Discharge system, vehicle and discharge method for automobile high-voltage bus capacitor

Abstract

The present application relates to a discharge system for a high-voltage bus capacitor of an automobile, characterized in that it includes: a thin film capacitor, an IGBT circuit, a motor, a microprocessor, a thermistor, and a thermistor controller; the thin film capacitor is arranged on the high-voltage bus between the power battery and the IGBT circuit, the motor is electrically connected to the IGBT circuit, and the microprocessor is coupled to the motor; the microprocessor is used to control the on and off of the upper bridge arm or the lower bridge arm in the IGBT circuit so that the thin film capacitor and the upper bridge arm or the lower bridge arm and the motor form a current loop to thereby reduce the voltage of the thin film capacitor; the thermistor is electrically connected to the thermistor controller and is connected in parallel to the thin film capacitor, and the thermistor controller is used to control the thermistor to be connected to the circuit including the thin film capacitor so that the thermistor converts the electrical energy of the thin film capacitor into heat energy to reduce the voltage of the thin film capacitor in the form of heat consumption.

Description

Technical Field

[0001] The present application relates to the field of automobile technology, and in particular to a discharge system, vehicle, and discharge method for automobile high-voltage bus capacitors. Background Art

[0002] Existing new energy vehicles widely use the control of the opening and closing of the upper bridge arm / lower bridge arm in the IGBT circuit, causing the film capacitor at the DC bus end to form a conductive loop with the drive motor. The drive motor is used to actively and quickly reduce the voltage of the film capacitor at the DC bus end to below the safe voltage range of 60VDC or 36VAC.

[0003] The control logic cannot perform active discharge in the following situations: (1) When there is a serious fault in the microprocessor, the upper bridge arm or the lower bridge arm in the IGBT circuit cannot be turned on; (2) When there is a serious fault in the drive motor, the upper bridge arm or the lower bridge arm in the IGBT circuit cannot be turned on; (3) When the microprocessor loses communication with the VCU, it is impossible to know the instruction request from the VCU to the microprocessor; (4) When the microprocessor loses communication with the VCU, it is impossible to know the BMS status, especially the status of the main positive relay and the main negative relay of the power battery pack.

[0004] If the microprocessor cannot be actively discharged, it can only be discharged passively using a passive discharge resistor. The film capacitor voltage at the DC bus end takes a long time to drop below the safe voltage of 60VDC or 36VAC, which increases the risk of electric shock to personnel and poses a safety hazard.

[0005] In view of the above problems, those skilled in the art have been seeking solutions. Summary of the Invention

[0006] The technical problem to be solved by the present application is to provide a discharge system, vehicle and discharge method for automobile high-voltage bus capacitors in response to the above-mentioned defects of the prior art.

[0007] In order to achieve the above objectives, this application is implemented through the following technical solutions:

[0008] A discharge system for a high-voltage bus capacitor in an automobile comprises: a thin-film capacitor, an IGBT circuit, a motor, a microprocessor, a thermistor, and a thermistor controller; the IGBT circuit is a three-phase bridge inverter circuit comprising: three parallel bridge arms, each bridge arm connected in series with two IGBTs, wherein the center points of the three bridge arms serve as three AC terminals, respectively connected to the three-phase AC ports of the motor; the thin-film capacitor is disposed on the high-voltage bus between the power battery and the IGBT circuit; the motor is electrically connected to the IGBT circuit; and the microprocessor is coupled to the motor; the microprocessor is configured to control the switching of an upper bridge arm or a lower bridge arm in the IGBT circuit so that the thin-film capacitor, the upper bridge arm or the lower bridge arm, and the motor form a current-carrying loop, thereby reducing the voltage of the thin-film capacitor; the thermistor is electrically connected to the thermistor controller and connected in parallel with the thin-film capacitor, the thermistor controller being configured to control the thermistor's connection to the circuit including the thin-film capacitor so that the thermistor converts the electrical energy of the thin-film capacitor into heat energy, thereby reducing the voltage of the thin-film capacitor in the form of heat consumption.

[0009] Optionally, the discharge system also includes a power battery management system (BMS); the BMS is communicatively connected to the microprocessor, and the thermistor controller is also used to connect the thermistor to a circuit including the thin film capacitor when the microprocessor does not receive the battery voltage information output by the battery management system so that the thermistor converts the electrical energy of the thin film capacitor into thermal energy to reduce the voltage of the thin film capacitor in the form of heat consumption.

[0010] Optionally, the discharge system also includes a vehicle controller; the vehicle controller is communicatively connected to the microprocessor, and the thermistor controller is also used to control the thermistor to connect to the circuit including the thin film capacitor when the vehicle controller and the microprocessor cannot communicate normally so that the thermistor converts the electrical energy of the thin film capacitor into thermal energy to reduce the voltage of the thin film capacitor in the form of heat consumption.

[0011] Optionally, the discharge system also includes a discharge resistor; the discharge resistor is connected in parallel to the thin film capacitor, and the microprocessor is also used to control the discharge resistor to be connected to the circuit including the thin film capacitor to reduce the voltage of the thin film capacitor after receiving the power-off command issued by the vehicle controller.

[0012] Optionally, the discharge system further includes a power supply circuit; the power supply circuit is electrically connected to the power battery and is used to convert the power battery into low voltage electricity to drive the IGBT circuit.

[0013] The present application also provides a vehicle comprising the above-mentioned discharge system.

[0014] The present application also provides a discharge method for a vehicle high-voltage system, comprising:

[0015] In the above-mentioned discharge system, confirming whether the microprocessor receives a power-off instruction issued by the vehicle controller;

[0016] If the microprocessor receives a power-off instruction from the vehicle controller, it confirms whether the thermistor is working properly and whether the IGBT circuit is working properly;

[0017] If the thermistor and the IGBT circuit operate normally, the microprocessor controls the switching of the upper bridge arm or the lower bridge arm in the IGBT circuit so that the film capacitor, the upper bridge arm or the lower bridge arm, and the motor form a current loop, and the thermistor controller controls the thermistor to be connected to the circuit including the film capacitor, so as to jointly reduce the voltage of the film capacitor to a preset voltage range;

[0018] If the thermistor operates normally and the IGBT circuit fails to operate normally, the thermistor controller controls the thermistor to be connected to the circuit including the thin film capacitor so that the thermistor converts the electrical energy of the thin film capacitor into heat energy and reduces the voltage of the thin film capacitor to a preset voltage range in the form of heat consumption;

[0019] If the thermistor fails to work properly and the IGBT circuit works properly, the microprocessor controls the on and off of the upper bridge arm or the lower bridge arm in the IGBT circuit so that the thin film capacitor forms a current loop with the upper bridge arm or the lower bridge arm and the motor, thereby reducing the voltage of the thin film capacitor to a preset voltage range.

[0020] Optionally, after confirming whether the microprocessor has received the power-off instruction issued by the vehicle controller, the method further includes:

[0021] The microprocessor does not receive the power-off instruction issued by the vehicle controller, confirming whether the thermistor is operating normally and confirming whether the IGBT circuit is operating normally;

[0022] If the thermistor operates normally and the IGBT circuit operates normally, the thermistor controller connects the thermistor to a circuit including the thin film capacitor so that the thermistor converts the electrical energy of the thin film capacitor into thermal energy and reduces the voltage of the thin film capacitor to a preset voltage range in the form of heat consumption.

[0023] Optionally, after confirming whether the thermistor is operating normally and confirming whether the IGBT circuit is operating normally, the method further includes:

[0024] If the thermistor operates normally and the IGBT circuit does not operate normally, the thermistor controller connects the thermistor to a circuit including the thin film capacitor so that the thermistor converts the electrical energy of the thin film capacitor into thermal energy and reduces the voltage of the thin film capacitor to a preset voltage range in the form of heat consumption.

[0025] Optionally, after confirming whether the microprocessor has received the power-off instruction issued by the vehicle controller, the method further includes:

[0026] When the microprocessor does not receive the battery voltage information output by the battery management system, the thermistor controller controls the thermistor to be connected to the circuit including the thin film capacitor so that the thermistor converts the electrical energy of the thin film capacitor into thermal energy and reduces the voltage of the thin film capacitor to a preset voltage range in the form of heat consumption.

[0027] The present application provides a discharge system, vehicle, and discharge method for a high-voltage bus capacitor in an automobile. When at least one of a motor, a microprocessor, and a thermistor is capable of controlled discharge, the motor and / or thermistor can be used to actively and quickly reduce the voltage of the thin-film capacitor to below a safe voltage range, thereby reducing the voltage reduction time, making personnel protection safer, and avoiding electric shock.

[0028] In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present application will be described in detail below with reference to the accompanying drawings and specific implementation methods;

[0030] Figure 1 This is a schematic diagram of the structure of a discharge system provided in one embodiment of the present application;

[0031] Figure 2 This is a flow chart of a discharge method provided in one embodiment of the present application;

[0032] Figure 3 It is a flow chart of another discharge method provided in one embodiment of the present application. DETAILED DESCRIPTION

[0033] It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0034] Figure 1 This is a schematic diagram of the structure of the discharge system provided in one embodiment of the present application. Figure 1The present application provides a discharge system for a high-voltage bus capacitor of an electric vehicle, comprising: a thin film capacitor C, an IGBT circuit, a motor, a microprocessor (not shown in the figure), a thermistor PTC, and a thermistor controller (not shown in the figure).

[0035] The IGBT circuit is a three-phase bridge inverter circuit, including three bridge arms connected in parallel, with two IGBT single tubes connected in series on each bridge arm. The center points of the three bridge arms serve as three AC ends and are respectively connected to the three-phase AC ports of the motor.

[0036] The film capacitor C is arranged on the high-voltage bus between the power battery and the IGBT circuit. The motor is electrically connected to the IGBT circuit. The microprocessor is coupled to the motor. The thermistor PTC is electrically connected to the thermistor controller and is connected in parallel to the film capacitor C.

[0037] The microprocessor is used to control the on / off of the upper bridge arm or the lower bridge arm in the IGBT circuit so that the film capacitor C forms a current loop with the upper bridge arm or the lower bridge arm and the motor, thereby reducing the voltage of the film capacitor C.

[0038] The thermistor controller is used to control the thermistor PTC to be connected to a circuit including the film capacitor C so that the thermistor PTC converts the electrical energy of the film capacitor C into thermal energy to reduce the voltage of the film capacitor C in the form of heat consumption.

[0039] In this embodiment, the microprocessor is an MCU (Microcontroller Unit).

[0040] like Figure 1 As shown, the IGBT circuit includes three parallel bridge arms: the first arm, the second arm, and the third arm. The first arm is connected in series with the first IGBT single tube VT1 and the fourth IGBT single tube VT4. The second arm is connected in series with the third IGBT single tube VT3 and the sixth IGBT single tube VT6. The third arm is connected in series with the fifth IGBT single tube VT5 and the second IGBT single tube VT2. The center points of the first, second, and third arms serve as the U, V, and W terminals, respectively, connected to the three-phase AC power ports of the motor. The first, third, and fifth IGBT single tubes VT1, VT3, and VT5 form the upper arm of the IGBT circuit, while the fourth, sixth, and second IGBT single tubes VT4 and VT6 form the lower arm of the IGBT circuit.

[0041] This embodiment includes two discharge paths. Among them, the microprocessor controls the on and off of the upper bridge arm or the lower bridge arm in the IGBT circuit so that the film capacitor C forms a current loop with the upper bridge arm or the lower bridge arm and the motor, thereby reducing the voltage of the film capacitor C. This is path A; the thermistor controller controls the thermistor PTC to be connected to the circuit including the film capacitor C so that the thermistor PTC converts the electrical energy of the film capacitor C into thermal energy and reduces the voltage of the film capacitor C in the form of heat consumption. This is path B.

[0042] Specifically, in path A, since the motor is connected to the high-voltage bus and is connected to the film capacitor C, by controlling the IGBT circuit to alternately perform equal-cycle upper arm short-circuiting and lower arm short-circuiting, a discharge loop is formed with the motor windings (U, V, W), and the electrical energy of the film capacitor C on the high-voltage bus is released in the form of heat loss; in path B, the thermistor is the air-conditioning heat source of new energy vehicles and is an energy-consuming device. The electrical energy of the film capacitor C is converted into heat energy for heat consumption through PTC heating of the on-board air conditioner, which can reduce the voltage of the film capacitor C.

[0043] Optionally, the discharge system also includes a power battery management system (BMS) (not shown in the figure); the BMS is communicatively connected to the microprocessor, and the thermistor controller is also used to connect the thermistor PTC to a circuit including a thin film capacitor C when the microprocessor does not receive the battery voltage information output by the battery management system so that the thermistor PTC converts the electrical energy of the thin film capacitor C into thermal energy and reduces the voltage of the thin film capacitor C in the form of heat consumption.

[0044] Optionally, the discharge system further includes a vehicle controller (not shown). The vehicle controller is in communication with the microprocessor, and the thermistor controller is further configured to control the thermistor PTC to be connected to a circuit including the film capacitor C when the vehicle controller and the microprocessor cannot communicate normally, so that the thermistor PTC converts the electrical energy of the film capacitor C into heat energy to reduce the voltage of the film capacitor C in the form of heat consumption.

[0045] Optionally, the discharge system also includes a discharge resistor R; the discharge resistor R is connected in parallel to the film capacitor C, and the microprocessor is also used to control the discharge resistor R to be connected to the circuit including the film capacitor C to reduce the voltage of the film capacitor C after receiving the power-off command issued by the vehicle controller.

[0046] In one embodiment, the discharge system further includes an inverter DCDC and a charger OBC. The high-voltage input end of the inverter DCDC is connected to the film capacitor C, and the low-voltage output end thereof is connected to the charger OBC. By transmitting the voltage of the film capacitor C to the charger OBC, the voltage of the film capacitor C can also be reduced.

[0047] In one embodiment, the discharge system further includes a compressor EAC, which is connected in parallel with the film capacitor C. The compressor EAC utilizes the electrical energy of the film capacitor C to adiabatically compress the refrigerant, which then undergoes other refrigeration cycle processes to achieve in-vehicle air conditioning cooling, and can also achieve voltage reduction of the film capacitor C.

[0048] Optionally, the discharge system further includes a power circuit; the power circuit is electrically connected to the power battery and is used to convert the power battery into low voltage electricity to drive the IGBT circuit.

[0049] The present application also provides a vehicle comprising the above-mentioned discharge system.

[0050] Figure 2 is a flow chart of a discharge method provided in one embodiment of the present application. Figure 3 This is a flow chart of another discharge method provided by an embodiment of the present application. Please also refer to Figure 2 and Figure 3 , the present application also provides a discharge method for a vehicle high-voltage system, comprising:

[0051] In the above-mentioned discharge system, confirm whether the microprocessor receives the power-off command issued by the vehicle controller;

[0052] If the microprocessor receives a power-off command from the vehicle controller, it checks whether the thermistor is working properly and whether the IGBT circuit is working properly;

[0053] If the thermistor is operating normally and the IGBT circuit is operating normally, the microprocessor controls the on / off switching of the upper bridge arm or the lower bridge arm in the IGBT circuit so that the film capacitor, the upper bridge arm or the lower bridge arm, and the motor form a current flow loop, and the thermistor controller controls the thermistor to be connected to the circuit including the film capacitor, and together reduce the voltage of the film capacitor to a preset voltage range;

[0054] If the thermistor operates normally but the IGBT circuit fails to operate normally, the thermistor controller controls the thermistor to be connected to a circuit including a film capacitor so that the thermistor converts the electrical energy of the film capacitor into heat energy and reduces the voltage of the film capacitor to a preset voltage range in the form of heat consumption;

[0055] If the thermistor fails to work properly and the IGBT circuit works properly, the microprocessor controls the on and off of the upper bridge arm or lower bridge arm in the IGBT circuit so that the film capacitor forms a current loop with the upper bridge arm or lower bridge arm and the motor, thereby reducing the voltage of the film capacitor to a preset voltage range.

[0056] In one embodiment, the preset voltage range is set to a safety voltage of 60VDC or below 36VAC.

[0057] In one embodiment, if the microprocessor and vehicle controller are communicating normally, the thermistor is operating normally, and the IGBT circuit is operating normally, path A and path B can be used to jointly reduce the voltage of the thin-film capacitor to a preset voltage range. If the thermistor is not operating normally (for example, the thermistor is damaged), path A can be used to reduce the voltage of the thin-film capacitor. If the thermistor is operating normally, but at least one of the following two conditions exists: the microprocessor and vehicle controller are not communicating normally, or the IGBT circuit is not operating normally, path B can be used to reduce the voltage of the thin-film capacitor. Furthermore, if the thermistor, the microprocessor, the vehicle controller, and the IGBT circuit are not operating normally, the microprocessor can be used to control the discharge resistor connected to the circuit including the thin-film capacitor to divide the voltage of the thin-film capacitor, thereby reducing the voltage of the thin-film capacitor.

[0058] Specifically, the reasons for the microprocessor and the vehicle controller not being able to communicate normally and the IGBT circuit not being able to work normally include but are not limited to the following: (1) The microprocessor has a serious fault and cannot communicate with the vehicle controller and cannot control the opening and closing of the IGBT circuit; (2) The motor has a serious fault and cannot form a complete current loop with the IGBT circuit, so that the IGBT circuit becomes an open circuit; (3) The microprocessor has other normal functions but has lost communication interaction with the vehicle controller and cannot obtain the vehicle controller's instruction request to the microprocessor.

[0059] Optionally, after confirming whether the microprocessor has received the power-off instruction issued by the vehicle controller, the method further includes:

[0060] The microprocessor does not receive the power-off command issued by the vehicle controller, and confirms whether the thermistor is working properly and whether the IGBT circuit is working properly;

[0061] If the thermistor and the IGBT circuit operate normally, the thermistor controller connects the thermistor to a circuit including a film capacitor so that the thermistor converts the electrical energy of the film capacitor into heat energy and reduces the voltage of the film capacitor to a preset voltage range in the form of heat consumption.

[0062] Optionally, after confirming whether the thermistor is operating normally and confirming whether the IGBT circuit is operating normally, the method further includes:

[0063] If the thermistor operates normally and the IGBT circuit does not operate normally, the thermistor controller connects the thermistor to a circuit including a film capacitor so that the thermistor converts the electrical energy of the film capacitor into heat energy and reduces the voltage of the film capacitor to a preset voltage range in the form of heat consumption.

[0064] Optionally, after confirming whether the microprocessor has received the power-off instruction issued by the vehicle controller, the method further includes:

[0065] When the microprocessor doesn't receive battery voltage information from the battery management system, the thermistor controller connects the thermistor to the circuit including the thin-film capacitor, causing the thermistor to convert the capacitor's electrical energy into heat, dissipating the heat and reducing the capacitor's voltage to a preset voltage range. Specifically, the microprocessor communicates with the vehicle controller and the BMS. If this communication is lost, the microprocessor loses access to BMS status information, particularly the operating status of the main positive and negative relays in the power battery.

[0066] The discharge system, vehicle and discharge method of the present application, when the motor, microprocessor and thermistor PTC can all participate in the discharge, the motor and thermistor PTC are used (that is, path A and path B work together) to actively and quickly reduce the voltage of the thin film capacitor to a safe voltage of 60VDC or below 36VAC, which shortens the usage time and makes personnel protection safer; when the motor or microprocessor cannot open the upper arm or lower arm of the IGBT circuit, the thermistor PTC can be used to actively and quickly reduce the voltage of the thin film capacitor to a safe voltage of 60VDC or below 36VAC, ensuring that the discharge time meets the design requirements and avoiding electric shock to personnel; when the microprocessor loses communication with the vehicle controller / BMS, the thermistor PTC can be used to actively and quickly reduce the voltage of the thin film capacitor to a safe voltage of 60VDC or below 36VAC, ensuring that the discharge time meets the design requirements and avoiding electric shock to personnel.

[0067] The technical solution of the present application does not require adjustment or modification of the hardware structure, and only requires adaptive optimization of software interaction. It does not increase costs, is safe and reliable, and is easy to implement.

[0068] Obviously, those skilled in the art can make various changes and modifications to the invention without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application also intends to include these modifications and variations. The various technical features of the above-mentioned embodiments can be combined in any way. To keep the description concise, not all possible combinations of the various technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0069] It should be noted that, in this document, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element. In addition, components, features, and elements with the same name in different embodiments of the present application may have the same meaning or different meanings, and their specific meanings need to be determined by their explanation in the specific embodiment or further combined with the context of the specific embodiment.

[0070] It should be understood that although the terms first, second, third, etc. may be used herein to describe various elements, these elements should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this article, the first element may also be referred to as the second element, and similarly, the second element may also be referred to as the first element. Depending on the context, as used herein, the singular forms "one," "an," and "the" are intended to also include the plural forms, unless otherwise indicated in the context. It should be further understood that the terms "comprise," "include," and "include" indicate the presence of the described features, steps, operations, elements, components, items, types, and / or groups, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, components, items, types, and / or groups. The terms "or" and "and / or" used herein are interpreted as inclusive, or mean any one or any combination. Therefore, "A, B, or C" or "A, B, and / or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B, and C." An exception to this definition occurs only when a combination of elements, functions, steps, or operations are inherently mutually exclusive in some manner.

[0071] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements or improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A discharge system for automobile high-voltage bus capacitors, characterized in that: include: Thin film capacitors, IGBT circuits, motors, microprocessors, thermistors, and thermistor controllers; The IGBT circuit is a three-phase bridge inverter circuit, comprising: three bridge arms connected in parallel, each bridge arm having two IGBT single tubes connected in series, wherein the center points of the three bridge arms serve as three AC terminals respectively connected to the three-phase AC ports of the motor; The film capacitor is arranged on the high-voltage bus between the power battery and the IGBT circuit, the motor is electrically connected to the IGBT circuit, and the microprocessor is coupled to the motor; The microprocessor is used to control the on / off of the upper bridge arm or the lower bridge arm in the IGBT circuit so that the film capacitor, the upper bridge arm or the lower bridge arm and the motor form a current loop, thereby reducing the voltage of the film capacitor; The thermistor is electrically connected to the thermistor controller and is connected in parallel to the thin film capacitor. The thermistor controller is used to control the thermistor to be connected to the circuit including the thin film capacitor so that the thermistor converts the electrical energy of the thin film capacitor into thermal energy to reduce the voltage of the thin film capacitor in the form of heat consumption; The discharge system further includes a power battery management system (BMS); the BMS is in communication with the microprocessor, and the thermistor controller is further configured to connect the thermistor to a circuit including the thin film capacitor when the microprocessor does not receive battery voltage information output by the battery management system, so that the thermistor converts electrical energy of the thin film capacitor into heat energy to reduce the voltage of the thin film capacitor in the form of heat consumption; The discharge system further includes a vehicle controller; the vehicle controller is in communication with the microprocessor, and the thermistor controller is further configured to control the thermistor to connect to a circuit including the thin film capacitor when the vehicle controller and the microprocessor cannot communicate normally, so that the thermistor converts the electrical energy of the thin film capacitor into heat energy to reduce the voltage of the thin film capacitor in the form of heat consumption; The discharge system also includes a discharge resistor; the discharge resistor is connected in parallel to the thin film capacitor, and the microprocessor is also used to control the discharge resistor to be connected to the circuit including the thin film capacitor to reduce the voltage of the thin film capacitor after receiving the power-off command issued by the vehicle controller.

2. The discharge system according to claim 1, wherein: The discharge system further includes a power supply circuit; the power supply circuit is electrically connected to the power battery and is used to convert the power battery into low voltage electricity to drive the IGBT circuit.

3. A vehicle, characterized in that: The device comprises a discharge system according to any one of claims 1 to 2.

4. A discharge method for a vehicle high voltage system, characterized in that: include: In the discharge system according to any one of claims 1 to 2, confirming whether the microprocessor receives a power-off instruction issued by the vehicle controller; If the microprocessor receives a power-off instruction from the vehicle controller, it confirms whether the thermistor is working properly and whether the IGBT circuit is working properly; If the thermistor and the IGBT circuit operate normally, the microprocessor controls the switching of the upper bridge arm or the lower bridge arm in the IGBT circuit so that the film capacitor, the upper bridge arm or the lower bridge arm, and the motor form a current loop, and the thermistor controller controls the thermistor to be connected to the circuit including the film capacitor, so as to jointly reduce the voltage of the film capacitor to a preset voltage range; If the thermistor operates normally and the IGBT circuit fails to operate normally, the thermistor controller controls the thermistor to be connected to the circuit including the thin film capacitor so that the thermistor converts the electrical energy of the thin film capacitor into heat energy and reduces the voltage of the thin film capacitor to a preset voltage range in the form of heat consumption; If the thermistor fails to work properly and the IGBT circuit works properly, the microprocessor controls the on and off of the upper bridge arm or the lower bridge arm in the IGBT circuit so that the thin film capacitor forms a current loop with the upper bridge arm or the lower bridge arm and the motor, thereby reducing the voltage of the thin film capacitor to a preset voltage range.

5. The discharge method according to claim 4, wherein: After confirming whether the microprocessor has received the power-off instruction issued by the vehicle controller, the method further includes: The microprocessor does not receive the power-off instruction issued by the vehicle controller, confirming whether the thermistor is operating normally and confirming whether the IGBT circuit is operating normally; If the thermistor operates normally and the IGBT circuit operates normally, the thermistor controller connects the thermistor to a circuit including the thin film capacitor so that the thermistor converts the electrical energy of the thin film capacitor into thermal energy and reduces the voltage of the thin film capacitor to a preset voltage range in the form of heat consumption.

6. The discharge method according to claim 5, wherein: After confirming whether the thermistor is operating normally and confirming whether the IGBT circuit is operating normally, the method further includes: if the thermistor is operating normally and the IGBT circuit is not operating normally, the thermistor controller connects the thermistor to a circuit including the thin film capacitor so that the thermistor converts the electrical energy of the thin film capacitor into heat energy and reduces the voltage of the thin film capacitor to a preset voltage range in the form of heat consumption.

7. The discharge method according to claim 6, wherein: After confirming whether the microprocessor has received the power-off instruction issued by the vehicle controller, the method further includes: When the microprocessor does not receive the battery voltage information output by the battery management system, the thermistor controller controls the thermistor to be connected to the circuit including the thin film capacitor so that the thermistor converts the electrical energy of the thin film capacitor into thermal energy and reduces the voltage of the thin film capacitor to a preset voltage range in the form of heat consumption.

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