WO2019223303A1 - Electric vehicle fault diagnosis method and apparatus, and electric vehicle - Google Patents

Abstract

An electric vehicle fault diagnosis method and apparatus, and an electric vehicle, wherein same relate to the field of electric vehicles. In the electric vehicle fault diagnosis method, the cooperation between multiple fault grades and multiple processing policies is used. The method comprises: firstly acquiring a current fault grade of a vehicle, then determining a corresponding processing policy according to the current fault grade of the vehicle, and thirdly, carrying out a corresponding operation according to a pre-determined processing policy, wherein different fault grades are distinguished according to one or more of the following parameters: the probability of endangering the safety of a person in a vehicle, whether the performance of a vehicle battery or the whole vehicle is affected, and whether a fault can self-recover. Therefore, the fault grades obtained by means of division are more accurate, such that the processing policies can be made more pertinently to make the result of carrying out the corresponding operation according to the processing policy ideal.

Description

Method and device for fault diagnosis of electric vehicle and electric vehicle Technical field

The present invention relates to the field of electric vehicles, and in particular, to a method and an apparatus for diagnosing faults of an electric vehicle, and an electric vehicle.

Background technique

At present, people pay more and more attention to the protection of the environment and the rational use of energy. Therefore, efficient, energy-saving and environmentally friendly electric vehicles have become the development trend of the automotive industry. The electric vehicle as a whole can be divided into a hardware system and a control system. Most of the hardware systems are composed of hardware that can be directly observed by the naked eye, such as wheels, engines and other structures. The control system is mainly controlled by the various structures in the hardware system. Software system, such as drive system, charging system and so on.

There is a very important system in the control system, which is the battery management system (BMS, Battery Management). The battery management system is the link between the battery and the user. It is mainly to improve the power utilization of the battery and prevent the battery from becoming excessive. Charging and over-discharging.

On the whole, the main role of the battery management system is to control the battery through predetermined strategies, thereby achieving the purpose of ensuring battery performance and ensuring overall vehicle safety.

Summary of the Invention

An object of the present invention is to provide a fault diagnosis method and device for an electric vehicle, and an electric vehicle.

In a first aspect, an embodiment of the present invention provides a fault diagnosis method for an electric vehicle, including:

Obtain the current fault level of the vehicle; different fault levels are distinguished according to one or more of the following parameters: the probability of endangering the safety of the on-board personnel, whether it affects the car battery or the performance of the vehicle, and whether the fault can be recovered by itself;

Determine the corresponding processing strategy according to the current fault level of the vehicle;

Perform the corresponding operation according to the processing strategy.

With reference to the first aspect, an embodiment of the present invention provides a first possible implementation manner of the first aspect, wherein the step of determining a corresponding processing strategy according to a current fault level of the vehicle includes:

If the current fault level is the first-level fault, the corresponding processing strategy is:

The power supply function of the car battery is turned off, and the car battery is locked so that the car battery cannot output electric energy; the first-level failure is a failure that endangers the safety of the on-board personnel and exceeds a predetermined threshold.

With reference to the first aspect, the embodiment of the present invention provides a second possible implementation manner of the first aspect, wherein if the current fault level is a first-level fault, the corresponding processing strategy further includes:

If the unlock command is received, the car battery is unlocked so that the car battery can output electric energy.

With reference to the first aspect, an embodiment of the present invention provides a third possible implementation manner of the first aspect, wherein the step of determining a corresponding processing strategy according to a current fault level of the vehicle includes:

If the current fault level is a second-level fault, the corresponding processing strategy is:

Select a corresponding processing strategy based on whether the vehicle's VCU high-voltage power supply circuit disconnection instruction is received within a predetermined time threshold after the occurrence of the second-level fault, and whether the current of the main circuit of the vehicle battery exceeds a preset current threshold; The VCU high voltage power supply circuit disconnection instruction is a control instruction issued when the vehicle VCU is under normal high voltage or abnormal emergency high voltage. The second level of failure is a failure that affects the performance of the vehicle battery or the vehicle and cannot be recovered by itself.

With reference to the first aspect, an embodiment of the present invention provides a fourth possible implementation manner of the first aspect, wherein the step of determining a corresponding processing strategy according to a current fault level of the vehicle includes:

If the current fault level is a second-level fault, the corresponding processing strategy is:

If within the predetermined time threshold after the occurrence of the second-level fault, the VCU high-voltage power supply circuit disconnection instruction is not received, then each circuit switch connected to the input end or output end of the car battery is immediately set to the off state. ; The second-level failure is a failure that affects the performance of the car battery or the entire vehicle and cannot be recovered by itself;

and / or,

If within the predetermined time threshold after the occurrence of the second-level fault, the VCU high-voltage power supply circuit disconnection instruction is received, and the first current of the main circuit of the car battery does not exceed the preset current threshold, the input of the car battery is immediately input. Each circuit switch connected to the terminal or output terminal is set to the off state;

and / or,

If within the predetermined time threshold after the occurrence of the second-level fault, a VCU high-voltage power supply circuit disconnection command is received, and the first current of the main circuit of the car battery exceeds a preset current threshold, then the timing starts. Before the cut-off time, it is detected that the second current of the main circuit of the car battery is lower than the preset current threshold, then immediately set each circuit switch connected to the input end or output end of the car battery to the off state; Before the time reaches the cut-off time, each circuit switch connected to the input end or output end of the car battery is not set to the off state. After the counting time reaches the cut-off time, the input end or output end of the car battery is connected. Each circuit switch is set to the off state.

With reference to the first aspect, an embodiment of the present invention provides a fifth possible implementation manner of the first aspect, wherein the step of determining a corresponding processing strategy according to a current fault level of the vehicle includes:

If the current fault level is a third-level fault, the corresponding processing strategy is:

Limit the maximum power supply of the car battery so that the maximum output power of the car battery is less than a preset threshold; the third level of failure is a failure that affects the performance of the car battery or the entire vehicle and can be recovered on its own.

With reference to the first aspect, an embodiment of the present invention provides a sixth possible implementation manner of the first aspect, wherein the step of determining a corresponding processing strategy according to a current fault level of the vehicle includes:

If the current fault level is a fourth-level fault, the corresponding processing strategy is:

Drives the alarm equipment corresponding to the current cause of the fault. The fourth-level fault is a fault that does not affect the performance of the car battery or the vehicle and can be recovered by itself.

With reference to the first aspect, the embodiment of the present invention provides a seventh possible implementation manner of the first aspect, wherein the predetermined time threshold is 4-6 seconds; and the preset current threshold is 6-10A.

In a second aspect, an embodiment of the present invention further provides an electric vehicle fault diagnosis device, including:

The acquisition module is used to obtain the current fault level of the vehicle; different fault levels are distinguished according to one or more of the following parameters: the probability of endangering the safety of vehicle personnel, whether it affects the car battery or the performance of the vehicle, and whether the fault can be recovered by itself ;

A determination module, configured to determine a corresponding processing strategy according to the current failure level of the vehicle;

The execution module is used to perform corresponding operations according to the processing strategy.

In a third aspect, an embodiment of the present invention further provides an electric vehicle, which is provided with a BMS control system, and the BMS control system is configured to perform corresponding operations according to the method of the first aspect.

The electric vehicle fault diagnosis method provided by the embodiment of the present invention uses a combination of multiple fault levels and multiple processing strategies to first obtain the current fault level of the vehicle, and then determines a corresponding processing strategy according to the current fault level of the vehicle, and then, according to a predetermined The corresponding processing strategy is to perform corresponding operations. In this solution, different fault levels are distinguished according to one or more of the following parameters: the probability of jeopardizing the safety of vehicle personnel, whether it affects the car battery or the performance of the vehicle, and whether the fault can be determined by itself. Recovery; furthermore, the classified fault level is more accurate, so that the processing strategy can be formulated more specifically, so that the corresponding operation results according to the processing strategy are more ideal.

In order to make the foregoing objects, features, and advantages of the present invention more comprehensible, preferred embodiments are described below in detail with reference to the accompanying drawings, as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to explain the technical solution of the embodiments of the present invention more clearly, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and therefore are not It should be regarded as a limitation on the scope. For those of ordinary skill in the art, other related drawings can be obtained according to these drawings without paying creative work.

FIG. 1 shows a basic flowchart of an electric vehicle fault diagnosis method according to an embodiment of the present invention;

FIG. 2 shows a partial circuit structure diagram of a circuit in which an automobile battery is located in a fault diagnosis method for an electric vehicle according to an embodiment of the present invention; FIG.

3 shows a basic block diagram of an electric vehicle fault diagnosis device according to an embodiment of the present invention;

FIG. 4 shows a schematic diagram of a controller according to an embodiment of the present invention.

Detailed ways

In the following, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. The components of embodiments of the invention, generally described and illustrated in the figures herein, can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts fall within the protection scope of the present invention.

In related technologies, electric vehicles have entered millions of households, and many auto manufacturers are increasingly optimistic about the future prospects of electric vehicles. Furthermore, as an important part of electric vehicles, the research and development of battery management systems are increasingly being used by auto manufacturers. Attention.

In related technologies, the battery management system (BMS) mainly covers the following functions:

1. Battery working status monitoring: mainly refers to the real-time monitoring or calculation of a series of battery-related parameters such as battery voltage, temperature, working current, and battery power during the working process of a car battery, and to judge the current battery status based on these parameters To prevent the battery from being overcharged or over discharged.

2. Battery charge and discharge management: During the process of charging or discharging the battery, manage the charging or discharging of the battery according to relevant parameters such as environmental status and battery status, and set the optimal charging or discharging curve of the battery, such as charging current and charging. Upper limit voltage value, lower discharge voltage value, etc.

3. Balance between single cells: It means that the single cells are charged and discharged uniformly, so that each battery in the battery pack reaches a balanced and consistent state.

4. Fault diagnosis and treatment: According to the priorities of BMS failures, divide the corresponding failure levels, and formulate corresponding failure treatment methods for the divided failure levels.

Among them, battery fault diagnosis and fault handling is a particularly important part of the battery management system, because adopting good fault diagnosis and fault handling methods can improve the overall safety of electric vehicles. If the electric vehicle battery management system lacks a proper fault diagnosis and treatment method, the battery is likely to be overcharged, overcharged, or even caught in a fire and explosion, thereby endangering the personal safety of the on-board personnel.

The inventor of the present application believes that the working mechanism of the current battery management system is insufficient, and furthermore, the present application provides an electric vehicle fault diagnosis method, which can be applied to a battery management system in an electric vehicle, as shown in FIG. The methods provided include:

S101: Obtain the current fault level of the vehicle; different fault levels are distinguished according to one or more of the following parameters: the probability of jeopardizing the safety of on-board personnel, whether it affects the car battery or the performance of the vehicle, and whether the fault can be recovered by itself;

S102. Determine a corresponding processing strategy according to the current fault level of the vehicle.

S103. Perform a corresponding operation according to the processing strategy.

It should be noted that the current fault level obtained in the above step S101 is generally generated based on various sensors installed in the vehicle or feedback signals generated by the feedback mechanism, and is not based on the probability of jeopardizing the safety of on-board personnel and whether it affects the car. Battery or vehicle performance, and whether these parameters can be restored by themselves are determined. Whether it affects the performance of the car battery or the entire vehicle, and whether the fault can be restored by itself. The function of these parameters is to distinguish different fault levels. For example, a fault with a higher probability of endangering the safety of the on-board personnel can be considered as the highest-level fault. , Of course, you should use a processing strategy that can ensure the safety of the vehicle personnel to the greatest extent to perform the corresponding operation.

For example, the following table can be preset in an electric vehicle fault diagnosis system (such as a BMS system):

Table 1

It can be seen from Table 1 that the fault levels can be divided into three levels. Each fault level has a judgment rule. For example, if it receives A and B signals at the same time, it is judged that the car is currently at the first level fault level, and XXXXX should be used. Processing strategy; for example, if only B signal is received, the vehicle is judged to be at the third-level fault level, then the processing strategy of ZZZZZ should be adopted.

Specifically, compared with the second-level fault, the first-level fault may correspond to the first-level fault. The current vehicle condition is likely to endanger the safety of the on-board personnel, and the second-level fault is not easy to endanger. To the safety of on-board personnel.

Specifically, the corresponding processing strategy may be determined according to actual needs. For example, the XXXXX processing strategy in the above table may be emergency braking and cut off the output of the car battery. There are many specific processing strategies, which are not described here, and will be described in more detail later.

In step S103, performing the corresponding operation according to the processing strategy may refer to controlling the corresponding mechanism (the mechanism on the electric vehicle) to perform the corresponding operation according to the processing strategy, or it may be that the control signal is sent out, that is, it will be able to control When the corresponding mechanism sends a signal, it can be considered that step S103 has been performed.

In the solution provided in this application, different failure levels are divided according to one or more of the probability of endangering the safety of vehicle personnel, whether it affects the car battery or the entire vehicle performance, and whether the failure can be recovered on its own. There are corresponding processing strategies, and each fault processing strategy of the same fault level is the same. According to this division provided in this application, faults of each level can be effectively processed.

In the solution provided in this application, fault levels can be divided into at least two, but considering the actual situation, if too many levels are divided, the response speed of the system's processing will be increased (causing too long to determine the processing strategy) , But affects vehicle safety); if there are too few levels, it is impossible to effectively determine corresponding processing strategies for different levels. Therefore, in the solution provided by this application, the number of failure levels is preferably 3-4, and further There are also 3-4 corresponding processing strategies.

The following describes the specific fault levels and corresponding processing strategies involved in this application:

That is, the steps to determine the corresponding processing strategy according to the current fault level of the vehicle include:

If the current fault level is the first-level fault, the corresponding processing strategy is:

The power supply function of the car battery is turned off, and the car battery is locked so that the car battery cannot output electric energy; the first-level failure is a failure that endangers the safety of the on-board personnel and exceeds a predetermined threshold.

Among them, turning off the power supply function of the car battery refers to setting each circuit switch connected to the input end or output end of the car battery to the off state, and locking the car battery (so that the circuit switch remains in the off state), so that The car battery can no longer supply power to other electric equipment in the car, which cuts off the main power of the car. Generally, it is not safe to just set the circuit switch to the off state without locking. This is because in the unlocked state, some control systems in the car can also open the circuit in the off state. The switch is set to the connected state; while in the locked state, some control systems in the car cannot set the disconnected circuit switch to the connected state.

Generally speaking, the first-level fault is the most serious fault, that is, the first-level fault is a fault that the probability of endangering the safety of the on-board personnel exceeds a predetermined threshold.

After the car battery is locked, the car battery is unlocked only after receiving the unlock instruction, so that the car battery can output electric energy.

Under normal circumstances, the unlock instruction is manually generated by the maintenance personnel. That is, the unlocking instruction is generated by the maintenance personnel after manually repairing the vehicle and manually triggering a physical button corresponding to the car battery control system (such as pressing a physical button such as a switch). It is not generated by some auxiliary systems (if If you can generate it yourself, the overall security of the system cannot be guaranteed). Under normal circumstances, the driver cannot trigger the unlock instruction by himself. The unlock instruction can only be generated by a professional maintenance engineer.

Enabling the power supply function of a car battery refers to setting each circuit switch connected to the input end or output end of the car battery to a connected state, so that the car battery can supply power to other electric equipment in the car.

As shown in FIG. 2, a partial circuit structure diagram of a circuit where an automobile battery is located is shown. According to the partial circuit structure diagram, it can be seen that the anode of the automobile battery is connected to node A through the main positive relay; the anode of the automobile battery is connected to the precharge relay. Node A is connected to the pre-charging resistor, where the series circuit formed by the pre-charging relay and the pre-charging resistor in series is connected in parallel with the main positive relay; the anode of the car battery is connected to node C through the fast-charging relay; the anode of the car battery is connected through the slow-charging relay. Node D; the negative electrode of the car battery is connected to node B through the main negative relay; nodes A, B, C, and D are electrically connected to different structures inside the electric vehicle (such as node A is connected to the motor, and node C is connected to the first charging interface) connection). The partial circuit structure diagram of the circuit where the automobile battery shown in FIG. 2 is only an exemplary diagram. In specific use, the name of each relay or a certain circuit can be deleted, or other relays or circuits can be added.

The circuit switch connected to the input or output of the car battery refers to one or more relays in Figure 2. Of course, as described in the previous paragraph, the circuit switch connected to the input or output of the car battery is also Can refer to other relays or devices with switching functions.

When the current fault level is a first-level fault, the corresponding processing strategy may also include the following:

Send a first-level fault alarm signal to the vehicle owner's network, and / or, light up the corresponding fault alarm light on the car.

In addition to the first-level fault, there is a second-level fault, that is, the steps to determine the corresponding processing strategy according to the current fault level of the vehicle include:

If the current fault level is a second-level fault, the corresponding processing strategy is:

Select a corresponding processing strategy based on whether the vehicle's VCU high-voltage power supply circuit disconnection instruction is received within a predetermined time threshold after the occurrence of the second-level fault, and whether the current of the main circuit of the vehicle battery exceeds a preset current threshold; The VCU high voltage power supply circuit disconnection instruction is a control instruction issued when the vehicle VCU is under normal high voltage or abnormal emergency high voltage. The second level of failure is a failure that affects the performance of the vehicle battery or the vehicle and cannot be recovered by itself. Compared with the first-level fault, the second-level fault is a lighter fault. The second-level fault has a lower probability of endangering the safety of on-board personnel, and will affect the performance of the car battery or the entire vehicle. These failures cannot be repaired autonomously. Because second-level faults generally do not endanger the safety of on-board personnel, they can be handled more gently. That is, instead of urgently turning off the power supply function of the car battery, it is determined according to the current conditions and then decide how to deal with it, that is, whether to receive the disconnection command of the VCU high-voltage power supply circuit of the vehicle and the main circuit of the car battery. If the current exceeds a preset current threshold, a corresponding processing strategy is selected, and then processing is performed according to the selected processing strategy.

In general, the strategy for handling second-level faults is to disconnect the high-voltage power supply circuit of the car battery when the current of the car battery is low, so as to stop the high-voltage power supply circuit, that is, in the case of the second-level fault. The high-voltage power supply circuit of automobile batteries is more prone to problems. At this time, the high-voltage power supply circuit should be disconnected. Certain second-level faults (such as the main positive / negative relay adhesion in the battery pack, too low insulation resistance, etc.) also need to lock the car battery. The car battery can only be checked after inspection or repair. Unlocking allows the car battery to power other appliances.

Specifically, the second-level fault can be divided into three cases, which are described below:

In the first case, if the current fault level is a second-level fault, the corresponding processing strategy is:

If within the predetermined time threshold (4S-6S) after the occurrence of the second-level fault, no VCU high-voltage power supply circuit disconnection instruction is received, immediately switch each circuit connected to the input or output terminal of the car battery Set to disconnected state; the second-level fault is a fault that affects the performance of the car battery or the entire vehicle and cannot be recovered by itself;

and / or,

In the second case, if the vehicle VCU high-voltage power supply circuit disconnection instruction is received within a predetermined time threshold (4S-6S) after the second-level fault occurs, and the first current of the main circuit of the vehicle battery does not exceed a preset Current threshold (6A-10A), then immediately set each circuit switch connected to the input end or output end of the car battery to the off state;

and / or,

In the third case, if the VCU high-voltage power supply circuit disconnection instruction is received within a predetermined time threshold (4S-6S) after the second-level fault occurs, and the first current of the main circuit of the car battery exceeds a preset current threshold (6A-10A), start timing, if before the timing time to the cut-off time (after 5S to the cut-off time), it is detected that the second current of the main circuit of the car battery is lower than the preset current threshold (6A-10A) , Immediately set each circuit switch connected to the input terminal or output terminal of the car battery to the off state; if the counting time reaches the cut-off time, each circuit connected to the input terminal or output terminal of the car battery is not set When the switch is set to the off state, each circuit switch connected to the input end or the output end of the car battery is set to the off state after the counting time has expired.

Among them, in the third case, it can also be executed in a circular judgment manner.

In step 201, it is determined whether a high-voltage power supply circuit disconnection instruction of the entire vehicle is received within a predetermined time threshold after the occurrence of the second-level fault, and whether the first current of the main circuit of the vehicle battery exceeds a preset current threshold; if step 201 If both of the judgments are yes, go to step 202;

Step 202: After a predetermined time delay, detect the second current of the main circuit of the automobile battery;

In step 203, it is determined whether the second current of the main circuit of the automobile battery exceeds a preset current threshold; if the determination in step 203 is yes, then step 202 is performed again; if the determination in step 203 is no, the input end or output of the automobile battery is immediately Each circuit switch connected to the terminal is set to the off state.

Regardless of the above-mentioned second-level fault, the corresponding processing strategy also includes the following: sending a second-level fault alarm signal to the vehicle owner's network, and / or, lighting the corresponding fault alarm light on the car.

In addition to the first and second level failures, there are third and fourth level failures, that is, the steps to determine the corresponding processing strategy according to the current fault level of the vehicle include:

If the current fault level is a third-level fault, the corresponding processing strategy is:

Limit the maximum power supply of the car battery so that the maximum output power of the car battery is less than a preset threshold; the third level of failure is a failure that affects the performance of the car battery or the entire vehicle and can be recovered on its own.

The steps to determine the corresponding processing strategy according to the current fault level of the vehicle include:

If the current fault level is a fourth-level fault, the corresponding processing strategy is:

Drives the alarm equipment corresponding to the current cause of the fault. The fourth-level fault is a fault that does not affect the performance of the car battery or the vehicle and can be recovered by itself.

Generally speaking, the third-level fault is lighter than the second-level fault, and the fourth-level fault is lighter than the third-level fault. Therefore, the processing strategies of the two-level faults are adjusted accordingly.

The maximum output power of a car battery is less than a preset threshold. The preset threshold may be 50%, that is, in the case of a third-level failure, the maximum output power of the car battery is only half (50%) of the original.

In the case of a third-level fault, the corresponding processing strategy also includes the following: sending a third-level fault alarm signal to the vehicle owner's network, and / or, lighting the corresponding fault alarm light on the car.

The fourth-level fault is the slightest, and generally does not affect the driving of the vehicle too much, and can generally recover on its own (the vehicle itself can complete repairs). Therefore, only the alarm equipment (such as an alarm) corresponding to the current cause of the fault is required. Indicator light, sound prompter). Of course, it is better to send a fourth-level fault alarm signal to the owner's network.

In the solution provided in this application, the first-level fault to the fourth-level fault are determined according to the severity of the fault. For example, the battery overvoltage fault may exist in the second-, third-, and fourth-level faults, but at different levels. The battery voltage thresholds corresponding to the faults are not the same. Generally speaking, the first-level faults are generally the faults that occur when the entire vehicle collides, and the second-level faults are generally relay adhesion or the vehicle's insulation is too low.

Corresponding to the above method, this application also provides an electric vehicle fault diagnosis device, as shown in FIG. 3, including:

The acquisition module 301 is used to acquire the current fault level of the vehicle; different fault levels are distinguished according to one or more of the following parameters: the probability of jeopardizing the safety of on-board personnel, whether it affects the car battery or the performance of the vehicle, and whether the fault can be determined by itself restore;

A determining module 302, configured to determine a corresponding processing strategy according to a current fault level of the vehicle;

The execution module 303 is configured to perform a corresponding operation according to a processing strategy.

Corresponding to the above method, the present application also provides an electric vehicle. The electric vehicle is provided with a BMS control system, and the BMS control system is configured to perform corresponding operations according to, for example, an electric vehicle fault diagnosis method.

As shown in FIG. 4, which is a schematic diagram of a controller according to an embodiment of the present application. The controller 40 includes a processor 41, a memory 42, and a bus 44. The memory 42 stores execution instructions. When the controller runs, the processor 41 The processor 41 communicates with the memory 42 through the bus 44, and the processor 41 executes the steps of the foregoing electric vehicle fault diagnosis method stored in the memory 42.

Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments, and are not repeated here.

When the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention is essentially a part that contributes to the existing technology or a part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including Several instructions are used to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in various embodiments of the present invention. The foregoing storage media include: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disks or optical disks and other media that can store program codes .

The above are only specific embodiments of the present invention, but the scope of protection of the present invention is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present invention. It should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (10)

The electric vehicle fault diagnosis method is characterized in that it includes: Obtain the current fault level of the vehicle; different fault levels are distinguished according to one or more of the following parameters: the probability of endangering the safety of the on-board personnel, whether it affects the car battery or the performance of the vehicle, and whether the fault can be recovered by itself; Determine the corresponding processing strategy according to the current fault level of the vehicle; Perform the corresponding operation according to the processing strategy. The method according to claim 1, wherein the step of determining a corresponding processing strategy according to a current fault level of the vehicle comprises: If the current fault level is the first-level fault, the corresponding processing strategy is: The power supply function of the car battery is turned off, and the car battery is locked so that the car battery cannot output electric energy; the first-level fault is a fault that the probability of endangering the safety of the on-board personnel exceeds a predetermined threshold. The method according to claim 2, wherein if the current fault level is a first-level fault, the corresponding processing strategy further comprises: If the unlock command is received, the car battery is unlocked so that the car battery can output electric energy. The method according to claim 1, wherein the step of determining a corresponding processing strategy according to a current fault level of the vehicle comprises: If the current fault level is a second-level fault, the corresponding processing strategy is: Select a corresponding processing strategy based on whether the vehicle's VCU high-voltage power supply circuit disconnection instruction is received within a predetermined time threshold after the occurrence of the second-level fault, and whether the current of the main circuit of the car battery exceeds a preset current threshold; The vehicle VCU high voltage power supply circuit disconnection instruction is a control instruction issued when the vehicle VCU is under normal or abnormal emergency high voltage; the second-level failure is a failure that affects the performance of the vehicle battery or the vehicle and cannot be recovered by itself . The method according to claim 1, wherein the step of determining a corresponding processing strategy according to a current fault level of the vehicle comprises: If the current fault level is a second-level fault, the corresponding processing strategy is: If within the predetermined time threshold after the occurrence of the second-level fault, the VCU high-voltage power supply circuit disconnection instruction is not received, then each circuit switch connected to the input end or output end of the car battery is immediately set to the off state. The second-level failure is a failure that affects the performance of the car battery or the entire vehicle and cannot be recovered by itself; and / or, If within the predetermined time threshold after the occurrence of the second-level fault, the VCU high-voltage power supply circuit disconnection instruction is received, and the first current of the main circuit of the car battery does not exceed the preset current threshold, the input of the car battery is immediately input. Each circuit switch connected to the terminal or output terminal is set to the off state; and / or, If within the predetermined time threshold after the occurrence of the second-level fault, a VCU high-voltage power supply circuit disconnection command is received, and the first current of the main circuit of the car battery exceeds a preset current threshold, then the timing starts. Before the cut-off time, it is detected that the second current of the main circuit of the car battery is lower than the preset current threshold, then immediately set each circuit switch connected to the input end or output end of the car battery to the off state; Before the time reaches the cut-off time, each circuit switch connected to the input end or output end of the car battery is not set to the off state. After the counting time reaches the cut-off time, the input end or output end of the car battery is connected. Each circuit switch is set to the off state. The method according to claim 1, wherein the step of determining a corresponding processing strategy according to a current fault level of the vehicle comprises: If the current fault level is a third-level fault, the corresponding processing strategy is: Limiting the maximum power supply of the car battery so that the maximum output power of the car battery is less than a preset threshold; the third-level fault is a fault that affects the performance of the car battery or the entire vehicle and can be recovered by itself. The method according to claim 1, wherein the step of determining a corresponding processing strategy according to a current fault level of the vehicle comprises: If the current fault level is a fourth-level fault, the corresponding processing strategy is: Drive the alarm device corresponding to the current cause of the fault to work; the fourth-level fault is a fault that does not affect the performance of the car battery or the entire vehicle and can be recovered by itself. The method according to claim 5, wherein the predetermined time threshold is 4-6 seconds; and the preset current threshold is 6-10A. The electric vehicle fault diagnosis device is characterized in that it includes: The acquisition module is used to obtain the current fault level of the vehicle; different fault levels are distinguished according to one or more of the following parameters: the probability of endangering the safety of vehicle personnel, whether it affects the car battery or the performance of the vehicle, and whether the fault can be recovered by itself ; A determination module, configured to determine a corresponding processing strategy according to the current failure level of the vehicle; An execution module is configured to perform a corresponding operation according to the processing strategy. An electric vehicle is characterized in that it is provided with a BMS control system for performing corresponding operations according to the method according to any one of claims 1-8.

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