KR102837603B1 - Battery apparatus and switch diagnosis apparatus and method - Google Patents

Abstract

In the battery device, the switch circuit includes a plurality of switches connected in parallel between the output terminal of the battery pack and the connection terminal connecting the battery device to an external device. The temperature sensor measures the temperature of the switch circuit. The processing circuit measures the temperature change of the switch circuit for a predetermined period of time after turning on the plurality of switches, and diagnoses the switch circuit based on the measured temperature change.

Description

{BATTERY APPARATUS AND SWITCH DIAGNOSIS APPARATUS AND METHOD}

The present invention relates to a battery device, a switch diagnostic device and a method.

Electric vehicles are vehicles that mainly use batteries as power sources to drive motors, and research is actively being conducted on them as an alternative to solve pollution and energy problems of internal combustion vehicles. In addition, rechargeable batteries are used in various electronic devices in addition to battery vehicles. In order to supply power to external devices such as battery vehicles or electronic devices from a battery module or to charge a battery module, a relay is provided between the external connection terminal for connection to an external device and the battery module.

Recently, mechanical relays are being replaced by electronic switches, such as transistors. These switches are components through which high voltage and high power electric energy constantly passes, and it is important to diagnose whether there is a failure.

The object of the present invention is to provide a battery device, a switch diagnostic device, and a method capable of diagnosing a switch failure.

According to one embodiment of the present invention, a battery device including a battery pack, a switch circuit, a temperature sensor, and a processing circuit is provided. The switch circuit includes a plurality of switches connected in parallel between an output terminal of the battery pack and a connection terminal connecting the battery device to an external device. The temperature sensor measures a temperature of the switch circuit. The processing circuit controls an operation of the switch circuit, measures a temperature change amount of the switch circuit for a predetermined period of time after turning on the plurality of switches, and diagnoses the switch circuit based on the measured temperature change amount.

The above processing circuit can diagnose the switch circuit as faulty if the measured temperature change amount is less than the temperature change amount of the switch circuit for the predetermined time when the plurality of switches are operating normally.

The above processing circuit can diagnose that among the plurality of switches, there is a switch that has an open stuck failure.

The above processing circuit can diagnose the switch circuit as having failed if the measured temperature change amount is less than the temperature change amount during normal operation by a predetermined ratio.

The above predetermined time can be measured from the turning on time of the plurality of switches.

Each switch may include a first transistor and a second transistor connected in series.

The above processing circuit may include a gate driver for transmitting a control signal to the gates of the first transistor and the second transistor of the plurality of switches through one channel, and a processor for diagnosing the switch circuit.

According to another embodiment of the present invention, a switch diagnosis device of a battery device including a battery pack is provided. The switch diagnosis device includes a switch circuit, a gate driver, a temperature sensor, and a processor. The switch circuit includes a plurality of switches connected in parallel between an output terminal of the battery pack and a connection terminal connecting the battery device to an external device, and each switch includes a first transistor and a second transistor connected in series. The gate driver turns on the first transistor and the second transistor of the plurality of switches simultaneously. The temperature sensor measures the temperature of the switch circuit. The processor measures a temperature change amount of the switch circuit for a predetermined period of time after turning on the plurality of switches, and diagnoses the switch circuit based on the measured temperature change amount.

According to another embodiment of the present invention, a method for diagnosing a switch of a battery device is provided, which includes a battery pack, and a switch circuit including a plurality of switches connected in parallel between an output terminal of the battery pack and a connection terminal connected to an external device. The switch diagnosis method includes a step of turning on the plurality of switches, a step of measuring a temperature change amount of the switch circuit for a predetermined period of time, and a step of diagnosing the switch circuit based on the measured temperature change amount.

According to one embodiment of the present invention, a fault in a switch circuit can be quickly diagnosed.

FIG. 1 is a drawing showing a battery device according to one embodiment of the present invention.
FIG. 2 is a diagram showing a switch diagnostic circuit according to one embodiment of the present invention.
FIG. 3 is a flowchart illustrating a switch diagnosis method according to one embodiment of the present invention.
FIG. 4 is a diagram showing a switch diagnostic circuit according to another embodiment of the present invention.

Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In addition, in order to clearly describe the present invention in the drawings, parts that are not related to the description are omitted, and similar parts are assigned similar drawing reference numerals throughout the specification.

When it is said that a component is "connected" to another component, it should be understood that it may be directly connected to that other component, but that there may be other components in between. On the other hand, when it is said that a component is "directly connected" to another component, it should be understood that there are no other components in between.

FIG. 1 is a drawing showing a battery device according to one embodiment of the present invention.

Referring to FIG. 1, the battery device (100) has a structure that can be electrically connected to an external device through a positive connection terminal (DC(+)) and a negative connection terminal (DC(-)). When the external device is a load, the battery device (100) operates as a power source that supplies power to the load and is discharged. When the external device is a charger, the battery device (100) is charged by receiving external power through the charger. The external device that operates as a load may be, for example, an electronic device, a means of transportation, or an energy storage system (ESS), and the means of transportation may be, for example, an electric vehicle, a hybrid vehicle, or smart mobility.

The battery device (100) includes a battery pack (110), a switching circuit, a monitoring circuit (130), and a processing circuit (140).

The battery pack (110) includes a plurality of battery cells (not shown) that are electrically connected and have a positive output terminal (PV(+)) and a negative output terminal (PV(-)). In some embodiments, the battery cells may be rechargeable secondary batteries. In some embodiments, the battery pack (110) may include a battery module in which a predetermined number of battery cells are connected in series. In some embodiments, a predetermined number of battery modules in the battery pack (110) may be connected in series or in parallel to supply a desired energy.

A switch circuit is connected in series between the battery pack (110) and the external device (10) to control the electrical connection between the battery pack (110) and the external device (10). The switch circuit includes a switch (121) connected between one output terminal of the battery pack (110), for example, a positive output terminal (PV(+)), and one connection terminal of the battery device (100), for example, a positive connection terminal (DC(+)). In some embodiments, the switch circuit may further include a switch (122) connected between another output terminal of the battery pack (110), for example, a negative output terminal (PV(-)), and one connection terminal of the battery device (100), for example, a negative connection terminal (DC(-)).

In some embodiments, the switch (121) may include a plurality of transistor pairs connected in parallel. In some embodiments, each transistor pair may include two transistors connected in series.

The monitoring circuit (130) measures the temperature of the switches (121, 122). In some embodiments, the monitoring circuit (130) may further measure the voltage of the switches (121, 122).

The processing circuit (140) controls the operation of the switches (121, 122). In some embodiments, the processing circuit (140) may be a circuit including a processor, and the processor may be, for example, a micro controller unit (MCU). In some embodiments, the processing circuit (140) may further include a gate driver to control the operation of the switches (121, 122).

FIG. 2 is a diagram showing a switch diagnostic circuit according to one embodiment of the present invention.

Referring to FIG. 2, the switch diagnostic circuit includes a switch circuit (210), a temperature sensor (220), and a processing circuit (230).

The switch circuit (210) includes a plurality of transistor pairs connected in parallel. Each transistor pair includes two transistors connected in series. In Fig. 2, for convenience of explanation, the switch circuit (210) is illustrated as including three transistor pairs, namely, a transistor pair (FET11, FET12), a transistor pair (FET21, FET22), and a transistor pair (FET31, FET32).

In some embodiments, each transistor can be a metal-oxide semiconductor field-effect transistor (MOSFET). In one embodiment, each transistor can be an n-channel transistor having a body diode, for example, an NMOS transistor, as illustrated in FIG. 2.

In some embodiments, the switch circuit (210) may be a switch connected between a positive output terminal (PV(+)) of the battery pack (110 of FIG. 1) and a positive connection terminal (DC(+)) of the battery device (100 of FIG. 1). In one embodiment, a source of the transistor (FETi1) and a source of the transistor (FETi2) may be connected, a drain of the transistor (FETi1) may be connected to the positive output terminal (PV(+)) of the battery pack (110), and a drain of the transistor (FETi2) may be connected to the positive connection terminal (DC(+)) of the battery device (100). Here, i is an integer from 1 to 3. In one embodiment, the transistor (FETi1) may operate as a discharge switch to supply current from the battery pack (110) to an external device (10 in FIG. 1) when turned on, and the transistor (FETi2) may operate as a charge switch to supply current from an external device (charger) to the battery pack (110) when turned on.

The temperature sensor (220) detects the temperature of the switch circuit (210), and the processing circuit (230) receives the temperature of the switch circuit (210) detected by the temperature sensor (220). The processing circuit (230) includes a gate driver (231) and a processor (232).

In some embodiments, for controlling the switch circuit (210), the output of the gate driver (231) may have one channel. In this case, the output of the gate driver (231) may be connected to the gates of the transistors (FET11, FET12, FET21, FET22, FET31, FET32). Accordingly, the transistors (FET11, FET12, FET21, FET22, FET31, FET32) may be turned on or off simultaneously according to the control signal of the gate driver (231). In one embodiment, when the transistors (FET11, FET12, FET21, FET22, FET31, FET32) are n-channel transistors, the gate driver (231) can output a high-level control signal to turn on the transistors (FET11, FET12, FET21, FET22, FET31, FET32), and output a low-level control signal to turn off the transistors (FET11, FET12, FET21, FET22, FET31, FET32). In another embodiment, when the transistors (FET11, FET12, FET21, FET22, FET31, FET32) are p-channel transistors, the gate driver (231) can output a low-level control signal to turn on the transistors (FET11, FET12, FET21, FET22, FET31, FET32), and output a high-level control signal to turn off the transistors (FET11, FET12, FET21, FET22, FET31, FET32).

The processor (232) controls the operation of the gate driver (231). In addition, the processor (232) diagnoses a failure of the switch circuit (210) based on the amount of temperature change detected by the temperature sensor (220). For this purpose, the processor (232) may store the amount of temperature change when the switch circuit (210) is normal.

In some embodiments, the temperature sensor (220) may include a temperature variable resistor element whose resistance value varies with temperature. In one embodiment, the temperature variable resistor element may be a thermistor. In one embodiment, the temperature variable resistor element may be a negative temperature coefficient (NTC) thermistor. In some embodiments, the temperature variable resistor element may be connected in series with another resistor (e.g., a pull-down resistor), such that the processor (232) may measure the temperature based on the voltage at the junction of the temperature variable resistor element and the resistor.

In some embodiments, the temperature sensor (220) may be located approximately in the center of the switch circuit (210) for accurate temperature measurement of the switch circuit (210). For example, if the switch circuit (210) includes three transistor pairs, it may be installed at a location corresponding to the contact point of the middle transistor pair (FET21, FET22 of FIG. 2).

Below, a switch diagnosis method is explained with reference to FIGS. 2 and 3.

FIG. 3 is a flowchart illustrating a switch diagnosis method according to one embodiment of the present invention.

Referring to FIGS. 2 and 3, first, under the control of the processor (232), the gate driver (231) outputs a control signal to turn on the transistor of the switch circuit (210) (S310). Accordingly, the transistors (FET11, FET12, FET21, FET22, FET31, FET32) are turned on. In this case, if the external device (10 of FIG. 1) is a load, current can be supplied from the battery pack (110 of FIG. 1) to the external device (10). If the external device (10) is a charger, current can be supplied from the external device (10) to the battery pack (110), so that the battery pack (110) can be charged.

The temperature sensor (220) detects the temperature of the switch circuit (210) and transmits it to the processor (232) (S320). The processor (232) measures the amount of temperature change for a predetermined period of time (S330).

In some embodiments, the processor (232) may measure the temperature change as the difference between the temperature detected by the temperature sensor (220) at the time point (t0) when the transistor (FET11, FET12, FET21, FET22, FET31, FET32) is turned on and the temperature detected by the temperature sensor (220) after a predetermined time has elapsed from the time point t0. In one embodiment, the time point t0 may be the time point when the gate driver (231) outputs a control signal for turning on the transistor. In one embodiment, the time point (t0) when the gate driver (231) outputs a control signal for turning on the transistor may be the time point when the processor (232) applies a control signal to the gate driver (231) so that the gate driver (231) outputs a control signal for turning on the transistor.

In some embodiments, the predetermined time may be shorter than the time it takes for sufficient current to flow through the switch circuit (210) such that the temperature of the switch circuit (210) saturates to a certain temperature. Accordingly, a failure of the switch circuit (210) can be diagnosed within a shorter time than when the failure of the switch circuit (210) is diagnosed based on the temperature of the switch circuit (210).

Next, the processor (232) compares the measured temperature change amount with the temperature change amount when the switch circuit (210) is normal (S340), and if the measured temperature change amount is less than the temperature change amount when the switch circuit (210) is normal, the switch circuit (210) is diagnosed as faulty (S350). That is, if any one of the transistors (FET11, FET12, FET21, FET22, FET31, FET32) of the switch circuit (210) is open stuck faulty, current does not flow through the transistor pair including the corresponding transistor, so the temperature of the switch circuit (210) increases slowly. For example, as described above, if the switch circuit (210) includes three transistor pairs, when one transistor of the transistor pair (e.g., FET11 or FET12) has an open-stuck fault, current flows only through two transistor pairs (FET21, FET22, FET31, FET32), and therefore the temperature change can be measured as 2/3 of the temperature change in the normal case. When two transistors of the transistor pairs (e.g., FET11 or FET12, FET21 or FET22) have an open-stuck fault, current flows only through one transistor pair (FET31, FET32), and therefore the temperature change can be measured as 1/3 of the temperature change in the normal case.

In some embodiments, if the processor (232) determines that there is a transistor in the switch circuit (210) that is in an open stuck fault, it may notify the fault (S360).

Meanwhile, unlike one embodiment of the present invention, a temperature sensor is installed in each transistor pair of the switch circuit (210), and a failure of the transistor can be diagnosed based on the temperature of each transistor pair. After the temperature of each transistor reaches saturation, the processor can diagnose a failure of the switch circuit (210) by checking a transistor that has not reached a temperature in the normal case. In this case, there is an advantage in that a failure of the transistor can be individually diagnosed, but there is a problem in that the temperature of the transistor must be waited until the temperature of the transistor reaches saturation for the failure diagnosis.

However, according to one embodiment of the present invention, since a failure of a switching circuit can be diagnosed before the temperature of the transistor reaches saturation, follow-up measures can be taken quickly in response to the failure. In addition, by using only one temperature sensor, the unit cost of components for failure diagnosis can be reduced.

Although the present invention has been described above with respect to diagnosing an open stuck fault in a switch circuit, it is also possible to diagnose a close stuck fault in a switch circuit.

FIG. 4 is a diagram showing a switch diagnostic circuit according to another embodiment of the present invention.

Referring to FIG. 4, the switch diagnostic circuit includes a switch circuit (310), a temperature sensor (320), a processing circuit (330), and a voltage measurement circuit (340). In some embodiments, the processing circuit (330) may include a gate driver (331) and a processor (332).

The switch circuit (310), temperature sensor (320), and processing circuit (330) can operate similarly to the switch circuit (210), temperature sensor (220), and processing circuit (230) described with reference to FIGS. 2 and 3.

The voltage measurement circuit (340) measures the voltage of a voltage measurement point of the switch circuit (210). In some embodiments, the voltage measurement point may include a node (N1) through which the switch circuit (210) is connected to a positive output terminal (PV(+)) of the battery pack (110 of FIG. 1) and a node (N2) through which the switch circuit (210) is connected to a positive connection terminal (DC(+)) of the battery device (100 of FIG. 1). In one embodiment, the node (N1) may be connected to a drain of a transistor (FET11, FET21, FET31), and the node (N2) may be connected to a drain of a transistor (FET12, FET22, FET32).

In this case, the processor (332) can diagnose that a close-stuck failure has occurred in the switch circuit (310) when the voltages of the two nodes (N1, N2) measured by the voltage measurement circuit (340) are substantially the same.

In some embodiments, the voltage measurement points may further include, in addition to the two nodes (N1, N2), contacts (N3, N4, N5) of each transistor pair. In one embodiment, node (N3) may be connected to the sources of two transistors (FET11, FET12), node (N4) may be connected to the sources of two transistors (FET21, FET22), and node (N5) may be connected to the sources of two transistors (FET31, FET32).

In this case, the processor (332) can diagnose a failure of the switch circuit (310) based on the voltages of the nodes (N1, N2, N3, N4, N5). For example, the processor (332) can diagnose a close stuck failure of the transistor (FET11) when the voltage of the node (N1) and the voltage of the node (N3) are substantially the same, can diagnose a close stuck failure of the transistor (FET21) when the voltage of the node (N1) and the voltage of the node (N4) are substantially the same, and can diagnose a close stuck failure of the transistor (FET31) when the voltage of the node (N1) and the voltage of the node (N5) are substantially the same. Additionally, the processor (332) can diagnose a close stuck failure of the transistor (FET12) when the voltage of the node (N2) and the voltage of the node (N3) are substantially the same, can diagnose a close stuck failure of the transistor (FET22) when the voltage of the node (N2) and the voltage of the node (N4) are substantially the same, and can diagnose a close stuck failure of the transistor (FET32) when the voltage of the node (N2) and the voltage of the node (N5) are substantially the same.

In this way, according to another embodiment of the present invention, it is possible to diagnose not only an open stuck failure but also a closed stuck failure of the switch circuit (310).

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention.

Claims (15)

As a battery device,
battery pack,
A switch circuit comprising a plurality of switches connected in parallel between an output terminal of the battery pack and a connection terminal for connecting the battery device to an external device,
a temperature sensor shared by the above plurality of switches and measuring the temperature of the switch circuit; and
A processing circuit is included that controls the operation of the above switch circuit, measures the temperature change amount of the above switch circuit for a predetermined period of time after turning on the plurality of switches, and diagnoses the above switch circuit based on the measured temperature change amount.
A battery device, wherein the above predetermined time is measured from the turning on time of the plurality of switches. In paragraph 1,
A battery device, wherein the processing circuit diagnoses the switch circuit as faulty when the measured temperature change amount is less than the temperature change amount of the switch circuit for the predetermined period of time when the plurality of switches are operating normally. In paragraph 2,
A battery device, wherein the above processing circuit diagnoses that a switch among the plurality of switches has an open stuck failure. In paragraph 2,
A battery device wherein the processing circuit diagnoses the switch circuit as having a fault if the measured temperature change amount is less than the temperature change amount during normal operation by a predetermined ratio. delete In paragraph 1,
A battery device, each switch comprising a first transistor and a second transistor connected in series. In Article 6,
The above processing circuit,
A gate driver for transmitting a control signal to the gates of the first transistor and the second transistor of the plurality of switches through one channel, and
A processor that diagnoses the above switch circuit
A battery device comprising: As a switch diagnostic device for a battery device including a battery pack,
A switch circuit comprising a plurality of switches connected in parallel between an output terminal of the battery pack and a connection terminal for connecting the battery device to an external device, each switch including a first transistor and a second transistor connected in series;
A gate driver that turns on the first transistor and the second transistor of the plurality of switches simultaneously,
a temperature sensor shared by the above plurality of switches and measuring the temperature of the switch circuit; and
A processor is included that measures the temperature change amount of the switch circuit for a predetermined period of time after turning on the plurality of switches, and diagnoses the switch circuit based on the measured temperature change amount.
A switch diagnostic device, wherein the above-mentioned predetermined time is measured from the on-time of the plurality of switches. In Article 8,
A switch diagnostic device, wherein the processor diagnoses the switch circuit as faulty when the measured temperature change amount is less than the temperature change amount of the switch circuit for the predetermined time when the plurality of switches are operating normally. In Article 9,
A switch diagnostic device, wherein the processor diagnoses that a switch among the plurality of switches has an open stuck failure. A method for diagnosing a switch of a battery device comprising a battery pack and a switch circuit including a plurality of switches connected in parallel between an output terminal of the battery pack and a connection terminal connected to an external device, the method comprising:
Step of turning on the above multiple switches,
A step of measuring the temperature change amount of the switch circuit for a predetermined period of time using a temperature sensor shared by the plurality of switches, and
A step of diagnosing the switch circuit based on the measured temperature change amount is included.
A switch diagnostic method, wherein the above-mentioned predetermined time is measured from the on-time of the plurality of switches. In Article 11,
A switch diagnosis method, wherein the step of diagnosing the switch circuit includes the step of diagnosing the switch circuit as faulty when the measured temperature change amount is less than the temperature change amount of the switch circuit for the predetermined time when the plurality of switches are operating normally. In Article 12,
A switch diagnosis method, wherein the step of diagnosing the switch circuit as having a fault includes the step of diagnosing that a switch among the plurality of switches has an open stuck fault. delete In Article 11,
Each switch comprises a first transistor and a second transistor connected in series,
The step of turning on the plurality of switches includes the step of turning on the first transistor and the second transistor of the plurality of switches simultaneously.
How to diagnose a switch.