embodiment, a temperature control switch is connected between the charging cable and a third power source, which supplies power to the relay coil. When the temperature control switch disconnects due to overheating, the third power source is disconnected from the charging cable. Since the third power source cannot supply power to the relay coil, the charging cable is automatically disconnected, causing the charger to stop charging. Compared to software control, this reduces the safety risks of the charger.

The charging cable can be an AC charging cable or a DC charging cable, and can provide AC power or DC power.

The number of relays can be one or at least two.

The charging cable in Figure 15 is shown as an example with a thick wire.

Optionally, the charging cable may include a first phase wire, a second phase wire, and a ground wire. The number of relays may be two.

Please refer to Figure 16, which is a schematic diagram of another charger provided in an embodiment of this application. The charging cable in Figure 16 includes a first phase wire, a second phase wire, and a ground wire (PE). The number of relays in Figure 16 is two, namely a first relay K1 and a second relay K2. As shown in Figure 16, the charger includes a power plug 10, a temperature control switch, and a function box 20. The power plug 10 and the function box 20 are connected via the first phase wire, the second phase wire, and the ground wire (PE). The function box 20 includes a third power source (power module 1 as shown in Figure 16), a first relay K1, and a second relay K2. The first relay K1 is connected in series with the first phase wire, and the second relay K2 is connected in series with the second phase wire. The input terminal of the power module 1 (which includes a first input terminal and a second input terminal) is connected to the charging cable via the temperature control switch. The first output terminal of the power module 1 is connected to the coils of the first relay K1 and the second relay K2 to control the opening or closing of the first relay K1 and the second relay K2. The first segment of the first phase wire is located in the power supply plug 10 and the function box 20, and the second segment of the first phase wire is located in the function box 20. The first segment of the first phase wire is connected to the second segment of the first phase wire through the first relay K1. The first segment of the second phase wire is located in the power supply plug 10 and the function box 20, and the second segment of the second phase wire is located in the function box 20. The first segment of the second phase wire is connected to the second segment of the second phase wire through the second relay K2. The ground wire PE is located in the power supply plug 10 and the function box 20. A temperature control switch is connected in series between the first segment of the first phase wire and the first input terminal of the power module 1. The power module 1 is used to draw power from the first segment of the second phase wire and the temperature control switch from the first phase wire, and to supply power to the coils of the first relay K1 and the second relay K2. As shown in Figure 16, the first terminal of the temperature control switch is connected to the first segment of the first phase wire, the second terminal of the temperature control switch is connected to the first input terminal of the power module 1, the second input terminal of the power module 1 is connected to the second phase wire, and the first output terminal of the power module 1 is connected to the coil of the first relay K1 (i.e., coil 1 in Figure 16) and the coil of the second relay K2 (i.e., coil 2 in Figure 16).

In this embodiment, a temperature control switch is connected in series between the first phase line and the first input terminal of the power module 1. If an abnormal temperature occurs in the coupling area between the power plug 10 and the mains socket, heat is conducted to the temperature control switch. When the temperature of the temperature control switch exceeds the material's heat distortion temperature, the temperature control switch will automatically physically disconnect. When the temperature of the temperature control switch is lower than the upper temperature limit for normal operation of the charger, the temperature control switch will automatically physically close. The upper temperature limit for normal operation of the charger is less than the heat distortion temperature.

The following factors can be considered when setting the thermal distortion temperature of the temperature control switch:

① The operating temperature T0 of the charger;

② The power plug of the charger is made of material with a temperature resistance of T1;

③ The power plug 10 of the charger is matched with a mains socket material with a temperature resistance of T2;

④ The maximum long-term current carrying temperature rise Tk of the charger;

The heat distortion temperature Tb of the temperature control switch: the maximum value between T2 and T1 > Tb > T0 + Tk.

If the temperature of the temperature control switch is greater than T0+Tk, thermal deformation will occur.

The temperature control switch is installed inside the power plug 10 and connected in series in the circuit of the power module 1. For example, the temperature control switch can be attached to the power supply plug 10. The first phase line is used. The temperature control switch automatically disconnects after overheating. Even in the event of software or third controller malfunctions, it can also disconnect the first relay K1 and the second relay K2, preventing the power supply plug 10 from burning out, thus enhancing safety. Since the temperature control switch is not connected in series in the main power circuit, the current carrying capacity and lifespan requirements for the switch are lower, resulting in higher stability. For example, the temperature control switch may include at least one temperature spring. In this embodiment, the temperature control switch can be a single temperature spring or multiple temperature springs connected in series. For example, the temperature control switch is fixed in the power supply plug 10 using processes such as potting or encapsulation.

The coil of the first relay K1 can also be called the control coil or low-voltage coil of the first relay K1. The coil of the second relay K2 can also be called the control coil or low-voltage coil of the second relay K2. When current flows through the coil of the first relay K1, the first relay K1 is closed; when no current flows through the coil of the first relay K1, the first relay K1 is open. When current flows through the coil of the second relay K2, the second relay K2 is closed; when no current flows through the coil of the second relay K2, the second relay K2 is open. The temperature control switch, power module 1, and the coils of the first relay K1 and the second relay K2 are connected in series in a circuit. When the temperature control switch is open, the first relay K1 and the second relay K2 are also open. The position of the lead wire at the first end of the temperature control switch is not fixed; it can be placed in the function box 20 or in the power supply plug 10. In Figure 16, the lead wire at the first end of the temperature control switch is located in the function box 20, which facilitates wiring. Only one temperature control switch is installed in the power supply plug 10, making the size and manufacturing process simpler and the cost lower. The lead wire at the first end of the temperature control switch can be effectively electrically connected to the temperature control switch through welding, crimping, screwing, or other methods.

It should be noted that the coils of the first relay K1 and the second relay K2 can be different coils or the same coil. Figure 16 illustrates an example where the coils of the first relay K1 and the second relay K2 are different coils. When the first relay K1 and the second relay K2 share the same coil, one coil controls the opening and closing of both relays (the first relay K1 and the second relay K2), meaning that the first relay K1 and the second relay K2 are simultaneously turned off and simultaneously closed.

The first phase line can be any one of L1, L2, and N, and the second phase line can be any one of L1, L2, and N. The first phase line and the second phase line are different, and at least one of the first phase line and the second phase line is L1. In Figure 16, the first phase line is L1, and the second phase line is either L2 or N (neutral line). In one possible embodiment, the first phase line is either L2 or N (neutral line), and the second phase line is L1.

In this embodiment, L1 and L2 are two different phases of a two-phase power supply. When the power plug 10 is inserted into the mains socket, the voltage difference between L1 and L2 is generally around 200V, the voltage difference between L1 and N is generally around 100V, the voltage between L1 and PE is generally around 220V, and the voltage between L2 and PE is generally around 220V.

In this embodiment, a temperature control switch is connected in series between the first phase line and the third power supply. The third power supply powers the coils of the first and second relays via a fourth switch. When the temperature control switch disconnects due to overheating, the third power supply cannot power the coils of the first and second relays, thus automatically disconnecting the first and second phase lines and stopping the charger from charging. Compared to software control, this reduces the safety risks of the charger.

Optionally, the temperature control switch is disposed in the power supply plug 10. With the temperature control switch accurately sensing the heat generated by the power supply plug 10, the power supply to the relay coil can be disconnected when the power supply plug 10 becomes hot, thereby disconnecting the relay.

Please refer to Figure 17, which is a schematic diagram of another charger provided in an embodiment of this application. Figure 17 is derived from Figure 16. The functional box 20 also includes a fourth switch S4, and the first output terminal of the third power supply is connected to the coil of the relay through the fourth switch S4. When the fourth switch S4 is closed and the temperature control switch is not open, the power module 1 can supply power to the coil of the first relay K1 and the coil of the second relay K2. When the fourth switch S4 is open or the temperature control switch is open, the power module 1 cannot supply power to the coil of the first relay K1 and the coil of the second relay K2. As shown in Figure 17, the first output terminal of the power module 1 is connected to the first terminal of the fourth switch S4, the second terminal of the fourth switch S4 is connected to the first terminal of the coil of the first relay K1 and the first terminal of the coil of the second relay K2, and the second terminal of the coil of the first relay K1 and the second terminal of the coil of the second relay K2 are grounded.

Optionally, as shown in Figure 17, the function box 20 further includes a fourth power supply (i.e., power module 2 in Figure 17); the first input terminal of power module 2 includes input terminal 1 and input terminal 2. Input terminal 1 of power module 2 is connected to the first phase line, and input terminal 2 of power module 2 is connected to the second phase line; the first output terminal of power module 2 is connected to the coil of the first relay K1 and the coil of the second relay K2. Power module 2 can supply power to the coils of the first relay K1 and the second relay K2. Specifically, power module 2, labeled 232 in Figure 17, corresponds to the fourth power supply, and power module 12 in Figure 17 also corresponds to the fourth power supply.

Optionally, as shown in Figure 17, the function box 20 also includes a fifth switch S5. The first output terminal of the power module 2 is connected to the coil of the first relay K1 and the coil of the second relay K2 through the fifth switch S5. Adding the fifth switch S5 allows for flexible control over whether the power module 2 supplies power to the coils of the first relay K1 and the second relay K2.

Optionally, as shown in Figure 17, the function box 20 also includes a third controller; the second output terminal of the power module 2 is connected to the power supply terminal of the third controller. The power module 2 is used to draw power from the first phase line and the second phase line, and to supply power to the third controller. The control module 22 in Figure 17 corresponds to the third controller.

Optionally, as shown in Figure 17, the function box 20 also includes a fourth voltage detection circuit (i.e., voltage detection 1 in Figure 17), which is used to detect the voltage between the first phase line and the second phase line; the third controller is used to determine whether the power supply plug 10 is inserted into the mains socket based on the voltage detected by voltage detection 1.

The third controller is also used to control the fourth switch S4 to close and the fifth switch S5 to open when the power plug 10 is inserted into the mains socket and charging is ready. The voltage detection 1 labeled 211 in Figure 17 corresponds to the fourth voltage detection circuit.

Optionally, as shown in Figure 17, the function box 20 also includes a fifth voltage detection circuit (i.e., voltage detection 2 in Figure 17), which is used to detect the voltage at the first input terminal of the power module 1.

The third controller is also used to determine when the temperature control switch is turned off based on the voltage detected by voltage detector 2. In Figure 17, voltage detector 2, labeled 212, corresponds to the fifth voltage detection circuit.

The third controller can determine whether the power plug 10 is inserted into the mains socket based on the voltage detected by voltage detector 1. Specifically, it can determine whether the power plug 10 is inserted into the mains socket based on the voltage between the first phase line and the second phase line detected by voltage detector 1. The voltage between the first phase line and the second phase line can be the voltage difference between the first phase line and the second phase line, or the voltage difference between the first phase line and the ground line, or the voltage difference between the second phase line and the ground line.

"Charging ready" is the standard for a charger to be ready for charging as specified in the charging protocol.

In this embodiment, both the fourth and fifth voltage detection circuits may include a voltage acquisition circuit, or a voltage acquisition circuit and a voltage processing circuit. The voltage acquisition circuit is used to acquire voltage, and the voltage processing circuit is used to process the voltage acquired by the voltage acquisition circuit. Furthermore, the voltage acquisition circuit can be a sensor, and the voltage processing circuit can be located within the sensor or within the backend controller.

Optionally, the third controller determines whether the temperature control switch is open based on the voltage between the first and second phase lines, including:

If the voltage between the first and second phase lines is less than the tenth threshold, the third controller determines that the temperature control switch is open.

If the voltage between the first phase line and the second phase line is greater than the eleventh threshold, the third controller determines that the temperature control switch is closed, and the eleventh threshold is greater than the tenth threshold.

In this embodiment, the tenth threshold can be set to a value less than 50. For example, the tenth threshold can be set to 30V.

When the first phase line is L1 and the second phase line is L2, the eleventh threshold can be set to a value greater than 150V and less than 200V. For example, the eleventh threshold can be set to 180V. When the first phase line is L1 and the second phase line is N, the eleventh threshold can be set to a value greater than 50V and less than 100V. For example, the eleventh threshold can be set to 80V.

If the voltage between the first and second phase lines is the voltage difference between L1 and ground, the eleventh threshold can be set to a value greater than 150V and less than 200V. For example, the eleventh threshold can be set to 180V.

In this embodiment, the tenth and eleventh thresholds can be preset. The third controller can accurately determine whether the temperature control switch is off based on the tenth and eleventh thresholds.

In this embodiment, the third controller determines whether the temperature control switch is open based on the voltage detected by voltage detector 2. Voltage detector 2 detects the voltage at the first input terminal of power module 1. The voltage signal is V1 when the temperature control switch is on and V2 when the temperature control switch is off. If the voltage detected by voltage detector 2 is less than the twelfth threshold, the temperature control switch is confirmed to be open; if the voltage detected by voltage detector 2 is greater than the twelfth threshold, the temperature control switch is confirmed to be on.

For example, if the first phase line is L1 in a two-phase circuit, when the temperature control switch is on, the voltage V1 detected by voltage detector 2 is around 220V, and the voltage V2 detected by voltage detector 2 is around 0V. The twelfth threshold can be set to any value between 20-220V. For example, the twelfth threshold can be set to 100V.

In this embodiment, a temperature control switch is connected in series between the first phase line and the power module 1. The power module 1 supplies power to the coils of the first relay K1 and the second relay K2 via a fourth switch S4. When the temperature control switch disconnects due to overheating, the power module 1 cannot supply power to the coils of the first relay K1 and the second relay K2, thereby automatically disconnecting the first and second phase lines and stopping the charger from charging. Compared with software control, this reduces the safety risks of the charger.

Please refer to Figure 18, which is a schematic diagram of another charger provided in an embodiment of this application. Figure 18 is derived from Figure 17. As shown in Figure 18, the first end of the temperature control switch is connected to the first phase line, and the second end of the temperature control switch is connected to the first input line of the power module 1. The second input terminal of the power module 1 is connected to the second phase line, the first output terminal of the power module 1 is connected to the first terminal of the fourth switch S4, and the second terminal of the fourth switch S4 is connected to the coil of the first relay K1 and the coil of the second relay K2. The function box 20 also includes a sixth voltage detection circuit (i.e., voltage detection 3 shown in Figure 18), which is used to detect the voltage at the second terminal of the fourth switch S4.

If the temperature control switch is not turned off, the third controller determines that the power module 1 has failed based on the voltage detected by voltage detector 3.

In the event of a failure in power module 1, the third controller controls the fourth switch S4 to open and the fifth switch S5 to close.

In Figure 18, voltage detection 3, labeled 213, corresponds to the sixth voltage detection circuit.

In this embodiment, the sixth voltage detection circuit may include a voltage acquisition circuit, or a voltage acquisition circuit and a voltage processing circuit. The voltage acquisition circuit is used to acquire voltage, and the voltage processing circuit is used to process the voltage acquired by the voltage acquisition circuit; meanwhile, the voltage acquisition circuit can be a sensor, and the voltage processing circuit can be set in the sensor or in the back-end controller.

In this embodiment, when the temperature control switch is not disconnected (i.e., the temperature control switch is on), if the voltage detected by voltage detector 3 is less than the thirteenth threshold, then a fault is confirmed in power module 1; if the voltage detected by voltage detector 3 is greater than the thirteenth threshold, then a fault is confirmed in power module 1. When the temperature control switch is on and power module 1 is not faulty, the voltage detected by voltage detector 3 is approximately 220V. When the temperature control switch is on and power module 1 is faulty, the voltage V2 detected by voltage detector 2 is approximately 0V. The thirteenth threshold can be set to any value between 20-220V. For example, the thirteenth threshold can be set to 100V.

Power module 1 supplies power to the coils of the first relay K1 and the second relay K2 via the fourth switch S4. If the temperature control switch is not open and power module 1 malfunctions, the coils of the first relay K1 and the second relay K2 lose power, causing them to disconnect. In this case, the disconnection of the first relay K1 and the second relay K2 is not due to over-temperature protection. To ensure that the first relay K1 and the second relay K2 can operate normally without being affected by the power module 1 malfunction, the third controller controls the fourth switch S4 to open and the fifth switch S5 to close. The coils of the first relay K1 and the second relay K2 are then powered by power module 2, thus ensuring the normal operation of the first relay K1 and the second relay K2.

It should be noted that even if power module 1 malfunctions, the third controller can still determine whether the temperature control switch is open based on the voltage detected by voltage detector 2. For details, please refer to the above embodiment, which will not be repeated here. If the third controller determines that the temperature control switch is open based on the voltage detected by voltage detector 2 when power module 1 malfunctions, it can send a control signal to the first relay K1 and the second relay K2 to turn them off. Even if the temperature control switch is detected to be open when power module 1 malfunctions, the third controller can still control the first relay K1 and the second relay K2 to open via software control, thereby achieving the over-temperature protection function.

Optionally, when the temperature control switch is off, the third controller determines the protection strategy based on the cumulative number of times the temperature control switch has been off since the power plug 10 was inserted into the mains socket.

In this embodiment, when the temperature control switch is open, the third controller determines the protection strategy based on the cumulative number of times the temperature control switch has been opened since the power plug 10 was inserted into the mains socket. Generally, the greater the cumulative number of times the temperature control switch has been opened since the power plug 10 was inserted into the mains socket, the stronger the protection. For example, each time the temperature control switch is opened, as the cumulative number increases, the operating current of the charger will decrease, or even drop to zero, when the temperature control switch is closed again. The opening of the temperature control switch may be due to a high operating current of the charger (a high operating current of the charger may cause the temperature to rise). By reducing the operating current of the charger, the temperature control switch is less likely to open, thereby extending the working time of the charger and allowing the charger to charge the vehicle as much power as possible in the event of a charger failure.

Optionally, when the power plug 10 is inserted into the mains socket, the cumulative number of disconnections stored in the third controller is 0;

After the power plug 10 is inserted into the mains socket, the third controller will increment the cumulative disconnection count by 1 each time the temperature control switch is detected to be disconnected;

When the power plug 10 is disconnected from the mains socket, the cumulative number of disconnections stored in the third controller is cleared to zero.

In this embodiment, the third controller can store a cumulative number of disconnections. When the power plug 10 is inserted into the mains socket, that is, when the third controller is first powered on, the cumulative number of disconnections is 0.

When the third controller is powered (when the power plug 10 is plugged into the mains socket), the cumulative disconnection count is incremented by 1 each time the temperature control switch is detected to be disconnected. When the third controller is not powered (when the power plug 10 is disconnected from the mains socket), i.e. when the third controller is de-energized, the cumulative disconnection count is cleared to zero.

In this embodiment, the cumulative disconnection count is guaranteed to be the cumulative disconnection count of the temperature control switch after the power plug 10 is inserted into the mains socket. If this cumulative disconnection count continues to increase (i.e., it does not reset to zero), then after the power plug 10 is inserted into the mains socket, the charging current of the charger to the vehicle will be limited, or even the charger will stop charging the vehicle (for example, if the cumulative disconnection count is greater than or equal to a first threshold). The current method (when the power is off) does not conform to actual usage scenarios. By resetting the cumulative disconnection count to zero when the third controller is powered off, it can be ensured that the cumulative disconnection count is reset from 0 every time the power plug 10 is plugged into the mains socket, which can improve the user experience.

Voltage detector 2 can periodically detect the voltage at the first input terminal of power module 1. The third controller can determine whether the temperature control switch is open based on the voltage detected by voltage detector 2. Each time the temperature control switch is detected to be open, it means each time the temperature control switch is detected to go from closed to open.

The cumulative disconnection count refers to the number of times the temperature control switch is detected to have gone from closed to open after the power plug 10 is inserted into the mains socket. For example, the third controller determines whether the temperature control switch is open based on the voltage detected by voltage detector 2. For instance, if voltage detector 2 measures the voltage difference 10 times (during these 10 measurements, the third controller is continuously powered, i.e., the power plug 10 is continuously coupled to the mains socket), the corresponding states of the temperature control switch are: closed, closed, open, open, open, closed, closed, closed, open, open. Then the cumulative disconnection count is 2 times.

Optionally, the third controller is used to determine the protection strategy based on the cumulative number of times the temperature control switch disconnects after the power plug 10 is inserted into the mains socket, including:

If the cumulative number of times the temperature control switch is disconnected is less than the first threshold, the third controller determines the target current reduction strategy based on the cumulative number of times the temperature control switch is disconnected; wherein, the degree of current reduction of the target current reduction strategy is positively correlated with the cumulative number of times the temperature control switch is disconnected.

If the cumulative number of times the temperature control switch disconnects is greater than or equal to the first threshold, the third controller determines the charging stop strategy.

In this embodiment, the first threshold can be preset. The first threshold can be an integer greater than or equal to 2. The target current reduction strategy refers to the strategy of reducing the operating current of the charger. Each time the temperature control switch is opened, if the cumulative number of times the temperature control switch is opened is less than the first threshold, the operating current of the charger will be lower when the temperature control switch is closed next time compared with the previous time the temperature control switch was closed.

The charging stop strategy refers to the strategy by which the charger stops charging. When the cumulative number of times the temperature control switch disconnects is greater than or equal to a first threshold, the third controller can control the charger to stop working, that is, stop charging the vehicle.

For example, if the first threshold is 3, and the power plug 10 is inserted into the mains socket, if the charger's operating current is the rated current (e.g., 15A), the temperature control switch will open for the first time, resulting in a cumulative opening count of 1. The next time the temperature control switch closes, the charger's operating current will be controlled at 12A. If the temperature control switch opens for the second time, the cumulative opening count will be 2, and the next time it closes, the charger's operating current will be controlled at 10A. If the temperature control switch opens for the third time, the cumulative opening count will be 3, and the next time it closes, the charger will stop working, i.e., stop charging the vehicle.

Optionally, please refer to Figure 19, which is a schematic diagram of another charger provided in an embodiment of this application. Figure 19 is derived from Figure 18. As shown in Figure 19, based on Figure 18, the functional box 20 of the charger further includes: a control guide; the third controller is also used to determine the target duty cycle corresponding to the target current reduction strategy according to the cumulative number of times the temperature control switch is disconnected, and send a target CP signal to the vehicle's on-board charger through the control guide, wherein the duty cycle of the target CP signal is the target duty cycle.

The CP signal is a signal sent by the third controller to the vehicle's on-board charger. The CP signal can be generated by the control pilot (CP) module, and the control signal can control the duty cycle of the CP signal generated by the CP module.

When the vehicle's on-board charger receives the CP signal, if the on-board charger detects a change in the duty cycle of the CP signal (the duty cycle of the currently received CP signal is different from the duty cycle of the previously received CP signal), the on-board charger will automatically adjust the load, thereby adjusting the charger's operating current.

In this embodiment, the third controller can send a target CP signal to the vehicle's on-board charger (OBC) via the CP module, thereby controlling the charger's operating current.

The greater the cumulative number of times the temperature control switch is disconnected, the lower the target duty cycle corresponding to the target current reduction strategy, which means the lower the operating current of the charger.

For example, if the first threshold is 3, after the power plug 10 is inserted into the mains socket, if the charger's operating current is the rated current (e.g., 15A), the duty cycle of the CP signal sent by the third controller to the vehicle's on-board charger via the CP module is 25%. When the temperature control switch is opened for the first time, the cumulative number of times the temperature control switch has been opened is 1. When the temperature control switch is closed again, the charger's operating current can be controlled to 12A, and the duty cycle of the CP signal sent by the third controller to the vehicle's on-board charger via the CP module is 20%. When the temperature control switch is opened for the second time, the cumulative number of times the temperature control switch has been opened is 2. When the temperature control switch is closed again, the charger's operating current can be controlled to 10A, and the duty cycle of the CP signal sent by the third controller to the vehicle's on-board charger via the CP module is 16.67%. When the temperature control switch is disconnected for the third time, the cumulative number of disconnections is 3. When the temperature control switch closes again, it can control the charger to stop working. At this time, the duty cycle of the CP signal sent by the third controller to the vehicle's on-board charger through the CP module is 0% or 100%. This means stopping the charging of the vehicle.

Optionally, as shown in Figure 19, the function box 20 also includes a second current sampling circuit; the third controller is further used to control the fourth switch S4 and the fifth switch S5 to open when the second current sampling circuit detects that the current of the charging line (e.g., the first phase line or the second phase line) is greater than the ninth threshold. The current sampling circuit 28 in Figure 19 corresponds to the second current sampling circuit.

The second leakage current detection circuit is used to detect whether leakage occurs in the first phase line and the second phase line. The second current sampling circuit is used to detect the current in the first phase line, thereby detecting whether the charging current is abnormal.

When the third controller detects a charger leakage through the second leakage detection circuit, it controls the fourth switch S4 to open; when the third controller is powered only by the power module 2, it opens the fifth switch S5. This allows the first relay K1 and the second relay K2 to be opened when a charger leakage is detected, improving the charging safety of the charger. The leakage detection circuit 27 in Figure 19 corresponds to the second leakage detection circuit.

Optionally, as shown in Figure 19, the charger also includes a vehicle plug 30, which establishes a charging circuit with the vehicle when the vehicle plug 30 is inserted into the vehicle socket 40.

Among them, the vehicle socket 40 can be connected to the vehicle's on-board charger (OBC), enabling the charger to establish a charging circuit with the vehicle. This charging system can establish a charging circuit between the mains socket, power plug 10, function box 20, vehicle plug 30, vehicle socket 40, vehicle's OBC, and power battery, thereby enabling the charging of the power battery.

The vehicle plug 30 is coupled with the vehicle socket 40 to conduct electrical energy from the mains socket to the vehicle's power battery and storage battery, thereby realizing the charging function.

Function box 20 and power plug 10, and function box 20 and vehicle plug 30 can all be integrated structures, or function box 20 as shown in Figure 19 can be located between power plug 10 and vehicle plug 30. This application does not limit the specific embodiment.

The charger includes a power plug 10, a function box 20, and a vehicle plug 30. The power plug 10 and the function box 20 are connected by power lines (the power lines L1 and L2 in Figure 19 that connect to power module 2 and power module 1), and the function box 20 and the vehicle plug 30 are connected by a charging cable (the cable in Figure 19 that connects to L1, L2, PE, and CP of the vehicle plug 30).

Optionally, as shown in Figure 19, the CP module includes a CP detection and control circuit, a sixth switch S6, a first resistor R1, and a seventh switch S7; the first output terminal of the CP detection and control circuit is connected to the first terminal of the sixth switch S6, the second output terminal of the CP detection and control circuit is connected to the second terminal of the sixth switch S6, the third terminal of the sixth switch S6 is connected to the first terminal of the first resistor R1, the second terminal of the first resistor R1 is connected to the first terminal of the seventh switch S7, and the second terminal of the seventh switch S7 is connected to the CP port of the vehicle plug 30.

In this embodiment, the first output terminal of the CP detection and control circuit can output a 12V voltage, and the second output terminal of the CP detection and control circuit can output a pulse width modulation (PWM) signal.

The charger's power plug 10 is coupled to the mains socket, forming an electrical connection. At this time, the temperature spring is in a normally closed state. The fourth switch S4 can be in a normally open or normally closed state. When the fourth switch S4 is in the normally open state and the power plug 10 is connected to the mains socket, the coils of the first relay K1 and the second relay K2 are not powered. When charging is ready, the third controller controls the fourth switch S4 to close, the power module 1 de-supplys the coils of the first relay K1 and the second relay K2, and the first relay K1 and the second relay K2 are energized. When the fourth switch S4 is in the normally closed state, the voltage at the first detection point of the CP can be used to determine whether the vehicle plug 30 is connected to the vehicle socket 40. If the connection fails, the fourth switch S4 can be immediately disconnected.

The first detection point of the CP is located at the connection point of the sixth switch S6 and the first resistor R1 in Figure 19. After the vehicle plug 30 and the vehicle socket 40 are connected, the voltage at the first detection point of the CP will change. The third controller can determine whether the vehicle plug 30 and the vehicle socket 40 are coupled by detecting the voltage at the first detection point of the CP. If they are coupled, the fourth switch S4 is kept in the normally closed state; if they are not coupled, the fourth switch S4 is opened to reduce the risk of electric shock.

Optionally, if the cumulative number of times the temperature control switch is disconnected is greater than or equal to 1, the third controller sends a stop charging message to the vehicle so that the charger stops charging the vehicle.

In this embodiment, as soon as the temperature control switch is detected to be open, a stop charging message is sent to the vehicle to stop the charger from charging the vehicle. When the temperature control switch is detected to be open, the charger stops charging the vehicle. After the temperature control switch over-temperature protection trips, the charger stops working, preventing the charger from experiencing over-temperature conditions again. This protects the charger, avoids repeated opening and closing of the temperature control switch, and extends the lifespan of the temperature control switch.

Specifically, the third controller sends a stop charging message to the vehicle so that the charger stops charging the vehicle. Specifically, the third controller sends a specific CP signal to the vehicle's on-board charger through the CP module.

Optionally, the specific CP signal can be the CP signal specified in the national standard: for example, a CP signal with a duty cycle of 100% or 0%.

Optionally, the specific CP signal can be a CP signal agreed upon by the charger and the vehicle: for example, a CP signal with alternating duty cycles of 100% and 20%. For example, the first half of the CP signal has a 100% duty cycle, and the second half has a 20% duty cycle.

Optionally, when the third controller sends a stop charging message to the vehicle, the vehicle sends a notification message to the user terminal to inform the user terminal that the charger has failed to charge.

In this embodiment, the third controller sends a stop charging message to the vehicle, causing the vehicle to adjust its load, thereby stopping the charger from charging the vehicle. The vehicle can establish communication with the user terminal. For example, the vehicle can notify the user via a cloud platform or APP (displaying the notification message on the user terminal), and can also display the notification message on the vehicle's instrument panel or display screen the next time the vehicle is started.

The embodiments of this application can promptly notify the user when the charger experiences an overheating fault, thereby improving the user experience.

Please refer to Figure 20, which is a schematic diagram of another charger provided in an embodiment of this application. Figure 20 is derived from Figure 19. As shown in Figure 20, based on Figure 19, the function box 20 of this charger further includes an indicator. When the temperature control switch is off, the function box 20 issues an indicator message through the indicator, which is used to indicate that the power plug 10 has an over-temperature fault. The indicator module 25 in Figure 20 corresponds to this indicator.

The prompter can be at least one of a voice module and a display module. The prompter can issue at least one of voice prompts, text prompts, and optical prompts. The prompts can include at least one of voice prompts and text prompts, and can indicate that the power plug 10 has an overheating fault. The prompter on the function box 20 can promptly alert the user. For example, the prompter can include a display module that can issue audio-visual prompts.

Optionally, the third controller is also used to stop charging when the power module 2 is determined to have failed based on the voltage detected by the voltage detector 3, provided that the third controller controls the fourth switch S4 to be open and the fifth switch S5 to be closed.

In this embodiment, if both power module 1 and power module 2 fail, the coils of the first relay K1 and the second relay K2 will lose power, and the charger will stop charging the vehicle.

Please refer to Figure 21, which is a schematic diagram of another charger provided in this application embodiment. Figure 21 is based on Figure 20. As shown in Figure 21, based on Figure 20, the functional box 20 of the charger further includes: a reverse current blocking device (the reverse current blocking device in Figure 21 is exemplified by diode D1). The second output terminal of the power module 1 is connected to the second input terminal of the power module 2 through the reverse current blocking device. The reverse current blocking device is used to prevent the power module 2 from supplying power to the power module 1. When the temperature control switch is off, it can prevent the power module 1 from supplying power to the coil of the first relay K1 and the coil of the second relay K2 through the fourth switch S4, thereby improving the safety of the charger.

Optionally, in the event of a failure in power module 2, power module 1 supplies power to the third controller via a reverse current-cutting device.

In Figure 21, the reverse current-cutting device uses diode D1 as an example. The positive terminal of the diode is connected to the second output terminal of power module 1, and the negative terminal of the diode is connected to the third input terminal of power module 2.

In this embodiment, when power module 2 fails, power module 1 can supply power to the third controller via a reverse current-cutting device. Specifically, when power module 2 fails, the second output terminal of power module 1 is connected to the third input terminal of power module 2 via the reverse current-cutting device, and the first output terminal of power module 2 is connected to the third input terminal of power module 2, so that power module 1 can supply power to the third controller via the reverse current-cutting device.

In this embodiment, the charger can still operate normally even if either power module 2 or power module 1 fails. This increases the charger's lifespan. When power module 2 fails, the charger can still operate and provides over-temperature protection, resulting in a higher safety factor. When power module 1 fails, the charger can still operate. The third controller can determine whether there is over-temperature (whether the temperature control switch is open) through voltage detection 2. If over-temperature occurs (when the temperature control switch is open), it controls the first relay K1 and the second relay K2 to disconnect. This embodiment designs two power modules (power module 2 and power module 1), ensuring the charger's operation even if one power module fails, reducing the charger's failure rate and increasing the safe charging time.

When the power plug 10 is effectively inserted into the mains socket, the third controller of the function box 20 can be powered through the power module 2 and/or the power module 1. The power module 1 powers the coils of the first relay K1 and the second relay K2 through the fourth switch S4.

Please refer to Figure 22, which is a schematic flowchart of a voltage detection method provided in an embodiment of this application. The method in Figure 22 can be based on the charger shown in Figure 21. As shown in Figure 22, the method includes the following steps.

801, Begin.

802, the fourth voltage detection circuit detects the voltage between the first and second phase lines, or the voltage between the first phase line and ground, or the voltage between the second phase line and ground. The third controller determines the charging plug based on the voltage detected by the fourth voltage detection circuit. Is it plugged into a mains power outlet?

Among them, the voltage detection circuit 1 determines whether the charging plug is connected to the mains power by detecting the voltage between the phase lines (L1 and L2, L1 and N) or between the phase lines (L1, L2, N) and PE; optionally, when the plug is effectively inserted into the mains power and S1 is in the normally open state, the charging preparation is ready, and at this time the third controller can control S1 to close.

803. With the charging plug inserted into the AC power socket, the third controller uses voltage detection 2 to detect whether there is voltage at the first input terminal of the power module 1. If yes, proceed to step 804; if no, proceed to step 805.

The temperature control switch is connected in series at the input terminal of power module 1; the voltage between the temperature control switch and the relay coil is the mains voltage. Detection voltage 2 detects the input voltage of power module 1. When the temperature control switch is on, the voltage signal detected by detection voltage 2 is V1; when the temperature control switch is off, the voltage signal detected by detection voltage 2 is V2.

804. The third controller detects whether there is voltage at the second terminal of the fourth switch S4 via voltage detector 3. If yes, proceed to step 806; otherwise, proceed to step 807.

Power module 2 supplies power to the third controller. Power module 1 can supply power to power module 2, but power module 2 cannot directly supply power to the circuit of power module 1.

805, the third controller confirms that the temperature control switch is off, issues an over-temperature warning, controls the CP module to adjust the duty cycle of the CP signal and counts the cumulative number of disconnections.

In this embodiment of the application, when the temperature control switch is turned off, the fifth switch S5 is not closed and remains in the open state.

806, the third controller confirms that the charging connection is normal.

807, the third controller confirms a fault in power module 1, disconnects the fourth switch S4, and closes the fifth switch S5.

When voltage detector 2 detects voltage but voltage detector 3 detects no voltage, power module 1 is confirmed to have failed. At this time, the power supply circuit for the coils of the first relay K1 and the second relay K2 is broken, and the first relay K1 and the second relay K2 are disconnected. The third controller is powered by power module 2 and controls S1 to be normally open. When voltage detector 2 detects voltage but voltage detector 3 detects no voltage, the third controller controls S2 to close, the power supply circuit for the relay coils is turned on, and the first relay K1 and the second relay K2 are closed; at this time, switch S2 completely replaces the function of S1.

After executing step 807, proceed to step 808.

808. The third controller detects whether there is voltage at the second terminal of the fourth switch S4 via voltage detector 3. If yes, proceed to step 806; otherwise, proceed to step 809.

When the third controller detects that the second terminal of the fourth switch S4 changes from no voltage to voltage through voltage detection 3, it controls the CP pilot signal to send a PWM signal, and the charging connection is normal. The fifth voltage detection circuit continuously detects the voltage. If the fifth voltage detection circuit detects no voltage, it can be determined that the temperature control switch is open. At this time, charging can be stopped or the charging current can be reduced.

809, power module 2 is confirmed to be faulty.

When power module 2 fails, power module 1, as shown in Figure 21, can supply power to all output circuits of power module 2. When the temperature control switch is turned off, function box 20 loses power and cannot calculate the number of over-temperature cycles. At this time, the charging reduction strategy cannot be implemented, but the basic function of power-off over-temperature can still be guaranteed to prevent the power plug from burning out.

810, End.

When the temperature inside the power plug 10 is too high and the temperature spring is at its heat deformation temperature, the temperature spring will automatically disconnect.

When power module 1 is de-energized, the input terminals of the relay coils are in an open-circuit state. At this time, the coils of the first relay K1 and the second relay K2 (which can be called low-voltage coils) are not powered, and the contacts of the first relay K1 and the second relay K2 (which can be called high-voltage contacts) will open, thus passively disconnecting the charger from charging. The contacts of the first relay K1 can be the contacts of the first relay K1 connected in series with the first phase line, and the contacts of the second relay K2 can be the contacts of the second relay K2 connected in series with the first phase line.

The third controller identifies that the voltage detected by voltage detector 2 is 0V; the voltage detected by voltage detector 3 is also 0V, and S2 is not closed. The third controller adjusts the CP signal (also known as the CP pilot signal) based on the voltage value V2 of voltage detection point 2, and the vehicle adjusts the charging current demand based on the CP signal.

Once the plug temperature drops to the point where the temperature control switch closes, the coil's power supply circuit is activated, and the first relay K1 and the second relay K2 are engaged, initiating charging.

During the temperature recovery period of the temperature spring, the third controller can control the seventh switch S7 to open. This allows the vehicle to detect a connection confirmation (CC) signal, but without power voltage or CP signal input, indicating a default power-off state. The vehicle will not report any issues. This fault allows the charger to be compatible with more vehicle brands (because some vehicles will go into sleep mode for a certain period of time when they cannot detect power input, and need a rising CP signal to wake them up). The CC signal can also be called the plug signal.

This application also provides a charging system, which may include the charger and the vehicle described above. The charger can charge the vehicle's power battery.

It should be noted that the same functions of the first controller, the second controller and the third controller mentioned above can be implemented by one of the three controllers, or they can be implemented separately, or they can be implemented by a controller that includes the first controller, the second controller and the third controller.

Excessive current during charging can burn out the charger. To protect the charger and extend its lifespan, technology incorporates a temperature switch on the charging cable. When the temperature exceeds a threshold, the switch trips, protecting the charger.

However, due to the large current of the charging cable, placing the temperature switch on the charging cable places high requirements on the current carrying capacity of the temperature switch, and the temperature switch has a short service life.

This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a charger that uses a temperature control switch to provide over-temperature protection, thereby reducing the current carrying capacity requirement of the temperature control switch and extending its service life.

The present invention also aims to provide a charging system having the above-described charger.

Referring to FIG23, a charger 100 according to an embodiment of the first aspect of the present invention includes a power supply plug 10, a charging plug 20, and a temperature control branch 80. The power supply plug 10 is detachably connected to a power supply 70, and the charging plug 50 is detachably connected to a device 60 to be charged. The charging plug 50 and the power supply plug 10 are connected via a charging cable. The input terminal of the temperature control branch 80 is connected to the charging cable. The temperature control branch 80 includes a temperature control switch 11 and a fifth power supply connected in series with the temperature control switch 11. The potential difference across the fifth power supply 42 is greater than a preset threshold.

Specifically, referring to FIG23, the charger 100 in this embodiment of the invention includes a power supply plug 10, which is detachably connected to a power supply 70 to allow power to be supplied or de-energized with the power supply 70. The power supply 70 can be a mains power supply, etc. A charging plug 50 is detachably connected to a device 60 to be charged to charge the device 60 when powered on. The device 60 to be charged can be an electric vehicle, etc. The charging plug 50 and the power supply plug 10 are connected by a charging cable to conduct electricity between the charging plug 50 and the power supply plug 10. The charging cable includes at least a phase wire and a ground wire. For example, the charging cable may include two phase wires and one ground wire, or one phase wire, one neutral wire, and one ground wire.

The charger 100 also includes a temperature control branch 80, which is used to regulate the conduction or deactivation of the charging cable according to the temperature of the target component. The input terminal of the temperature control branch 80 is connected to the charging cable, so that the voltage at the input terminal of the temperature control branch 80 is the same as the voltage at the end of the charging cable connected to it. The temperature control branch 80 includes a temperature control switch 11 and a fifth power supply 42 connected in series with the temperature control switch 11. That is, the temperature control switch 11 and the fifth power supply 42 are connected in series in the temperature control branch 80. The potential difference across the fifth power supply 42 is greater than a preset threshold, which makes the current in the temperature control branch 80 smaller. By placing the temperature control switch 11 in the temperature control branch 80, the current carrying capacity requirement of the temperature control switch 11 is reduced, and the service life of the temperature control switch 11 is extended.

It should be noted that the preset threshold of the potential difference across the fifth power supply 42 can be set according to the maximum current carrying capacity of the temperature control switch 11 in order to extend the service life of the temperature control switch 11.

Therefore, referring to FIG23, the charger 100 according to the present invention, by setting a temperature control branch 80 connected to the input terminal and the charging cable, and connecting a temperature control switch 11 and a fifth power supply 42 with a potential difference between the two ends greater than a preset threshold in series on the temperature control branch 80, the current on the temperature control branch 80 is smaller. By setting the temperature control switch 11 on the temperature control branch 80, the current carrying requirement of the temperature control switch 11 is reduced, and the service life of the temperature control switch 11 is extended.

In some embodiments, the temperature control switch 41 can be a temperature switch. Of course, it can also be any other component capable of changing the on/off state of the temperature control branch 80 according to temperature changes.

In some embodiments of the present invention, referring to FIG23, the charger 100 further includes a function box 20, through which a charging cable passes, and the function box 20 includes a fifth power supply 42.

The function box 20 facilitates the setup of the fifth power supply 42. Of course, the function box 20 can also be used to set up other components, etc.

In some embodiments, the function box 20 is located between the power supply plug 10 and the charging plug 50, or it can be located on the same side of the power supply plug 10 and the charging plug 50. For example, it can be located on the upper side, lower side, left side or right side of the power supply plug 10 and the charging plug 50.

In some embodiments of the present invention, referring to FIG23, the functional box 20 further includes an electronic control switch 51, which includes a control terminal 511 and a switch assembly 512. The switch assembly 512 is disposed on the charging cable. The input terminal of the temperature control branch 80 is connected to the charging cable between the power supply plug 10 and the switch assembly 512, and the output terminal is connected to the control terminal 511.

The electric control switch 51 is used to control the on/off state of the charging cable. The control terminal 511 controls the opening and closing of the switch assembly 512, which is located on the charging cable and is used to connect or disconnect the charging cable. When the switch assembly 512 is open, the charging cable is disconnected; when the switch assembly 512 is closed, the charging cable is energized. The input terminal of the temperature control branch 80 is connected to the charging cable between the power supply plug 10 and the switch assembly 512. When the power supply plug 10 is connected to the power supply 70, the temperature control branch 80 is energized, and its output terminal is connected to the control terminal 511. Thus, the control terminal 511 is energized, controlling the switch assembly 512 to close. When the temperature control switch 11 on the temperature control branch 80 is open, the temperature control branch 80 is de-energized, the control terminal 511 is de-energized, and the control switch assembly 512 is opened.

By setting the electronic control switch 51, the on and off of the temperature control switch 11 can control the on and off of the charging cable, without the need for the temperature control switch 11 to interact with the fourth controller 52. In this way, even if the fourth controller 52 fails, it will not affect the over-temperature protection of the charging cable by the temperature control switch 11.

In some embodiments, the control terminal 511 can be a coil, and the electronic switch 51 can be a relay, etc. The phase wire and neutral wire can each be equipped with a switch assembly 512, and there can be one or two control terminals 511.

In some embodiments of the present invention, referring to FIG23, a temperature control switch 11 is disposed on the power supply plug 10; the temperature control switch 11 is further configured to conduct the temperature control branch 80 when the temperature of the power supply plug 10 is less than the temperature threshold, so as to energize the control terminal 511; the control terminal 511 is further configured to control the switch assembly 512 to close when energized, so as to energize the charging cable; the temperature control switch 11 is configured to disconnect the temperature control branch 80 when the temperature of the power supply plug 10 is greater than the temperature threshold, so as to de-energize the control terminal 511; the control terminal 511 is configured to control the switch assembly 512 to open when de-energized, so as to de-energize the charging cable.

The temperature control switch 11 is located on the power plug 10 and can control the on/off state of the charging cable according to the temperature of the power plug 10. Of course, this application is not limited to this, and the temperature control switch 11 can also be located on the function box 20 or the charging plug 50.

When the temperature of the power plug 10 is below the temperature threshold, the power plug 10 will not be at risk of burning out and can work normally. At this time, the temperature control switch 11 is in the closed state, which connects the temperature control branch 80. Thus, the temperature control branch 80 is energized, thereby energizing the control terminal 511. The control terminal 511, in the energized state, can control the switch assembly 512 to close, so that the charging cable can be energized and can charge normally.

When the temperature of the power plug 10 exceeds the temperature threshold, the power plug 10 may burn out. To protect the power plug 10 and extend its service life, the temperature control switch 11 is turned off, thereby disconnecting the temperature control branch 80. This de-energizes the temperature control branch 80, which in turn de-energizes the control terminal 511. In the de-energized state, the control terminal 511 can control the switch assembly 512 to open, thus de-energizing the charging cable and stopping charging.

In some embodiments of the present invention, referring to FIG23, the input terminal of the temperature control branch 80 is connected to the charging cable inside the function box 20.

The input terminal of the temperature control branch 80 is connected to the charging cable inside the function box 20 for easy wiring. Of course, this application is not limited to this; the input terminal of the temperature control branch 80 can also be connected to the charging cable of the power plug 10.

In some embodiments of the present invention, referring to FIG23, the functional box 20 further includes a fourth controller 52. One end of the fourth controller 52 is connected to the input terminal of the fifth power supply 42, and the other end is connected to the charging plug 50. The fourth controller 52 is used to determine the conduction state of the temperature control switch 11 according to the voltage of the input terminal of the fifth power supply 42, and adjust the charging current output by the charging cable according to the conduction state of the temperature control switch 11.

The fourth controller 52 is connected at one end to the input terminal of the fifth power supply 42 to obtain the voltage at the input terminal of the fifth power supply 42. The other end is connected to the charging plug 50 to send control signals to the charging plug 50. Based on the voltage at the input terminal of the fifth power supply 42, the fourth controller 52 can determine the on/off state of the temperature control switch 11. For example, when the voltage at the input terminal of the fifth power supply 42 is 0V, the temperature control switch 11 is off; when the voltage at the input terminal of the fifth power supply 42 is 220V, the temperature control switch 11 is on. The fourth controller adjusts the charging current output by the charging cable according to the on/off state of the temperature control switch 11. That is, when the temperature control switch 11 is off, it indicates that the current of the charging cable is too high, and the fourth controller 52 reduces the charging current output by the charging cable to lower the temperature of the power supply plug 10. When the temperature control switch 11 is on, it indicates that the current of the charging cable is normal, and the charging current output by the charging cable can remain unchanged.

In some embodiments of the present invention, referring to FIG23, the fourth controller 52 includes a processor 521 and a seventh voltage detection circuit 522. One end of the seventh voltage detection circuit 522 is connected to the input terminal of the fifth power supply 42, and the other end is connected to the processor 521. The seventh voltage detection circuit 522 is used to detect the voltage at the input terminal of the fifth power supply 42 and send the voltage at the input terminal of the fifth power supply 42 to the processor 521.

By setting up a seventh voltage detection circuit 522, and connecting one end of the seventh voltage detection circuit 522 to the input terminal of the fifth power supply 42, the seventh voltage detection circuit 522 can detect the voltage at the input terminal of the fifth power supply 42. The other end is connected to the processor 521 so that the detected voltage at the input terminal of the fifth power supply 42 can be sent to the processor 521, so that the processor 521 can determine the conduction state of the temperature control switch 11 based on the voltage at the input terminal of the fifth power supply 42.

In some embodiments, a voltage detection device may be provided at the input terminal of the fifth power supply 42, and the voltage detection device and the processor 521 may interact via electrical signals.

In some embodiments of the present invention, referring to FIG23, the fourth controller 52 further includes a current detection circuit 523. One end of the current detection circuit 523 is connected to the charging cable and the other end is connected to the processor 521. The current detection circuit 523 is used to detect the charging current output by the charging cable and send the charging current output to the processor 521.

By setting up a current detection circuit 523, with one end of the current detection circuit 523 connected to the charging cable, the current detection circuit 523 can detect the charging current output by the charging cable. The other end is connected to the processor 521 so that the detected charging current output by the charging cable can be sent to the processor 521. The processor 521 can obtain the charging current output by the charging cable in real time. When the temperature control switch 11 is open, the charging current output by the charging cable can be adjusted according to the charging current output by the charging cable when the temperature control switch 11 is open.

In some embodiments, a current sensing element may be provided on the charging cable, and the current sensing element and the processor 521 may interact via electrical signals.

In some embodiments of the present invention, referring to FIG23, the fourth controller 52 further includes a control circuit 524, one end of which is connected to the processor 521 and the other end is connected to the charging plug 50; the control circuit 524 is used to adjust the duty cycle when the voltage at the input terminal of the fifth power supply 42 is 0, so as to adjust the charging current output by the charging cable.

A control circuit 524 is used to regulate the output charging current of the charging cable. One end of the control circuit 524 is connected to the processor 521 so that when the processor 521 receives a signal that the temperature control switch 11 is open, i.e., the voltage at the input terminal of the fifth power supply 42 is 0, it adjusts the charging current output on the charging cable. The other end is connected to the charging plug 50. The control circuit 524 reduces the duty cycle according to the duty cycle corresponding to the charging current output on the charging cable when the voltage at the input terminal of the fifth power supply 42 is 0, and sends the signal with the reduced duty cycle to the device 60 to be charged through the interaction between the charging plug 50 and the device 60 to be charged. The device 60 to be charged adjusts the charging current, thereby regulating the charging current output on the charging cable.

In some embodiments of the present invention, referring to FIG23, an eighth switch 53 is provided on the line between the control circuit 524 and the charging plug 50. The eighth switch 53 is used to turn on or off the line between the control circuit 524 and the charging plug 50.

By setting the eighth switch 53, the connection or disconnection of the line between the regulating circuit 524 and the charging plug 50 can be controlled. Preferably, the eighth switch 53 is disconnected when the temperature control switch 11 is off. In this way, the device to be charged 60 cannot detect the voltage signal and the CP signal, and can be assumed to be in a power-off state without reporting a fault. In this way, the charger 100 can be compatible with a variety of models of devices to be charged 60. This is because some devices to be charged 60 will go into sleep mode for a certain period of time when no voltage signal is detected, and waking up requires a rise in the CP signal.

Understandably, the opening and closing of the eighth switch 53 can be controlled by the processor 521.

In some embodiments of the present invention, referring to FIG23, the output terminal of the fifth power supply 42 is connected to the fourth controller 52 to supply power to the processor 521, and a reverse current isolation device is provided between the output terminal of the fifth power supply 42 and the processor 521.

The output terminal of the fifth power supply 42 is connected to the fourth controller 52. Specifically, the output terminal of the fifth power supply 42 is connected to the processor 521 so that it can briefly supply power to the processor 521 in the event of a failure of other power supplies, ensuring the normal operation of the processor 521. A reverse current isolation device is provided between the output terminal of the fifth power supply 42 and the processor 521 to prevent other power supplies from supplying power to the output terminal of the fifth power supply 42 through the circuit, and thus to the electronic control switch 51.

In some embodiments of the present invention, referring to FIG23, a ninth switch 54 is provided on the line between the fifth power supply 42 and the control terminal 511 of the electronic control switch 51. The ninth switch 54 is used to energize or de-energize the charging cable.

A ninth switch 54 can be installed on the line between the fifth power supply 42 and the control terminal 511 of the electronic control switch 51 to control the opening and closing of the electronic control switch 51. Preferably, the ninth switch 54 is normally open. When the processor 521 receives power between the power supply plug 10 and the power supply 70, and when the charging plug 50 is connected to the device to be charged 60, the ninth switch 54 can be closed to ensure the safe use of the charger 100.

The ninth switch 54 can also be a switching circuit, such as a transistor, operational amplifier, comparator, etc.

In some embodiments of the present invention, referring to FIG23, the charger 100 further includes a sixth power supply 57, one end of which is connected to a charging cable and the other end of which is connected to a fourth controller 52.

Specifically, the sixth power supply 57 is located in the function box 20. One end of the sixth power supply 57 is connected to the charging cable. Furthermore, one end of the sixth power supply 57 is connected to the charging cable between the power supply plug 10 and the electronic control switch 51, and the other end is connected to the processor 521 to supply power to the processor 521.

In some embodiments, the function box 20 further includes an eighth voltage detection circuit 55, which is connected to the phase line and the neutral line respectively, and is connected to the processor 521. In this way, the eighth voltage detection circuit 55 can detect whether the charging cable is energized and send the detection result to the processor 521 so that the processor 521 can control the opening and closing of the ninth switch 54 according to the signal and the connection signal between the charging plug 50 and the device to be charged 60.

In some embodiments, the functional box 20 further includes a ninth voltage detection circuit 56. One end of the ninth voltage detection circuit 56 is connected to the output terminal of the fifth power supply 42, and the other end is connected to the processor 521. The ninth voltage detection circuit 56 can obtain the voltage at the output terminal of the fifth power supply 42 and determine whether the fifth power supply 42 has malfunctioned through the processor 521.

In some embodiments, the function box 20 further includes a leakage current detection circuit 58, one end of which is connected to the charging cable and the other end is connected to the processor 521. The leakage current detection circuit 58 can detect whether the charging cable is leaking current and send the result to the processor 521.

In some embodiments, the function box 20 further includes a display 59, which is connected to the processor 521. Fault signals acquired by the processor 521, such as leakage signals, can be displayed on the display 59.

In this embodiment, the seventh voltage detection circuit 522, the eighth voltage detection circuit 55, and the ninth voltage detection circuit 56 may each include a voltage acquisition circuit, or a voltage acquisition circuit and a voltage processing circuit. The voltage acquisition circuit is used to acquire voltage, and the voltage processing circuit is used to process the voltage acquired by the voltage acquisition circuit; at the same time, the voltage acquisition circuit can be a sensor, and the voltage processing circuit can be set in the sensor or in the back-end controller.

According to a second aspect embodiment of the present invention, the charging system 1000, as shown in FIG24, includes a power supply 70, a charger 100 as described above, and a device 60 to be charged. The power supply plug 10 is detachably electrically connected to the power supply 70, and the charging plug 50 is detachably electrically connected to the device 60 to be charged.

According to the embodiments of the present invention, the charging system 1000, by employing the charger 100 of the above embodiments, ensures stable and normal operation of the charging system 1000.

It is understandable that the power supply 70 can be AC power, and the device to be charged 60 can be a vehicle, etc.

It should be noted that in Figures 23 and 24, SA represents a switch and R represents a resistor.

The above embodiments mainly describe the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be elaborated here.

While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims (57)

A charger, comprising: The power plug (10) is connected to the charging cable; and Temperature control switch (11) is connected to the charging cable; Specifically, when the temperature control switch disconnects due to over-temperature, the charger stops charging. The charger according to claim 1, wherein, The power supply plug includes the temperature control switch, and the power supply plug includes: The first segment of the first phase wire, the second phase wire, and the ground wire (PE); The charger also includes a function box (20), which further includes: The first voltage detection circuit (21) is used to detect the voltage between the second end of the first phase line and the second phase line or the voltage between the second end of the first phase line and the ground line when the power supply plug is inserted into the mains socket. A first controller (22) is configured to determine whether the temperature control switch is open based on the voltage, and, if the temperature control switch is open, the first controller is further configured to determine a protection strategy based on the cumulative number of times the temperature control switch has been opened since the power plug was inserted into the mains socket; and, The second segment of the first phase line, wherein the temperature control switch is connected between the first segment of the first phase line and the second segment of the first phase line. According to claim 2, the charger wherein the temperature control switch includes a temperature spring. The charger according to any one of claims 2 to 3, wherein, The functional box also includes: A first power supply (23) is used to power the first controller. According to the charger of claim 4, the first input terminal of the first power supply is connected to the first segment of the first phase line, the second input terminal of the first power supply is connected to the second phase line, and the output terminal of the first power supply is connected to the power supply terminal of the first controller. According to the charger of claim 5, when the power supply plug is inserted into the mains socket, the first power supply powers the first controller, and the cumulative number of disconnections stored in the first controller is 0; After the power plug is inserted into the mains socket, the first controller increments the cumulative disconnection count by 1 each time the temperature control switch is detected to be disconnected. When the power supply plug is disconnected from the mains socket, the first power supply stops powering the first controller, and the cumulative number of disconnections stored in the first controller is cleared to zero. The charger according to any one of claims 2 to 6, wherein, The power plug also includes: Temperature sensor (12); The functional box also includes: Temperature detector (26), the first output terminal of the temperature sensor is connected to the first input terminal of the temperature detector, the second output terminal of the temperature sensor is connected to the second input terminal of the temperature detector, and the output terminal of the temperature detector is connected to the first input terminal of the first controller; the temperature detector is used to determine the temperature of the temperature sensor based on the voltage of the first input terminal and the second input terminal of the temperature detector. According to the charger of claim 7, the first controller is further configured to determine whether the temperature control switch is normal based on the temperature of the temperature sensor and the state of the temperature control switch. The charger according to claim 7, wherein the first controller is further configured to: If the temperature of the temperature sensor exceeds the upper limit temperature for the temperature control switch to disconnect, and the temperature control switch is closed, the first controller determines that the temperature control switch is malfunctioning. If the temperature of the temperature sensor is lower than the lower closing limit temperature of the temperature control switch and the temperature control switch is open, the first controller determines that the temperature control switch is abnormal. If the temperature of the temperature sensor is lower than the lower closing limit temperature of the temperature control switch, and the temperature control switch is closed, the first controller determines that the temperature control switch is normal. If the temperature of the temperature sensor exceeds the upper limit temperature for the temperature control switch to disconnect, and the temperature control switch is disconnected, the first controller determines that the temperature control switch is normal. According to the charger of claim 8, the first controller is further configured to issue an alarm prompt in the event of an abnormality in the temperature control switch. The charger according to any one of claims 2 to 10, wherein the first controller is configured to determine whether the temperature control switch is open based on the voltage, comprising: If the voltage is less than the second threshold, the first controller determines that the temperature control switch is off; If the voltage is greater than a third threshold, the first controller determines that the temperature control switch is closed, and the third threshold is greater than the second threshold. The charger according to claim 1, wherein the charger further comprises: The function box, the power plug and the function box are connected by a charging cable, a portion of the charging cable being located inside the function box; the function box includes: A second power source (23), the input terminal of which is connected to the charging cable; and A relay is connected to the charging line, and the output terminal of the second power supply is connected to the coil of the relay through the temperature control switch to control the opening or closing of the relay. The charger according to claim 12, wherein, The functional box also includes: The first switch (S1) is connected to the first terminal of the temperature control switch through the first switch, and the second terminal of the temperature control switch is connected to the coil of the relay. The charger according to claim 13, wherein, The functional box also includes: The second voltage detection circuit (211) is used to detect the voltage on the charging line. The charger according to claim 14, wherein, The functional box also includes: The third voltage detection circuit (212) is used to detect the voltage at the second terminal of the temperature control switch. The charger according to claim 15, wherein, The functional box also includes: The second controller (22) is further configured to supply power to the second controller; the second controller is configured to determine whether the power supply plug is inserted into the mains socket based on the voltage detected by the second voltage detection circuit; the second controller is further configured to control the first switch to close when the power supply plug is inserted into the mains socket and charging is ready, and to determine whether the temperature control switch is to open based on the voltage detected by the third voltage detection circuit. According to the charger of claim 16, the second controller is further configured to determine a protection strategy based on the cumulative number of times the temperature control switch has been disconnected after the power supply plug is inserted into the mains socket when the temperature control switch is disconnected; or the second controller is configured to determine a protection strategy based on the continuous charging time of the charger; or the second controller is configured to determine a protection strategy based on the cumulative number of times the temperature control switch has been disconnected after the power supply plug is inserted into the mains socket and the continuous charging time of the charger. According to the charger of claim 17, the second controller is configured to determine a protection strategy based on the continuous charging duration of the charger, including: If the continuous charging time of the charger exceeds a fourth threshold, it is determined that the continuous charging time of the charger falls within a target duration interval, and a target charging current corresponding to the target duration interval is determined; wherein, the target charging current is positively correlated with the target duration interval; If the continuous charging time of the charger is less than or equal to the fourth threshold, the second controller determines a charging stop strategy. The charger according to any one of claims 16 to 18, wherein, The functional box also includes: First leakage current detection circuit (27); The second controller is further configured to control the first leakage detection circuit when the first leakage detection circuit detects leakage in the charger. The switch is off. The charger according to any one of claims 16 to 19, wherein, The functional box also includes: First current sampling circuit (28); The second controller is further configured to control the first switch to open when the first current sampling circuit detects that the current on the charging line is greater than a fifth threshold. The charger according to claim 1, wherein the charger further comprises: The function box, the power plug and the function box are connected by a charging cable, a portion of the charging cable being located inside the function box; the function box includes: A third power supply (231), the input terminal of which is connected to the charging cable via the temperature control switch; and A relay is connected to the charging line, and the first output terminal of the third power supply is connected to the coil of the relay to control the opening or closing of the relay. The charger according to any one of claims 12 to 21, wherein the temperature control switch is disposed in the power supply plug. The charger according to any one of claims 12 to 22, wherein the temperature control switch includes a temperature switch. The charger according to any one of claims 21 to 23, wherein, The functional box also includes: The fourth switch (S4) connects the first output terminal of the third power supply to the coil of the relay. The charger according to any one of claims 21 to 24, wherein, The functional box also includes: A fourth power supply (232) is provided, wherein the first input terminal of the fourth power supply is connected to the charging cable, and the first output terminal of the fourth power supply is connected to the coil of the relay. The charger according to claim 25, wherein, The functional box also includes: The fifth switch (S5) connects the first output terminal of the fourth power supply to the coil of the relay. The charger according to claim 26, wherein, The functional box also includes: The third controller (22); the second output terminal of the fourth power supply is connected to the power supply terminal of the third controller. The charger according to claim 27, wherein, The functional box also includes: A fourth voltage detection circuit (211) is used to detect the voltage on the charging line; The third controller is used to determine whether the power supply plug is inserted into the mains socket based on the voltage detected by the fourth voltage detection circuit. The third controller is also used to control the fourth switch to close and the fifth switch to open when the power plug is inserted into the AC socket and charging is ready. The charger according to claim 28, wherein, The functional box also includes: The fifth voltage detection circuit (212) is used to detect the voltage at the input terminal of the third power supply; The third controller is also used to determine whether the temperature control switch is open based on the voltage detected by the fifth voltage detection circuit. The charger according to claim 29, wherein, The functional box also includes: A sixth voltage detection circuit (213) is used to detect the voltage at the second terminal of the fourth switch; The third controller is also used to determine, based on the voltage detected by the sixth voltage detection circuit, that the third power supply has failed when the temperature control switch is not disconnected. The third controller is also used to control the fourth switch to open and the fifth switch to close in the event of a failure of the third power supply. The charger according to any one of claims 29 to 30, wherein the third controller is further configured to determine a protection strategy based on the cumulative number of times the temperature control switch has been disconnected after the power supply plug is inserted into the mains socket when the temperature control switch is disconnected. The charger according to any one of claims 2-11, 16-20, and 31, wherein the controller is further configured to determine a protection strategy based on the cumulative number of times the temperature control switch disconnects after the power supply plug is inserted into the mains socket, including: If the cumulative number of times the temperature control switch is disconnected is less than a first threshold, the controller determines a target current reduction strategy based on the cumulative number of times the temperature control switch is disconnected; wherein, the degree of current reduction of the target current reduction strategy is positively correlated with the cumulative number of times the temperature control switch is disconnected. If the cumulative number of times the temperature control switch is disconnected is greater than or equal to the first threshold, the controller determines a strategy to stop charging. The charger according to claim 32, wherein, The functional box also includes: Control guide (24); The controller is further configured to determine the target duty cycle corresponding to the target current reduction strategy based on the cumulative number of times the temperature control switch is disconnected, and send a target CP signal to the vehicle's on-board charger through the control guide, wherein the duty cycle of the target CP signal is the target duty cycle. The charger according to any one of claims 2-11, 16-20, and 31, wherein the controller is further configured to determine a protection strategy based on the cumulative number of times the temperature control switch disconnects after the power supply plug is inserted into the mains socket, including: If the cumulative number of times the temperature control switch is disconnected is greater than or equal to 1, the controller sends a stop charging message to the vehicle. The charger according to any one of claims 2 to 34, wherein, The functional box also includes: Prompt (25); When the temperature control switch is off, the function box is used to issue a prompt message through the indicator, which is used to indicate that the power supply plug has an over-temperature fault. The charger according to any one of claims 17 to 31, wherein when the power supply plug is inserted into the mains socket, the cumulative number of disconnections stored by the controller is 0; After the power plug is inserted into the mains socket, the controller increments the cumulative disconnection count by 1 each time the temperature control switch is detected to be disconnected. When the power plug is disconnected from the mains socket, the cumulative number of disconnections stored in the controller is reset to zero. The charger according to claim 30, wherein, The third controller is further configured to stop charging when the fourth power supply fails, based on the voltage detected by the sixth voltage detection circuit, under the control of the third controller to open the fourth switch and close the fifth switch. The charger according to any one of claims 25 to 34, wherein, The functional box also includes: A reverse current blocking device (D1) is used to prevent the second output terminal of the third power supply from supplying power to the third power supply. The charger according to any one of claims 27 to 38, wherein, The functional box also includes: The second leakage detection circuit (27); the third controller is also used to control the fourth switch and the fifth switch to disconnect when the second leakage detection circuit detects leakage in the charger. The charger according to any one of claims 27 to 39, wherein, The functional box also includes: The second current sampling circuit (28); the third controller is also used to control the fourth switch and the fifth switch to disconnect when the second current sampling circuit detects that the current of the charging line is greater than the ninth threshold. The charger according to any one of claims 1 to 40, wherein the charger further includes a vehicle plug (30), wherein when the vehicle plug is inserted into a vehicle socket (40), the charger establishes a charging circuit with the vehicle. According to claim 1, the charger, wherein the power plug (10) is detachably connected to the power supply (70); the charger further includes: A charging plug (50) for detachable connection to a device (60) to be charged, the charging plug being connected to the power supply plug via a charging cable; and A temperature control branch (80), the input terminal of which is connected to the charging cable; the temperature control branch includes: The temperature control switch (11) and the fifth power supply (42) connected in series with the temperature control switch, wherein the potential difference between the two ends of the fifth power supply is greater than a preset threshold. The charger according to claim 42, wherein the charger further comprises: Function box (20), through which the charging cable passes, the function box includes: The fifth power source. The charger according to claim 43, wherein, The functional box also includes: Electrically controlled switch (51), the electrically controlled switch comprising: Control terminal (511); and A switch assembly (512) is disposed on the charging line, the input end of the temperature control branch is connected to the charging line between the power supply plug and the switch assembly, and the output end is connected to the control end. The charger according to claim 44, wherein the temperature control switch is disposed on the power supply plug; The temperature control switch is used to activate the temperature control branch when the temperature of the power supply plug is lower than a temperature threshold, so as to energize the control terminal; the control terminal is used to control the switch assembly to close when energized, so as to energize the charging cable. The temperature control switch is also used to disconnect the temperature control branch when the temperature of the power supply plug is greater than the temperature threshold, so as to de-energize the control terminal; the control terminal is also used to control the switch assembly to open in the power-off state, so as to de-energize the charging cable. According to claim 44, the input terminal of the temperature control branch is connected to the charging cable inside the function box. The charger according to claim 45, wherein, The functional box also includes: The fourth controller (52) is connected at one end to the input terminal of the fifth power supply and at the other end to the charging plug. The fourth controller is used to determine the conduction state of the temperature control switch according to the voltage of the input terminal of the fifth power supply, and to adjust the charging current output by the charging cable according to the conduction state of the temperature control switch. The charger according to claim 47, wherein, The fourth controller includes: Processor (521); and A seventh voltage detection circuit (522) is provided, with one end connected to the input terminal of the fifth power supply and the other end connected to the processor. The seventh voltage detection circuit is used to detect the voltage at the input terminal of the fifth power supply and send the voltage at the input terminal of the fifth power supply to the processor. The charger according to claim 48, wherein, The fourth controller also includes: A current detection circuit (523) is provided, with one end connected to the charging cable and the other end connected to the processor. The current detection circuit is used to detect the charging current output by the charging cable and send the charging current output by the charging cable to the processor. The charger according to claim 48, wherein, The fourth controller also includes: A control circuit (524) is provided, with one end connected to the processor and the other end connected to the charging plug. The control circuit is used to adjust the duty cycle when the voltage at the fifth power input terminal is 0, so as to adjust the charging current output by the charging cable. According to the charger of claim 50, an eighth switch (53) is provided on the line between the control circuit and the charging plug, the eighth switch being used to connect or disconnect the line between the control circuit and the charging plug. According to the charger of claim 48, the output terminal of the fifth power supply is connected to the fourth controller to supply power to the processor, and a reverse current isolation element is provided between the output terminal of the fifth power supply and the processor. According to the charger of claim 44, the line between the fifth power source and the control terminal of the electronic control switch is provided with There is a ninth switch (54), which is used to energize or de-energize the charging cable. The charger according to claim 47, wherein the charger further comprises: The sixth power supply (57) is connected at one end to the charging cable and at the other end to the fourth controller. A charging system, comprising: The charger as described in any one of claims 1 to 54; and Devices awaiting charging. The charging system according to claim 55, wherein the charging system further comprises: The power supply plug is detachably electrically connected to the power supply, and the charging plug is detachably electrically connected to the device to be charged (60). The charging system according to claim 55, wherein, The device to be charged includes: vehicle.