Bridge arm short circuit fault detection method and device, trailer protection method and device, vehicle and storage medium

Abstract

The invention discloses a bridge arm short-circuit fault detection method, a trailer protection method and device and a vehicle. The method comprises the steps that a motor controller of the vehicle carries out bridge arm fault or overcurrent fault detection; and when the motor controller detects the bridge arm fault or the overcurrent fault and is in a shutdown state, determining whether the motor controller has the bridge arm short circuit fault or not based on three-phase current in a three-phase bridge circuit of the motor controller. According to the method, the device and the vehicle, bridge arm fault or overcurrent fault detection is performed on the motor controller, whether the bridge arm short circuit fault exists in the motor controller or not is judged according to the three-phase current, the bridge arm short circuit fault can be detected by utilizing an existing universal hardware scheme, and the method is high in universality, simple and reliable in identification and high in reliability. The method is suitable for bridge arm short-circuit fault detection of various motor controllers, and extra hardware cost is not needed.

Description

Technical Field

[0001] The present application relates to the field of automobile technology, and more specifically to a bridge arm short circuit fault detection method, a trailer protection method, a device, a vehicle and a storage medium. Background Art

[0002] The new energy vehicle industry has a broad development prospect. In new energy vehicles, the motor controller uses a three-phase bridge circuit to convert the DC voltage of the battery into an AC voltage to drive the permanent magnet synchronous motor. As a key core component in new energy vehicles, the motor controller has various failure modes, such as a bridge arm short circuit failure. The bridge arm short circuit failure may be caused by a switch tube short circuit, abnormal pulse width modulation output of the main control chip, reverse level, abnormal gate drive, abnormal driver chip output, etc. The bridge arm short circuit failure may cause the motor controller to stop working at the least, and may cause damage to the motor controller in severe cases, affecting the driving safety of the vehicle.

[0003] In the related art, a dedicated driver chip is used to detect the voltage drop of the switch tube in the three-phase bridge circuit in the motor controller to realize bridge arm short circuit fault detection. However, the chip cost is high, and the switch tube types of the three-phase bridge circuits of different motor controllers are different, and the voltage drops of the switch tubes are not the same. Therefore, it is not easy to expand the application and the solution is not universal. Summary of the invention

[0004] The present application is proposed to solve the above problems. According to one aspect of the present application, a bridge arm short circuit fault detection method is provided, the method comprising: a motor controller of a vehicle performs bridge arm fault or overcurrent fault detection; when the motor controller detects the bridge arm fault or the overcurrent fault and is in a shutdown state, determining whether the motor controller has a bridge arm short circuit fault based on the three-phase current in the three-phase bridge circuit of the motor controller.

[0005] In one embodiment of the present application, the method of determining whether the motor controller has a bridge arm short circuit fault based on the three-phase current in the three-phase bridge circuit of the motor controller includes: performing low-pass filtering on the three-phase current to obtain the three-phase current after low-pass filtering; when the absolute value of each phase current in the three-phase current after low-pass filtering is greater than or equal to a preset current threshold, and the duration is greater than or equal to a first time threshold, determining that the motor controller has the bridge arm short circuit fault; and / or, when the absolute value of each phase current in the three-phase current after low-pass filtering is less than the preset current threshold, or when the absolute value of each phase current in the three-phase current after low-pass filtering is greater than or equal to the preset current threshold, but the duration is less than the first time threshold, determining that the motor controller does not have the bridge arm short circuit fault.

[0006] In one embodiment of the present application, the method further includes: determining the location of the bridge arm short circuit fault based on the three-phase current after low-pass filtering.

[0007] In one embodiment of the present application, determining the location of the bridge arm short-circuit fault based on the three-phase current after low-pass filtering includes: determining the maximum value of the absolute value of each phase current in the three-phase current after low-pass filtering, wherein the phase where the maximum value is located is the short-circuited phase of the bridge arm short-circuit fault; when the current value of the short-circuited phase after low-pass filtering is a positive value, determining that the location of the bridge arm short-circuit fault is on the upper bridge; when the current value of the short-circuited phase after low-pass filtering is a negative value, determining that the location of the bridge arm short-circuit fault is on the lower bridge.

[0008] In one embodiment of the present application, before determining whether the motor controller has a bridge arm short circuit fault based on the three-phase current in the three-phase bridge circuit of the motor controller, it also includes: confirming that the motor controller meets the short circuit state detection condition, wherein the short circuit state detection condition includes: the low voltage power supply of the motor controller is normal, the current sensor in the motor controller is normal, the motor controller is in a non-three-phase active short circuit state, and the motor speed of the vehicle is greater than or equal to a first speed threshold.

[0009] According to another aspect of the present application, a trailer protection method is provided, the method comprising: a motor controller of a vehicle performs bridge arm fault or overcurrent fault detection; when the motor controller detects the bridge arm fault or the overcurrent fault and is in a shutdown state, determining whether the motor controller has a bridge arm short circuit fault based on the three-phase current in the three-phase bridge circuit of the motor controller; when the motor controller has the bridge arm short circuit fault, performing trailer status detection; and executing a protection action when the vehicle is in a trailer state.

[0010] In one embodiment of the present application, the method of determining whether the motor controller has a bridge arm short circuit fault based on the three-phase current in the three-phase bridge circuit of the motor controller includes: performing low-pass filtering on the three-phase current to obtain the three-phase current after low-pass filtering, and when the absolute value of each phase current in the three-phase current after low-pass filtering is greater than or equal to a preset current threshold, and the duration is greater than or equal to a first time threshold, determining that the motor controller has the bridge arm short circuit fault; and / or, when the absolute value of each phase current in the three-phase current after low-pass filtering is less than the preset current threshold, or when the absolute value of each phase current in the three-phase current after low-pass filtering is greater than or equal to the preset current threshold, but the duration is less than the first time threshold, determining that the motor controller does not have the bridge arm short circuit fault.

[0011] In one embodiment of the present application, the method further includes: determining the location of the bridge arm short circuit fault based on the three-phase current after low-pass filtering.

[0012] In one embodiment of the present application, determining the location of the bridge arm short-circuit fault based on the three-phase current after low-pass filtering includes: determining the maximum value of the absolute value of each phase current in the three-phase current after low-pass filtering, wherein the phase where the maximum value is located is the short-circuited phase of the bridge arm short-circuit fault; when the current value of the short-circuited phase after low-pass filtering is a positive value, determining that the location of the bridge arm short-circuit fault is on the upper bridge; when the current value of the short-circuited phase after low-pass filtering is a negative value, determining that the location of the bridge arm short-circuit fault is on the lower bridge.

[0013] In one embodiment of the present application, the execution of the protection action includes: when the location of the bridge arm short-circuit fault is on the upper bridge, controlling the upper bridges in the three-phase bridge circuit to be completely turned on and the lower bridges to be completely turned off; when the location of the bridge arm short-circuit fault is on the upper bridge, controlling the upper bridges in the three-phase bridge circuit to be completely turned off and the lower bridges to be completely turned on.

[0014] In one embodiment of the present application, before determining whether the motor controller has a bridge arm short circuit fault based on the three-phase current in the three-phase bridge circuit of the motor controller, it also includes: determining that the motor controller meets the short circuit state detection condition, wherein the short circuit state detection condition includes: the low voltage power supply of the motor controller is normal, the current sensor in the motor controller is normal, the motor controller is in a non-three-phase active short circuit state, and the motor speed of the vehicle is greater than or equal to a first speed threshold.

[0015] In one embodiment of the present application, the trailer status detection includes: at least one of the following when the motor controller is in a shutdown state: when the position sensor of the motor controller is in a normal state, the motor speed of the vehicle is greater than or equal to a second speed threshold and the duration is greater than or equal to a second time threshold, and it is determined that the trailer status exists; when the position sensor of the motor controller is in an abnormal state, the drive wheel speed of the vehicle is greater than or equal to a preset wheel speed threshold and the duration is greater than or equal to a third time threshold, and it is determined that the trailer status exists.

[0016] In one embodiment of the present application, the executing protection action includes: the motor controller sends a heat dissipation request to the vehicle controller of the vehicle, and the vehicle controller and / or the motor controller controls the heat dissipation system to enable maximum heat dissipation capacity.

[0017] In one embodiment of the present application, before the motor controller of the vehicle performs bridge arm fault or overcurrent fault detection, it also includes: performing fault detection on the motor controller; if it is determined that the motor controller has a fault and has caused the vehicle to be in an undriveable state, lighting up the vehicle's instrument alarm prompt.

[0018] According to another aspect of the present application, a bridge arm short circuit fault detection device is provided, the device comprising a processor and a memory, wherein the memory stores a computer executable program run by the processor, and when the computer executable program is run by the processor, the processor executes the above-mentioned bridge arm short circuit fault detection method.

[0019] According to another aspect of the present application, a trailer protection device is provided, the device comprising a processor and a memory, wherein the memory stores a computer executable program run by the processor, and when the computer executable program is run by the processor, the processor executes the above-mentioned trailer protection method.

[0020] According to yet another aspect of the present application, a vehicle is provided, the vehicle comprising the above-mentioned bridge arm short-circuit fault detection device or trailer protection device.

[0021] According to another aspect of the present application, a storage medium is provided, on which a computer program executed by a processor is stored. When the computer program is executed by the processor, the processor executes the above-mentioned bridge arm short circuit fault detection method or trailer protection method.

[0022] The bridge arm short circuit fault detection method, trailer protection method, device and vehicle of the present application perform bridge arm fault or overcurrent fault detection on the motor controller, and judge whether the motor controller has a bridge arm short circuit fault according to the three-phase current in the three-phase bridge circuit. The bridge arm short circuit fault can be detected by using the existing general hardware solution. The method has strong versatility, simple and reliable identification, and is applicable to bridge arm short circuit fault detection of various motor controllers without requiring additional hardware costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] By describing the embodiments of the present application in more detail in conjunction with the accompanying drawings, the above and other purposes, features and advantages of the present application will become more apparent. The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0024] Figure 1 A schematic flowchart of a bridge arm short circuit fault detection method according to an embodiment of the present application is shown.

[0025] Figure 2 A schematic flow chart of a trailer protection method according to an embodiment of the present application is shown.

[0026] Figure 3 A schematic structural block diagram of a bridge arm short-circuit fault detection device according to an embodiment of the present application is shown.

[0027] Figure 4 A schematic structural block diagram of a trailer protection device according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present application more obvious, the example embodiments according to the present application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application, and it should be understood that the present application is not limited to the example embodiments described herein. Based on the embodiments of the present application described in the present application, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present application.

[0029] First, refer to Figure 1 The bridge arm short circuit fault detection method 100 according to an embodiment of the present application is described. Figure 1 FIG. 1 is a schematic flow chart of a bridge arm short circuit fault detection method 100 according to an embodiment of the present application. Figure 1 As shown, the bridge arm short circuit fault detection method 100 according to the embodiment of the present application may include the following steps:

[0030] In step S110 , the motor controller of the vehicle performs bridge arm fault or overcurrent fault detection.

[0031] In step S120 , when the motor controller detects a bridge arm fault or an overcurrent fault and is in a shutdown state, it is determined whether the motor controller has a bridge arm short circuit fault based on the three-phase current in the three-phase bridge circuit of the motor controller.

[0032] In the embodiments of the present application, firstly, the motor controller of the vehicle needs to perform fault detection. When the motor controller detects a bridge arm fault or an overcurrent fault and the motor controller is in a shutdown state, the motor controller is subjected to a short circuit state detection. Since there are many types of bridge arm faults in the motor controller, a short circuit state detection is performed to determine whether the bridge arm fault is a short circuit fault (i.e., a bridge arm short circuit fault); secondly, in the short circuit state detection, in order to ensure the accuracy and reliability of the detection, the detection conditions of the short circuit state need to be met; finally, after the detection conditions of the short circuit state are met, the three-phase current in the three-phase bridge circuit of the motor controller can be used to determine whether the motor controller has a bridge arm short circuit fault. This solution is simple and reliable to identify and has strong versatility.

[0033] Therefore, according to the bridge arm short circuit fault detection method 100 of the embodiment of the present application, by performing bridge arm fault or overcurrent fault detection on the motor controller, it is determined whether the motor controller has a bridge arm short circuit fault according to the three-phase current in the three-phase bridge circuit, and the bridge arm short circuit fault can be detected using the existing general hardware solution. This method has strong versatility, simple and reliable identification, and is suitable for bridge arm short circuit fault detection of various motor controllers without the need for additional hardware costs.

[0034] In an embodiment of the present application, the motor controller of the vehicle in step S110 performs bridge arm fault or overcurrent fault detection. Specifically, before the motor controller of the vehicle performs bridge arm fault or overcurrent fault detection, the motor controller needs to perform self-fault detection, determine that the motor controller has a fault and makes the vehicle in an undriveable state, then light up the instrument alarm prompt of the vehicle, for example, the overcurrent fault, overvoltage fault, overheating fault and other faults of the motor controller can stop the vehicle from running (that is, the vehicle is in an undriveable state). And when the motor controller detects its own fault, the self-fault is a bridge arm fault or an overcurrent fault, and the next bridge arm short circuit fault detection is performed. When the bridge arm fault is not detected, but the internal module of the motor controller itself has a fault, since the vehicle motor keeps rotating at this time, an overcurrent fault will occur, so it is also necessary to detect the overcurrent fault. Among them, the bridge arm fault can be detected by the driver chip of the motor controller, and the overcurrent fault can be detected by the current comparison circuit in the motor controller. It should be noted that the bridge arm fault and the overcurrent fault are generally implemented by hardware circuits, which belong to the prior art and are not specifically described here.

[0035] In an embodiment of the present application, when the motor controller detects a bridge arm fault or an overcurrent fault and is in a shutdown state in step S120, it is determined whether the motor controller has a bridge arm short circuit fault based on the three-phase current in the three-phase bridge circuit of the motor controller. Specifically, when it is detected that the motor controller has a bridge arm or an overcurrent fault, and the motor controller is in a shutdown state at this time, since there are many types of bridge arm faults in the motor controller, it is necessary to detect the short circuit fault in the bridge arm fault (that is, to perform a short circuit state detection) to determine whether the motor controller has a bridge arm short circuit fault. Among them, the bridge arm fault can be a short circuit between the drain and source of the power tube (that is, the power tube DS is short-circuited), the pulse width modulation (PWM) output of the main control chip is abnormal, the gate drive is abnormal, and the driver chip output is abnormal.

[0036] In this embodiment, it is determined whether the motor controller has a bridge arm short circuit fault based on the three-phase current in the three-phase bridge circuit of the motor controller. Specifically, the motor controller includes a three-phase bridge circuit, and each phase bridge arm of the three-phase bridge circuit includes an upper bridge arm and a lower bridge arm. The motor controller is usually equipped with a three-phase current detection circuit, which can obtain the value of the three-phase current in real time. The bridge arm short circuit fault of the motor controller can be judged by the three-phase current value (that is, the current value of each phase bridge arm of the three-phase bridge circuit).

[0037] In an embodiment of the present application, before determining whether the motor controller has a bridge arm short circuit fault based on the three-phase current in the three-phase bridge circuit of the motor controller, it also includes: determining that the motor controller meets the short circuit state detection condition, wherein the short circuit state detection condition includes: the low-voltage power supply of the motor controller is normal, the current sensor in the motor controller is normal, the motor controller is in a non-three-phase active short circuit state, and the motor speed of the vehicle is greater than or equal to the first speed threshold. Specifically, ensuring that the low-voltage power supply of the motor controller is normal and the internal power module is normal can exclude faults caused by the vehicle's battery. The low-voltage power supply can be a battery that can provide low-voltage direct current. The voltage provided by the battery can be a suitable voltage such as +12V, +24V or +48V; ensuring that the current sensor is normal can exclude faults caused by the current sensor. The current sensor is used to detect the actual working current of the motor, including bus current and three-phase AC; the motor controller is in a non-three-phase active short circuit state, that is, it excludes the motor controller from being in a three-phase active short circuit fault; the motor speed of the vehicle is greater than or equal to the first speed threshold to exclude the motor fault of the vehicle. By satisfying the above short-circuit state detection conditions, the influencing factors of the bridge arm short-circuit fault can be eliminated, thereby improving the accuracy of bridge arm short-circuit fault detection.

[0038] In an embodiment of the present application, based on the three-phase current in the three-phase bridge circuit of the motor controller, it is determined whether the motor controller has a bridge arm short circuit fault, including: low-pass filtering the three-phase current to obtain the three-phase current after low-pass filtering; when the absolute value of each phase current in the three-phase current after low-pass filtering is greater than or equal to the preset current threshold, and the duration is greater than or equal to the first time threshold, it is determined that the motor controller has a bridge arm short circuit fault; and / or, when the absolute value of each phase current in the three-phase current after low-pass filtering is less than the preset current threshold, or when the absolute value of each phase current in the three-phase current after low-pass filtering is greater than or equal to the preset current threshold, but the duration is less than the first time threshold, it is determined that the motor controller does not have a bridge arm short circuit fault. Specifically, the waveform of the three-phase current is affected by factors such as the uneven magnetic field of the motor controller itself, the change of the load, and the interference in the signal acquisition circuit, so that the collected current waveform has a large interference deformation, which is quite different from the ideal waveform. In order to reduce the influence of interference factors, it is necessary to low-pass filter the three-phase current. When the absolute value of each phase current in the three-phase current after low-pass filtering is greater than or equal to the preset current threshold, and the time greater than or equal to the preset current threshold lasts for more than a certain time threshold (that is, the first time threshold), it can be determined that there is a bridge arm short circuit fault in the motor controller.

[0039] In an embodiment of the present application, after detecting that a bridge arm short-circuit fault exists in the motor controller, it also includes: determining the location of the bridge arm short-circuit fault based on the three-phase current after low-pass filtering. Specifically, when a bridge arm fault is detected in the motor controller, since the three-phase bridge circuit includes three phases, and each phase is divided into an upper bridge arm and a lower bridge arm, the specific short-circuit location of the bridge arm short-circuit fault can also be determined, that is, the bridge arm short-circuit fault occurs in a certain phase in the three-phase bridge circuit, and the phase where the short-circuit fault occurs is located in the three-phase upper bridge or the three-phase lower bridge.

[0040] In an embodiment of the present application, the position of the bridge arm short circuit fault is determined based on the three-phase current after low-pass filtering, including: determining the maximum value of the absolute value of each phase current in the three-phase current after low-pass filtering, wherein the phase where the maximum value is located is the short-circuited phase of the bridge arm short circuit fault; when the current value of the short-circuited phase after low-pass filtering is positive, the position of the bridge arm short circuit fault is determined to be in the upper bridge; when the current value of the short-circuited phase after low-pass filtering is negative, the position of the bridge arm short circuit fault is determined to be in the lower bridge. Wherein, the bridge arm in the three-phase bridge circuit is composed of two complementary switch tubes, and the switch tube can be an insulated gate bipolar transistor (also known as IGBT) or an insulated gate field effect transistor (also known as MOS tube). In order to determine the position of the motor controller bridge arm short circuit fault (that is, to determine that a certain switch tube has a short circuit), the short-circuited phase of the bridge arm short circuit fault can be determined by the absolute value of each phase current of the three-phase current after low-pass filtering, and the maximum value of the absolute value of the current after low-pass filtering is found, and the phase where the maximum value is located is determined as the short-circuited phase of the bridge arm short circuit fault. Furthermore, by determining the direction of the value of the short-circuited phase current after low-pass filtering, it can be determined whether the bridge arm short-circuit fault is in the upper bridge arm or lower bridge arm of the short-circuited phase. When the current value after low-pass filtering of the short-circuited phase is a positive value, it can be determined that a short-circuit fault has occurred in the upper bridge arm of the short-circuited phase. When the current value after low-pass filtering of the short-circuited phase is a negative value, it can be determined that a short-circuit fault has occurred in the lower bridge arm of the short-circuited phase. This scheme detects that a specific switch tube in the three-phase bridge circuit in the motor controller has a short circuit by filtering the phase current size and polarity. This method identification scheme is simple and reliable, and is applicable to various motor controllers.

[0041] In one example, for a controller that samples the current of a three-phase motor, after the short-circuit state detection conditions are met, when the absolute values ​​of the three-phase currents after low-pass filtering are all greater than the preset current threshold and the duration exceeds the preset time, it is determined to be a short circuit, and then the maximum value of the absolute value of the phase current after low-pass filtering is found, and the phase with the largest absolute value is the short-circuited phase; then the direction of the value of the short-circuited phase current after low-pass filtering is determined. If the value of the phase current after low-pass filtering is positive, it is determined that a short circuit has occurred in the upper bridge of the phase, and if the value of the phase current after low-pass filtering is negative, it is determined that a short circuit has occurred in the lower bridge of the phase. In other examples, for a motor controller that obtains the error status of six driver chips and for a motor controller that can obtain the error status of the three-phase upper bridge and lower bridge of the motor controller, after identifying the short-circuit state, it can be known that the short-circuit fault occurs in the specific position of the three-phase upper bridge arm or the three-phase lower bridge arm based on the obtained driver chip error information. After the short-circuit state detection conditions are met, when the absolute values ​​of the three-phase current path currents after low-pass filtering are greater than the preset current threshold and the duration exceeds the preset time, it is determined to be a short circuit. If there is an error in the three-phase upper bridge drive chip, it can be identified as a bridge arm short circuit in the upper bridge. If there is an error in the three-phase lower bridge drive chip, it can be identified as a bridge arm short circuit in the lower bridge.

[0042] In one embodiment, when the motor controller detects a bridge arm short circuit fault, the bridge arm short circuit fault can be stored in an electrically erasable programmable read-only memory (EEPROM). When the EEPROM is powered on again, the bridge arm short circuit fault is read, the bridge arm short circuit fault is sent to the vehicle controller of the vehicle, and an alarm is given to the user; when the EEPROM is powered on again, the bridge arm short circuit fault has been restored, and the fault flag in the EEPROM is cleared, wherein the condition for fault recovery is that the motor controller does not detect the bridge arm fault and does not detect the overcurrent fault, and the motor controller is in normal working state.

[0043] Therefore, according to the bridge arm short circuit fault detection method of the embodiment of the present application, the motor controller is subjected to bridge arm fault or overcurrent fault detection, and it is determined whether the motor controller has a bridge arm short circuit fault according to the three-phase current in the three-phase bridge circuit. The bridge arm short circuit fault can be detected using the existing general hardware solution. This method has strong versatility, simple and reliable identification, and is suitable for bridge arm short circuit fault detection of various motor controllers without the need for additional hardware costs.

[0044] Refer to the following Figure 2 The trailer protection method 200 according to an embodiment of the present application is described. Figure 2 FIG. 2 shows a schematic flow chart of a trailer protection method 200 according to an embodiment of the present application. Figure 2 As shown, the trailer protection method 200 according to the embodiment of the present application may include the following steps:

[0045] In step S210 , the motor controller of the vehicle performs bridge arm fault or overcurrent fault detection.

[0046] In step S220 , when the motor controller detects a bridge arm fault or an overcurrent fault and is in a shutdown state, it is determined whether the motor controller has a bridge arm short circuit fault based on the three-phase current in the three-phase bridge circuit of the motor controller.

[0047] In step S230, when a bridge arm short circuit fault occurs in the motor controller, a trailer status detection is performed.

[0048] In step S240, when the vehicle is in the trailer state, a protection action is performed.

[0049] In an embodiment of the present application, the motor controller of the vehicle in step S210 performs bridge arm fault or overcurrent fault detection. Specifically, before the motor controller of the vehicle performs bridge arm fault or overcurrent fault detection, it is necessary to perform self-fault detection on the motor controller, determine that the motor controller has a fault and makes the vehicle in an undriveable state, and light up the instrument alarm prompt of the vehicle. And when the motor controller detects its own fault, the self-fault is a bridge arm fault or an overcurrent fault, and the next bridge arm short circuit fault detection is performed. When the bridge arm fault is not detected, but the internal module of the motor controller itself has a fault, since the vehicle motor is always rotating at this time, an overcurrent fault will occur, so it is also necessary to detect the overcurrent fault. Among them, the bridge arm fault can be detected by the driving chip of the motor controller, and the overcurrent fault can be detected by the current comparison circuit in the motor controller. It should be noted that the bridge arm fault detection and overcurrent fault detection are generally implemented by hardware circuits, which belong to the prior art and will not be elaborated in detail here.

[0050] In an embodiment of the present application, when the motor controller detects a bridge arm fault or an overcurrent fault and is in a shutdown state in step S220, it is determined whether the motor controller has a bridge arm short circuit fault based on the three-phase current in the three-phase bridge circuit of the motor controller. Specifically, when it is detected that the motor controller has a bridge arm or an overcurrent fault, and the motor controller is in a shutdown state at this time, since there are many types of bridge arm faults in the motor controller, it is necessary to detect the short circuit fault in the bridge arm fault (that is, to perform a short circuit state detection) to determine whether the motor controller has a bridge arm short circuit fault. Among them, the bridge arm fault can be a short circuit between the drain and source of the power tube (that is, a short circuit of the power tube DS), an abnormal output of the pulse width modulation (PWM) of the main control chip, an abnormal gate drive, and an abnormal output of the driver chip.

[0051] In this embodiment, it is determined whether the motor controller has a bridge arm short circuit fault based on the three-phase current in the three-phase bridge circuit of the motor controller. Specifically, the motor controller includes a three-phase bridge circuit, and each phase bridge arm of the three-phase bridge circuit includes an upper bridge arm and a lower bridge arm. The motor controller is usually equipped with a three-phase current detection circuit, which can obtain the value of the three-phase current in real time. The bridge arm short circuit fault of the motor controller can be judged by the three-phase current value (that is, the current value of each phase bridge arm of the three-phase bridge circuit).

[0052] In an embodiment of the present application, before determining whether the motor controller has a bridge arm short circuit fault based on the three-phase current in the three-phase bridge circuit of the motor controller, it also includes: determining that the motor controller meets the short circuit state detection conditions, wherein the short circuit state detection conditions include: the low-voltage power supply of the motor controller is normal, the current sensor in the motor controller is normal, the motor controller is in a non-three-phase active short circuit state, and the motor speed of the vehicle is greater than or equal to the first speed threshold. Specifically, ensuring that the low-voltage power supply of the motor controller is normal and the internal power module is normal can exclude faults caused by the vehicle's battery. The low-voltage power supply can be a battery that can provide low-voltage direct current. The voltage provided by the battery can be a suitable voltage such as +12V, +24V or +48V; ensuring that the current sensor is normal can exclude faults caused by the current sensor. The current sensor is used to detect the actual working current of the motor, including bus current and three-phase AC; the motor controller is in a non-three-phase active short circuit state, that is, it excludes the motor controller from being in a three-phase active short circuit fault; the motor speed of the vehicle is greater than or equal to the first speed threshold to exclude the vehicle's motor fault. After the above short-circuit state detection conditions are met, the short-circuit state detection is performed on the motor controller, thereby improving the accuracy of bridge arm short-circuit fault detection.

[0053] In an embodiment of the present application, based on the three-phase current in the three-phase bridge circuit of the motor controller, determining whether the motor controller has a bridge arm short circuit fault includes: low-pass filtering the three-phase current to obtain the three-phase current after low-pass filtering; when the absolute value of each phase current in the three-phase current after low-pass filtering is greater than or equal to the preset current threshold, and the duration is greater than or equal to the first time threshold, determining that the motor controller has a bridge arm short circuit fault; and / or when the absolute value of each phase current in the three-phase current after low-pass filtering is less than the preset current threshold, or when the absolute value of each phase current in the three-phase current after low-pass filtering is greater than or equal to the preset current threshold, but the duration is less than the first time threshold, determining that the motor controller does not have a bridge arm short circuit fault. Specifically, the waveform of the three-phase current is affected by factors such as the uneven magnetic field of the motor controller itself, the change of the load, and the interference in the signal acquisition circuit, so that the collected current waveform has a large interference deformation, which is far from the ideal waveform. In order to reduce the influence of interference factors, it is necessary to low-pass filter the three-phase current. When the absolute value of each phase current in the three-phase current after low-pass filtering is greater than or equal to the preset current threshold, and the duration of being greater than or equal to the preset current threshold exceeds a certain time threshold (ie, the first time threshold), it can be determined that there is a bridge arm short circuit fault in the motor controller.

[0054] In an embodiment of the present application, after detecting that a bridge arm short-circuit fault exists in the motor controller, it also includes: determining the location of the bridge arm short-circuit fault based on the three-phase current after low-pass filtering. Specifically, when it is detected that a bridge arm fault exists in the motor controller, since the three-phase bridge circuit includes three phases, and each phase is divided into an upper bridge arm and a lower bridge arm, the specific short-circuit location of the bridge arm short-circuit fault can also be detected, that is, the bridge arm short-circuit fault occurs in a certain phase in the three-phase bridge circuit and the phase where the short-circuit fault occurs is located in the three-phase upper bridge or the three-phase lower bridge.

[0055] In an embodiment of the present application, the position of the bridge arm short circuit fault is determined based on the three-phase current after low-pass filtering, including: determining the maximum value of the absolute value of each phase current in the three-phase current after low-pass filtering, wherein the phase where the maximum value is located is the short-circuited phase of the bridge arm short circuit fault; when the current value of the short-circuited phase after low-pass filtering is positive, the position of the bridge arm short circuit fault is determined to be in the upper bridge; when the current value of the short-circuited phase after low-pass filtering is negative, the position of the bridge arm short circuit fault is determined to be in the lower bridge. Wherein, the bridge arm in the three-phase bridge circuit is composed of two complementary switch tubes, and the switch tube can be an insulated gate bipolar transistor (also known as IGBT) or an insulated gate field effect transistor (also known as MOS tube). In order to determine the position of the motor controller bridge arm short circuit fault, the short-circuited phase of the bridge arm short circuit fault can be determined by the absolute value of each phase current of the three-phase current after low-pass filtering, and the maximum value of the absolute value of the current after low-pass filtering is found, and the phase where the maximum value is located is determined as the short-circuited phase of the bridge arm short circuit fault. Furthermore, it is also possible to determine whether the bridge arm short-circuit fault is in the upper bridge arm or lower bridge arm of the short-circuited phase by judging the direction of the value of the short-circuited phase current after low-pass filtering. When the current value of the short-circuited phase after low-pass filtering is a positive value, it can be determined that a short-circuit fault has occurred in the upper bridge arm of the short-circuited phase. When the current value of the short-circuited phase after low-pass filtering is a negative value, it can be determined that a short-circuit fault has occurred in the lower bridge arm of the short-circuited phase. This scheme detects that a specific switch tube in the three-phase bridge circuit in the motor controller has a short circuit by filtering the phase current size and polarity. The identification scheme is simple and reliable and is applicable to various motor controllers.

[0056] In an embodiment of the present application, when the motor controller has a bridge arm short circuit fault in step S230, the trailer status is detected. Since it is possible that when the motor controller is towing in the case of a bridge arm short circuit fault, the short-circuited bridge arm of the motor controller is directly connected due to the existence of the anti-parallel diode short circuit, the inter-phase back electromotive force loop impedance of the three-phase bridge circuit mainly comes from the resistance and inductance of the motor. At this time, even if the motor speed of the trailer is low, a huge short-circuit current will be generated, and even the controller will catch fire and a serious accident will occur. Therefore, it is necessary to detect the trailer status of the vehicle when a bridge arm short circuit fault is detected. Through the detection result of the trailer status, the motor controller performs corresponding protection actions, which can effectively avoid the excessive short-circuit current when towing under the bridge arm short circuit fault. Further damage to the motor controller.

[0057] In an embodiment of the present application, when the vehicle is in a trailer state in step S240, a protection action is performed. Wherein, the trailer state detection includes: at least one of the following when the motor controller is in a shutdown state; when the position sensor of the motor controller is in a normal state, the motor speed of the vehicle is greater than or equal to the second speed threshold and the duration is greater than or equal to the second time threshold, and it is determined that there is a trailer state; when the position sensor of the motor controller is in an abnormal state, the driving wheel speed of the vehicle is greater than or equal to the preset wheel speed threshold and the duration is greater than or equal to the third time threshold, and it is determined that there is a trailer state. Specifically, the position sensor enables the motor controller to accurately provide the position information and speed information of the vehicle motor, so it can be determined whether the vehicle has moved. When the position sensor is in a normal state, since the motor speed will gradually increase with the increase of the trailer speed in the driving wheel trailer working condition, it can be determined whether there is a trailer state by the motor speed and duration. If the motor speed of the vehicle exceeds a certain speed threshold (that is, the second speed threshold) and the duration exceeds a certain time threshold (that is, the second time threshold), it can be determined that there is a trailer state. When the position sensor is in an abnormal state, since the vehicle's drive motor acts on the drive wheel through the motor transmission system, the presence of a trailer can be determined by the drive wheel speed. In general, cars are divided into front-wheel drive and rear-wheel drive. For front-wheel drive vehicles, the drive wheels are the front wheels, and for rear-wheel drive vehicles, the drive wheels are the rear wheels. When the drive wheel speed exceeds a certain wheel speed threshold and the time it exceeds the wheel speed threshold exceeds a certain time threshold (that is, the third time threshold), it indicates that the motor is rotating (that is, the motor speed exceeds a certain speed threshold and the time it lasts exceeds a certain time threshold), then it can be determined that a trailer state exists.

[0058] In an embodiment of the present application, executing a protection action includes: when the position of the bridge arm short-circuit fault is on the upper bridge, controlling the upper bridges in the three-phase bridge circuit to be all turned on and the lower bridges to be all turned off; when the position of the bridge arm short-circuit fault is on the upper bridge, controlling the upper bridges in the three-phase bridge circuit to be all turned off and the lower bridges to be all turned on. Specifically, when it is detected that the trailer is still being towed in the case of a bridge arm short-circuit fault, the short-circuited bridge arm of the motor controller is directly connected due to the existence of the anti-parallel diode short circuit, and the inter-phase back electromotive force loop impedance mainly comes from the resistance and inductance of the motor. At this time, even if the motor speed of the trailer is low, a huge short-circuit current will be generated, and even the controller will catch fire and a serious accident will occur. Therefore, the motor controller needs to perform a protection action. According to the position of the bridge arm short-circuit fault detected earlier, a corresponding protection is performed. In one example, when a bridge arm short-circuit fault occurs in any phase upper bridge of the three-phase bridge circuit, an active short circuit of the three-phase upper bridge is performed (that is, the three-phase upper bridge arms are all turned on and the three-phase lower bridge arms are all turned off). In another example, when a bridge arm short circuit fault occurs in any phase lower bridge of a three-phase bridge circuit, the three-phase lower bridge is actively short-circuited (that is, the three-phase lower bridge arms are all turned on, and the three-phase upper bridge arms are all turned off). The three-phase short circuit is performed according to the location where the bridge arm short circuit fault occurs, so that the short-circuit current is in a three-phase balanced state, solving the problem of continuous excessive current in one phase and unexpected torque caused by the short circuit.

[0059] In an embodiment of the present application, executing the protection action also includes: the motor controller sends a heat dissipation request to the vehicle controller of the vehicle, and the vehicle controller and / or the motor controller control the heat dissipation system to enable the maximum heat dissipation capacity. Specifically, the heat dissipation system may include a fan, a water pump, an oil pump, etc. By enabling the heat dissipation capacity, the motor and the motor controller of the vehicle can be cooled, which can alleviate the problem of overheating of the motor and the motor controller of the vehicle caused by the bridge arm short circuit fault to a certain extent.

[0060] Therefore, according to the trailer protection method of the embodiment of the present application, by detecting the bridge arm fault or overcurrent fault of the motor controller, judging whether the motor controller has a bridge arm short circuit fault according to the three-phase current in the three-phase bridge circuit, the bridge arm short circuit fault can be detected by using the existing general hardware solution. The method has strong versatility, simple and reliable identification, and is applicable to bridge arm short circuit fault detection of various motor controllers without requiring additional hardware costs. In addition, according to the identified bridge arm short circuit fault, an active short circuit is performed in the trailer state, the short circuit current is balanced and reduced, the reliability of the trailer protection is enhanced, the fault tolerance is better, and the risk of trailer in the case of a bridge arm short circuit fault is reduced.

[0061] Combine the following Figure 3 A bridge arm short circuit fault detection device provided according to another aspect of the present application is described. Figure 3 FIG. 2 shows a schematic structural block diagram of a bridge arm short circuit fault detection device 300 according to an embodiment of the present application. Figure 3As shown, the bridge arm short circuit fault detection device 300 includes a memory 310 and a processor 320, wherein: the memory 310 stores a computer executable program run by the processor 320, and when the computer executable program is run by the processor 320, the processor 320 executes the bridge arm short circuit fault detection method 100 described above. Those skilled in the art can understand the structure and specific operation of each module in the bridge arm short circuit fault detection device 300 according to the embodiment of the present application in combination with the above contents, and for the sake of brevity, they will not be repeated here.

[0062] Combine the following Figure 4 A trailer protection device according to another aspect of the present application is described. Figure 4 FIG. 4 shows a schematic structural block diagram of a trailer protection device 400 according to an embodiment of the present application. Figure 4 As shown, the trailer protection device 400 includes a memory 410 and a processor 420, wherein: the memory 410 stores a computer executable program executed by the processor 420, and when the computer executable program is executed by the processor 420, the processor 420 executes the trailer protection method 100 described above. Those skilled in the art can understand the structure and specific operation of each module in the trailer protection device 400 according to the embodiment of the present application in combination with the above contents, and for the sake of brevity, they are not described here in detail.

[0063] In addition, according to an embodiment of the present application, a vehicle is also provided, which may include the bridge arm short circuit fault detection device 300 or the trailer protection device 400 described above.

[0064] In addition, the present application also provides a storage medium on which a computer program is stored. When the computer program is executed by a processor, the processor executes the bridge arm short circuit fault detection method 100 or the trailer protection method 200 according to the embodiment of the present application described above. The storage medium may include, for example, a memory card of a smart phone, a storage component of a tablet computer, a hard disk of a personal computer, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a portable compact disk read-only memory (CD-ROM), a USB memory, or any combination of the above storage media. The computer-readable storage medium may be any combination of one or more computer-readable storage media.

[0065] Based on the above description, the bridge arm short circuit fault detection method, trailer protection method, device and vehicle of the embodiments of the present application perform bridge arm fault or overcurrent fault detection on the motor controller, and judge whether the motor controller has a bridge arm short circuit fault according to the three-phase current in the three-phase bridge circuit. The bridge arm short circuit fault can be detected using the existing general hardware solution. The method has strong versatility, simple and reliable identification, and is suitable for bridge arm short circuit fault detection of various motor controllers without requiring additional hardware costs.

[0066] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present application to this. Those of ordinary skill in the art may make various changes and modifications therein without departing from the scope and spirit of the present application. All these changes and modifications are intended to be included within the scope of the present application as required by the appended claims.

[0067] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0068] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of the units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed.

[0069] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0070] Similarly, it should be understood that in order to streamline the present application and help understand one or more of the various inventive aspects, in the description of the exemplary embodiments of the present application, the various features of the present application are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the present application should not be interpreted as reflecting the following intention: the claimed application requires more features than the features clearly stated in each claim. More specifically, as reflected in the corresponding claims, the inventive point is that the corresponding technical problem can be solved with features less than all the features of a single disclosed embodiment. Therefore, the claims following the specific embodiment are hereby explicitly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present application.

[0071] It will be understood by those skilled in the art that, except for mutually exclusive features, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this specification may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose.

[0072] In addition, those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the claims, any one of the claimed embodiments may be used in any combination.

[0073] The various component embodiments of the present application can be implemented in hardware, or implemented in software modules running on one or more processors, or implemented in a combination thereof. It should be understood by those skilled in the art that a microprocessor or digital signal processor (DSP) can be used in practice to implement some or all functions of some modules according to the embodiments of the present application. The application can also be implemented as a part or all of a program (e.g., a computer program and a computer program product) for performing the method described herein. Such a program implementing the present application can be stored on a computer-readable medium, or can have the form of one or more signals. Such a signal can be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0074] It should be noted that the above embodiments illustrate the present application rather than limit the present application, and that those skilled in the art may design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets should not be constructed as a limitation to the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present application may be implemented by means of hardware comprising a number of different elements and by means of a suitably programmed computer.

[0075] The above is only a specific implementation or description of a specific implementation of the present application, and the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. The protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A bridge arm short circuit fault detection method, characterized in that: The method comprises: The vehicle's motor controller performs bridge arm fault or overcurrent fault detection; When the motor controller detects the bridge arm fault or the overcurrent fault and is in a shutdown state, it is determined whether the motor controller has a bridge arm short circuit fault based on the three-phase current in the three-phase bridge circuit of the motor controller.

2. The method according to claim 1, characterized in that The determining whether the motor controller has a bridge arm short circuit fault based on the three-phase current in the three-phase bridge circuit of the motor controller comprises: Performing low-pass filtering on the three-phase current to obtain the three-phase current after low-pass filtering; When the absolute value of each phase current in the three-phase current after low-pass filtering is greater than or equal to the preset current threshold, and the duration is greater than or equal to the first time threshold, it is determined that the motor controller has the bridge arm short-circuit fault; and / or, When the absolute value of each phase current in the three-phase current after low-pass filtering is less than the preset current threshold, or when the absolute value of each phase current in the three-phase current after low-pass filtering is greater than or equal to the preset current threshold, but the duration is less than the first time threshold, it is determined that the motor controller does not have the bridge arm short circuit fault.

3. The method according to claim 2, characterized in that The method further includes: determining the location of the bridge arm short circuit fault based on the three-phase current after low-pass filtering.

4. The method according to claim 3, characterized in that The determining the position of the bridge arm short circuit fault based on the three-phase current after low-pass filtering includes: Determine the maximum value among the absolute values ​​of each phase current in the three-phase current after low-pass filtering, wherein the phase where the maximum value is located is the short-circuited phase of the bridge arm short-circuit fault; When the current value of the short-circuited phase after low-pass filtering is a positive value, it is determined that the position of the bridge arm short-circuit fault is on the upper bridge; When the current value of the short-circuited phase after low-pass filtering is a negative value, it is determined that the position of the bridge arm short-circuit fault is at the lower bridge.

5. The method according to claim 1, characterized in that Before determining whether the motor controller has a bridge arm short circuit fault based on the three-phase current in the three-phase bridge circuit of the motor controller, the method further includes: Determine that the motor controller meets the short-circuit state detection condition, wherein the short-circuit state detection condition includes: the low-voltage power supply of the motor controller is normal, the current sensor in the motor controller is normal, the motor controller is in a non-three-phase active short-circuit state, and the motor speed of the vehicle is greater than or equal to a first speed threshold.

6. A trailer protection method, characterized in that: The method comprises: The vehicle's motor controller performs bridge arm fault or overcurrent fault detection; When the motor controller detects the bridge arm fault or the overcurrent fault and is in a shutdown state, determining whether the motor controller has a bridge arm short circuit fault based on the three-phase current in the three-phase bridge circuit of the motor controller; When the bridge arm short circuit fault occurs in the motor controller, a trailer status detection is performed; When the vehicle is in a towing state, a protection action is performed.

7. The method according to claim 6, characterized in that The determining whether the motor controller has a bridge arm short circuit fault based on the three-phase current in the three-phase bridge circuit of the motor controller comprises: Performing low-pass filtering on the three-phase current to obtain the three-phase current after low-pass filtering; When the absolute value of each phase current in the three-phase current after low-pass filtering is greater than or equal to the preset current threshold, and the duration is greater than or equal to the first time threshold, it is determined that the motor controller has the bridge arm short-circuit fault; and / or, When the absolute value of each phase current in the three-phase current after low-pass filtering is less than the preset current threshold, or when the absolute value of each phase current in the three-phase current after low-pass filtering is greater than or equal to the preset current threshold, but the duration is less than the first time threshold, it is determined that the motor controller does not have the bridge arm short circuit fault.

8. The method according to claim 7, characterized in that The method further includes: determining the location of the bridge arm short circuit fault based on the three-phase current after low-pass filtering.

9. The method according to claim 8, characterized in that The determining the position of the bridge arm short circuit fault based on the three-phase current after low-pass filtering includes: Determine the maximum value among the absolute values ​​of each phase current in the three-phase current after low-pass filtering, wherein the phase where the maximum value is located is the short-circuited phase of the bridge arm short-circuit fault; When the current value of the short-circuited phase after low-pass filtering is a positive value, it is determined that the position of the bridge arm short-circuit fault is on the upper bridge; When the current value of the short-circuited phase after low-pass filtering is a negative value, it is determined that the position of the bridge arm short-circuit fault is at the lower bridge.

10. The method according to claim 9, characterized in that The execution protection action includes: When the bridge arm short-circuit fault occurs at the upper bridge, all upper bridges in the three-phase bridge circuit are controlled to be turned on and all lower bridges are controlled to be turned off; When the bridge arm short-circuit fault is located at the upper bridge, the upper bridges in the three-phase bridge circuit are controlled to be completely turned off and the lower bridges are controlled to be completely turned on.

11. The method according to claim 6, characterized in that Before determining whether the motor controller has a bridge arm short circuit fault based on the three-phase current in the three-phase bridge circuit of the motor controller, the method further includes: Determine that the motor controller meets the short-circuit state detection condition, wherein the short-circuit state detection condition includes: the low-voltage power supply of the motor controller is normal, the current sensor in the motor controller is normal, the motor controller is in a non-three-phase active short-circuit state, and the motor speed of the vehicle is greater than or equal to a first speed threshold.

12. The method according to claim 6, characterized in that The trailer state detection includes at least one of the following when the motor controller is in a shutdown state: When the position sensor of the motor controller is in a normal state, the motor speed of the vehicle is greater than or equal to a second speed threshold and the duration is greater than or equal to a second time threshold, it is determined that the trailer state exists; When the position sensor of the motor controller is in an abnormal state, the driving wheel speed of the vehicle is greater than or equal to a preset wheel speed threshold and the duration is greater than or equal to a third time threshold, it is determined that the trailer state exists.

13. The method according to claim 6, characterized in that The execution protection action includes: The motor controller sends a heat dissipation request to the vehicle controller of the vehicle, and the vehicle controller and / or the motor controller controls the heat dissipation system to enable maximum heat dissipation capacity.

14. The method according to claim 6, characterized in that Before the motor controller of the vehicle performs bridge arm fault or overcurrent fault detection, the motor controller of the vehicle further includes: Performing fault detection on the motor controller; If it is determined that the motor controller is faulty and has caused the vehicle to be in an undriveable state, an instrument alarm prompt of the vehicle is illuminated.

15. A bridge arm short circuit fault detection device, characterized in that: The device includes a memory and a processor, wherein the memory stores a computer executable program run by the processor, and when the computer executable program is run by the processor, the processor executes the bridge arm short circuit fault detection method as described in any one of claims 1-5.

16. A trailer protection device, characterized in that: The device includes a memory and a processor, wherein the memory stores a computer executable program executed by the processor, and when the computer executable program is executed by the processor, the processor executes the trailer protection method according to any one of claims 6 to 14.

17. A vehicle, characterized in that: The vehicle comprises the bridge arm short circuit fault detection device according to claim 15 or the trailer protection device according to claim 16.

18. A storage medium, characterized in that: The storage medium stores a computer program executed by a processor, and when the computer program is executed by the processor, the processor executes the bridge arm short circuit fault detection method as described in any one of claims 1 to 5 or the trailer protection method as described in any one of claims 6 to 14.

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