Electric vehicle motor controller fault processing method and system

Abstract

The invention discloses a fault processing method and system for a motor controller of an electric vehicle, and belongs to the field of vehicle safety. The method comprises the steps that a motor controller carries out fault diagnosis to obtain fault signals and carries out grading processing on the fault signals, and the fault grades comprise a first-level fault, a second-level fault and a third-level fault; judging the running state of the current vehicle; when the current vehicle is in a driving state, obtaining a corresponding fault level according to the fault signal; when the current vehicle is in a parking or charging state, fault levels corresponding to all fault signals are set as first-level faults; and according to the corresponding fault level, the motor controller executes a corresponding fault action. Based on fault grading processing, the application scenes are further refined, and the motor controller is controlled to execute different actions according to different application scenes, so that the vehicle safety and the user experience are improved.

Description

Technical Field

[0001] The present invention belongs to the field of vehicle safety, and in particular, relates to a method and system for handling faults of a motor controller of an electric vehicle. Background Art

[0002] As an important component of electric vehicles, the permanent magnet synchronous motor drive system is the key to realizing the mutual conversion between electrical energy and mechanical energy. In the permanent magnet synchronous motor drive system, the motor controller is a software, hardware, and structural assembly that actively controls the motor to work in the set direction, speed, angle, and response time. In electric vehicles, the function of the motor controller is to receive torque control instructions issued by the vehicle controller according to the gear position, throttle, brake and other states, and convert the electrical energy stored in the power battery into the electrical energy required to drive the motor to control the start-up, forward and backward speed, climbing strength and other driving states of the electric vehicle, or to help the electric vehicle perform electric braking and recover part of the braking energy into the power battery. It is one of the key components of electric vehicles.

[0003] In order to prevent the motor controller and the motor from being damaged when a serious fault occurs in the motor controller, it is necessary to detect the fault signal and control the motor controller to perform corresponding actions to protect the motor controller and the motor according to different fault signals. However, in the existing fault handling, the handling methods for various fault scenarios are often mixed up. For example, when the vehicle is in motion and only a minor fault is detected, the motor controller needs to be shut down and powered on and off again, which reduces the user experience and even causes unnecessary vehicle abnormalities.

[0004] To this end, the present application proposes a method and system for handling faults of an electric vehicle motor controller. Summary of the invention

[0005] The present invention aims to overcome the shortcomings of the prior art and to achieve the following objectives by proposing a method and system for handling faults in an electric vehicle motor controller: based on fault classification processing, further refining the application scenarios, and controlling the motor controller to perform different actions according to different application scenarios, thereby improving vehicle safety and user experience.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is: a method for handling faults of an electric vehicle motor controller, the method comprising the following steps:

[0007] Step S1, the motor controller performs fault diagnosis to obtain a fault signal, and performs graded processing on the fault signal, wherein the fault levels include primary fault, secondary fault, and tertiary fault;

[0008] Step S2, determining the current running state of the vehicle;

[0009] Step S3: when the current vehicle is in a driving state, a corresponding fault level is obtained according to the fault signal; when the current vehicle is in a parking or charging state, the fault levels corresponding to all fault signals are set to level one fault; according to the corresponding fault level, the motor controller performs a corresponding fault action.

[0010] Preferably, when the fault level is a level one fault, the motor controller only records the fault; when the fault level is a level two fault, the motor controller outputs torque reduction processing; when the fault level is a level three fault, the motor controller immediately turns off the IGBT.

[0011] Preferably, when the fault level is a level 3 fault, the fault level cannot be restored in the current power-on cycle, and the current fault level will not be cleared until the power is turned on and off again and there is no fault signal.

[0012] Preferably, in step S1, the motor controller broadcasts a fault diagnosis command to each vehicle device through the vehicle CAN network to obtain a fault signal. At the same time, after the motor controller executes the corresponding fault action, the current motor controller state is fed back to the vehicle CAN network for each vehicle device to read.

[0013] Preferably, the vehicle equipment includes a vehicle controller VCU, a power manager BMS, a vehicle charger CMDC, a vehicle heater PTC, and a vehicle cooler AC, and the vehicle controller VCU, the power manager BMS, the vehicle charger CMDC, the vehicle heater PTC, and the vehicle cooler AC are all connected to the motor controller via a CAN bus.

[0014] Preferably, in step S2: if the vehicle speed is not 0 km / h, the vehicle is judged to be in a driving state; if the vehicle speed is 0 km / h and lasts for a preset period of time, it is judged to be in a parking state; if the vehicle speed is 0 km / h and a charging signal is detected, it is judged to be in a charging state.

[0015] Preferably, the preset time is 60 seconds.

[0016] Preferably, after acquiring the fault signal, the motor controller performs freeze frame data processing on the fault signal, including recording GPS time, fault code, and sensor data.

[0017] Preferably, the first-level fault includes a communication fault; the second-level fault includes an over-temperature warning and an under-voltage warning; and the third-level fault includes an over-voltage fault and an over-current fault.

[0018] At the same time, the present application also proposes an electric vehicle motor controller fault processing system based on the above-mentioned electric vehicle motor controller fault processing method, the system comprising:

[0019] Fault diagnosis module, used for motor controller to obtain fault signals of various vehicle equipment and classify them;

[0020] The vehicle status judgment module is used to judge the current running status of the vehicle and obtain the fault level in combination with the fault signal;

[0021] The execution module is used to control the motor controller to execute corresponding fault actions according to the corresponding fault level.

[0022] The technical effect of the present invention is as follows: the present application performs hierarchical processing on different fault signals, and then determines the application scenario according to the operating status of the entire vehicle, especially in the vehicle parking or charging scenarios, further refines the fault processing logic, and improves vehicle safety and user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of the structure of a vehicle electric drive system provided by an embodiment of the present invention;

[0024] Figure 2 The present invention is a flowchart of a method for handling a fault of an electric vehicle motor controller according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following is a further detailed description of the specific implementation of the present invention through the description of the embodiments with reference to the accompanying drawings, the purpose of which is to help those skilled in the art have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention, and to facilitate its implementation. It should be noted that the words "first", "second" and the like described in this application are only for the convenience of describing the technical solution to distinguish different components, and are not used to limit this application. In order to make the technical solution of the present invention clearer, the present invention is explained through the following embodiments.

[0026] like Figure 1The figure shows a schematic diagram of the structure of the vehicle electric drive system in the electric vehicle provided in this embodiment. Among them, the vehicle electric drive system is provided with a plurality of vehicle devices, including a vehicle controller VCU, a power manager BMS, a vehicle charger CMDC, a vehicle heater PTC, and a vehicle cooler AC; the VCU, BMS, CMDC, PTC, and AC are all connected to the motor controller through the CAN bus, so that the devices communicate with each other through the CAN network and interact with each other in real time. The CAN network has high communication efficiency, simple layout, and low application cost, and is widely used in the field of vehicles. The battery is used to provide low-voltage power to the VCU, BMS, CMDC, PTC, and AC. The power manager BMS is connected to the power battery to monitor the power battery status. The power battery is used to provide high-voltage power to the motor controller, CMDC, PTC, and AC. The motor controller has IGBT (power transistor) integrated inside, and the output end of the IGBT is connected to the motor. The motor controller control unit receives the torque command of the vehicle controller through the CAN bus, and drives the IGBT to convert the high-voltage DC power of the power battery into AC three-phase electric drive motor output; at the same time, when the vehicle is powered off or an emergency occurs, the motor controller control unit drives the IGBT to turn on to drive the motor rotor to rotate and discharge the remaining high voltage in the high-voltage circuit. During this process, the motor does not generate output torque, that is, the vehicle remains in a parked state.

[0027] based on Figure 1 The vehicle electric drive system structure shown in the figure, this embodiment proposes a method for handling electric vehicle motor controller faults. Figure 2 The electric vehicle motor controller fault handling method flow chart shown provides a detailed description of the method steps of the present application.

[0028] Step S1, the motor controller performs fault diagnosis to obtain a fault signal, and performs graded processing on the fault signal, wherein the fault grades include primary fault, secondary fault, and tertiary fault.

[0029] Specifically, the motor controller broadcasts a fault diagnosis command to each vehicle device through the vehicle CAN network to obtain a fault signal. Each vehicle device performs a self-check upon receiving the fault diagnosis command and sends the detected fault signal to the motor controller for unified processing. During the process, the motor controller also performs a self-check to generate a fault signal.

[0030] The motor controller classifies and processes these faults based on the fault classification processing strategy. From minor to serious, they can be divided into three levels, namely, level 1 fault, level 2 fault, and level 3 fault. Among them, the level 1 fault is a minor fault, mainly including communication failures between nodes in the CAN network; the level 2 fault is a medium-level fault, which will affect driving but will not cause safety problems, mainly including warning faults such as over-temperature warnings and under-voltage warnings; the level 3 fault is a serious fault type, which usually seriously endangers vehicle safety, mainly including over-voltage faults, over-current faults, etc.

[0031] In addition, in this embodiment, after receiving the fault signal from each vehicle device, the motor controller will perform freeze frame data processing on the fault signal, including recording the GPS time, fault code, sensor data, etc. when the fault occurs, thereby facilitating subsequent fault troubleshooting and vehicle maintenance.

[0032] It should be noted that in this embodiment, for the case of a level 3 fault, the fault level of the motor controller in the current power-on cycle cannot be automatically restored, and the current fault level will not be cleared until the power is turned on and off again and there is no fault signal. This is a level 3 fault, which is a serious fault and may involve the failure of key functions of the motor controller or serious performance degradation. In this case, the controller will immediately limit some or all functions of the vehicle to prevent the fault from causing greater safety hazards. The functional limitation will continue until the vehicle is powered on and off again (restart to restore the vehicle status) and the motor controller detects no fault signal.

[0033] Step S2: determine the current operating state of the vehicle, which includes driving state, parking state, and charging state (fast charging or slow charging). The determination of different vehicle operating states represents the determination of different application scenarios, which is the premise for subsequent fault handling in different application scenarios.

[0034] In this embodiment, if the vehicle speed is not 0km / h, the vehicle is judged to be in a driving state. If the vehicle speed is 0km / h and lasts for a preset period of time, it is judged to be in a parking state. In actual driving, when the driver is waiting for a red light or stopping for a short time, he usually does not think that the vehicle has entered a parking state. Therefore, this embodiment sets the duration when the vehicle speed is 0km / h, thereby avoiding misjudgment. Among them, the preset time of this embodiment is 60 seconds, which is more in line with the user's driving habits and cognition, and helps to improve the user experience. The preset time can be flexibly selected according to the actual situation during specific implementation, and the present invention is not limited by this. If the vehicle speed is 0km / h and a charging signal is detected, it is judged to be in a charging state. The charging signal includes the CC signal or CP signal of the slow charging gun, the charging current or voltage detected by the BMS, etc.

[0035] Step S3: When the current vehicle is in a driving state, the corresponding fault level is obtained according to the fault signal; when the current vehicle is in a parking or charging state, the fault levels corresponding to all fault signals are set to a first-level fault. According to the corresponding fault level, the motor controller performs a corresponding fault action. After the motor controller performs the corresponding fault action, the current motor controller state is fed back to the vehicle CAN network for each vehicle device to read.

[0036] Specifically, the motor controller fault action of this embodiment is as follows: when the fault level is a level 1 fault, the motor controller only records the fault; when the fault level is a level 2 fault, the motor controller outputs torque reduction processing; when the fault level is a level 3 fault, the motor controller immediately turns off the IGBT, that is, the motor controller stops converting the high-voltage DC power of the power battery into an AC three-phase electric drive motor output. This embodiment adopts different motor controller protection measures according to different fault levels, which can be adapted to various vehicle application environments, improving vehicle safety while improving the user experience of the vehicle.

[0037] When the vehicle is in motion, the motor controller is in an awake state, and the IGBT inside the motor controller works normally to drive the vehicle. At this time, the motor controller normally determines the fault level according to the acquired fault signal, and then further takes corresponding protection measures.

[0038] When the vehicle is parked or charging, the IGBT inside the motor controller is in the off state, and the motor has no power output. According to the current architecture of electric vehicles, when charging is completed and the vehicle key is turned off or an emergency occurs, the high voltage needs to be discharged immediately. This function is generally implemented by the vehicle's electric drive system, which requires the motor controller to always be awake and ready to meet the high-voltage discharge requirements through the discharge resistor. However, under this condition, if a secondary or tertiary fault occurs, the output torque of the motor controller needs to be limited according to the above fault handling method, or even the IGBT needs to be directly turned off, which leads to a decrease in the efficiency of high-voltage discharge, or even nowhere to discharge, further endangering vehicle safety.

[0039] For example, when the vehicle is parked or charging, if the vehicle power battery has a fault such as thermal runaway, the high-voltage output of the power battery will be cut off urgently. At the same time, the motor controller drives the IGBT to open for high-voltage discharge. However, since the motor controller is connected in series to the high-voltage circuit of the whole vehicle, once the battery is cut off under load, it is easy to cause the voltage to rise and reach the overvoltage protection threshold preset by the motor controller, causing the voltage controller to have an overvoltage fault alarm. At this time, if the overvoltage fault belongs to the third-level fault according to the fault level, the motor controller needs to immediately turn off the IGBT, so that the high voltage has nowhere to be discharged, further damaging the vehicle's high-voltage system. At the same time, afterwards, the user has to power on and off again to restore the fault level, and the user experience is extremely poor. Therefore, in response to this situation, when the current vehicle is parked or charging, the fault level corresponding to all fault signals is set to a first-level fault. At this time, the motor controller only records the fault, which can not only meet the high-voltage discharge requirements at the end of fast and slow charging, but also avoid abnormalities under this working condition, causing users to power on and off to clear the fault, causing unnecessary vehicle abnormalities.

[0040] At the same time, the present application also proposes an electric vehicle motor controller fault processing system based on the above-mentioned electric vehicle motor controller fault processing method, the system comprising:

[0041] Fault diagnosis module, used for motor controller to obtain fault signals of various vehicle equipment and classify them;

[0042] The vehicle status judgment module is used to judge the current running status of the vehicle and obtain the fault level in combination with the fault signal;

[0043] The execution module is used to control the motor controller to execute corresponding fault actions according to the corresponding fault level.

[0044] In summary, this embodiment proposes a method and system for handling faults of an electric vehicle motor controller, which adopts different fault handling measures according to the vehicle operation state (driving, parking, charging) through fault diagnosis and classification processing. In the driving state, corresponding protection measures are taken according to the fault level; in the parking or charging state, all fault levels are set to level one, and only faults are recorded to ensure the normal function of the high-voltage discharge function, thereby improving vehicle safety and user experience.

[0045] The present invention is described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention; or the above concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A method for handling faults in an electric vehicle motor controller, characterized in that: The method comprises the following steps: Step S1, the motor controller performs fault diagnosis to obtain a fault signal, and performs graded processing on the fault signal, wherein the fault levels include primary fault, secondary fault, and tertiary fault; Step S2, determining the current running state of the vehicle; Step S3: when the current vehicle is in a driving state, a corresponding fault level is obtained according to the fault signal; when the current vehicle is in a parking or charging state, the fault levels corresponding to all fault signals are set to level one fault; according to the corresponding fault level, the motor controller performs a corresponding fault action.

2. The electric vehicle motor controller fault handling method according to claim 1, characterized in that: When the fault level is level one, the motor controller only records the fault; when the fault level is level two, the motor controller outputs torque reduction processing; When the fault level is level 3, the motor controller immediately turns off the IGBT.

3. A method for handling electric vehicle motor controller faults according to claim 1 or 2, characterized in that: When the fault level is level 3, the fault level cannot be restored in the current power-on cycle, and the current fault level will be cleared only after the power is turned on and off again and there is no fault signal.

4. The electric vehicle motor controller fault handling method according to claim 1, characterized in that: In step S1, the motor controller broadcasts a fault diagnosis command to each vehicle device through the vehicle CAN network to obtain a fault signal. At the same time, after the motor controller performs the corresponding fault action, the current motor controller state is fed back to the vehicle CAN network for each vehicle device to read.

5. The electric vehicle motor controller fault handling method according to claim 4 is characterized in that: The vehicle equipment includes a vehicle controller VCU, a power manager BMS, a vehicle charger CMDC, a vehicle heater PTC, and a vehicle cooler AC. The vehicle controller VCU, the power manager BMS, the vehicle charger CMDC, the vehicle heater PTC, and the vehicle cooler AC are all connected to the motor controller via a CAN bus.

6. The electric vehicle motor controller fault handling method according to claim 1, characterized in that: In step S2: if the vehicle speed is not 0 km / h, the vehicle is judged to be in a driving state; if the vehicle speed is 0 km / h and continues for a preset period of time, it is judged to be in a parking state; if the vehicle speed is 0 km / h and a charging signal is detected, it is judged to be in a charging state.

7. The electric vehicle motor controller fault handling method according to claim 1, characterized in that: The preset time is 60 seconds.

8. The electric vehicle motor controller fault handling method according to claim 1, characterized in that: After acquiring the fault signal, the motor controller performs freeze frame data processing on the fault signal, including recording GPS time, fault code, and sensor data.

9. The electric vehicle motor controller fault handling method according to claim 1, characterized in that: The first-level fault includes a communication fault; the second-level fault includes an over-temperature warning and an under-voltage warning; the third-level fault includes an over-voltage fault and an over-current fault.

10. An electric vehicle motor controller fault processing system according to any one of claims 1 to 9, characterized in that: The system comprises: Fault diagnosis module, used for motor controller to obtain fault signals of various vehicle equipment and classify them; The vehicle status judgment module is used to judge the current operating status of the vehicle and obtain the fault level in combination with the fault signal; The execution module is used to control the motor controller to execute corresponding fault actions according to the corresponding fault level.

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