Active discharge system and method for a motor controller

Abstract

The application provides an active discharge system and method of a motor controller, the active discharge system comprising: a low-voltage battery source; an isolation power supply electrically connected with the low-voltage battery source; a signal isolation module electrically connected with the isolation power supply and externally connected with a microcontroller; a delay discharge module electrically connected with the isolation power supply and the signal isolation module; a discharge driving module electrically connected with the delay discharge module; an abnormality protection module electrically connected with the emergency power supply, the isolation power supply and the discharge driving module; a high-voltage capacitor storing excess electric quantity and electrically connected with the emergency power supply and the abnormality protection module; and a discharge execution module electrically connected with the discharge driving module and the high-voltage capacitor. The above technical scheme can meet the requirement of active discharge under low-voltage abnormality and ensure that the active discharge resistor will not be damaged due to overheating caused by the non-disconnection of the high-voltage battery.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of motor controller, in particular to a motor controller active discharge system and method. BACKGROUND

[0002] The existing motor controller active discharge many uses discharge resistance to realize, for saving cost, the discharge resistance selected generally power is not big, can only bear normal discharge power, when the whole vehicle main relay sticking and other abnormal discharge condition occurs, the discharge resistance burnout problem is very easy to occur, the current traditional protection method is realized by using the series fuse in the active discharge circuit or increasing the over-temperature protection circuit of the active discharge resistance temperature monitoring, however, the control method of this way is single, the response speed of protection action is slow, the effect is low, and it cannot adapt to various different application occasions.

[0003] In order to solve the above problems, the prior art has proposed many ways to judge the bus voltage of the motor controller by software logic to execute the action of protecting the active discharge resistance quickly, but in these solutions, the discharge logic cannot meet the demand of low-voltage abnormal discharge, that is, when the low-voltage battery loses power, the high-voltage capacitor still has excess power, which cannot be protected.

[0004] Therefore, a new motor controller active discharge system and method are needed to realize the safe operation of the active discharge resistance of the motor controller through a hardware fast protection circuit. SUMMARY

[0005] In order to overcome the above technical defects, the purpose of the present application is to provide a motor controller active discharge system and method, which can execute active discharge under low-voltage abnormal conditions while ensuring that the active discharge resistance will not be overheated and damaged due to the high-voltage battery not being disconnected.

[0006] The present application discloses a motor controller active discharge system, which comprises:

[0007] A low-voltage battery source;

[0008] An isolation power supply electrically connected to the low-voltage battery source;

[0009] A signal isolation module electrically connected to the isolation power supply and externally connected to a microcontroller;

[0010] A delay discharge module electrically connected to the isolation power supply and the signal isolation module;

[0011] A discharge driving module electrically connected to the delay discharge module;

[0012] An abnormal protection module electrically connected to the emergency power supply, the isolation power supply and the discharge driving module;

[0013] A high-voltage capacitor, which stores excess electricity and is electrically connected with the emergency power supply and the abnormal protection module;

[0014] A discharge execution module, which is electrically connected with the discharge driving module and the high-voltage capacitor;

[0015] When the primary-side power supply of the microcontroller and the signal isolation module is abnormally lost, the microcontroller generates a discharge signal to the signal isolation module, or the signal isolation module sends a low-voltage signal to the signal isolation module, the signal isolation module sends a discharge request signal to the delay discharge module, the delay discharge module generates a discharge delay signal to the discharge driving module based on the discharge request signal, and the discharge driving module generates a driving signal to the discharge execution module based on the discharge delay signal, so that the discharge execution module discharges the excess electricity of the high-voltage capacitor, and the output voltage of the high-voltage capacitor is lower than a voltage threshold.

[0016] Preferably, the emergency power supply and the low-voltage battery source jointly supply power to the isolation power supply, and the second input voltage provided by the low-voltage battery source to the isolation power supply is less than the first input voltage provided by the low-voltage battery source to the isolation power supply when there is no power loss;

[0017] The isolation power supply supplies power to the abnormal protection module, the signal isolation module, the delay discharge module, and the discharge driving module, respectively.

[0018] Preferably, the abnormal protection module monitors the output voltage value of the high-voltage capacitor, and the abnormal protection module is pre-set with a voltage drop slope circuit, which records a voltage threshold, a slope threshold, and a discharge duration threshold;

[0019] From the time when the isolation power supply sends a low-voltage signal to the abnormal protection module due to the power loss of the low-voltage battery source, to the time when the output voltage value monitored by the abnormal protection module is higher than the voltage threshold after the discharge duration threshold, the abnormal protection module generates an interrupt signal to the discharge driving module to reset the driving signal and close the discharge execution module.

[0020] Preferably, when the abnormal protection module monitors that the output voltage drop slope of the high-voltage capacitor is higher than the slope threshold, so that the output voltage value is lower than the voltage threshold, the discharge execution module continuously controls the high-voltage capacitor to discharge the excess electricity until the output voltage value is lower than 55V.

[0021] Preferably, the active discharge system further comprises:

[0022] A voltage sampling module, which is electrically connected with the microcontroller and the abnormal protection module, respectively;

[0023] When the abnormal protection module monitors that the output voltage drop slope of the high-voltage capacitor is higher than the slope threshold, the microcontroller acquires the bus voltage value of the motor controller from the voltage sampling module within a preset time duration;

[0024] When the bus voltage value is less than an expected value, the discharge execution module continuously controls the high-voltage capacitor to discharge the excess electric quantity;

[0025] When the bus voltage value is greater than an expected value, the abnormal protection module generates an interrupt signal to the discharge driving module within a discharge duration threshold to reset the driving signal to close the discharge execution module, and the microcontroller reissues the discharge signal after an interval time and repeats n times.

[0026] The application further discloses an active discharge method of a motor controller, comprising the following steps:

[0027] The application further discloses an active discharge method of a motor controller, comprising the following steps:

[0028] When the primary power supply of the microcontroller and the signal isolation module is abnormally lost, the microcontroller generates a discharge signal to the signal isolation module, or the isolation power supply sends a low-voltage signal to the signal isolation module, the signal isolation module sends a discharge request signal to the delay discharge module, the delay discharge module generates a discharge delay signal to the discharge driving module based on the discharge request signal, and the discharge driving module generates a driving signal to the discharge execution module based on the discharge delay signal, so that the discharge execution module discharges the excess electric quantity of the high-voltage capacitor, and the output voltage of the high-voltage capacitor is lower than a voltage threshold.

[0029] Preferably, the emergency power supply and the low-voltage battery supply jointly supply power to the isolation power supply, and the second input voltage provided by the low-voltage battery supply to the isolation power supply is less than the first input voltage provided by the low-voltage battery supply to the isolation power supply when there is no power loss.

[0030] The isolation power supply supplies power to the abnormal protection module, the signal isolation module, the delay discharge module and the discharge driving module respectively.

[0031] Preferably, the abnormal protection module monitors the output voltage value of the high-voltage capacitor, and the abnormal protection module is pre-set with a voltage drop slope circuit, which records a voltage threshold, a slope threshold and a discharge duration threshold.

[0032] From the time when the low-voltage battery supply loses power and the isolation power supply sends a low-voltage signal to the abnormal protection module to the discharge duration threshold, when the abnormal protection module monitors that the output voltage value is higher than the voltage threshold, an interrupt signal is generated to the discharge driving module to reset the driving signal to close the discharge execution module.

[0033] Preferably, when the abnormal protection module monitors that the output voltage of the high-voltage capacitor drops at a slope higher than a slope threshold value, so that the output voltage value is lower than a voltage threshold value, the discharge execution module continues to control the high-voltage capacitor to discharge the excess electric quantity until the output voltage value is lower than 55V.

[0034] After the above technical solutions are adopted, compared with the prior art, the following beneficial effects are achieved:

[0035] 1. By simultaneously supplying power to the modules constituting the active discharge control circuit by the low-voltage battery source and the emergency power supply, it is ensured that the active discharge circuit can still operate normally to discharge the high-voltage capacitor voltage to below a safety value within a specified time under a low-voltage abnormal power-off condition.

[0036] 2. The hardware fast protection discharge resistor is adopted, and the number or volume of the active discharge resistor is optimized to reduce the cost.

[0037] 3. Since the hardware detection abnormal protection time is short, multiple discharge attempts can be achieved without increasing the discharge resistor, and the system robustness is improved. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 Fig. 1 is a structural schematic diagram of an active discharge system of a motor controller according to an embodiment of the present application. DETAILED DESCRIPTION

[0039] The advantages of the present application will be further described below in combination with the accompanying drawings and specific embodiments.

[0040] Exemplary embodiments will be described in detail herein below with reference to the drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments are not meant to represent all implementations consistent with the present disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0041] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used in this disclosure and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0042] It should be understood that, although the terms first, second, third, etc. can be employed in this disclosure to describe various information, these information should not be limited to these terms. These terms are only used to differentiate one piece of information from another piece of information. For example, without departing from the scope of the disclosure, the first information can also be referred to as the second information, and similarly, the second information can also be referred to as the first information. Depending on the context, the word "if" as used herein can be interpreted as "when" or "upon" or "in response to determining".

[0043] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0044] In the description of the present application, unless otherwise specified and limited, it should be noted that the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be mechanical connection or electrical connection, it can be the communication between two elements, it can be direct connection or indirect connection through intermediate medium, and the specific meaning of the above terms can be understood by those skilled in the art according to the specific circumstances.

[0045] In the subsequent description, the suffix such as "module", "component" or "unit" used to represent elements is only for the convenience of the description of the present application, and has no specific meaning in itself. Therefore, "module" and "component" can be used interchangeably.

[0046] Referring to Figure 1 , in order to meet the structure of the active discharge system of the motor controller in a preferred embodiment of the present application, the active discharge system comprises:

[0047] - low voltage battery source

[0048] The low voltage battery source is used as the main power source of the motor controller, and the voltage value is generally 9-12V, such as the battery of an electric vehicle with a motor controller, to provide the required electric energy to the power load connected with the low voltage battery source.

[0049] - isolation power supply

[0050] The isolation power supply generally refers to the process of reducing high voltage to low voltage through a transformer and rectifying it into direct current. The conversion process is not dangerous because it is not connected to the ground. The isolation power supply is electrically connected with the low voltage battery source to obtain electric energy from the low voltage battery source.

[0051] - signal isolation module

[0052] The signal isolation module is electrically connected with the isolation power supply and externally connected with a microcontroller (MCU) for receiving control signals from the microcontroller and isolating external signals from other module signals in the active discharge circuit. The signal isolation module obtains electric energy from the P5V_HV output terminal of the isolation power supply.

[0053] - delay discharge module

[0054] The delay discharge module is electrically connected with the isolation power supply and the signal isolation module, obtains electric energy from the isolation power supply (for example, through the P15V_HV output terminal of the isolation power supply), receives a control signal in the form of Adis_req_HV from the signal isolation module, and delays sending a further control signal according to the internal circuit design.

[0055] - discharge drive module

[0056] The discharge drive module is electrically connected with the isolation power supply (for example, through the P15V_HV output terminal of the isolation power supply) and the delay discharge module, and forms a drive signal according to the control signal after the delay discharge module delays sending a further control signal.

[0057] - abnormality protection module

[0058] The abnormality protection module is used for actively discharging devices in the active discharge system of the motor controller when a fault occurs (for example, the above-mentioned relay sticking, or the user expects active discharge), is connected with the isolation power supply, obtains electric energy from the isolation power supply (for example, through the P10V_HV output terminal of the isolation power supply), and is electrically connected with the discharge drive module to send a control signal for adjusting the drive signal to the discharge drive module.

[0059] - high-voltage capacitor

[0060] The high-voltage capacitor is a capacitor isolated from the discharge execution module, stores excess electric energy, and is electrically connected with the emergency power supply and the abnormality protection module. Part of the electric energy of the high-voltage capacitor will be delivered to the emergency power supply to increase the endurance of the emergency power supply.

[0061] - discharge execution module

[0062] The discharge execution module is electrically connected with the discharge drive module and the high-voltage capacitor to control whether the high-voltage capacitor is discharged according to the drive signal of the discharge drive module.

[0063] Specifically, when the signal isolation module receives a discharge signal from the microcontroller (for example, an active discharge request formed in the MCU according to the user's requirements) or the isolation power supply sends a low-voltage signal to the signal isolation module (due to the abnormal loss of the primary power supply of the microcontroller and the signal isolation module), the signal isolation module sends a discharge request signal to the delay discharge module, so that the Adis_req_HV signal turns to the active state, the delay discharge module generates a discharge delay signal (Adis_req_delay signal) based on the discharge request signal, and sends the discharge delay signal to the discharge drive module after a certain period of time. The discharge drive module generates a drive signal (Adis_con signal) to the discharge execution module based on the discharge delay signal, so that the discharge execution module is turned on. If the high-voltage capacitor has been disconnected from the high-voltage battery at this time, the discharge execution module can be used to discharge the excess power of the high-voltage capacitor until the desired value, such as the voltage threshold (60V) or below. On the other hand, if the abnormal protection module monitors the voltage of the high-voltage capacitor based on the discharge signal and does not discharge as expected, so that the bus voltage does not decrease as required, the discharge drive module will be turned off to stop the discharge operation of the discharge execution module.

[0064] Through the above configuration, when the low-voltage battery source is abnormal, a one-time active discharge operation can be performed without losing the timeout protection function.

[0065] In a preferred embodiment, the emergency power supply and the low-voltage battery source jointly supply power to the isolation power supply, but the connection between the emergency power supply and the isolation power supply is often hung at a low voltage. Therefore, the low-voltage battery source supplies power during normal operation, so that the second input voltage provided by the low-voltage battery source to the isolation power supply is less than the first input voltage provided by the low-voltage battery source to the isolation power supply when there is no power loss. When the low-voltage battery source loses power, the emergency power supply can be used for power supply. Further, the emergency power supply and the low-voltage battery source are respectively provided with a diode between each and the isolation power supply to prevent current from flowing backward. On the other side, the isolation power supply supplies power to the abnormal protection module, the signal isolation module, the delay discharge module and the discharge drive module, so that even if the low-voltage battery source loses power, the isolation power supply can still supply power to the above-mentioned modules, ensuring that the active discharge circuit formed by the above-mentioned modules works normally.

[0066] Further, the abnormal protection module is electrically connected with the high-voltage capacitor, and the output voltage value of the high-voltage capacitor is monitored at all times to determine whether the excess electric quantity of the high-voltage capacitor is discharged when the relay sticking fault occurs, and the abnormal protection module is preconfigured with a voltage drop slope circuit, and the voltage drop slope circuit records the voltage threshold value, a slope threshold value and a discharge time threshold value. The abnormal protection module starts timing from the time when the low-voltage battery source loses power and the isolation power supply sends a low-voltage signal to the abnormal protection module, and determines whether the excess electric quantity of the high-voltage capacitor is normally discharged after the discharge time threshold value, that is, within a specified time, and when the abnormal protection module monitors that the output voltage value is higher than the voltage threshold value, it indicates that the high-voltage capacitor cannot normally discharge, and the abnormal protection module generates an interrupt signal (OTP signal) to the discharge driving module to reset the driving signal to close the discharge execution module. In other words, the above process can be continuously executed, that is, the Adis_req signal is continuously reset and enabled.

[0067] In the above embodiment, when the abnormal protection module monitors that the output voltage drop slope of the high-voltage capacitor is higher than the slope threshold value, and the high-voltage capacitor is discharged to the output voltage below 60V, which is the expected value, the discharge can not continue. In some embodiments, the discharge can be configured to continue until the output voltage value is lower than 55V, that is, when the emergency power supply is usually configured as 55V-900V, the high-voltage capacitor will no longer supply part of the electric quantity to the emergency power supply.

[0068] Further preferably, the active discharge system further comprises a voltage sampling module electrically connected with the microcontroller and the abnormal protection module, and connected with the busbar of the motor controller to sample the bus voltage; when the abnormal protection module monitors that the output voltage drop slope of the high-voltage capacitor is higher than the slope threshold value, the microcontroller obtains the bus voltage value of the motor controller from the voltage sampling module within a preconfigured time; when the bus voltage value is less than an expected value, it indicates that the influence of the discharge of the high-voltage capacitor on the bus voltage is in the expected state, and the discharge execution module continues to control the discharge of the excess electric quantity of the high-voltage capacitor; when the bus voltage value is greater than an expected value, it indicates that the discharge process may fail, and the abnormal protection module generates an interrupt signal to the discharge driving module within the discharge time threshold value to reset the driving signal to close the discharge execution module, and the microcontroller reissues the discharge signal after an interval time, until the normal discharge, if the discharge failure still occurs and is repeated n times (for example, 5 times), but after n times of attempts, the interval time can be increased and the attempts can be repeatedly performed.

[0069] The application also discloses an active discharge method of a motor controller, comprising the following steps: configuring an active discharge circuit, comprising: a low-voltage battery source; an isolation power supply, electrically connected with the low-voltage battery source; a signal isolation module, electrically connected with the isolation power supply and externally connected with a microcontroller; a delay discharge module, electrically connected with the isolation power supply and the signal isolation module; a discharge driving module, electrically connected with the delay discharge module; an abnormality protection module, electrically connected with the emergency power supply, the isolation power supply and the discharge driving module; a high-voltage capacitor, storing excess electric quantity and electrically connected with the emergency power supply and the abnormality protection module; and a discharge execution module, electrically connected with the discharge driving module and the high-voltage capacitor; when the primary side power supply of the microcontroller and the signal isolation module is abnormally lost, the microcontroller generates a discharge signal to the signal isolation module, or the isolation power supply sends a low-voltage signal to the signal isolation module, the signal isolation module sends a discharge request signal to the delay discharge module, the delay discharge module generates a discharge delay signal to the discharge driving module based on the discharge request signal, and the discharge driving module generates a driving signal to the discharge execution module based on the discharge delay signal, so that the discharge execution module discharges the excess electric quantity of the high-voltage capacitor, and the output voltage of the high-voltage capacitor is lower than a voltage threshold.

[0070] Preferably, the emergency power supply and the low-voltage battery source jointly supply power to the isolation power supply, and the second input voltage provided by the low-voltage battery source to the isolation power supply is smaller than the first input voltage provided by the low-voltage battery source to the isolation power supply when the power supply is not lost; and the isolation power supply supplies power to the abnormality protection module, the signal isolation module, the delay discharge module and the discharge driving module respectively.

[0071] Preferably, the abnormality protection module monitors the output voltage value of the high-voltage capacitor, and a voltage drop slope circuit is preset in the abnormality protection module, and the voltage drop slope circuit records a voltage threshold, a slope threshold and a discharge duration threshold; from the time when the low-voltage battery source is lost and the isolation power supply sends a low-voltage signal to the abnormality protection module to the time after the discharge duration threshold, when the abnormality protection module monitors that the output voltage value is higher than the voltage threshold, an interrupt signal is generated to the discharge driving module to reset the driving signal to close the discharge execution module.

[0072] Preferably, when the abnormality protection module monitors that the output voltage drop slope of the high-voltage capacitor is higher than the slope threshold, so that the output voltage value is lower than the voltage threshold, the discharge execution module continuously controls the high-voltage capacitor to discharge the excess electric quantity until the output voltage value is lower than 55V.

[0073] It should be noted that the embodiments of the application have better implementation, and do not limit the application in any form, and any skilled person in the art can change or modify the equivalent effective embodiments by using the above disclosed technical content, as long as it does not deviate from the technical solution of the application, and any modification or equivalent change and modification of the above embodiments according to the technical essence of the application still belongs to the scope of the technical solution of the application.

Claims

1. An active discharge system for a motor controller, comprising: The active discharge system comprises: a low-voltage battery source; an isolation power supply electrically connected to the low-voltage battery source; a signal isolation module electrically connected to the isolation power supply and externally connected to a microcontroller; a delay discharge module electrically connected to the isolation power supply and the signal isolation module; a discharge driving module electrically connected to the delay discharge module; an abnormal protection module electrically connected to the emergency power supply, the isolation power supply and the discharge driving module; a high-voltage capacitor storing excess power and electrically connected to the emergency power supply and the abnormal protection module; a discharge execution module electrically connected to the discharge driving module and the high-voltage capacitor; When the primary power supply of the microcontroller and the signal isolation module is abnormally lost, the microcontroller generates a discharge signal to the signal isolation module, or the isolation power supply sends a low-voltage signal to the signal isolation module, the signal isolation module sends a discharge request signal to the delay discharge module, the delay discharge module generates a discharge delay signal to the discharge driving module based on the discharge request signal, and the discharge driving module generates a driving signal to the discharge execution module based on the discharge delay signal, so that the discharge execution module discharges the excess power of the high-voltage capacitor, so that the output voltage of the high-voltage capacitor is lower than a voltage threshold.

2. The active discharge system of claim 1, wherein: the emergency power supply and the low-voltage battery source jointly supply power to the isolation power supply, and the second input voltage provided by the low-voltage battery source to the isolation power supply is less than the first input voltage provided by the low-voltage battery source to the isolation power supply when not lost; the isolation power supply supplies power to the abnormal protection module, the signal isolation module, the delay discharge module and the discharge driving module respectively.

3. The active discharge system of claim 2, wherein: the abnormal protection module monitors the output voltage value of the high-voltage capacitor, and the abnormal protection module is pre-set with a voltage drop slope circuit, which records the voltage threshold, a slope threshold and a discharge duration threshold; from the time when the low-voltage battery source is lost and the isolation power supply sends a low-voltage signal to the abnormal protection module, to the time when the output voltage value monitored by the abnormal protection module is higher than the voltage threshold after the discharge duration threshold, the abnormal protection module generates an interrupt signal to the discharge driving module to reset the driving signal and close the discharge execution module.

4. The active discharge system of claim 3, wherein: when the abnormal protection module monitors that the output voltage drop slope of the high-voltage capacitor is higher than the slope threshold, so that the output voltage value is lower than the voltage threshold, the discharge execution module continuously controls the high-voltage capacitor to discharge excess power until the output voltage value is lower than 55V.

5. The active discharge system of claim 4, wherein, The active discharge system further comprises: a voltage sampling module electrically connected to the microcontroller and the abnormal protection module respectively; when the abnormal protection module monitors that the output voltage drop slope of the high-voltage capacitor is higher than the slope threshold, the microcontroller acquires the bus voltage value of the motor controller from the voltage sampling module within a preset time duration. When the bus voltage value is less than a desired value, the discharge execution module continuously controls the high-voltage capacitor to discharge excess electricity; When the bus voltage value is greater than a desired value, the abnormal protection module generates an interrupt signal to the discharge driving module within the discharge duration threshold to reset the driving signal to close the discharge execution module, and the microcontroller reissues a discharge signal after an interval time and repeats n times.

6. A method of active discharge of a motor controller, characterized by, The method comprises the following steps: An active discharge circuit is configured, comprising: a low-voltage battery source; an isolation power supply electrically connected to the low-voltage battery source; a signal isolation module electrically connected to the isolation power supply and externally connected to a microcontroller; a delay discharge module electrically connected to the isolation power supply and the signal isolation module; a discharge driving module electrically connected to the delay discharge module; an abnormal protection module electrically connected to the emergency power supply, the isolation power supply, and the discharge driving module; a high-voltage capacitor storing excess electricity and electrically connected to the emergency power supply and the abnormal protection module; and a discharge execution module electrically connected to the discharge driving module and the high-voltage capacitor. When the primary power supply of the microcontroller and the signal isolation module is abnormally lost, the microcontroller generates a discharge signal to the signal isolation module, or the isolation power supply sends a low-voltage signal to the signal isolation module, the signal isolation module sends a discharge request signal to the delay discharge module, the delay discharge module generates a discharge delay signal to the discharge driving module based on the discharge request signal, and the discharge driving module generates a driving signal to the discharge execution module based on the discharge delay signal, so that the discharge execution module discharges excess electricity from the high-voltage capacitor, and the output voltage of the high-voltage capacitor is lower than a voltage threshold.

7. The active discharge method of claim 6, wherein: The emergency power supply and the low-voltage battery source jointly supply power to the isolation power supply, and the second input voltage provided by the low-voltage battery source to the isolation power supply is less than the first input voltage provided by the low-voltage battery source to the isolation power supply when there is no power loss; The isolation power supply supplies power to the abnormal protection module, the signal isolation module, the delay discharge module, and the discharge driving module, respectively.

8. The active discharge method of claim 6, wherein: The abnormal protection module monitors the output voltage value of the high-voltage capacitor, and a voltage drop slope circuit is pre-set in the abnormal protection module, which records the voltage threshold, a slope threshold, and a discharge duration threshold; From the time when the low-voltage battery source loses power and the isolation power supply sends a low-voltage signal to the abnormal protection module, to after the discharge duration threshold, when the abnormal protection module monitors that the output voltage value is higher than the voltage threshold, an interrupt signal is generated to the discharge driving module to reset the driving signal and close the discharge execution module.

9. The active discharge method of claim 8, wherein: When the abnormal protection module monitors that the output voltage of the high-voltage capacitor decreases at a slope higher than the slope threshold value, so that the output voltage value is lower than the voltage threshold value, the discharge execution module continues to control the high-voltage capacitor to discharge the excess electric quantity until the output voltage value is lower than 55 V.

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