Active short circuit control method and device, vehicle and storage medium

Abstract

The application relates to an active short-circuit control method and device, a vehicle and a storage medium. The method comprises the following steps: in the case that a motor meets preset pre-energy release conditions based on a current fault type of the motor, determining a target energy release mode according to hardware configuration information of a system corresponding to the motor, and performing energy release; controlling power switch tubes of a first-phase lower bridge arm and a second-phase lower bridge arm of the motor to be in a conduction state, and controlling a power switch tube of a third-phase lower bridge arm of the motor to be in an off state, and when a duration of the power switch tube of the third-phase lower bridge arm being in the off state reaches a first preset duration, controlling the power switch tube of the third-phase lower bridge arm to be in the conduction state. In this way, the problem that power devices and permanent magnets are prone to damage due to excessively large impact current and significant current oscillation in the related art is solved by means of phased and progressive short-circuit, and the impact current and current oscillation during high-speed fault are significantly reduced.

Description

Technical Field

[0001] This application relates to the fields of motor control and power electronics technology, and in particular to an active short-circuit control method, device, vehicle, and storage medium. Background Technology

[0002] Permanent magnet synchronous motors are widely used in electric drive systems such as electric vehicles, industrial servos, power tools, and drones due to their advantages such as high power density and high efficiency. However, when the motor is running at high speed, if a fault such as overcurrent, overvoltage, or loss of controller communication occurs, the motor will enter an uncontrolled power generation state, generating extremely high back electromotive force and causing serious safety risks.

[0003] In related technologies, when dealing with the above-mentioned faults, active short circuit (ASC) is usually used as a fault protection strategy. That is, when a fault occurs, all three-phase lower bridge arm power switches of the inverter are turned on to form a short circuit loop in the motor windings, so as to suppress the speed and prevent runaway.

[0004] However, under high-speed operating conditions, the back electromotive force of the motor can reach hundreds of volts. The aforementioned sudden short circuit will generate huge instantaneous impact current and strong current oscillation (LC resonance) for several cycles. This not only poses a threat of overcurrent burnout to the power switching transistors, but the severe electromagnetic stress and thermal stress generated will also cause irreversible demagnetization of the motor's permanent magnets, which urgently needs to be solved. Summary of the Invention

[0005] This application provides an active short-circuit control method, device, vehicle, and storage medium to solve the problem that power devices and permanent magnets are easily damaged due to excessive inrush current and significant current oscillation in related technologies. It significantly reduces the inrush current and current oscillation during high-speed faults, effectively protects power devices, and prevents permanent magnet demagnetization.

[0006] To achieve the above objectives, the first aspect of this application proposes an active short-circuit control method, comprising the following steps: Obtain the current fault type of the motor; If, based on the current fault type, it is determined that the motor meets the preset pre-discharge conditions, the hardware configuration information of the system corresponding to the motor is obtained, the target discharge mode is determined according to the hardware configuration information, and energy is discharged according to the target discharge mode. The power switch transistors of the first and second phase lower bridge arms of the motor are controlled to be in the ON state, and the power switch transistor of the third phase lower bridge arm of the motor is controlled to be in the OFF state. When the duration of the power switch transistor of the third phase lower bridge arm being in the OFF state reaches a first preset duration, the power switch transistor of the third phase lower bridge arm of the motor is controlled to be in the ON state.

[0007] According to one embodiment of this application, determining the target energy dissipation mode based on the hardware configuration information and discharging energy according to the target energy dissipation mode includes: Based on the hardware configuration information, determine whether the system corresponding to the motor is equipped with an energy dissipation unit; If the motor-corresponding system is equipped with the energy dissipation unit, then the braking power switch is turned on based on the first energy dissipation mode to dissipate energy through the energy dissipation unit until the first stop dissipation condition is met; wherein... The first condition for stopping the discharge includes: The bus voltage of the motor is less than the first preset voltage; Alternatively, the duration of energy discharge through the energy dissipation unit may exceed the second preset duration; Alternatively, the speed of the motor is less than the first preset speed.

[0008] According to one embodiment of this application, after determining whether the system corresponding to the motor is configured with an energy dissipation unit based on the hardware configuration information, the method further includes: If the system corresponding to the motor is not configured with the energy dissipation unit, then determine whether the current battery management system allows charging; When the current battery management system does not allow charging, based on the second energy discharge mode, the power switches of any two lower bridge arms are turned on according to a preset cycle, and energy is dissipated using the motor winding resistance, until the second stop discharge condition is reached; wherein, The second condition for stopping the discharge includes: The speed of the motor is less than the second preset speed; Alternatively, the duration of the conduction control of the power switches of any two lower bridge arms according to a preset period is longer than a third preset duration.

[0009] According to one embodiment of this application, after determining whether the current battery management system allows charging, the method further includes: If the current battery management system allows charging, obtain the current battery level and current battery temperature; If the current battery charge is less than a preset charge and the current battery temperature is within a preset temperature range, then current limiting feedback is performed based on the third energy discharge mode until the third discharge stop condition is met; wherein, The third condition for stopping the discharge includes: The current battery level is greater than the preset battery level; Alternatively, the current battery management system receives a charging disallow command; Alternatively, the speed of the motor is less than the third preset speed; Alternatively, the duration of the current-limiting feedback based on the third energy leakage mode is longer than the fourth preset duration.

[0010] According to one embodiment of this application, before obtaining the current fault type of the motor, the method further includes: The phase current of the motor, the status of at least one power switch, the bus voltage, and the bus communication status are obtained. If the phase current of the motor is greater than a first preset current value, and / or, at least one power switch is in a preset desaturation fault state, and / or, the bus voltage is greater than a second preset voltage value, and / or, the duration of the bus communication state in a preset communication loss state is greater than a fifth preset duration, then the motor is determined to be in a fault state.

[0011] According to one embodiment of this application, after obtaining the current fault type of the motor, the method further includes: If, based on the current fault type, it is determined that the current fault type does not meet the preset pre-discharge condition, the power switch of the first phase lower bridge arm and the power switch of the second phase lower bridge arm of the motor are controlled to be in the on state, and the power switch of the third phase lower bridge arm of the motor is controlled to be in the off state. When the duration of the power switch of the third phase lower bridge arm being in the off state reaches a first preset duration, the power switch of the third phase lower bridge arm of the motor is controlled to be in the on state.

[0012] According to one embodiment of this application, the situation where the current fault type does not meet the preset pre-discharge energy condition includes: The current fault type is an overcurrent fault, and the phase current of the motor is greater than the second preset current value; And / or, the current fault type is an overvoltage fault, and the bus voltage is greater than a third preset voltage value; And / or, at least one power switch is in a preset desaturation fault state.

[0013] According to the active short-circuit control method proposed in this application, based on the current fault type of the motor and determining that the motor meets the preset pre-discharge conditions, the target discharge mode is determined according to the hardware configuration information of the corresponding system of the motor, and energy is discharged; the power switches of the first and second phase lower bridge arms of the motor are controlled to be in the on state, and the power switch of the third phase lower bridge arm of the motor is controlled to be in the off state. When the duration of the power switch of the third phase lower bridge arm being in the off state reaches a first preset duration, the power switch of the third phase lower bridge arm of the motor is controlled to be in the on state. Thus, by using a phased and progressive short circuit, the problem of easy damage to power devices and permanent magnets caused by excessive inrush current and significant current oscillation in related technologies is solved. The inrush current and current oscillation during high-speed faults are significantly reduced, effectively protecting power devices and preventing demagnetization of permanent magnets.

[0014] To achieve the above objectives, a second aspect of this application provides an active short-circuit control device, comprising: The acquisition module is used to acquire the current fault type of the motor; The energy discharge module is used to obtain the hardware configuration information of the system corresponding to the motor when it is determined that the motor meets the preset pre-energy discharge conditions based on the current fault type, determine the target energy discharge mode according to the hardware configuration information, and discharge energy according to the target energy discharge mode. The control module is used to control the power switch transistors of the first and second phase lower bridge arms of the motor to be in the ON state, and to control the power switch transistor of the third phase lower bridge arm of the motor to be in the OFF state. When the duration of the power switch transistor of the third phase lower bridge arm being in the OFF state reaches a first preset duration, the control module is used to control the power switch transistor of the third phase lower bridge arm of the motor to be in the ON state.

[0015] According to one embodiment of this application, the energy dissipation module is used for: Based on the hardware configuration information, determine whether the system corresponding to the motor is equipped with an energy dissipation unit; If the motor-corresponding system is equipped with the energy dissipation unit, then the braking power switch is turned on based on the first energy dissipation mode to dissipate energy through the energy dissipation unit until the first stop dissipation condition is met; wherein... The first condition for stopping the discharge includes: The bus voltage of the motor is less than the first preset voltage; Alternatively, the duration of energy discharge through the energy dissipation unit may exceed the second preset duration; Alternatively, the speed of the motor is less than the first preset speed.

[0016] According to one embodiment of this application, after determining whether the system corresponding to the motor is configured with an energy dissipation unit based on the hardware configuration information, the dissipation module is further configured to: If the system corresponding to the motor is not configured with the energy dissipation unit, then determine whether the current battery management system allows charging; When the current battery management system does not allow charging, based on the second energy discharge mode, the power switches of any two lower bridge arms are turned on according to a preset cycle, and energy is dissipated using the motor winding resistance, until the second stop discharge condition is reached; wherein, The second condition for stopping the discharge includes: The speed of the motor is less than the second preset speed; Alternatively, the duration of the conduction control of the power switches of any two lower bridge arms according to a preset period is longer than a third preset duration.

[0017] According to one embodiment of this application, after determining whether the current battery management system allows charging, the discharge module is further configured to: If the current battery management system allows charging, obtain the current battery level and current battery temperature; If the current battery charge is less than a preset charge and the current battery temperature is within a preset temperature range, then current limiting feedback is performed based on the third energy discharge mode until the third discharge stop condition is met; wherein, The third condition for stopping the discharge includes: The current battery level is greater than the preset battery level; Alternatively, the current battery management system receives a charging disallow command; Alternatively, the speed of the motor is less than the third preset speed; Alternatively, the duration of the current-limiting feedback based on the third energy leakage mode is longer than the fourth preset duration.

[0018] According to one embodiment of this application, before obtaining the current fault type of the motor, the obtaining module is further configured to: The phase current of the motor, the status of at least one power switch, the bus voltage, and the bus communication status are obtained. If the phase current of the motor is greater than a first preset current value, and / or, at least one power switch is in a preset desaturation fault state, and / or, the bus voltage is greater than a second preset voltage value, and / or, the duration of the bus communication state in a preset communication loss state is greater than a fifth preset duration, then the motor is determined to be in a fault state.

[0019] According to one embodiment of this application, after obtaining the current fault type of the motor, the obtaining module is further configured to: If, based on the current fault type, it is determined that the current fault type does not meet the preset pre-discharge condition, the power switch of the first phase lower bridge arm and the power switch of the second phase lower bridge arm of the motor are controlled to be in the on state, and the power switch of the third phase lower bridge arm of the motor is controlled to be in the off state. When the duration of the power switch of the third phase lower bridge arm being in the off state reaches a first preset duration, the power switch of the third phase lower bridge arm of the motor is controlled to be in the on state.

[0020] According to one embodiment of this application, the situation where the current fault type does not meet the preset pre-discharge energy condition includes: The current fault type is an overcurrent fault, and the phase current of the motor is greater than the second preset current value; And / or, the current fault type is an overvoltage fault, and the bus voltage is greater than a third preset voltage value; And / or, at least one power switch is in a preset desaturation fault state.

[0021] According to the active short-circuit control device proposed in this application, based on the current fault type of the motor and determining that the motor meets the preset pre-discharge conditions, the target discharge mode is determined according to the hardware configuration information of the corresponding system of the motor, and energy is discharged; the power switches of the first and second phase lower bridge arms of the motor are controlled to be in the on state, and the power switches of the third phase lower bridge arms of the motor are controlled to be in the off state. When the duration of the power switch of the third phase lower bridge arm being in the off state reaches a first preset duration, the power switch of the third phase lower bridge arm of the motor is controlled to be in the on state. Thus, by using a phased and progressive short circuit, the problem of easy damage to power devices and permanent magnets caused by excessive inrush current and significant current oscillation in related technologies is solved. The inrush current and current oscillation during high-speed faults are significantly reduced, effectively protecting power devices and preventing demagnetization of permanent magnets.

[0022] To achieve the above objectives, a third aspect of this application provides a vehicle comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the active short-circuit control method as described in the above embodiments.

[0023] To achieve the above objectives, a fourth aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the active short-circuit control method as described in the above embodiments.

[0024] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0025] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a flowchart of an active short-circuit control method provided according to an embodiment of this application; Figure 2 This is a circuit topology diagram of a three-phase inverter according to an embodiment of this application; Figure 3 This is a flowchart of an active short-circuit control method according to an embodiment of this application; Figure 4 This is a block diagram of an active short-circuit control device provided according to an embodiment of this application; Figure 5 This is a structural schematic diagram of a vehicle provided according to an embodiment of this application. Detailed Implementation

[0026] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0027] The active short-circuit control method, apparatus, vehicle, and storage medium according to embodiments of this application are described below with reference to the accompanying drawings.

[0028] First, the active short-circuit control method proposed according to the embodiments of this application will be described with reference to the accompanying drawings. The active short-circuit control method of this application is a protection control method for a permanent magnet synchronous motor when a fault occurs under high-speed operation. By adopting a phased active short-circuit control strategy, a three-stage progressive short circuit is performed to achieve fast response, smooth attenuation and low oscillation. It is applicable to electric drive systems equipped with permanent magnet synchronous motors, such as electric vehicles, industrial servos, power tools, and UAV ESCs.

[0029] Specifically, Figure 1 This is a flowchart illustrating an active short-circuit control method provided in an embodiment of this application.

[0030] like Figure 1 As shown, the active short-circuit control method includes the following steps: In step S101, the current fault type of the motor is obtained.

[0031] Furthermore, in some embodiments, before obtaining the current fault type of the motor, the method further includes: obtaining the phase current of the motor, the state of at least one power switch, the bus voltage, and the bus communication state; if the phase current of the motor is greater than a first preset current value, and / or, at least one power switch is in a preset desaturation fault state, and / or, the bus voltage is greater than a second preset voltage value, and / or, the duration of the bus communication state in a preset communication loss state is greater than a fifth preset duration, then the motor is determined to be in a fault state.

[0032] The first preset current value can be a current value preset by those skilled in the art, the second preset voltage value can be a voltage value preset by those skilled in the art, and the fifth preset duration can be a duration preset by those skilled in the art, which will not be specified here.

[0033] Specifically, the controller uses built-in sensors and diagnostic circuits to continuously collect the phase current of the motor, the DC bus voltage, the desaturation state of the power switching transistors, and the signal status of the system communication bus (such as the CAN bus).

[0034] Furthermore, these real-time collected data are compared with preset safety thresholds: for example, when the phase current exceeds the set overcurrent threshold, the bus voltage exceeds the set overvoltage threshold, a power transistor desaturation fault is detected, or the duration of communication loss exceeds the tolerance, the corresponding fault flag will be triggered. Finally, by analyzing these triggered specific fault flags, the specific fault type (overcurrent fault, overvoltage fault, desaturation fault, or communication loss fault) can be accurately identified and determined, thus providing a precise decision-making basis for subsequent selection of whether to enter the pre-discharge stage and how to select the discharge mode.

[0035] In step S102, if the motor meets the preset pre-discharge conditions based on the current fault type, the hardware configuration information of the system corresponding to the motor is obtained, the target discharge mode is determined according to the hardware configuration information, and energy is discharged according to the target discharge mode.

[0036] Upon entering the pre-energy discharge phase, the controller acquires the hardware configuration information of the motor's corresponding system and selects the optimal energy discharge path based on the available hardware resources. Specifically, it checks whether the current system is equipped with an external energy dissipation unit (such as a braking chopper or braking resistor) and whether the battery management system allows the absorption of regenerative energy. Based on this hardware information, the target energy discharge mode is determined.

[0037] If a braking chopper is configured, the energy dissipation braking mode is selected first, and energy is fed into the braking resistor by conducting the braking IGBT. If this hardware is not available, the battery status is further determined. If charging is allowed, energy is fed back to the battery based on the controllable regenerative braking mode. If charging is not allowed, the built-in phase-damped braking mode is finally activated, which dissipates energy by periodically conducting the two lower phase tubes of the motor and utilizing the resistance of the motor windings themselves.

[0038] Therefore, the progressive selection mechanism based on hardware configuration ensures that an effective energy dissipation path can be determined under any system architecture, thereby achieving maximum safety redundancy and system compatibility without increasing additional hardware costs. Finally, according to the determined target energy dissipation mode, corresponding control commands are executed to perform rapid and controlled energy dissipation, creating a safer and more stable system state for subsequent damped short-circuit and full short-circuit phases.

[0039] Furthermore, in some embodiments, determining a target energy dissipation mode based on hardware configuration information and discharging energy according to the target energy dissipation mode includes: determining whether the system corresponding to the motor is configured with an energy dissipation unit based on the hardware configuration information; if the system corresponding to the motor is configured with an energy dissipation unit, then turning on the braking power switch based on the first energy dissipation mode to dissipate energy through the energy dissipation unit until a first stop dissipation condition is reached; wherein, the first stop dissipation condition includes: the bus voltage of the motor is less than a first preset voltage; or, the duration of energy dissipation through the energy dissipation unit is greater than a second preset duration; or, the speed of the motor is less than a first preset speed.

[0040] Specifically, the system first makes a logical judgment on whether the motor drive system is equipped with a dedicated energy dissipation unit based on pre-stored or real-time acquired hardware configuration information. The energy dissipation unit can be a hardware combination consisting of a braking chopper circuit, a braking power switch, and a braking resistor, and its function is to provide an external energy dissipation path for the system.

[0041] If the system is determined to have the energy dissipation unit configured, the first energy dissipation mode will be executed. In this mode, the controller outputs a drive signal to turn on the braking power switch, thereby guiding the regenerative energy generated during motor braking to the braking resistor and dissipating it as heat. This energy dissipation process will continue until any of the preset first stop dissipation conditions are met.

[0042] The stopping conditions are a set of parallel logical judgment criteria, the purpose of which is to ensure the safety and timeliness of the discharge process. Specifically, they include: the DC bus voltage of the motor drops below the first preset voltage threshold, which indicates that the system energy has been discharged to a safe level; or, the total duration of the energy discharge action exceeds the second preset duration, which is a safety time protection mechanism to prevent the discharge process from continuing indefinitely due to certain faults; or, the motor speed drops below the first preset speed, which indicates that the kinetic energy of the motor itself has been significantly reduced and there is no need to dissipate the main energy through external resistors.

[0043] Furthermore, in some embodiments, after determining whether the motor-corresponding system is configured with an energy dissipation unit based on hardware configuration information, the method further includes: if the motor-corresponding system is not configured with an energy dissipation unit, determining whether the current battery management system allows charging; if the current battery management system does not allow charging, based on the second energy dissipation mode, controlling the power switching transistors of any two lower bridge arms to conduct according to a preset period, and using the motor winding resistance to dissipate energy until the second stop dissipation condition is reached; wherein, the second stop dissipation condition includes: the motor speed is less than the second preset speed; or, the duration of controlling the power switching transistors of any two lower bridge arms to conduct according to a preset period is greater than the third preset duration.

[0044] Specifically, if it is determined that the motor drive system is not equipped with an external energy dissipation unit, the control logic proceeds to the next decision level, which assesses the feasibility of the energy feedback path. At this point, the controller needs to query the current status of the battery management system to confirm whether it allows the power battery to receive charging current.

[0045] If the feedback indicates that the battery management system does not allow charging, the second energy dissipation mode will be activated. The core of this mode is that it does not rely on any external hardware, but only utilizes the motor itself and its inverter to form an energy dissipation loop. Specifically, the process involves cyclically controlling the lower arm power switches of any two phases in the inverter to enter the conducting state according to a pre-set cycle. For example, as... Figure 2 As shown, the lower bridge arm power switch S4 of phase U and the lower bridge arm power switch S5 of phase V are turned on. When the two lower bridge arms are turned on, two phases of the motor's three-phase windings will form a closed loop through the turned-on switches. The current flowing through this loop will cause the inherent resistance of the motor windings to generate Joule heat, thereby continuously converting the motor's rotational kinetic energy into heat energy and dissipating it, thus achieving the deceleration and energy dissipation of the system.

[0046] This energy dissipation process will continue until any of the preset second stop dissipation conditions are met. Specifically, these conditions include: the real-time speed of the motor dropping below a second preset speed threshold, indicating that the system's kinetic energy has decreased to an acceptable low level; or, the cumulative duration of the periodic conduction control exceeding a third preset duration. This is a safety backup mechanism to prevent the energy dissipation process from executing indefinitely when the speed detection is abnormal under specific fault conditions. Through the above control sequence, a low-cost, highly compatible, and safe energy dissipation strategy can still be achieved under the limited conditions of lacking an external braking resistor and being unable to perform energy feedback.

[0047] Furthermore, in some embodiments, after determining whether the current battery management system allows charging, the method further includes: if the current battery management system allows charging, obtaining the current battery level and current battery temperature; if the current battery level is less than a preset level and the current battery temperature is within a preset temperature range, then performing current limiting feedback based on a third energy discharge mode until a third stop discharge condition is met; wherein the third stop discharge condition includes: the current battery level is greater than a preset level; or, the current battery management system receives a charging disallowance command; or, the motor speed is less than a third preset speed; or, the duration of current limiting feedback based on the third energy discharge mode is greater than a fourth preset duration.

[0048] When the current battery management system indicates that it can receive charging energy, the real-time status parameters of the power battery are obtained through the vehicle bus system, mainly including the current battery charge and current battery temperature. These parameters are then compared with preset safe operating boundary conditions. If both the current battery charge is below the preset upper limit and the current battery temperature is within the preset allowable charging temperature range, energy feedback conditions are determined to be met, and the third energy release mode is activated. In this mode, the output current on the motor side is precisely limited, thereby controlling the amount of energy recovery and achieving controlled current-limited regenerative braking. This ensures that during the process of converting the motor's kinetic energy into electrical energy and feeding it back to the power battery, the charging current is always limited to a range that is safe and acceptable to the battery and its management system, thus ensuring battery safety and lifespan while achieving energy recovery.

[0049] This current-limiting feedback process will continue to run until it terminates when any of the preset third discharge-stopping conditions are met. Specifically, these conditions include: the current battery charge has recovered to more than the preset charge threshold, indicating that the battery energy storage space is approaching saturation; or, the battery management system issues a new instruction during the process, changing the state to disallow charging; or, the motor speed has dropped below the third preset speed, meaning that the recoverable kinetic energy has significantly decreased; or, the total duration of the current-limiting feedback action exceeds the fourth preset duration. This is a project safety timing protection mechanism used to prevent the process from being abnormally prolonged.

[0050] In step S103, the power switch of the first phase lower bridge arm and the power switch of the second phase lower bridge arm of the control motor are in the on state, and the power switch of the third phase lower bridge arm of the control motor is in the off state. When the duration of the power switch of the third phase lower bridge arm being in the off state reaches the first preset duration, the power switch of the third phase lower bridge arm of the control motor is in the on state.

[0051] Specifically, after completing the aforementioned pre-discharge stage, a damped short-circuit stage is executed. This involves controlling the lower arm power switches of the first and second phases in the inverter to be turned on, while simultaneously keeping the power switch of the third phase's lower arm off. This specific switching combination ensures that two phases of the motor's three-phase windings form a closed loop through the turned-on switches, while the third phase winding remains open or in a high-resistance state. This topology creates a short-circuit path with specific damping characteristics within the motor. Its core function is to effectively suppress LC circuit oscillations that may be caused by the instantaneous energy release during a fault, and to smooth the current rise rate (di / dt), utilizing the motor windings' own resistance and inductance.

[0052] This damped short-circuit state will be maintained for a first preset duration. After this duration is reached, the fully active short-circuit stage begins. In this stage, the controller outputs a drive signal to switch the previously off third-phase lower bridge arm power switch to the on state. At this point, all three-phase lower bridge arm power switches of the inverter are on, causing the three-phase winding terminals of the motor to be simultaneously shorted to the negative terminal of the DC bus, forming a stable three-phase short-circuit loop.

[0053] Furthermore, in some embodiments, after obtaining the current fault type of the motor, the method further includes: if, based on the current fault type, it is determined that the current fault type does not meet the preset pre-discharge condition, controlling the power switch of the first phase lower bridge arm and the power switch of the second phase lower bridge arm of the motor to be in the on state, and controlling the power switch of the third phase lower bridge arm of the motor to be in the off state, and when the duration of the power switch of the third phase lower bridge arm being in the off state reaches a first preset duration, controlling the power switch of the third phase lower bridge arm of the motor to be in the on state.

[0054] In some embodiments, the situations in which the current fault type does not meet the preset pre-discharge conditions include: the current fault type is an overcurrent fault, and the phase current of the motor is greater than the second preset current value; and / or, the current fault type is an overvoltage fault, and the bus voltage is greater than the third preset voltage value; and / or, at least one power switch is in a preset desaturation fault state.

[0055] Specifically, after obtaining the current fault type of the motor, if the analysis of the current fault type determines that it does not meet the preset pre-discharge conditions, the pre-discharge stage will be skipped, and the subsequent phased short-circuit control program will be executed directly. This application does not adopt a uniform handling method for all faults, but first filters the severity and urgency characteristics of the fault based on whether the preset pre-discharge conditions are met. Among them, the situation where the preset pre-discharge conditions are not met is set as an urgent and serious fault situation. For example, when the fault type is determined to be "overcurrent fault" and its phase current value has exceeded a higher second preset current value (this value is higher than the threshold for initial triggering fault protection), it indicates that the system is experiencing an extremely severe current surge; or, when the fault type is "overvoltage fault" and the bus voltage exceeds a higher third preset voltage value, it indicates that the system energy has accumulated to a dangerous level; or, a "de-saturation fault" is directly detected in the power switch (such as IGBT), which is a direct precursor to the device burning out. If the current fault type meets any one or more of the above conditions, it is determined that the motor does not meet the preset pre-discharge conditions, and the pre-discharge stage must be skipped and the damped short circuit stage must be entered to prevent catastrophic consequences.

[0056] Under this path, a damped short-circuit operation will be immediately implemented. Specifically, the power switches of the first and second lower bridge arms of the motor will be turned on, while the power switch of the third lower bridge arm will remain off. This switching combination creates a two-phase short-circuit loop in the motor, utilizing the damping characteristics of the windings themselves to suppress current oscillations and voltage spikes. This damped short-circuit state will last for a first preset duration to ensure effective attenuation of transient energy.

[0057] Once the duration reaches the first preset duration, the controller immediately issues a command to switch the power switch of the third phase lower bridge arm, which was in the off state, to the on state. At this point, all three lower bridge arms of the inverter are on, and the motor enters a fully active short-circuit state, achieving a symmetrical three-phase short circuit in the windings. This embodiment optimizes the response speed and smoothness of the shutdown process by omitting the pre-discharge stage in emergency faults, while retaining the damped short-circuit stage ensures the overall reliability of the system transitioning from high speed to a fully short-circuit state.

[0058] Therefore, this application achieves multiple beneficial effects through a phased active short-circuit control strategy: First, it can significantly reduce the amplitude of the inrush current when a fault occurs and effectively suppress current oscillation, reducing its oscillation period to within 1-2 cycles; second, by reducing the rate of change of current (di / dt) and thermal stress, it effectively protects power devices and motor permanent magnets, avoiding the risk of device burnout due to overcurrent and permanent magnet demagnetization; in addition, this method has good hardware compatibility and cost advantages, supports "phase-by-phase damping braking," and can achieve energy dissipation without the need for additional external hardware; finally, it supports safety graded response, enabling rapid response under hard faults and smooth shutdown under soft faults, thereby comprehensively improving the reliability and safety of the system.

[0059] To facilitate a clearer and more intuitive understanding of the active short-circuit control method of this application by those skilled in the art, the following is combined with... Figure 3 Please provide a detailed explanation.

[0060] like Figure 3 As shown, the active short-circuit control method includes the following steps: First, fault signal detection is performed to determine if a system fault has occurred. If a fault occurs, it checks whether the phase current exceeds the set threshold A or a DESAT fault occurs, whether the bus voltage exceeds the set threshold B, and whether the duration of CAN communication loss exceeds the set threshold T3. If any condition is met, a fault is confirmed, and the process proceeds to the next step.

[0061] Upon confirming the fault, immediately shut down the PWM output to turn off all IGBTs. Then, determine if it is a serious fault, based on conditions including: whether the phase current exceeds the set threshold A+ΔI, or whether the bus voltage exceeds the set threshold B+ΔU, or whether a DESAT fault occurs. If any serious condition is met, skip the pre-discharge stage and directly enter the damped short-circuit stage.

[0062] If it is not a serious fault, the pre-discharge mode is selected according to the system configuration: if the system is equipped with a braking resistor, then mode A is executed, energy consumption braking, the Brake IGBT is turned on, and when the bus voltage is detected to drop below the safety threshold (e.g., from 800V to 680V), or the duration exceeds the threshold T0, or the speed is lower than the threshold n, the damping short circuit stage is entered.

[0063] If the system is configured without a braking resistor, it determines whether charging is allowed. If charging is not allowed, it executes mode B, phase-by-phase damping braking, periodically conducts two phase lower tubes, and enters the damping short-circuit stage when the duration exceeds the threshold T1 or the speed is lower than the threshold n.

[0064] If the system is configured without a braking resistor and charging is allowed, then mode C is executed to perform regenerative braking and current-limited feedback until the battery is full, or charging is not allowed, or the speed is lower than the threshold n, or the duration exceeds the threshold T2, and then the system enters the damped short-circuit stage.

[0065] During the damped short-circuit phase, any two phases of the lower tube are turned on for a duration of 0.5~2ms to suppress LC oscillation.

[0066] During the fully active short circuit phase, all three phases of the lower tube are conducting, and the system enters a stable and safe state.

[0067] According to the active short-circuit control method proposed in this application, based on the current fault type of the motor and determining that the motor meets the preset pre-discharge conditions, the target discharge mode is determined according to the hardware configuration information of the corresponding system of the motor, and energy is discharged; the power switches of the first and second phase lower bridge arms of the motor are controlled to be in the on state, and the power switch of the third phase lower bridge arm of the motor is controlled to be in the off state. When the duration of the power switch of the third phase lower bridge arm being in the off state reaches a first preset duration, the power switch of the third phase lower bridge arm of the motor is controlled to be in the on state. Thus, by using a phased and progressive short circuit, the problem of easy damage to power devices and permanent magnets caused by excessive inrush current and significant current oscillation in related technologies is solved. The inrush current and current oscillation during high-speed faults are significantly reduced, effectively protecting power devices and preventing demagnetization of permanent magnets.

[0068] Next, the active short-circuit control device proposed according to the embodiments of this application is described with reference to the accompanying drawings.

[0069] Figure 4 This is a block diagram of an active short-circuit control device according to an embodiment of this application.

[0070] like Figure 4 As shown, the active short-circuit control device includes: an acquisition module 100, an energy dissipation module 200, and a control module 300.

[0071] The acquisition module 100 is used to acquire the current fault type of the motor; the energy discharge module 200 is used to acquire the hardware configuration information of the corresponding system of the motor based on the current fault type and the determination that the motor meets the preset pre-energy discharge conditions, determine the target energy discharge mode according to the hardware configuration information, and discharge energy according to the target energy discharge mode; the control module 300 is used to control the power switch of the first phase lower bridge arm and the power switch of the second phase lower bridge arm of the motor to be in the conducting state, and control the power switch of the third phase lower bridge arm of the motor to be in the off state, and when the duration of the power switch of the third phase lower bridge arm being in the off state reaches the first preset duration, control the power switch of the third phase lower bridge arm of the motor to be in the conducting state.

[0072] Furthermore, in some embodiments, the discharge module 200 is used to: determine whether the system corresponding to the motor is configured with an energy discharge unit based on hardware configuration information; if the system corresponding to the motor is configured with an energy discharge unit, then turn on the braking power switch based on the first energy discharge mode to discharge energy through the energy discharge unit until a first stop discharge condition is reached; wherein, the first stop discharge condition includes: the bus voltage of the motor is less than a first preset voltage; or, the duration of energy discharge through the energy discharge unit is greater than a second preset duration; or, the speed of the motor is less than a first preset speed.

[0073] Furthermore, in some embodiments, after determining whether the system corresponding to the motor is configured with an energy dissipation unit based on hardware configuration information, the dissipation module 200 is further configured to: if the system corresponding to the motor is not configured with an energy dissipation unit, determine whether the current battery management system allows charging; if the current battery management system does not allow charging, based on the second energy dissipation mode, control the power switching transistors of any two lower bridge arms to conduct according to a preset period, and dissipate energy using the motor winding resistance until the second stop dissipation condition is reached; wherein, the second stop dissipation condition includes: the motor speed is less than the second preset speed; or, the duration of the conduction control of the power switching transistors of any two lower bridge arms according to the preset period is greater than the third preset duration.

[0074] Furthermore, in some embodiments, after determining whether the current battery management system allows charging, the discharge module 200 is further configured to: if the current battery management system allows charging, acquire the current battery level and the current battery temperature; if the current battery level is less than a preset level and the current battery temperature is within a preset temperature range, then perform current limiting feedback based on a third energy discharge mode until a third stop discharge condition is met; wherein, the third stop discharge condition includes: the current battery level is greater than a preset level; or, the current battery management system receives a command not to allow charging; or, the motor speed is less than a third preset speed; or, the duration of current limiting feedback based on the third energy discharge mode is greater than a fourth preset duration.

[0075] Furthermore, in some embodiments, before obtaining the current fault type of the motor, the acquisition module 100 is also used to: acquire the phase current of the motor, the state of at least one power switch, the bus voltage and the bus communication state; if the phase current of the motor is greater than a first preset current value, and / or, at least one power switch is in a preset desaturation fault state, and / or, the bus voltage is greater than a second preset voltage value, and / or, the duration of the bus communication state in a preset communication loss state is greater than a fifth preset duration, then the motor is determined to be in a fault state.

[0076] Furthermore, in some embodiments, after obtaining the current fault type of the motor, the obtaining module 100 is further configured to: if, based on the current fault type, it is determined that the current fault type does not meet the preset pre-discharge condition, control the power switch of the first phase lower bridge arm and the power switch of the second phase lower bridge arm of the motor to be in the on state, and control the power switch of the third phase lower bridge arm of the motor to be in the off state, and when the duration of the power switch of the third phase lower bridge arm being in the off state reaches a first preset duration, control the power switch of the third phase lower bridge arm of the motor to be in the on state.

[0077] Furthermore, in some embodiments, the situation where the current fault type does not meet the preset pre-discharge conditions includes: the current fault type is an overcurrent fault, and the phase current of the motor is greater than the second preset current value; and / or, the current fault type is an overvoltage fault, and the bus voltage is greater than the third preset voltage value; and / or, at least one power switch is in a preset desaturation fault state.

[0078] It should be noted that the foregoing explanation of the active short-circuit control method embodiment also applies to the active short-circuit control device of this embodiment, and will not be repeated here.

[0079] According to the active short-circuit control device proposed in this application, based on the current fault type of the motor and determining that the motor meets the preset pre-discharge conditions, the target discharge mode is determined according to the hardware configuration information of the corresponding system of the motor, and energy is discharged; the power switches of the first and second phase lower bridge arms of the motor are controlled to be in the on state, and the power switches of the third phase lower bridge arms of the motor are controlled to be in the off state. When the duration of the power switch of the third phase lower bridge arm being in the off state reaches a first preset duration, the power switch of the third phase lower bridge arm of the motor is controlled to be in the on state. Thus, by using a phased and progressive short circuit, the problem of easy damage to power devices and permanent magnets caused by excessive inrush current and significant current oscillation in related technologies is solved. The inrush current and current oscillation during high-speed faults are significantly reduced, effectively protecting power devices and preventing demagnetization of permanent magnets.

[0080] Figure 5 This is a schematic diagram of a vehicle provided in an embodiment of the present invention. The vehicle may include: The memory 501, the processor 502, and the computer program stored on the memory 501 and capable of running on the processor 502.

[0081] When the processor 502 executes the program, it implements the active short-circuit control method provided in the above embodiments.

[0082] Furthermore, the vehicle also includes: Communication interface 503 is used for communication between memory 501 and processor 502.

[0083] The memory 501 is used to store computer programs that can run on the processor 502.

[0084] The memory 501 may include high-speed RAM (Random Access Memory) memory, and may also include non-volatile memory, such as at least one disk storage.

[0085] If the memory 501, processor 502, and communication interface 503 are implemented independently, then the communication interface 503, memory 501, and processor 502 can be interconnected via a bus to complete communication between them. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 5 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0086] Optionally, in a specific implementation, if the memory 501, processor 502, and communication interface 503 are integrated on a single chip, then the memory 501, processor 502, and communication interface 503 can communicate with each other through an internal interface.

[0087] Processor 502 may be a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement embodiments of the present invention.

[0088] This invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described active short-circuit control method.

[0089] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0090] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0091] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. An active short-circuit control method, characterized in that, Includes the following steps: Obtain the current fault type of the motor; If, based on the current fault type, it is determined that the motor meets the preset pre-discharge conditions, the hardware configuration information of the system corresponding to the motor is obtained, the target discharge mode is determined according to the hardware configuration information, and energy is discharged according to the target discharge mode. The power switch transistors of the first and second phase lower bridge arms of the motor are controlled to be in the on state, and the power switch transistors of the third phase lower bridge arms of the motor are controlled to be in the off state. When the duration of the power switch transistor of the third phase lower bridge arm being in the off state reaches a first preset duration, the power switch transistor of the third phase lower bridge arm of the motor is controlled to be in the on state. The step of determining the target energy dissipation mode based on the hardware configuration information and discharging energy according to the target energy dissipation mode includes: determining whether the system corresponding to the motor is configured with an energy dissipation unit based on the hardware configuration information; if the system corresponding to the motor is configured with the energy dissipation unit, then turning on the braking power switch based on the first energy dissipation mode to dissipate energy through the energy dissipation unit until a first stop dissipation condition is reached; wherein, the first stop dissipation condition includes: the bus voltage of the motor is less than a first preset voltage; or, the duration of energy dissipation through the energy dissipation unit is greater than a second preset duration; or, the rotational speed of the motor is less than a first preset rotational speed. After determining whether the motor-corresponding system is configured with an energy dissipation unit based on the hardware configuration information, the method further includes: if the motor-corresponding system is not configured with the energy dissipation unit, determining whether the current battery management system allows charging; if the current battery management system does not allow charging, based on the second energy dissipation mode, according to a preset period, controlling the power switching transistors of any two lower bridge arms to conduct, and using the motor winding resistance to dissipate energy until the second stop dissipation condition is reached; wherein, the second stop dissipation condition includes: the motor speed is less than the second preset speed; or, the duration of controlling the power switching transistors of any two lower bridge arms to conduct according to the preset period is greater than the third preset duration.

2. The method according to claim 1, characterized in that, After determining whether the current battery management system allows charging, the process also includes: If the current battery management system allows charging, obtain the current battery level and current battery temperature; If the current battery charge is less than a preset charge and the current battery temperature is within a preset temperature range, then current limiting feedback is performed based on the third energy discharge mode until the third discharge stop condition is met; wherein, The third condition for stopping the discharge includes: The current battery level is greater than the preset battery level; Alternatively, the current battery management system receives a charging disallow command; Alternatively, the speed of the motor is less than the third preset speed; Alternatively, the duration of the current-limiting feedback based on the third energy leakage mode is longer than the fourth preset duration.

3. The method according to claim 1, characterized in that, Before obtaining the current fault type of the motor, the following steps are also included: The phase current of the motor, the status of at least one power switch, the bus voltage, and the bus communication status are obtained. If the phase current of the motor is greater than a first preset current value, and / or, at least one power switch is in a preset desaturation fault state, and / or, the bus voltage is greater than a second preset voltage value, and / or, the duration of the bus communication state in a preset communication loss state is greater than a fifth preset duration, then the motor is determined to be in a fault state.

4. The method according to claim 1, characterized in that, After obtaining the current fault type of the motor, the process also includes: If, based on the current fault type, it is determined that the current fault type does not meet the preset pre-discharge condition, the power switch of the first phase lower bridge arm and the power switch of the second phase lower bridge arm of the motor are controlled to be in the on state, and the power switch of the third phase lower bridge arm of the motor is controlled to be in the off state. When the duration of the power switch of the third phase lower bridge arm being in the off state reaches a first preset duration, the power switch of the third phase lower bridge arm of the motor is controlled to be in the on state.

5. The method according to claim 4, characterized in that, The situations in which the current fault type does not meet the preset pre-discharge conditions include: The current fault type is an overcurrent fault, and the phase current of the motor is greater than the second preset current value; And / or, the current fault type is an overvoltage fault, and the bus voltage is greater than a third preset voltage value; And / or, at least one power switch is in a preset desaturation fault state.

6. An active short-circuit control device, characterized in that, include: The acquisition module is used to acquire the current fault type of the motor; The energy discharge module is used to obtain the hardware configuration information of the system corresponding to the motor when it is determined that the motor meets the preset pre-energy discharge conditions based on the current fault type, determine the target energy discharge mode according to the hardware configuration information, and discharge energy according to the target energy discharge mode. The control module is used to control the power switch of the first phase lower bridge arm and the power switch of the second phase lower bridge arm of the motor to be in the on state, and to control the power switch of the third phase lower bridge arm of the motor to be in the off state. When the duration of the power switch of the third phase lower bridge arm being in the off state reaches a first preset duration, the control module is used to control the power switch of the third phase lower bridge arm of the motor to be in the on state. The energy dissipation module is used to: determine, based on the hardware configuration information, whether the system corresponding to the motor is configured with an energy dissipation unit; if the system corresponding to the motor is configured with the energy dissipation unit, then conduct the braking power switch based on the first energy dissipation mode to dissipate energy through the energy dissipation unit until a first stop dissipation condition is reached; wherein, the first stop dissipation condition includes: the bus voltage of the motor is less than a first preset voltage; or, the duration of energy dissipation through the energy dissipation unit is greater than a second preset duration; or, the speed of the motor is less than a first preset speed. After determining whether the motor-corresponding system is configured with an energy dissipation unit based on the hardware configuration information, the energy dissipation module is further configured to: if the motor-corresponding system is not configured with the energy dissipation unit, determine whether the current battery management system allows charging; if the current battery management system does not allow charging, based on the second energy dissipation mode, control the power switching transistors of any two lower bridge arms to conduct according to a preset period, and dissipate energy using the motor winding resistance until the second stop dissipation condition is reached; wherein, the second stop dissipation condition includes: the motor speed is less than the second preset speed; or, the duration of controlling the power switching transistors of any two lower bridge arms to conduct according to the preset period is greater than the third preset duration.

7. A vehicle, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the computer program to implement the active short-circuit control method as described in any one of claims 1-5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, The computer program is executed by a processor to implement the active short-circuit control method as described in any one of claims 1-5.

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