Motor controller and discharging method, device and equipment thereof, storage medium and vehicle

Abstract

The invention discloses a motor controller and a discharging method, device and equipment thereof, a storage medium and a vehicle, the motor controller comprises a bus capacitor and an inverter circuit connected with the bus capacitor, and the discharging method of the motor controller comprises the following steps: obtaining a first voltage of the bus capacitor; an alternating conduction signal is sent to a discharge bridge arm group of the inverter circuit so as to discharge a bus capacitor; the discharge bridge arm group is at least one of a plurality of bridge arm groups of the inverter circuit, and the alternate conduction signal is used for driving an upper bridge arm and a lower bridge arm of the discharge bridge arm group to be alternately conducted; and under the condition that the first voltage is lower than the discharge voltage threshold value, a turn-off signal is sent to a discharge bridge arm group of the inverter circuit. According to the embodiment of the invention, the rapid discharge of the bus capacitor can be realized through the alternate conduction of the upper and lower bridge arms of the bridge arm group in the inverter circuit, no extra device is needed, and the device cost can be greatly reduced.

Description

Technical Field

[0001] The present application belongs to the technical field of electric vehicles, and in particular, relates to a motor controller and a discharge method, device, equipment, storage medium and vehicle thereof. Background Art

[0002] With the continuous development of the new energy vehicle field, the popularity of new energy vehicles continues to rise. In the circuit architecture inside new energy vehicles, in order to achieve the drive of the motor, a motor controller is usually set between the high-voltage battery and the motor. The motor controller inverts the DC voltage of the battery and converts it into AC voltage to drive the motor.

[0003] During the operation of the motor, the bus capacitor in the motor controller will store a large amount of charge, resulting in a high voltage across the bus capacitor. When the motor stops driving, such as when the vehicle is powered off, the charge stored in the bus capacitor is discharged slowly, resulting in a high voltage on the bus capacitor, which can easily cause safety hazards.

[0004] In the related art, after the battery is disconnected from the motor, the efficiency of discharging the bus capacitor in the motor controller is low, thereby failing to meet the demand for rapid discharge. Summary of the invention

[0005] The embodiments of the present application provide a motor controller and a discharge method, device, equipment, storage medium and vehicle thereof, which can solve the problem in the related art that the motor controller cannot discharge quickly.

[0006] In a first aspect, an embodiment of the present application provides a motor controller discharging method, wherein the motor controller includes a bus capacitor and an inverter circuit connected to the bus capacitor, and the motor controller discharging method includes:

[0007] Acquire a first voltage of a bus capacitor;

[0008] Sending an alternating conduction signal to a discharge bridge arm group of the inverter circuit to discharge the bus capacitor; the discharge bridge arm group is at least one of a plurality of bridge arm groups of the inverter circuit, and the alternating conduction signal is used to drive the upper bridge arm and the lower bridge arm of the discharge bridge arm group to alternately conduct;

[0009] When the first voltage is lower than the discharge voltage threshold, a shutdown signal is sent to the discharge bridge arm group of the inverter circuit.

[0010] In some embodiments, the inverter circuit includes three bridge arm groups, each bridge arm group includes an upper bridge arm and a lower bridge arm connected in series, the upper bridge arm includes a first power switch device, and the lower bridge arm includes a second power switch device; the first power switch device and the second power switch device include parasitic capacitance;

[0011] When the upper bridge arm is turned on and the lower bridge arm is turned off, the bus capacitor charges the parasitic capacitor of the second power switch device through the first power switch device, and the parasitic capacitor of the first power switch device discharges the first power switch device;

[0012] When the upper bridge arm is turned off and the lower bridge arm is turned on, the bus capacitor charges the parasitic capacitor of the first power switch device through the second power switch device, and the parasitic capacitor of the second power switch device discharges the second power switch device.

[0013] In some embodiments, sending an alternating conduction signal to a discharge bridge arm group of an inverter circuit includes:

[0014] Determining a target initial voltage interval corresponding to the first voltage from a plurality of initial voltage intervals;

[0015] Determine a first signal frequency corresponding to the target initial voltage interval from the first frequency correspondence relationship; wherein the first frequency correspondence relationship is a correspondence relationship between the initial voltage interval and the signal frequency;

[0016] An alternating conduction signal of a first signal frequency is sent to the discharge bridge arm group of the inverter circuit.

[0017] In some embodiments, determining the first signal frequency corresponding to the target initial voltage interval from the first frequency correspondence includes:

[0018] Obtaining a preset discharge time limit;

[0019] A first signal frequency corresponding to an initial voltage interval and a discharge time limit is obtained from a first frequency correspondence relationship; wherein the first frequency correspondence relationship is a correspondence relationship between an initial voltage interval, a discharge time limit and a signal frequency, the initial voltage interval has a positive correlation with the signal frequency, and the discharge time limit has a negative correlation with the signal frequency.

[0020] In some embodiments, the discharge phase of the discharge bridge arm group includes a plurality of discharge time intervals; sending an alternating conduction signal to the discharge bridge arm group of the inverter circuit includes:

[0021] In one of any two adjacent discharge time intervals, a second alternating conduction signal is sent to the discharge bridge arm group; wherein the signal frequency of the second alternating conduction signal is the maximum signal frequency within the frequency range of the alternating conduction signal.

[0022] In some embodiments, after sending the alternating conduction signal to the discharge bridge arm group of the inverter circuit, the method further includes:

[0023] Obtain the operating temperature of each discharge bridge arm group;

[0024] When the operating temperature of at least one discharge bridge arm group reaches a temperature threshold, the signal frequency of the alternating conduction signal is reduced from the first signal frequency to the third signal frequency, or a shutdown signal is sent to the discharge bridge arm group of the inverter circuit.

[0025] In some embodiments, the motor controller includes at least two inverter circuits, each inverter circuit is connected to a bus capacitor; sending an alternating conduction signal to a discharge bridge arm group of the inverter circuit includes:

[0026] Sending an alternating conduction signal to the discharge bridge arm groups corresponding to each inverter circuit; wherein the alternating conduction signals received by the discharge bridge arm groups of different inverter circuits are consistent;

[0027] When the operating temperature of at least one discharge bridge arm group reaches a temperature threshold, a shutdown signal is sent to the discharge bridge arm group of the inverter circuit corresponding to the discharge bridge arm group whose operating temperature reaches the temperature threshold.

[0028] In some embodiments, the motor controller is used to connect to the battery; after sending the alternating conduction signal to the discharge bridge arm group of the inverter circuit, it also includes:

[0029] After a preset discharge time, comparing a first voltage of the bus capacitor with a battery voltage;

[0030] When the difference between the first voltage and the battery voltage is less than the adhesion threshold, adhesion abnormality prompt information is generated; the adhesion abnormality prompt information is used to prompt the user that the battery and the motor controller are not completely disconnected.

[0031] In a second aspect, an embodiment of the present application further provides a motor controller discharge device, the motor controller discharge device comprising:

[0032] An acquisition module, used for acquiring a first voltage of a bus capacitor;

[0033] A discharge module, used for sending an alternating conduction signal to a discharge bridge arm group of an inverter circuit to discharge the bus capacitor; the discharge bridge arm group is at least one of a plurality of bridge arm groups of the inverter circuit, and the alternating conduction signal is used for driving an upper bridge arm and a lower bridge arm of the bridge arm group to alternately conduct;

[0034] The shutdown module is used to send a shutdown signal to the discharge bridge arm group of the inverter circuit when the first voltage is lower than the discharge voltage threshold.

[0035] In a third aspect, an embodiment of the present application further provides a motor controller for implementing the motor controller discharging method of the first aspect, the motor controller comprising:

[0036] Bus capacitor, the two ends of the bus capacitor are used to connect to the positive electrode of the battery and the negative electrode of the battery respectively;

[0037] At least one inverter circuit, a first DC input terminal and a second DC input terminal of the inverter circuit are respectively connected to two ends of the bus capacitor, and an AC output terminal of the inverter circuit is used to be connected to a corresponding motor;

[0038] The inverter circuit includes three bridge arm groups, each bridge arm group includes an upper bridge arm and a lower bridge arm connected in series, the upper bridge arm includes a first power switch device, and the lower bridge arm includes a second power switch device; the first power switch device and the second power switch device include parasitic capacitance.

[0039] In a fourth aspect, an embodiment of the present application further provides a motor controller discharge device, the motor controller discharge device comprising: a processor and a memory storing computer program instructions;

[0040] When the processor executes the computer program instructions, the motor controller discharging method of the first aspect is implemented.

[0041] In a fifth aspect, an embodiment of the present application further provides a computer-readable storage medium, on which computer program instructions are stored, and when the computer program instructions are executed by a processor, the motor controller discharge method of the first aspect is implemented.

[0042] In a sixth aspect, an embodiment of the present application further provides a vehicle, the vehicle comprising at least one of the motor controller discharge device of the second aspect, the motor controller discharge equipment of the fourth aspect, or the computer-readable storage medium of the fifth aspect.

[0043] The motor controller and its discharge method, device, equipment, storage medium and vehicle provided in the embodiment of the present application can detect the voltage at both ends of the bus capacitor by acquiring the first voltage of the bus capacitor in the process of sending an alternating conduction signal to drive the discharge bridge arm group in the inverter circuit to discharge the bus capacitor. In the process of discharging the bus capacitor by continuously alternating the upper and lower bridge arms of the discharge bridge arm group, if the first voltage is lower than the discharge voltage threshold, it can be determined that the voltage at both ends of the bus capacitor is reduced to a suitable voltage range at this time, and the discharge of the bus capacitor by the discharge bridge arm group is stopped. The discharge is achieved by alternating the upper and lower bridge arms in the bridge arm group, which can continuously consume the charge stored in the bus capacitor, thereby realizing the rapid discharge of the bus capacitor. In addition, since the bridge arm group is a device originally possessed by the motor controller, it is not necessary to set up additional devices by using the bridge arm group for discharge. The discharge function can be achieved by adjusting the control signal, which can greatly reduce the cost of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0045] Figure 1 It is a flow chart of a motor controller discharging method provided in one embodiment of the present application;

[0046] Figure 2 is a schematic diagram of the circuit structure of a motor controller provided in one embodiment of the present application;

[0047] Figure 3 is a schematic diagram of a circuit structure of a power switch device provided in an embodiment of the present application;

[0048] Figure 4 is a schematic diagram of an equivalent circuit structure of a bridge arm group provided in an embodiment of the present application;

[0049] Figure 5 is a flow chart of a motor controller discharging method provided by another embodiment of the present application;

[0050] Figure 6 is a flow chart of a motor controller discharging method provided by another embodiment of the present application;

[0051] Figure 7 is a flow chart of a motor controller discharging method provided in yet another embodiment of the present application;

[0052] Figure 8 is a circuit structure diagram of a motor controller provided by another embodiment of the present application;

[0053] Fig. 9 1 is a schematic diagram of a circuit structure of an upper bridge arm discharge process provided by an embodiment of the present application;

[0054] Fig.10 1 is a schematic diagram of a circuit structure of a lower bridge arm discharge process provided by an embodiment of the present application;

[0055] Fig.11 is a circuit structure diagram of a motor controller provided in yet another embodiment of the present application;

[0056] Fig.12 is a circuit structure diagram of a motor controller provided in yet another embodiment of the present application;

[0057] Fig.13 A schematic diagram of the structure of a motor controller discharge device provided in one embodiment of the present application;

[0058] Fig.14 A schematic diagram of the structure of a motor controller discharge device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0059] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0060] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0061] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including 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, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0062] With the continuous development of the new energy vehicle field, the popularity of new energy vehicles continues to rise. In the circuit architecture inside new energy vehicles, in order to achieve the drive of the motor, a motor controller is usually set between the high-voltage battery and the motor. The motor controller inverts the DC voltage of the battery and converts it into AC voltage to drive the motor.

[0063] During the operation of the motor, the bus capacitor in the motor controller will store a large amount of charge, resulting in a high voltage across the bus capacitor. When the motor stops driving, such as when the vehicle is powered off, the charge stored in the bus capacitor is discharged slowly, resulting in a high voltage on the bus capacitor, which can easily cause safety hazards.

[0064] In the related art, after the battery is disconnected from the motor, the efficiency of discharging the bus capacitor in the motor controller is low, thereby failing to meet the demand for rapid discharge.

[0065] In order to solve the above technical problems, the embodiments of the present application provide a motor controller and a discharge method, device, equipment, storage medium and vehicle thereof. The motor controller discharge method provided by the embodiments of the present application is described in detail below with reference to the accompanying drawings through some embodiments and their application scenarios.

[0066] Figure 1 A flow chart of a motor controller discharging method provided by an embodiment of the present application is shown. The motor controller includes a bus capacitor and an inverter circuit connected to the bus capacitor. The motor controller discharging method includes:

[0067] S110, obtaining a first voltage of a bus capacitor;

[0068] S120, sending an alternating conduction signal to a discharge bridge arm group of the inverter circuit to discharge the bus capacitor; the discharge bridge arm group is at least one of a plurality of bridge arm groups of the inverter circuit, and the alternating conduction signal is used to drive the upper bridge arm and the lower bridge arm of the discharge bridge arm group to be alternately turned on;

[0069] S130: When the first voltage is lower than the discharge voltage threshold, a shutdown signal is sent to the discharge bridge arm group of the inverter circuit.

[0070] The motor controller discharge method provided in the embodiment of the present application can be applied to a motor controller, which can be connected between a battery and a motor, and the battery voltage output by the battery is inverted to generate an AC voltage to power the motor to drive the motor to operate. After the battery is disconnected from the motor, the bus capacitor in the motor controller can be quickly discharged to improve the reliability and safety of the motor controller. The specific form of the motor controller is not limited in this embodiment.

[0071] In this embodiment, by obtaining the first voltage of the bus capacitor, the voltage at both ends of the bus capacitor can be detected in the process of sending an alternating conduction signal to drive the discharge bridge arm group in the inverter circuit to discharge the bus capacitor. In the process of discharging the bus capacitor by continuously alternating the upper and lower bridge arms of the discharge bridge arm group, if the first voltage is lower than the discharge voltage threshold, it can be determined that the voltage at both ends of the bus capacitor is reduced to a suitable voltage range at this time, and the discharge of the bus capacitor through the discharge bridge arm group is stopped. The discharge is achieved by alternating the upper and lower bridge arms in the bridge arm group, which can continuously consume the charge stored in the bus capacitor, thereby realizing the rapid discharge of the bus capacitor. In addition, since the bridge arm group is a device originally possessed by the motor controller, it is not necessary to set up additional devices when discharging using the bridge arm group. The discharge function can be achieved by adjusting the control signal, which can greatly reduce the cost of the device.

[0072] In S110, the motor controller includes a bus capacitor and an inverter circuit connected to the bus capacitor. One end of the motor controller can be connected to a battery. After the relay switch of the battery is turned on, the battery can output a battery voltage to the motor controller, and the battery voltage can charge the bus capacitor so that the voltage of the bus capacitor reaches the battery voltage. The inverter circuit can invert the DC voltage at both ends of the bus capacitor and convert the DC voltage into an AC voltage. The other end of the motor controller can be connected to the motor. Taking the motor as a three-phase motor as an example, the inverter circuit of the motor controller can convert the DC voltage into a three-phase AC voltage and supply power to the three-phase motor to drive the three-phase motor to operate.

[0073] Since the bus capacitor in the motor controller has a large capacitance, when the relay between the battery and the motor controller is disconnected, for example, when the vehicle is powered down, the battery and the motor controller are no longer connected. At this time, the bus capacitor in the motor controller still stores a large amount of charge, resulting in a high voltage across the bus capacitor. Therefore, in order to ensure the safety and reliability after the battery is disconnected from the motor controller, the bus capacitor needs to be discharged quickly so that the voltage across the bus capacitor is quickly reduced to an appropriate voltage range.

[0074] The device can respond to a discharge instruction and obtain a first voltage of the bus capacitor. The discharge instruction can be a vehicle power-down instruction, or other instructions for controlling the disconnection of the battery and the motor controller. This instruction can not only realize its original function, but also be reused as a discharge instruction to realize the rapid discharge of the motor controller. Of course, the above-mentioned discharge instruction can also be generated after obtaining relevant instructions. For example, after obtaining the power-down instruction or other instructions for controlling the disconnection of the battery and the motor controller, a discharge instruction is generated and sent to the motor controller.

[0075] In S120, after obtaining the first voltage of the bus capacitor, the device may send an alternating conduction signal to the discharge bridge arm group in the inverter circuit. The discharge bridge arm group may be at least one of the multiple bridge arm groups in the inverter circuit. Taking the inverter circuit including three bridge arm groups as an example, the discharge bridge arm group may be one of the three bridge arm groups, or two of the three bridge arm groups, or all three bridge arm groups are the discharge bridge arm group.

[0076] Taking one of the three bridge arm groups as a discharge bridge arm group as an example, the bridge arm group may include an upper bridge arm and a lower bridge arm. The alternating conduction signal can drive the upper bridge arm and the lower bridge arm of the discharge bridge arm group to be alternately turned on. By driving the upper bridge arm and the lower bridge arm to be alternately turned on, the bus capacitor can be quickly discharged, so that the first voltage of the bus capacitor is quickly reduced to a suitable voltage range.

[0077] As an optional implementation, Figure 2As shown, Batter is a battery, Cbus is a bus capacitor, and M1 is a motor. The inverter circuit may include multiple bridge arm groups, each bridge arm group includes an upper bridge arm and a lower bridge arm connected in series, the upper bridge arm includes a first power switch device, and the lower bridge arm includes a second power switch device; the first power switch device and the second power switch device include parasitic capacitance.

[0078] Taking the inverter circuit that can invert the DC voltage into a three-phase AC voltage as an example, in order to realize the three-phase inverter transformation, the inverter circuit includes three bridge arm groups, each bridge arm group can include an upper bridge arm and a lower bridge arm connected in series, and the connection point between the upper bridge arm and the lower bridge arm is a common node. The common nodes of the three bridge arm groups are respectively connected to the U, V, and W terminals of the three-phase motor. The upper bridge arms of the three bridge arm groups are all connected to the positive electrode of the battery, and the lower bridge arms of the three bridge arm groups are all connected to the negative electrode of the battery. The upper bridge arm and the lower bridge arm of each bridge arm group are controlled by the inverter control signal to realize the inverter transformation of the battery voltage.

[0079] Taking a single bridge arm group as an example, the upper bridge arm may include a first power switching device, and the lower bridge arm may include a second power switching device. The first power switching device and the second power switching device may be IGBT (Insulated gate bipolar transistor), MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) or other power devices that can realize switch on-off control.

[0080] like Figure 2 As shown, among the three bridge arm groups, the first bridge arm group includes the first power switch device T1 and the second power switch device T2, the second bridge arm group includes the first power switch device T3 and the second power switch device T4, and the third bridge arm group includes the first power switch device T5 and the second power switch device T6.

[0081] like Figure 3 As shown, taking the first power switch device and the second power switch device as IGBT as an example, the IGBT includes a first end, a second end and a control end, which are C (collector), E (emitter) and G (gate), respectively, wherein there is a parasitic capacitance Cce between the collector and the emitter, there is a parasitic capacitance Cgc between the collector and the gate, and there is a parasitic capacitance Cge between the emitter and the gate.

[0082] Take a single bridge arm group as an example, Figure 4As shown, when the upper bridge arm is turned on and the lower bridge arm is turned off, the first power switch device T1 is turned on and the second power switch device T2 is turned off. The turned-on first power switch device T1 can be regarded as an equivalent resistor R1. At this time, since the second power switch device T2 is not turned on, the bus capacitor Cbus can charge the parasitic capacitor C2 of the second power switch device T2 through the turned-on first power switch device T1. Taking IGBT as an example, the above parasitic capacitor can be the parasitic capacitor Cce between the collector and the emitter.

[0083] Furthermore, when the first power switch device T1 is turned on, the charge stored in the parasitic capacitor C1 of the first power switch device T1 in the previous alternating conduction cycle can be discharged through the turned-on first power switch device T1, thereby realizing the discharge of the charge. That is, when the upper bridge arm is turned on and the lower bridge arm is turned off, the parasitic capacitor C2 of the second power switch device T2 and the first power switch device T1 can form a charging path, and the bus capacitor can charge the parasitic capacitor C2 of the second power switch device T2 through the charging path; the first power switch device T1 and its own parasitic capacitor C1 can form a discharge path, and the first power switch device T1 can be connected in series with the parasitic capacitor C1 of the first power switch device T1 itself as an equivalent resistor R1, thereby discharging the parasitic capacitor C1 of the first power switch device T1 itself.

[0084] Correspondingly, when the upper bridge arm is turned off and the lower bridge arm is turned on, since the first power switch device T1 is turned off and the second power switch device T2 is turned on, the parasitic capacitor C1 of the first power switch device T1 and the second power switch device T2 can form a charging path, and the bus capacitor can charge the parasitic capacitor C1 of the first power switch device T1 through the charging path;

[0085] The second power switch device T2 can form a discharge path with its own parasitic capacitance C2. When the upper bridge arm is turned on and the lower bridge arm is turned off, the charge stored in the parasitic capacitance C2 of the second power switch device T2 itself charged by the bus capacitance can be discharged at this time. The turned-on second power switch device T2 can act as an equivalent resistor to discharge the parasitic capacitance C2 of the second power switch device T2 itself.

[0086] The alternating conduction of the upper bridge arm and the lower bridge arm can be realized through a single cycle of the alternating conduction signal, that is, the charging and discharging processes of the parasitic capacitance of the two power switching devices can be realized respectively. Since the charging of the parasitic capacitance is realized by discharging the bus capacitance, the bus capacitance can be discharged quickly in the process of the alternating conduction signal driving the upper bridge arm and the lower bridge arm in the discharge bridge arm group to be continuously and alternately conducted, so that the first voltage of the bus capacitance is continuously reduced during the discharge process.

[0087] Please refer to Figure 5 As an optional embodiment, the above S120 may include:

[0088] S210, determining a target initial voltage interval corresponding to the first voltage from a plurality of initial voltage intervals;

[0089] S220, determining a first signal frequency corresponding to the target initial voltage interval from the first frequency correspondence relationship; wherein the first frequency correspondence relationship is a correspondence relationship between the initial voltage interval and the signal frequency;

[0090] S230, sending an alternating conduction signal of a first signal frequency to the discharge bridge arm group of the inverter circuit.

[0091] In this embodiment, after obtaining the first voltage of the bus capacitor, a target initial voltage interval corresponding to the first voltage can be determined from multiple initial voltage intervals. By driving with an alternating conduction signal of a first signal frequency corresponding to the target initial voltage interval, the alternating conduction frequency of the discharge bridge arm group can be associated with the magnitude of the first voltage, thereby avoiding driving the discharge bridge arm group with a higher alternating conduction frequency when the first voltage is low, thereby avoiding overheating or damage of the discharge bridge arm group under high frequency driving.

[0092] In S210, after determining the first voltage across the bus capacitor, the first voltage may be compared with a plurality of starting intervals to determine a target initial voltage interval corresponding to the first voltage from the plurality of initial voltage intervals.

[0093] For a period of time after the battery is disconnected from the motor controller, since the bus capacitor is still connected to other devices or modules, even if the bus capacitor is not discharged through the discharge bridge arm group, the first voltage across the bus capacitor will slowly decrease. Therefore, when the device receives the discharge instruction, if the battery and the motor controller have been disconnected for a period of time, the first voltage of the bus capacitor will be reduced by a certain amount compared to the battery voltage. At this time, the signal frequency of the alternating conduction signal can be determined according to the magnitude of the first voltage.

[0094] The above-mentioned method of comparing the first voltage with multiple initial voltage intervals can be to determine whether the first voltage is within a certain initial voltage interval. For example, the initial voltage interval includes two, the first initial voltage interval is 100V-300V, and the second initial voltage interval is 300V-500V. If the first voltage is between 300V-500V, the initial voltage interval corresponding to the first voltage is the second initial voltage interval. If the first voltage is between 100V-300V, the initial voltage interval corresponding to the first voltage is the first initial voltage interval.

[0095] In S220, after determining the target initial voltage interval corresponding to the first voltage, the first signal frequency corresponding to the target initial voltage interval can be determined from the first frequency correspondence relationship, wherein the first frequency correspondence relationship is a correspondence relationship between the initial voltage interval and the signal frequency.

[0096] The first frequency correspondence between the initial voltage interval and the signal frequency may be preset. After determining the target initial voltage interval corresponding to the first voltage, the first signal frequency corresponding to the first voltage may be determined according to the preset first frequency correspondence.

[0097] In S230, after determining the first signal frequency corresponding to the first voltage, an alternating conduction signal of the first signal frequency can be generated and sent to the discharge bridge arm group of the inverter circuit to achieve rapid discharge of the bus capacitor by alternating conduction of the upper and lower bridge arms in the discharge bridge arm group.

[0098] It should be noted that, taking a single inverter circuit including three bridge arm groups as an example, when the three bridge arm groups are all set as discharge bridge arm groups, an alternating conduction signal of the first signal frequency can be sent to the three bridge arm groups. When one or two of the three bridge arm groups are set as discharge bridge arm groups, an alternating conduction signal of the first signal frequency can be sent to the one or two discharge bridge arm groups, and no alternating conduction signal is sent to the remaining bridge arm groups that are not set as discharge bridge arm groups.

[0099] Please refer to Figure 6 As an optional embodiment, the above S220 may include:

[0100] S310, obtaining a preset discharge time limit;

[0101] S320, obtaining a first signal frequency corresponding to an initial voltage interval and a discharge time limit from a first frequency correspondence relationship; wherein the first frequency correspondence relationship is a correspondence relationship between an initial voltage interval, a discharge time limit and a signal frequency, the initial voltage interval has a positive correlation with the signal frequency, and the discharge time limit has a negative correlation with the signal frequency.

[0102] In this embodiment, through the preset discharge time limit, a suitable first signal frequency can be determined according to the first frequency correspondence and the initial voltage interval corresponding to the first voltage, and the discharge bridge arm group is driven to discharge through the alternating conduction signal of the first signal frequency. On the basis of meeting the requirements of the discharge time limit, a suitable signal frequency is selected to prevent the discharge bridge arm group from overheating or being damaged when driven by a higher alternating conduction frequency.

[0103] In S310, the discharge time limit is the maximum time for discharging the voltage across the bus capacitor through the discharge bridge arm group and reducing the first voltage of the bus capacitor to a suitable range. The discharge time limit can be preset according to the battery voltage, the device parameters of the motor controller and other related parameters. For example, the discharge time limit can be set to 2 seconds or 3 seconds or other durations. Taking the discharge time limit of 2 seconds as an example, the time required for the discharge bridge arm group to start discharging the bus capacitor until the voltage across the bus capacitor is reduced to a suitable voltage range cannot exceed 2 seconds.

[0104] It should be noted that the above-mentioned presetting of the discharge time limit according to the device parameters can be based on the parameters of the high-voltage battery, motor controller, motor and other related devices set in the vehicle, and pre-selecting a suitable discharge time limit. For example, when it is determined that the high-voltage battery used in the vehicle is 400V and the maximum power of the motor is 200kW, a suitable discharge time limit can be selected, such as 2.5 seconds, and by selecting a suitable signal frequency, the above-mentioned motor controller discharge method can discharge the bus capacitor of the motor controller from a higher voltage to below the discharge voltage threshold, such as below 55V, within 2.5 seconds.

[0105] For different types of vehicles, the voltage of their high-voltage batteries and the maximum power of their motors may vary. For example, the voltage of the high-voltage battery of a pure electric new energy vehicle can usually reach 800V. When the relay between the battery and the motor controller is disconnected, the voltage across the bus capacitor may be close to 800V. Compared with a vehicle with a high-voltage battery voltage of approximately 400V, a vehicle with a high-voltage battery voltage of approximately 800V requires more time to discharge the voltage across the bus capacitor to the discharge voltage threshold. Therefore, for vehicles with higher battery voltages, since the time required for discharge is longer, the discharge time limit can be appropriately increased.

[0106] Similarly, for vehicles with different maximum motor powers, the device parameters of each power switch device in the motor controller they are set up with are also different. For example, for vehicles with larger maximum motor power, the requirements for selecting power switch devices in the motor controller are also higher, that is, compared with vehicles with smaller motor power, the switch withstand voltage and maximum switching frequency of the power switch device are higher. In the case where the power switch device can withstand a higher frequency alternating conduction signal, the discharge time limit can be appropriately reduced so that the vehicle can discharge the voltage across the bus capacitor to the discharge voltage threshold in a shorter time.

[0107] As an optional implementation, different discharge time limits can also be set for different configurations of the same vehicle model. For the low-end and high-end configurations of the same vehicle model, the discharge time limit under the high configuration can be set to be smaller than the discharge time limit under the low configuration, so that the vehicle under the high configuration can discharge the voltage across the bus capacitor to the discharge voltage threshold in a shorter time, thereby improving the safety of the high-end vehicle model. For example, there may be a difference in motor power or a difference between two-wheel drive and four-wheel drive between the high-end and low-end configurations of the same vehicle model. At this time, there may be differences in the selection of power switching devices between the high-end and low-end configurations. Usually, high-end power switching devices can withstand higher withstand voltages and higher switching frequencies. On this basis, the more excellent characteristics of high-end power switching devices can be fully utilized to appropriately reduce the discharge time limit to increase their discharge speed.

[0108] In S320, after the discharge time limit is determined, a first signal frequency corresponding to the initial voltage interval and the discharge time limit may be obtained from a preset first frequency correspondence.

[0109] The first frequency correspondence may be a correspondence between an initial voltage interval, a discharge time limit and a signal frequency. After determining the initial voltage interval and the discharge time limit corresponding to the first voltage, the corresponding first signal frequency may be obtained from the first frequency correspondence, and an alternating conduction signal of the first signal frequency may be generated.

[0110] In the above-mentioned first frequency correspondence, the initial voltage interval and the signal frequency may have a positive correlation, and the discharge time limit and the signal frequency may have a negative correlation. That is, when the discharge time limit is the same, the signal frequency corresponding to the larger initial voltage interval should be greater than or equal to the signal frequency corresponding to the smaller initial voltage interval; when the initial voltage interval is the same, the signal frequency corresponding to the larger discharge time limit should be less than or equal to the signal frequency corresponding to the smaller initial voltage interval.

[0111] The signal frequency of the alternating conduction signal can affect the discharge efficiency of the bus capacitor. When the first voltage of the bus capacitor is high, the corresponding initial voltage interval is high. Compared with the lower starting voltage device, if the voltage across the bus capacitor is to be reduced to a suitable voltage range within the same discharge time limit, the signal frequency of the alternating conduction signal needs to be increased to improve the discharge efficiency. Therefore, the higher the initial voltage interval, the greater the corresponding signal frequency.

[0112] Correspondingly, when the initial voltage range is the same, if the voltage across the bus capacitor is to be reduced to a suitable voltage range within a shorter discharge time limit, the signal frequency of the alternating conduction signal needs to be increased to improve the discharge efficiency. Therefore, the larger the discharge time limit, the lower the corresponding signal frequency.

[0113] As an optional implementation, when the discharge time limit is 2 seconds, the first signal frequency corresponding to the first voltage of 100V may be 2KHz, and the first signal frequency corresponding to the first voltage of 500V may be 10KHz.

[0114] When the first voltage is 500V, if the discharge time limit is 2 seconds, the corresponding first signal frequency may be 10KHz; if the discharge time limit is 4 seconds, the corresponding first signal frequency may be 5KHz.

[0115] As an optional embodiment, the discharge phase of the discharge bridge arm group includes multiple discharge time intervals; the above S120 may include:

[0116] S410, sending a second alternating conduction signal to the discharge bridge arm group in one of any two adjacent discharge time intervals; wherein the signal frequency of the second alternating conduction signal is the maximum signal frequency within the frequency range of the alternating conduction signal.

[0117] In this embodiment, the discharge phase of the discharge bridge arm group is the time interval when the voltage across the bus capacitor decreases from the initial first voltage to a suitable voltage range. The discharge phase of the discharge bridge arm group may include multiple discharge time intervals, and the time lengths of the various discharge time intervals may be the same or different.

[0118] In any two adjacent discharge time intervals, the alternating conduction signal corresponding to one of the discharge time intervals can be set to a second alternating conduction signal, and the signal frequency of the second alternating conduction signal can be set to a maximum signal frequency within a frequency range that the alternating conduction signal can support. It can be understood that the maximum signal frequency can be the maximum signal frequency of the alternating conduction signal that can be output without damaging the components in the discharge bridge arm group.

[0119] Under the drive of the second alternating conduction signal, the efficiency of discharging the bus capacitor in the discharge time interval is high, but maintaining the alternating conduction signal with a large signal frequency for a long time may cause damage to the various devices in the discharge bridge arm group. Therefore, in every two adjacent discharge time intervals, at most one discharge time interval can be driven by the second alternating conduction signal. After the discharge time interval ends, it is switched to an alternating conduction signal with a lower signal frequency for driving, thereby protecting the various devices in the discharge bridge arm group and preventing some devices from being damaged under long-term high-frequency driving.

[0120] As an optional implementation, the continuous driving duration of the second alternating conduction signal may be preset, and when the second alternating conduction signal is provided within a certain discharge time interval, the duration of the discharge time interval should not be longer than the continuous driving duration.

[0121] Please refer to Figure 7 As an optional embodiment, after the above S120, the following may also be included:

[0122] S510, obtaining the operating temperature of each discharge bridge arm group;

[0123] S520, when the operating temperature of at least one discharge bridge arm group reaches a temperature threshold, reducing the signal frequency of the alternating conduction signal from the first signal frequency to a third signal frequency, or sending a shutdown signal to the discharge bridge arm group of the inverter circuit.

[0124] In this embodiment, by obtaining the operating temperature of the discharge bridge arm group, when the operating temperature reaches the temperature threshold, the signal frequency of the alternating conduction signal can be timely reduced, for example, the signal frequency can be reduced from a higher first signal frequency to a lower third signal frequency, so as to avoid the discharge bridge arm group continuing to perform high-frequency discharge and causing the operating temperature to continue to rise, thereby protecting the components of the discharge bridge arm group. In addition, when the operating temperature reaches the temperature threshold, the discharge bridge arm group can also be stopped from being driven to discharge, thereby avoiding overheating damage to the discharge bridge arm group.

[0125] In S510, after sending the alternating conduction signal to the discharge bridge arm groups of the inverter circuit, the operating temperature of each discharge bridge arm group may be obtained.

[0126] When the power switch devices in the discharge bridge arm group, such as IGBT, discharge the bus capacitor quickly under the drive of the alternating conduction signal, the power switch devices will heat up, causing the operating temperature of the discharge bridge arm group to increase. When the operating temperature of the discharge bridge arm group is too high, it may cause damage to the power switch devices or other devices.

[0127] In S520, when the operating temperature of at least one of the multiple discharge bridge arm groups reaches the temperature threshold, the first signal frequency of the alternating conduction signal can be reduced from the first signal frequency to a third signal frequency. Driven by the alternating conduction signal with a lower signal frequency, the heat generated by the power switch device of the discharge bridge arm group will be reduced, so that the operating temperature of the discharge bridge arm group no longer rises or the operating temperature gradually starts to decrease.

[0128] In another embodiment, when the operating temperature of at least one discharge bridge arm group reaches a temperature threshold, a shutdown signal may be sent to all normally operating discharge bridge arm groups in the inverter circuit so that the discharge bridge arm group stops discharging the bus capacitor, thereby avoiding damage to the discharge bridge arm group due to excessive temperature.

[0129] As an optional embodiment, the motor controller includes at least two inverter circuits, each of which is connected to a bus capacitor; the above S120 may include:

[0130] S610, sending an alternating conduction signal to the discharge bridge arm groups corresponding to the respective inverter circuits; wherein the alternating conduction signals received by the discharge bridge arm groups of different inverter circuits are consistent;

[0131] S620: When the operating temperature of at least one discharge bridge arm group reaches a temperature threshold, a shutdown signal is sent to the discharge bridge arm group of the inverter circuit corresponding to the discharge bridge arm group whose operating temperature reaches the temperature threshold.

[0132] In this embodiment, when the motor controller includes multiple inverter circuits, the device can send the same alternating conduction signal to the discharge bridge arm groups in each inverter circuit, so that the upper and lower bridge arms in each discharge bridge arm group are kept synchronously turned on or synchronously turned off. In multiple inverter circuits, when the operating temperature of the discharge bridge arm group in a certain inverter circuit reaches the temperature threshold, a shutdown signal can be sent to all the discharge bridge arm groups in the inverter circuit to stop the discharge process of the over-temperature discharge bridge arm group and other discharge bridge arm groups in the inverter circuit, thereby protecting the devices in the inverter circuit from over-temperature damage.

[0133] In S610, the motor controller may be a dual electric control system or a multi-electric control system. Figure 8 As shown, taking the dual electric control system as an example, the motor controller includes two inverter circuits, each inverter circuit is connected to the bus capacitor Cbus, and the two inverter circuits include a first inverter circuit and a second inverter circuit, the first inverter circuit is connected to the three-phase motor M1, and the second inverter circuit is connected to the three-phase motor M2. When the battery Battery is connected to the motor controller, the first inverter circuit can power the first motor M1, and the second inverter circuit can power the second motor M2. Similarly, in a multi-electric control system, the motor controller may include multiple inverter circuits, each inverter circuit is connected to the bus capacitor, and drives different motors respectively. Each bridge arm group in each inverter circuit can be used as a discharge bridge arm group.

[0134] The device can send a conduction signal to the discharge bridge arm group corresponding to each inverter circuit. For example, when the two inverter circuits respectively include three bridge arm groups, a total of six bridge arm groups, any number of bridge arm groups can be selected from the six bridge arm groups as discharge bridge arm groups, and an alternating conduction signal can be sent to each discharge bridge arm group.

[0135] It is understandable that the discharge bridge arm groups in different inverter circuits receive the same alternating conduction signal, that is, the upper bridge arms of the discharge bridge arm groups in each inverter circuit are synchronously conducted, and the lower bridge arms are also synchronously conducted.

[0136] In S620, in the process of driving the discharge bridge arm groups in at least two inverter circuits to discharge the bus capacitor by alternatingly conducting the upper and lower bridge arms through the alternating conduction signal, the operating temperature of each discharge bridge arm group can be detected respectively, and it can be determined whether the operating temperature of each discharge bridge arm group reaches the temperature threshold.

[0137] When the operating temperature of at least one discharge bridge arm group reaches the temperature threshold, the inverter circuit corresponding to the discharge bridge arm group can be determined, and a shutdown signal can be sent to each discharge bridge arm group in the inverter circuit to control the discharge bridge arm group in the inverter circuit to stop discharging. For example, in two inverter circuits, the first inverter circuit includes two discharge bridge arm groups and the second inverter circuit includes three discharge bridge arm groups. If it is detected that the operating temperature of one discharge bridge arm group in the second inverter circuit reaches the temperature threshold, a shutdown signal is sent to the three discharge bridge arm groups in the second inverter circuit to stop the discharge process of the discharge bridge arm group in the second inverter circuit, and the bus capacitor is continued to be discharged only through the two discharge bridge arm groups in the first inverter circuit.

[0138] As an optional embodiment, please refer to Fig. 9 and Fig.10 In the dual electric control system, there are two inverter circuits, with a total of 6 bridge arm groups. In the process of discharging the bus capacitor Cbus, Fig. 9 As shown, the upper bridge arms of the six bridge arm groups can be driven to be turned on and the lower bridge arms can be turned off, that is, T1, T3, T5, T7, T9 and T11 are turned on, and T2, T4, T6, T8, T10 and T12 are turned off. At this time, the upper bridge arms of the six discharge bridge arm groups can discharge the parasitic capacitance, and the lower bridge arms of the six discharge bridge arm groups can charge the parasitic capacitance.

[0139] like Fig.10 As shown, when the upper bridge arms of the six bridge arm groups are cut off and the lower bridge arms are turned on, that is, T1, T3, T5, T7, T9 and T11 are cut off, and T2, T4, T6, T8, T10 and T12 are turned on, the upper bridge arms of the six discharge bridge arm groups can charge the parasitic capacitance, and the lower bridge arms of the six discharge bridge arm groups can discharge the parasitic capacitance.

[0140] By driving the upper and lower bridge arms of the six bridge arm groups to be turned on alternately, the bus capacitor Cbus can be discharged at the same time, thereby quickly reducing the voltage across the bus capacitor Cbus to a suitable voltage range.

[0141] As an optional embodiment, the motor controller is used to connect to the battery; the above S120 may include:

[0142] S710, after a preset discharge time, comparing a first voltage of the bus capacitor with a battery voltage;

[0143] S720, when the difference between the first voltage and the battery voltage is less than the adhesion threshold, generate adhesion abnormality prompt information; the adhesion abnormality prompt information is used to prompt the user that the battery and the motor controller are not completely disconnected.

[0144] In this embodiment, after a period of discharge through the discharge bridge arm group, the first voltage of the bus capacitor can be compared with the battery voltage. If the voltage difference between the first voltage after discharging for a period of time and the battery voltage is small, it can be determined that the battery and the motor controller are not completely disconnected, and there may be faults such as the relay not being disconnected normally or the relay being stuck.

[0145] In S710, one end of the motor controller may be connected to the battery, and the other end of the motor controller may be connected to the motor. A relay is provided between the motor controller and the battery, and when the relay is turned on, the battery is connected to the motor controller; when the relay is turned off, the battery is disconnected from the motor controller.

[0146] During the process of discharging the bus capacitor, the battery is not connected to the motor controller, that is, the relay between the battery and the motor controller is disconnected. After the bus capacitor is discharged for a preset discharge time through the discharge bridge arm group, the first voltage of the bus capacitor after discharge can be compared with the battery voltage.

[0147] In S720, after the bus capacitor is discharged for a preset discharge time, if the battery is disconnected from the motor controller, the first voltage at this time will be lower in amplitude than the first voltage at the start of discharge. If the relay between the battery and the motor controller is not disconnected, or the relay is not disconnected sufficiently, or a sticking fault occurs, the first voltage of the bus capacitor will remain high when the battery is connected to the motor controller.

[0148] The device can compare the first voltage after the preset discharge time with the battery voltage of the battery. If the difference between the first voltage and the battery voltage is less than the sticking threshold, it can be determined that the first voltage has not decreased within the preset discharge time, and the battery and the motor controller are not completely disconnected. The reasons for the above incomplete disconnection include but are not limited to the relay not shutting down normally or the relay sticking.

[0149] When it is determined that the battery and the motor controller are not completely disconnected, the device can stop the process of discharging the bus capacitor and send an adhesion abnormality prompt message to the user to remind the user that the motor and the motor controller are not completely disconnected.

[0150] In S130, in the process of discharging the bus capacitor by driving the discharge bridge arm group through the alternating conduction signal, the first voltage of the bus capacitor can be detected. If the first voltage is lower than the discharge voltage threshold, it can be determined that the voltage of the bus capacitor is reduced to an appropriate voltage range at this time. At this time, a shutdown signal can be sent to the discharge bridge arm group of the inverter circuit to stop discharging the bus capacitor.

[0151] As an optional implementation, the above discharge voltage threshold may be 55V. After the motor controller is disconnected from the battery, the bus capacitor can still provide a voltage source for some devices. If the first voltage of the bus capacitor is too low, some devices will lose power signals. Therefore, when the bus capacitor reaches a suitable voltage range, the bus capacitor can be stopped from being discharged.

[0152] The present application also provides a motor controller, please refer to Fig.11 and Fig.12 The motor controller is used to implement the motor controller discharge method in the above embodiment. The motor controller includes a bus capacitor Cbus and at least one inverter circuit 20.

[0153] The two ends of the bus capacitor Cbus are respectively connected to the positive electrode of the battery 10 and the negative electrode of the battery 10 . When the relay between the battery 10 and the motor controller is turned on, the voltage across the bus capacitor Cbus is the battery voltage of the battery 10 .

[0154] The inverter circuit 20 includes two DC input terminals, namely a first DC input terminal and a second DC input terminal, wherein the first DC input terminal is connected to one end of the bus capacitor Cbus, and the second DC input terminal is connected to the other end of the bus capacitor Cbus. The AC output terminal of the inverter circuit 20 is connected to the corresponding motor.

[0155] Fig.11 The circuit structure diagram is shown when the motor controller includes an inverter circuit 20 , and M1 is a motor connected to the inverter circuit 20 . Fig.12 It shows a circuit structure diagram when the motor controller includes two inverter circuits 20, and M1 and M2 are motors respectively connected to the two inverter circuits.

[0156] When the number of inverter circuits 20 is one, the number of motors connected to the motor controller is also one; and when the number of inverter circuits 20 is two, the number of motors connected to the motor controller is also two, that is, the two inverter circuits 20 can provide three-phase AC voltage to the corresponding two motors respectively.

[0157] like Fig.11 and Fig.12As shown, taking a single inverter circuit 20 as an example, the single inverter circuit 20 includes three bridge arm groups, each bridge arm group includes an upper bridge arm 21 and a lower bridge arm 22 connected in series. The upper bridge arm 21 includes a first power switch device, and the lower bridge arm 22 includes a second power switch device. The first power switch device and the second power switch device include parasitic capacitance. Fig.11 As shown, T1, T3 and T5 are first power switch devices, and T2, T4 and T6 are second power switch devices. Figure 2 As shown, when the motor controller includes two inverter circuits 20, T1, T3 and T5 are the first power switch devices of one of the inverter circuits 20, and T7, T9 and T11 are the first power switch devices of the other inverter circuit 20. Similarly, T2, T4 and T6 are the second power switch devices of one of the inverter circuits 20, and T8, T10 and T12 are the second power switch devices of the other inverter circuit 20.

[0158] In this embodiment, after the battery 10 is disconnected from the motor controller, there is still a high voltage across the bus capacitor Cbus of the motor controller. By sending an alternating conduction signal to the bridge arm group of each inverter circuit 20 in the motor controller, the upper bridge arm 21 and the lower bridge arm 22 of the bridge arm group that receives the alternating conduction signal can be alternately turned on. During the alternating conduction of the upper bridge arm 21 and the lower bridge arm 22, the bus capacitor Cbus can be discharged to quickly reduce the voltage across the bus capacitor Cbus, thereby realizing rapid discharge of the bus capacitor Cbus.

[0159] The present application also provides a motor controller discharge device, such as Fig.13 As shown, the motor controller discharge device includes:

[0160] An acquisition module 1301 is used to acquire a first voltage of a bus capacitor;

[0161] The discharge module 1302 is used to send an alternating conduction signal to the discharge bridge arm group of the inverter circuit to discharge the bus capacitor; the discharge bridge arm group is at least one of the multiple bridge arm groups of the inverter circuit, and the alternating conduction signal is used to drive the upper bridge arm and the lower bridge arm of the bridge arm group to be alternately turned on;

[0162] The shut-down module 1303 is configured to send a shut-down signal to the discharge bridge arm group of the inverter circuit when the first voltage is lower than the discharge voltage threshold.

[0163] Fig.14 A schematic diagram of the hardware structure of a motor controller discharge device provided in an embodiment of the present application is shown.

[0164] The motor controller discharge device may include a processor 1401 and a memory 1402 storing computer program instructions.

[0165] Specifically, the processor 1401 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.

[0166] The memory 1402 may include a large capacity memory for data or instructions. By way of example and not limitation, the memory 1402 may include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive, or a combination of two or more of these. Where appropriate, the memory 1402 may include removable or non-removable (or fixed) media. Where appropriate, the memory 1402 may be internal or external to the motor controller discharge device. In a particular embodiment, the memory 1402 is a non-volatile solid-state memory.

[0167] In certain embodiments, the memory 1402 may include a read-only memory (ROM), a random access memory (RAM), a magnetic disk storage medium device, an optical storage medium device, a flash memory device, an electrical, optical or other physical / tangible memory storage device. Thus, in general, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., a memory device) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to an aspect of the present disclosure.

[0168] The processor 1401 implements any one of the motor controller discharging methods in the above embodiments by reading and executing computer program instructions stored in the memory 1402 .

[0169] In one example, the motor controller discharge device may further include a communication interface 1403 and a bus 1410. Fig.14 As shown, the processor 1401, the memory 1402, and the communication interface 1403 are connected via a bus 1410 and communicate with each other.

[0170] The communication interface 1403 is mainly used to implement communication between various modules, devices, units and / or equipment in the embodiments of the present application.

[0171] Bus 1410 includes hardware, software or both, and the parts of the motor controller discharge device are coupled to each other. For example, but not limitation, the bus may include accelerated graphics port (AGP) or other graphics bus, enhanced industrial standard architecture (EISA) bus, front-side bus (FSB), hypertransport (HT) interconnection, industrial standard architecture (ISA) bus, infinite bandwidth interconnection, low pin count (LPC) bus, memory bus, micro channel architecture (MCA) bus, peripheral component interconnect (PCI) bus, PCI-Express (PCI-X) bus, serial advanced technology attachment (SATA) bus, video electronics standard association local (VLB) bus or other suitable bus or two or more of these combinations. In appropriate cases, bus 1410 may include one or more buses. Although the present application embodiment describes and shows a specific bus, the present application considers any suitable bus or interconnection.

[0172] In addition, in combination with the motor controller discharge method in the above embodiment, the embodiment of the present application can provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when the computer program instructions are executed by the processor, any one of the motor controller discharge methods in the above embodiment is implemented.

[0173] An embodiment of the present application also provides a vehicle, which may include at least one of the above-mentioned motor controller discharge device, motor controller discharge equipment or computer-readable storage medium.

[0174] It should be clear that the present application is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present application is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present application.

[0175] The functional blocks shown in the above block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0176] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.

[0177] Aspects of the present disclosure are described above with reference to the flowchart and / or block diagram of the method, device (system) and computer program product according to the embodiment of the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the implementation of the function / action specified in one or more boxes of the flowchart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field programmable logic circuit. It can also be understood that each box in the block diagram and / or flowchart and the combination of boxes in the block diagram and / or flowchart can also be implemented by dedicated hardware that performs a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0178] The above are only specific implementation methods of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.

Claims

1. A motor controller discharge method, characterized in that: The motor controller includes a bus capacitor and an inverter circuit connected to the bus capacitor, and the motor controller discharge method includes: Acquiring a first voltage of the bus capacitor; Sending an alternating conduction signal to a discharge bridge arm group of the inverter circuit to discharge the bus capacitor; the discharge bridge arm group is at least one of a plurality of bridge arm groups of the inverter circuit, and the alternating conduction signal is used to drive the upper bridge arm and the lower bridge arm of the discharge bridge arm group to be alternately turned on; When the first voltage is lower than a discharge voltage threshold, a shutdown signal is sent to the discharge bridge arm group of the inverter circuit.

2. The motor controller discharging method according to claim 1, characterized in that: The inverter circuit includes three bridge arm groups, each of the bridge arm groups includes an upper bridge arm and a lower bridge arm connected in series, the upper bridge arm includes a first power switch device, and the lower bridge arm includes a second power switch device; the first power switch device and the second power switch device include parasitic capacitance; When the upper bridge arm is turned on and the lower bridge arm is turned off, the bus capacitor charges the parasitic capacitance of the second power switch device through the first power switch device, and the parasitic capacitance of the first power switch device discharges the first power switch device; When the upper bridge arm is turned off and the lower bridge arm is turned on, the bus capacitor charges the parasitic capacitance of the first power switch device through the second power switch device, and the parasitic capacitance of the second power switch device discharges the second power switch device.

3. The motor controller discharging method according to claim 2, characterized in that: The sending of an alternating conduction signal to the discharge bridge arm group of the inverter circuit comprises: Determining a target initial voltage interval corresponding to the first voltage from a plurality of initial voltage intervals; Determining a first signal frequency corresponding to the target initial voltage interval from a first frequency correspondence relationship; wherein the first frequency correspondence relationship is a correspondence relationship between the initial voltage interval and the signal frequency; An alternating conduction signal of the first signal frequency is sent to the discharge bridge arm group of the inverter circuit.

4. The motor controller discharge method according to claim 3, characterized in that: The determining the first signal frequency corresponding to the target initial voltage interval from the first frequency correspondence relationship includes: Obtaining a preset discharge time limit; A first signal frequency corresponding to the initial voltage interval and the discharge time limit is obtained from a first frequency correspondence relationship; wherein the first frequency correspondence relationship is a correspondence relationship between the initial voltage interval, the discharge time limit and the signal frequency, the initial voltage interval has a positive correlation with the signal frequency, and the discharge time limit has a negative correlation with the signal frequency.

5. The motor controller discharging method according to claim 2, characterized in that: The discharge phase of the discharge bridge arm group includes a plurality of discharge time intervals; the sending of an alternating conduction signal to the discharge bridge arm group of the inverter circuit includes: In one of any two adjacent discharge time intervals, a second alternating conduction signal is sent to the discharge bridge arm group; wherein the signal frequency of the second alternating conduction signal is the maximum signal frequency within the frequency range of the alternating conduction signal.

6. The motor controller discharging method according to any one of claims 1 to 5, characterized in that: After sending the alternating conduction signal to the discharge bridge arm group of the inverter circuit, the method further includes: Obtain the operating temperature of each discharge bridge arm group; When the operating temperature of at least one discharge bridge arm group reaches a temperature threshold, the signal frequency of the alternating conduction signal is reduced from the first signal frequency to a third signal frequency, or a shutdown signal is sent to the discharge bridge arm group of the inverter circuit.

7. The motor controller discharging method according to any one of claims 1 to 5, characterized in that: The sending of an alternating conduction signal to the discharge bridge arm group of the inverter circuit comprises: Sending an alternating conduction signal to the discharge bridge arm groups corresponding to each inverter circuit; wherein the alternating conduction signals received by the discharge bridge arm groups of different inverter circuits are consistent; When the operating temperature of at least one discharge bridge arm group reaches a temperature threshold, a shutdown signal is sent to the discharge bridge arm group of the inverter circuit corresponding to the discharge bridge arm group whose operating temperature reaches the temperature threshold.

8. The motor controller discharging method according to any one of claims 1 to 5, characterized in that: The motor controller is used to connect to the battery; after sending the alternating conduction signal to the discharge bridge arm group of the inverter circuit, it also includes: After a preset discharge time, comparing the first voltage of the bus capacitor with the battery voltage; When the difference between the first voltage and the battery voltage is less than the adhesion threshold, adhesion abnormality prompt information is generated; the adhesion abnormality prompt information is used to prompt the user that the battery and the motor controller are not completely disconnected.

9. A motor controller, characterized in that: The motor controller is used to implement the motor controller discharging method according to any one of claims 1 to 8, and the motor controller includes: A bus capacitor, wherein two ends of the bus capacitor are respectively used to connect to the positive electrode of the battery and the negative electrode of the battery; At least one inverter circuit, wherein a first DC input terminal and a second DC input terminal of the inverter circuit are respectively connected to two ends of the bus capacitor, and an AC output terminal of the inverter circuit is used to be connected to a corresponding motor; The inverter circuit includes three bridge arm groups, each of which includes an upper bridge arm and a lower bridge arm connected in series, the upper bridge arm includes a first power switching device, and the lower bridge arm includes a second power switching device; the first power switching device and the second power switching device include parasitic capacitance.

10. A motor controller discharge device, characterized in that: The motor controller discharge device comprises: An acquisition module, used for acquiring a first voltage of a bus capacitor; A discharge module, used for sending an alternating conduction signal to a discharge bridge arm group of an inverter circuit to discharge the bus capacitor; the discharge bridge arm group is at least one of a plurality of bridge arm groups of the inverter circuit, and the alternating conduction signal is used for driving an upper bridge arm and a lower bridge arm of the bridge arm group to be alternately turned on; A shutdown module is used to send a shutdown signal to the discharge bridge arm group of the inverter circuit when the first voltage is lower than the discharge voltage threshold.

11. A motor controller discharge device, characterized in that: The motor controller discharge device includes: a processor and a memory storing computer program instructions; When the processor executes the computer program instructions, the motor controller discharging method according to any one of claims 1 to 8 is implemented.

12. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer program instructions, and when the computer program instructions are executed by a processor, the motor controller discharging method according to any one of claims 1 to 8 is implemented.

13. A vehicle, characterized in that: The vehicle comprises at least one of the following: The motor controller discharge device as claimed in claim 10; The motor controller discharge device as claimed in claim 11; The computer readable storage medium of claim 12.

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