TWI881689B - Charge-discharge device and electric vehicle charger - Google Patents

Abstract

A charge-discharge device is coupled to a power grid through a first cable and a plug, and coupled to an electric vehicle through a second cable and a connection port. The charge-discharge device includes a charge circuit, a power feedback circuit and a controller, the charge circuit provides a charge path for transmitting grid power from the plug to the connection port, and the power feedback circuit provides a power feedback path for transmitting vehicle power from the connection port to the plug. In a charge mode, the controller sets a first current flowing through the charge path. In a power feedback mode, the controller sets a second current flowing through the power feedback path.

Description

Charging and discharging device and electric vehicle charger

The present disclosure relates to a charging and discharging device and an electric vehicle charger, and in particular to a portable charging and discharging device and an electric vehicle charger.

Currently, electric vehicles are gradually being driven by electricity instead of fuel in order to save energy and reduce carbon emissions. Among them, the power source of the electric vehicle (generally referred to as an electric vehicle) is the battery, so the battery needs to be charged to maintain the endurance of the electric vehicle. Generally speaking, a common electric vehicle charger includes the following configuration architectures of Figures 1A to 1C. The charging technology in Figure 1A is to use a simple extension cord for home charging from a standard power socket. Specifically, this type of electric vehicle charger 100 involves electrically connecting the electric vehicle 300 to a standard household socket 200A, and the electric vehicle charger 100 usually has only a single cable connecting the electric vehicle 300 and the socket 200A. This type of electric vehicle charger 100 is generally suitable for light vehicles (such as electric motorcycles) due to its simple structure.

The charging technology in Figure 1B involves using a dedicated charging station or a household wall-mounted charging box (collectively referred to as a grid-side charging device 100B) to charge the electric vehicle 300. Since the connecting cable is provided by the grid-side charging device 100B, the electric vehicle 300 does not need to use a dedicated cable for charging, so it is currently the first choice for home charging. The charging technology in Figure 1C is generally referred to as "DC fast charging", or simply "fast charging". This type of charging usually requires a charging pile 100C, and can generally provide high-power charging. Specifically, this type of electric vehicle charger 100 generally provides DC power to charge the electric vehicle 300, and the current can reach hundreds of amperes and the power can reach hundreds of kW.

However, the current electric vehicle charger 100 only supports the technology of charging the electric vehicle, but does not include the technology of feeding back the electricity to the power grid. On the other hand, the current electric vehicle charger 100 of FIG. 1B is fixed at home or a specific location and cannot be moved, and cannot effectively support the power grid. Therefore, how to design a portable charging and discharging device and electric vehicle charger to combine the advantages of the two and eliminate the disadvantages, so as to make it easier for car owners to feed the electricity of the electric vehicle back to the power grid and provide a two-way charging function, is a major topic that the creator of this case wants to study.

In order to solve the above problems, the present disclosure provides a charging and discharging device to overcome the problems of the prior art. Therefore, the charging and discharging device of the present disclosure is coupled to the power grid through a first cable and a plug, and is coupled to the electric vehicle through a second cable and a connection port. The charging and discharging device includes a charging circuit, a feeding circuit and a controller, and the charging circuit and the feeding circuit are coupled to the first cable and the second cable respectively. The charging circuit provides a charging path for the power grid to be transmitted from the plug to the connection port, and the feeding circuit can provide a feeding path for the vehicle power to be transmitted from the connection port to the plug. The controller couples the charging circuit and the feeding circuit, and transmits current information and operation commands to the electric vehicle through the second cable to determine whether the electric vehicle is to be operated in a charging mode or a feeding mode according to the operation command. In the charging mode, the controller sets a first current that can flow through the charging path, and charges the electric vehicle according to the first current. In the feeding mode, the controller sets a second current that can flow through the feeding path, and feeds the power grid according to the second current.

In order to solve the above problems, the present disclosure provides an electric vehicle charger to overcome the problems of the prior art. Therefore, the portable electric vehicle charger disclosed in the present disclosure includes a plug, a first cable, a second cable and a charging and discharging device. The first cable is coupled to the plug, and the second cable is coupled to the connection port. The charging and discharging device couples the first cable and the second cable, and the charging and discharging device includes a charging circuit and a feeding circuit. The charging circuit couples the first cable and the second cable, and includes a first switching switch. The charging circuit provides a charging path for the grid power to be transmitted from the plug to the connection port, and one end of the first switching switch is coupled to the first cable, and the other end of the first switching switch is coupled to the second cable. The feeding circuit is coupled to the first cable and the second cable, and includes a second switch, a conversion circuit, and a third switch. The feeding circuit can provide a feeding path for transmitting the power of the vehicle from the connection port to the plug. One end of the second switch is coupled to the first cable, and one end of the conversion circuit is coupled to the second switch. One end of the third switch is coupled to the other end of the conversion circuit, and the other end of the third switch is coupled to the second cable.

The main purpose and effect of the present disclosure is that the electric vehicle charger of the present disclosure can provide a bidirectional charging function. That is, through the charging and discharging operation of the electric vehicle charger, the grid power provided by the grid can be used to charge the electric vehicle, and the vehicle power provided by the electric vehicle can also be fed back to the grid to achieve the effect of bidirectional power supply.

In order to further understand the technology, means and effects adopted by the present disclosure to achieve the intended purpose, please refer to the following detailed description and attached figures of the present disclosure. It is believed that the purpose, features and characteristics of the present disclosure can be understood in depth and concretely. However, the attached figures are only provided for reference and explanation, and are not used to limit the present disclosure.

The technical content and detailed description of this disclosure are as follows with accompanying drawings:

Please refer to FIG. 2 for a circuit block diagram of the portable electric vehicle charger disclosed herein, and refer to FIG. 1A to FIG. 1C for reference. The portable electric vehicle charger 100 (hereinafter referred to as the electric vehicle charger 100) couples the power grid 200 and the electric vehicle 300, and includes a plug 1, a first cable 2, a second cable 3, a charging and discharging device 4, and a connection port 5. The plug 1 can be coupled to the power grid 200 by plugging into the socket 200A, and the connection port 5 can be coupled to the electric vehicle 300 by plugging into the connection port 300A of the electric vehicle 300. One end of the first cable 2 is coupled to the plug 1, and the other end of the first cable 2 is coupled to one end of the charging and discharging device 4. One end of the second cable 3 is coupled to the connection port 5, and the other end of the second cable 3 is coupled to the other end of the charging and discharging device 4. The electric vehicle charger 100 does not include a grid-side charging device 100B as shown in FIG. 1B or a charging pile 100C as shown in FIG. 1C, but uses a conventional plug 1 (such as but not limited to US standard, European standard, etc.) to plug into a conventional socket 200A to obtain grid power Pac.

Furthermore, the main purpose and effect of the present disclosure is that the electric vehicle charger 100 of the present disclosure can provide a bidirectional charging function. That is, through the charging and discharging operation of the electric vehicle charger 100, the grid power Pac provided by the power grid 200 can be used to charge the electric vehicle 300, and the vehicle power Pv provided by the electric vehicle 300 can also be fed back to the power grid 200. Among them, the charging and discharging device 4 includes a charging path Lc and a feedback path Lf. When the grid power Pac charges the electric vehicle 300, the grid power Pac is provided to the electric vehicle 300 by the path of the plug 1, the first cable 2, the charging path Lc of the charging and discharging device 4, the second cable 3 and the connection port 5. On the contrary, when the vehicle power Pv is fed back to the power grid 200, the vehicle power Pv is fed back to the power grid 200 by the connection port 5, the second cable 3, the feeding path Lf of the charging and discharging device 4, the first cable 2 and the plug 1. The plug 1, the first cable 2, the charging and discharging device 4, the second cable 3 and the connection port 5 can be composed of an integrated electric vehicle charger 100, or a split electric vehicle charger 100. Specifically, when it is a split electric vehicle charger 100, the plug 1 and the first cable 2 are modular structures, and the connection between the first cable 2 and the charging and discharging device 4 is a pluggable (replaceable) connection structure. The charging and discharging device 4 can receive the specification information Is of the plug 1 through the first cable 2, and the specification information Is depends on the type of the plug 1 currently plugged into the charging and discharging device 4 through the first cable 2. In addition, the charging and discharging device 4 can also transmit the current information Ic and the operation command Co with the electric vehicle 300 through the second cable 3. Among them, the charging and discharging device 4 can know through the specification information Is whether the currently plugged plug 1 complies with the relevant specifications of the electric vehicle charger 100, and the specifications of the plug 1 (US standard, European standard, etc.), the voltage of the power grid is three-phase/single-phase, 110V/220V, the upper limit of the current (usually determined by the voltage), frequency, phase and other information.

On the other hand, the electric vehicle 300 and the charging and discharging device 4 can transmit the current information Ic so that the electric vehicle 300 can confirm and set the current that can be drawn, and the operation command Co is mainly to let the electric vehicle 300 and the charging and discharging device 4 know each other's current operation. For example, but not limited to, the electric vehicle 300 and the charging and discharging device 4 can confirm whether the electric vehicle 300 is correctly coupled to the charging and discharging device 4 and whether the plug 1 is correctly plugged into the socket 200A through the operation command Co to determine whether it is in the standby state. In addition, through the transmission of the operation command Co, the charging and discharging device 4 can also determine which mode the electric vehicle 300 wants to operate in (for example but not limited to, charging mode or feeding mode), and selectively provide corresponding paths (i.e., the charging mode provides the charging path Lc, and the feeding mode provides the feeding path Lf) to perform corresponding operations.

When the plug 1 is plugged into the socket 200A, the charging and discharging device 4 can receive the specification information Is of the plug 1 through the first cable 2. In the operation of the charging mode, the charging and discharging device 4 first confirms whether the electric vehicle 300 is correctly coupled to the connection port 5, and whether the plug 1 is correctly plugged into the socket 200A. When both are correctly coupled, the operation command Co indicates that the charging and discharging device 4 is in the standby state, and the electric vehicle 300 and the charging and discharging device 4 can know that the current state is the standby state according to the instruction of the operation command Co. Then, the value of the operation command Co can be adjusted according to the needs of the electric vehicle 300, and the charging and discharging device 4 determines whether the electric vehicle 300 wants to operate in the charging mode or the feeding mode according to the value of the operation command Co.

The charging path Lc is connected in parallel with the feeding path Lf, and the paths of the charging path Lc and the feeding path Lf are different (independent of each other) and the currents are opposite. In the charging mode, the charging and discharging device 4 forms the charging path Lc and cuts off the feeding path Lf to prevent the current on the charging path Lc from flowing to the feeding path Lf and causing additional power consumption. Conversely, in the feeding mode, the charging and discharging device 4 cuts off the charging path Lc and forms the feeding path Lf to convert the vehicle power Pv into the grid power Pac through the feeding path Lf. When the feeding circuit Lf converts the vehicle power Pv into the grid power Pac, the feeding circuit Lf can convert the three-phase or single-phase vehicle power Pv into the three-phase or single-phase grid power Pac. For example but not limited to, the feeding circuit Lf can convert the three-phase vehicle power Pv into the single-phase grid power Pac, or convert the single-phase vehicle power Pv into the three-phase grid power Pac. In this way, adaptive power conversion can be performed in response to the needs of the grid 200 and the electric vehicle 300 to avoid the situation where the two cannot be used due to the difference in wiring.

The operation command Co can preferably be a voltage value, and the current operation state of the charging and discharging device 4 is set by adjusting the voltage value. For example, when the electric vehicle 300 is not correctly coupled to the connection port 5, or the plug 1 is not correctly plugged into the socket 200A, the voltage value of the operation command Co is a specific value (such as but not limited to 0V), so that the electric vehicle 300 can know that the charging and discharging device 4 has not entered the standby state based on this specific value, otherwise (such as but not limited to 5V) it is known that the charging and discharging device 4 has entered the standby state.

In addition, when the electric vehicle 300 wants to operate in the charging mode or the feeding mode, the electric vehicle 300 can set the mode by adjusting the value of the operation command Co. For example, when the general charging and discharging device 4 has entered the standby state (same as the above example, the value of the operation command Co is 5V), the standby state is preset to the charging mode. Conversely, after the charging and discharging device 4 has entered the standby state, the electric vehicle 300 can adjust the value of the operation command Co (for example but not limited to, the electric vehicle 300 adjusts the value of the operation command Co from 5V to 3V) to inform the charging and discharging device 4 that it needs to operate in the feeding mode. The operation command Co is not limited to a voltage value, for example but not limited to, the operation command Co can also be a digital signal (for example but not limited to, logic 011 corresponds to a feeding mode), or a pulse width modulation signal (PWM), and the operation mode is adjusted by a duty cycle (DUTY) (for example but not limited to, a duty cycle of 50% corresponds to a feeding mode), and so on, which will not be elaborated here.

Taking the charging mode as an example, when the charging and discharging device 4 is coupled to the plug 1 through the first cable 2, the charging and discharging device 4 receives the specification information Is of the plug 1 through the first cable 2 to learn the upper limit value (for example but not limited to 18A, which usually varies according to the voltage of the power grid and the capacity of the plug 1) of the charging and discharging device 4. Then, the charging and discharging device 4 adjusts the current information Ic according to the upper limit value of the charging current, and the current information Ic corresponds to the first current I1 (generally preset to the current upper limit value) that can flow through the charging path Lc. When the charging and discharging device 4 is coupled to the electric vehicle 300 via the second cable 3, the charging and discharging device 4 can communicate with the electric vehicle 300 by transmitting the current information Ic and inform the electric vehicle 300 of the upper limit value of the current that can flow through the charging path Lc. Then, the electric vehicle 300 can adjust the current information Ic to determine the first current I1 for charging (for example, but not limited to, after the charging and discharging device 4 informs the electric vehicle 300 of the upper limit value of 18A, the electric vehicle 300 finally chooses a value of 15A for charging). Finally, the charging and discharging device 4 sets the first current I1 that can flow through the charging path Lc through the adjusted current information Ic.

The current information Ic may preferably be a pulse width modulation signal (PWM), and the size of the first current I1 may be changed by adjusting the duty cycle (DUTY) (for example, but not limited to, a duty cycle of 30% corresponds to a first current I1 of 18A), but is not limited thereto. For example, but not limited to, the current information Ic may also be a digital signal (for example, but not limited to, logic 011 corresponds to a first current I1 of 18A), or a voltage value (for example, but not limited to, a voltage of 5V corresponds to a first current I1 of 18A) to indicate the size of the first current I1, and so on, which will not be elaborated here. Finally, when the operation mode and the first current I1 are determined, the charging and discharging device 4 provides a corresponding charging path Lc to perform a charging operation, so as to charge the electric vehicle 300 according to the first current I1. On the other hand, after the operation command Co instructs the charging and discharging device 4 to be in a standby state, the charging and discharging device 4 can set the second current I2 that can flow through the feeding path Lf through the current information Ic, and after the operation mode and the second current I2 are determined, the charging and discharging device 4 provides a corresponding feeding path Lf to perform a feeding operation, so as to feed the power grid 200 according to the second current I2. In addition, the operation of the remaining feeding modes is similar to the above-mentioned charging mode, and will not be repeated here.

Please refer to FIG. 3 for a more detailed circuit block diagram of the portable electric vehicle charger disclosed herein, and refer to FIG. 2 in conjunction. FIG. 3 only shows a preferred implementation method under the structure of FIG. 2, but is not limited thereto. In FIG. 3, the charging and discharging device 4 includes a charging circuit 42, a feeding circuit 44 and a controller 46, and the charging circuit 42 is connected in parallel with the feeding circuit 44. The charging circuit 42 couples the first cable 2 and the second cable 3, and provides a charging path Lc for transmitting the grid power Pac from the plug 1 to the connection port 5. The feeding circuit 44 couples the first cable 2 and the second cable 3, and provides a feeding path Lf for transmitting the vehicle power Pv from the electric vehicle 300 to the plug 1 via the connection port 5. The controller 46 is coupled to the charging circuit 42 and the feeding circuit 44, and includes a protection pin, an identification pin, a control pilot pin CP, and a proximity pilot pin PP. The identification pin and the protection pin are coupled to the plug 1 through the first cable 2, and the plug 1 preferably includes a thermistor NTC and a detection resistor R (Recognize Resistance).

The protection pin is coupled to the thermistor NTC through the first cable 2 to determine whether to perform over-temperature protection of the charging and discharging device 4 according to the change of the thermistor NTC group value. The identification pin is coupled to the detection resistor R through the first cable 2 so that the controller 46 obtains the specification information Is through the detection resistor R. Therefore, if the plug 1 uses the detection resistor R, the identification pin can, for example but not limited to, provide a constant current source to generate a specific voltage in the detection resistor R, and this specific voltage is the specification information Is. The control guide pin CP is coupled to the electric vehicle 300 via the second cable 3, and the control guide pin CP and the electric vehicle 300 transmit current information Ic to each other, so that the controller 46 and the electric vehicle 300 set and adjust the first current I1 that can flow through the charging path Lc through the current information Ic, and charge the electric vehicle 300 according to the first current I1, or set and adjust the second current I2 that can flow through the feeding path Lf through the current information Ic, and feed the power grid 200 according to the second current I2. The connecting guide pin PP is coupled to the electric vehicle 300 via the second cable 3, and the connecting guide pin PP and the electric vehicle 300 transmit the operation command Co to each other, so that the controller 46 and the electric vehicle 300 determine the current operation state through the operation command Co.

It is worth mentioning that in one embodiment, the controller 46 can be a control chip, which can be a microcontroller, a signal processor, etc., but the controller 46 can also be a control circuit composed of a circuit or a logic gate. In addition, the controller 46 shown in FIG. 3 may not only include a control chip. It may also include circuits and circuit elements for detecting signals and transmitting signals (for example, but not limited to, analog-to-digital conversion circuits, resistors, etc.). Since these circuits and circuit elements not shown are not the main features of the present disclosure, they will not be elaborated here. On the other hand, the controller may also have a wireless communication function, such as but not limited to Wifi, Bluetooth, mobile communication (such as: 2/3/4/5G, etc.), so that the portable electric vehicle charger can communicate with the outside world.

The charging circuit 42 includes a first switching switch SW1. One end of the first switching switch SW1 is coupled to the first cable 2, and the other end of the first switching switch SW1 is coupled to the second cable 3. The controller 46 is coupled to the control end of the first switching switch SW1 to control the on/off of the first switching switch SW1 by providing a control signal. In the charging mode, the controller 46 controls the first switching switch SW1 to be turned on, so that the charging circuit 42 is formed and provides a charging path Lc. On the contrary, when the controller 46 controls the first switching switch SW1 to be turned off (for example but not limited to the standby state or the feeding mode, etc.), the two ends of the charging circuit 42 are disconnected to prevent the current from being incorrectly provided from the power grid 200 to the electric vehicle 300. The first switching switch SW1 can preferably be a switch such as a relay that allows a large current to flow through, and has the advantages of no leakage current when it is turned off and simple configuration.

The charging and discharging device 4 further includes an auxiliary circuit 48, and the auxiliary circuit 48 is coupled to the path between the first switch SW1 and the first cable 2. Regardless of whether the charging and discharging device 4 is operating in a standby state, a charging mode, or a discharging mode, the auxiliary circuit 48 converts the grid power Pac into the working power Pcc, so as to continuously supply power to the controller 46 after the plug 1 is coupled to the grid 200. Generally speaking, the controller 46 is usually a device that receives direct current, so the auxiliary circuit 48 can be a converter for converting alternating current into direct current. Preferably, the auxiliary circuit 48 can couple the grid power Pac on the path between the first switch SW1 and the first cable 2 through, for example but not limited to, coupling of an isolation transformer to electrically isolate the controller 46 from the main power transmission path.

On the other hand, the feeding circuit 44 includes a second switching switch SW2, a conversion circuit 442 and a third switching switch SW3. One end of the second switching switch SW2 is coupled to the first cable 2, and the other end of the second switching switch SW2 is coupled to the conversion circuit 442. One end of the third switching switch SW3 is coupled to the other end of the conversion circuit 442, and the other end of the third switching switch SW3 is coupled to the second cable 3. The controller 46 is coupled to the control end of the second switching switch SW2 and the third switching switch SW3 to control the conduction/disconnection of the second switching switch SW2 and the third switching switch SW3 by providing a control signal. In the feeding mode, the controller 46 controls the second switching switch SW2 and the third switching switch SW3 to be turned on, and activates the conversion circuit 442 to form a feeding path Lf. Therefore, the vehicle power Pv can be provided to the conversion circuit 442 through the third switch SW3, and the conversion circuit 442 converts the vehicle power Pv into the grid power Pac, and then provides it to the plug 1 through the second switch SW2. The three-phase or single-phase vehicle power Pv can be converted into the three-phase or single-phase grid power Pac. When the controller 46 controls the second switch SW2 and the third switch SW3 to be turned off, and the conversion circuit 442 is disabled (for example but not limited to the standby state or charging mode, etc.), the two ends of the feeding circuit 44 are disconnected to prevent the electric current from being incorrectly provided by the electric vehicle 300 to the grid 200.

Furthermore, the conversion circuit 442 may preferably include an AC/DC conversion circuit, a DC/AC conversion circuit, and an energy storage capacitor (not shown). One end of the AC/DC conversion circuit is coupled to the third switching switch SW3, and the other end is coupled to the energy storage capacitor (not shown). One end of the DC/AC conversion circuit is coupled to the energy storage capacitor (not shown), and the other end is coupled to the second switching switch SW2. Among them, the controller 46 controls the AC/DC conversion circuit to convert the carrier power Pv into the DC power Pdc, so as to store the DC power Pdc in the energy storage capacitor (not shown). Then, the controller 46 controls the DC/AC conversion circuit to convert the DC power Pdc into the grid power Pac to feed the grid 200.

Since the conversion circuit 442 includes an energy storage capacitor (not shown), the conversion circuit 442 can perform arbitrary conversion between three-phase and single-phase power. Preferably, the AC-DC conversion circuit AC/DC can convert the three-phase vehicle power Pv into DC power Pdc, and the DC-AC conversion circuit DC/AC then converts the DC power Pdc into single-phase grid power Pac. Alternatively, the AC-DC conversion circuit AC/DC converts the single-phase vehicle power Pv into DC power Pdc, and the DC-AC conversion circuit DC/AC then converts the DC power Pdc into three-phase grid power Pac. In this way, adaptive power conversion can be performed in response to the needs of the power grid 200 and the electric vehicle 300, avoiding the situation where the two cannot be used due to differences in wiring. It is worth mentioning that in one embodiment, the AC/DC conversion circuit and the DC/AC conversion circuit can be conversion circuits without isolation transformers (for example, but not limited to, conversion circuits without isolation transformers at the input and output ends such as Buck and Boost). The reason is that the voltage and current at both ends of the conversion circuit 442 are similar, so there is no need to use a larger isolation transformer, but it is not limited to this. In addition, the AC/DC conversion circuit and the DC/AC conversion circuit may not include an energy storage capacitor and its DC link (for example, but not limited to, a current source type or a matrix type AC/AC converter) between them to save the volume occupied by the energy storage capacitor.

Please refer to FIG. 4A for a schematic diagram of the current direction of the charging mode of the portable electric vehicle charger disclosed herein, and refer to FIG. 2-3 in conjunction. FIG. 4A shows the current direction of the charging mode, and the arrow direction A1 represents the flow direction of the first current I1. Specifically, when the plug 1 is plugged into the socket 200A, the auxiliary circuit 48 receives the grid power Pac and converts the grid power Pac into the working power Pcc to supply power to the controller 46. When the controller 46 is powered and operates normally, the controller 46 can receive the specification information Is of the plug 1 through the first cable 2 to obtain the upper limit values of the charging current (i.e., the first current I1) and the feeding current (i.e., the second current I2) of the charging and discharging device 4 (which usually varies according to the voltage of the grid and the capacity of the plug 1).

When the controller 46 confirms that the electric vehicle 300 is correctly coupled to the connection port 5 and the plug 1 is correctly plugged into the socket 200A, the controller 46 adjusts the value of the operation command Co to indicate that the charging and discharging device 4 is in a standby state. After the standby state, the controller 46 determines whether the electric vehicle 300 is to be operated in a charging mode or a feeding mode according to the value of the operation command Co. On the other hand, after the standby state, the controller 46 can also set the first current I1 and the second current I2 that can flow through the charging path Lc through the current information Ic. When the controller 46 determines that the operation mode is the charging mode and the size of the first current I1 is also set (by mutually transmitting the current information Ic with the electric vehicle 300), the controller 46 turns on the first switching switch SW1 to allow the charging circuit 42 to form a charging path.

Please refer to FIG. 4B for a schematic diagram of the current direction of the feeding mode of the portable electric vehicle charger disclosed herein, and refer to FIG. 2 to FIG. 4A in conjunction. FIG. 4B shows the current direction of the feeding mode, and the arrow direction A2 represents the flow direction of the second current I2. The difference between FIG. 4A and FIG. 4B is that when the controller 46 determines that the operation mode is the feeding mode, and the size of the second current I2 is also set (by transmitting current information Ic to and from the electric vehicle 300), the controller 46 turns on the second switching switch SW2 and the third switching switch SW3, and activates the conversion circuit 442 to form a feeding path Lf. It is worth mentioning that in one embodiment, the operation method not described in FIG. 4B is similar to that in FIG. 4A, and will not be repeated here.

Please refer to FIG. 5 for a more detailed circuit block diagram of the portable electric vehicle charger disclosed herein, and refer to FIG. 2 to FIG. 4B in conjunction. In FIG. 5, in addition to the components described in FIG. 2 to FIG. 4B above, multiple drivers, detectors (circuits), etc. are also included. Since most of these circuits are only for the protection of the electric vehicle charger 100 and are not the main features of the present disclosure, these circuits will not be described one by one. Therefore, the electric vehicle charger 100 disclosed herein still has protection functions such as leakage current, overcurrent, voltage, frequency, and grounding detection during the charging and feeding process to ensure the safety of users, electric vehicles, homes, and city power. In addition, in FIG. 5 , the second switching switch SW2 preferably includes a first switch Q1 and a second switch Q2 connected in series, and the third switching switch SW3 preferably includes a third switch Q3 and a fourth switch Q4 connected in series. When the controller 46 controls the second switching switch SW2 to be turned on, the first switch Q1 and the second switch Q2 are turned on, and vice versa. The purpose and effect of the second switching switch SW2 including the first switch Q1 and the second switch Q2 connected in series is that the first switch Q1 and the second switch Q2 can provide a mutual backup circuit breaker effect.

Specifically, when the feeding mode is exited, the controller 46 controls the second switching switch SW2 to be turned off. At this time, when the second switching switch SW2 fails and cannot be turned off smoothly, the grid power Pac will be provided to the conversion circuit 442 by mistake. Therefore, through the backup function of the first switch Q1 and the second switch Q2, when one of the two fails and cannot be turned off smoothly, the other switch that has not failed can still be turned off as a backup, so that the path from the first cable 2 to the conversion circuit 442 can still be normally disconnected. Similarly, when the controller 46 controls the third switching switch SW3 to be turned on, the third switch Q3 and the fourth switch Q4 are turned on, otherwise they are turned off. Its operation method and the effect that can be achieved are similar to those of the second switching switch SW2, and will not be repeated here.

However, the above description is only a detailed description and diagram of the preferred specific embodiment of the present disclosure, but the features of the present disclosure are not limited thereto, and are not used to limit the present disclosure. The entire scope of the present disclosure shall be subject to the following patent application scope. All embodiments that conform to the spirit of the patent application scope of the present disclosure and its similar variations shall be included in the scope of the present disclosure. Any changes or modifications that can be easily thought of by any person familiar with the art within the field of the present disclosure can be covered by the following patent scope of the present case.

100B: Grid charging device 100C: Charging pile 100: Electric vehicle charger 1: Plug NTC: Thermistor R: Detection resistor 2: First cable 3: Second cable 4: Charging and discharging device 42: Charging circuit SW1: First switch 44: Feedback circuit SW2: Second switch Q1: First switch Q2: Second switch SW3: Third switch Q3: Third switch Q4: Fourth switch 442: Conversion circuit AC/DC: AC-DC conversion circuit DC/AC: DC-AC conversion circuit 46: Controller 48: Auxiliary circuit CP: Control guide pin PP: Connection guide pin 5: Connection port Lc: Charging path I1: First current Lf: Feedback path I2: Second current 200: Power grid 200A: Socket 300: Electric vehicle 300A: Port Pac: Power grid Pv: Vehicle power Pcc: Working power Pdc: DC power Is: Specification information Ic: Current information Co: Operation command A1, A2: Arrow direction

FIG. 1A is a configuration diagram of a first embodiment of a conventional electric vehicle charger;

FIG. 1B is a configuration diagram of a second embodiment of a conventional electric vehicle charger;

FIG. 1C is a configuration diagram of a third embodiment of a conventional electric vehicle charger;

FIG. 2 is a circuit block diagram of the portable electric vehicle charger disclosed herein;

FIG3 is a more detailed circuit block diagram of the portable electric vehicle charger disclosed herein;

FIG4A is a schematic diagram showing the current direction of the charging mode of the portable electric vehicle charger disclosed herein;

FIG4B is a schematic diagram of the current direction of the charging mode of the portable electric vehicle charger disclosed in the present invention; and

FIG. 5 is a more detailed circuit block diagram of the portable electric vehicle charger disclosed herein.

100: Electric vehicle charger

1: Plug

NTC: Thermistor

R: Detection resistance

2: First cable

3: Second cable

4: Charging and discharging device

42: Charging circuit

SW1: First switch

44: Feedback circuit

SW2: Second switching switch

SW3: The third switch

442:Conversion circuit

AC/DC: AC/DC conversion circuit

DC/AC: DC to AC conversion circuit

46: Controller

48: Auxiliary circuit

CP: Control guide pin

PP: Connecting guide pins

5: Port

Lc: Charging path

I1: first current

Lf: Feedback path

I2: Second current

200: Power grid

200A: socket

300: Electric vehicle

Pac: Grid power

Pv: Vehicle power

Pcc: Working power

Pdc: Direct current power

Is: Specification Information

Ic: Current information

Co: Operation command

Claims (20)

A charging and discharging device is coupled to a power grid through a first cable and a plug, and is coupled to an electric vehicle through a second cable and a connection port, and the charging and discharging device includes: A charging circuit, coupling the first cable and the second cable, and providing a charging path for transmitting power from the power grid to the connection port; A feeding circuit, coupling the first cable and the second cable, and providing a feeding path for transmitting power from the connection port to the plug, wherein the charging circuit is connected in parallel with the feeding circuit; and A controller is coupled to the charging circuit and the feeding circuit, and transmits a current information and an operation command to the electric vehicle through the second cable, so as to determine whether the electric vehicle is to be operated in a charging mode or a feeding mode according to the operation command; Wherein, in the charging mode, the controller sets a first current that can flow through the charging path, and charges the electric vehicle according to the first current; in the feeding mode, the controller sets a second current that can flow through the feeding path, and feeds the power grid according to the second current. A charging and discharging device as described in claim 1, wherein the plug and the first cable are modular structures, and the connection between the first cable and the charging and discharging device is a pluggable connection structure; the controller receives specification information of the plug through the first cable, and provides the current information according to the specification information to set the first current and the second current accordingly. A charging and discharging device as described in claim 1, wherein the charging circuit comprises: A first switching switch, one end of which is coupled to the first cable, and the other end of which is coupled to the second cable; Wherein, in the charging mode, the controller turns on the first switching switch to form the charging path. The charging and discharging device as described in claim 3 further includes: an auxiliary circuit coupling the first switching switch and the first cable; wherein, in the charging mode or the feeding mode, the auxiliary circuit converts the grid power into a working power to power the controller. The charging and discharging device as described in claim 1, wherein the feeding circuit comprises: a second switching switch, one end of which is coupled to the first cable; a conversion circuit, one end of which is coupled to the second switching switch; and a third switching switch, one end of which is coupled to the other end of the conversion circuit and the other end of which is coupled to the second cable; wherein, in the feeding mode, the controller turns on the second switching switch and the third switching switch and activates the conversion circuit to form the feeding path. A charging and discharging device as described in claim 5, wherein the second switching switch includes a first switch and a second switch connected in series; and the third switching switch includes a third switch and a fourth switch connected in series. The charging and discharging device as described in claim 5, wherein the conversion circuit includes: an AC-DC conversion circuit coupled to the third switch; and a DC-AC conversion circuit coupled to the second switch and the AC-DC conversion circuit; wherein the controller controls the AC-DC conversion circuit to convert the vehicle power into DC power, and controls the DC-AC conversion circuit to convert the DC power into the grid power. A charging and discharging device as described in claim 5, wherein the conversion circuit converts the three-phase vehicle power into the single-phase grid power, or converts the single-phase vehicle power into the three-phase grid power. As described in claim 5, after the controller instructs the charging and discharging device to be in a standby state through the operation command, the controller then determines whether the electric vehicle is to operate in the charging mode or the feeding mode based on a value of the operation command. A charging and discharging device as described in claim 9, wherein after the standby state, the controller sets the first current that can flow through the charging path through the current information and turns on a first switching switch of the charging circuit. A charging and discharging device as described in claim 9, wherein after the standby state, the controller sets the second current that can flow through the feedback path through the current information, turns on a second switching switch and a third switching switch of the feedback circuit, and enables the conversion circuit. An electric vehicle charger, comprising: a plug; a first cable coupled to the plug; a second cable coupled to a connection port; a charging and discharging device coupled to the first cable and the second cable, and comprising: a charging circuit coupled to the first cable and the second cable, and providing a charging path for transmitting grid power from the plug to the connection port, the charging circuit comprising: a first switching switch, one end of which is coupled to the first cable, and the other end of which is coupled to the second cable; and A feeding circuit is coupled to the first cable and the second cable, and can provide a feeding path for transmitting vehicle power from the connection port to the plug, wherein the charging circuit is connected in parallel to the feeding circuit, and the feeding circuit includes: a second switching switch, one end of which is coupled to the first cable; a conversion circuit, one end of which is coupled to the second switching switch; and a third switching switch, one end of which is coupled to the other end of the conversion circuit, and the other end of which is coupled to the second cable. An electric vehicle charger as described in claim 12, wherein the charging and discharging device receives specification information of the plug via the first cable, and transmits current information and an operation command to an electric vehicle via the second cable, so as to determine whether the electric vehicle is to operate in a charging mode or a feeding mode according to the operation command. An electric vehicle charger as described in claim 13, wherein in the charging mode, the charging and discharging device provides the current information according to the specification information to set a first current that can flow through the charging path, and charges the electric vehicle according to the first current; in the feeding mode, the charging and discharging device provides the current information according to the specification information to set a second current that can flow through the feeding path, and feeds a power grid according to the second current. An electric vehicle charger as described in claim 12, wherein in a charging mode, a controller of the charging and discharging device turns on the first switching switch, and turns off the second switching switch, the third switching switch and disables the conversion circuit. An electric vehicle charger as described in claim 12, wherein in a feeding mode, a controller of the charging and discharging device turns off the first switching switch, and turns on the second switching switch, the third switching switch and the activation of the conversion circuit. An electric vehicle charger as described in claim 16, wherein the feeding circuit converts the three-phase vehicle power into the single-phase grid power, or converts the single-phase vehicle power into the three-phase grid power. An electric vehicle charger as described in claim 14, wherein the plug and the first cable are modular structures, and the connection between the first cable and the charging and discharging device is a pluggable connection structure; when the charging and discharging device is coupled to the plug via the first cable, the charging and discharging device receives the specification information of the plug via the first cable, and sets the first current that can flow through the charging path or the second current that can flow through the feeding path according to the specification information. An electric vehicle charger as described in claim 14, wherein when the operating command indicates that the charging and discharging device is in a standby state, the charging and discharging device then determines whether the electric vehicle is to operate in the charging mode or the feeding mode based on a value of the operating command. An electric vehicle charger as described in claim 19, wherein after the standby state, the charging and discharging device can set the first current to flow through the charging path through the current information and form the charging path, or after the standby state, the charging and discharging device can set the second current to flow through the feeding path through the current information and form the feeding path.

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