Method and device for protecting differential, electric vehicle and storage medium

Abstract

The application relates to the electric drive technology field of new energy vehicles, in particular to a differential protection method and device, an electric vehicle and a storage medium, wherein the method comprises the following steps: acquiring the output torque of a driving motor in the electric vehicle; if the output torque is in a preset torque interval, activating the differential protection function of the differential and / or the gravity control system of the electric vehicle, wherein the execution priorities of the gravity control system and the differential protection function are different; reducing the output torque of the driving motor by using the differential protection function and / or the gravity control system, so as to reduce the speed difference between the half shafts in the differential, until the speed difference is less than a first preset value. Thus, the problem that the differential is prone to failure and the vehicle is prone to failure due to long-time wear and tear of the differential exceeding the design boundary in the prior art is solved, the service life of the electric vehicle is reduced, and the user experience is poor.

Description

Technical Field

[0001] This application relates to the field of electric drive technology for new energy vehicles, and in particular to a method, device, electric vehicle, and storage medium for protecting a differential. Background Technology

[0002] With the rapid development of the new energy vehicle industry, the quality of electric vehicle differentials, a key factor, has attracted much attention from consumers. A differential is a differential transmission mechanism that allows the left and right (or front and rear) drive wheels to rotate at different speeds, ensuring power transmission to each drive wheel under various motion conditions and preventing tire slippage.

[0003] In related technologies, the power from the electric drive system enters the differential, directly driving the differential housing, which in turn drives the planetary gear shaft. Through the meshing of the planetary gears and the half-shaft gears, the power is distributed to the left and right half-shaft gears, driving the left and right drive wheels of the vehicle. The input torque is evenly distributed to the left and right half-shaft gears via this system, and the sum of the rotational speeds of the left and right half-shaft gears equals the rotational speed of the differential housing. Therefore, when the car is traveling straight, the left and right half-shaft gears and the differential housing are in a relatively balanced state, and the entire differential forms a unified power transmission system. When the car turns or slips, the outer wheel speed increases / slips, while the inner wheel speed decreases relatively.

[0004] However, if the wear of the difference in speed between the left and right wheels under traction conditions exceeds the design limit of the differential over a long period of time, the electric drive differential is prone to failure, leading to vehicle malfunction, reducing the lifespan of the electric vehicle, and resulting in a poor user experience. Summary of the Invention

[0005] This application provides a method, device, electric vehicle, and storage medium for protecting a differential, in order to solve the problems in the related art where differentials are prone to failure and vehicle malfunction due to wear exceeding design limits over a long period of time, thereby reducing the lifespan of electric vehicles and resulting in a poor user experience.

[0006] The first aspect of this application provides a method for protecting a differential, comprising the following steps: obtaining the output torque of a drive motor in an electric vehicle; if the output torque is within a preset torque range, activating the differential protection function of the differential and / or the gravity control system of the electric vehicle, wherein the execution priority of the gravity control system and the differential protection function is different; using the differential protection function and / or the gravity control system to reduce the output torque of the drive motor, thereby reducing the speed difference between the half-shafts in the differential, until the speed difference is less than a first preset value.

[0007] Based on the above technical means, the embodiments of this application can activate the differential protection function of the differential when the output torque of the drive motor is large, and can be linked with the gravity control system to protect the differential, avoiding damage to the differential due to excessive torque without differential protection. Thus, the timing of activation is determined by the motor torque, which not only avoids frequent start-stop or false triggering of the differential protection function, but also greatly reduces the wear and tear on the electric drive differential of electric vehicles, improves the lifespan of electric vehicles, reduces the failure rate, and enhances the user experience.

[0008] Optionally, the preset torque range includes a first torque range or a second torque range, wherein in the first torque range, the execution priority of the gravity control system is higher than the execution priority of the differential protection function, and in the second torque range, the execution priority of the differential protection function is higher than the execution priority of the gravity control system, and the minimum value of the second torque range is greater than the maximum value of the first torque range.

[0009] According to the above technical means, in the first torque range, the execution priority of the gravity control system is higher than the execution priority of the differential protection function, while in the second torque range, the execution priority of the differential protection function is higher than the execution priority of the gravity control system, thereby reducing the impact on chassis performance and reducing the wear and tear on the electric drive differential of the electric vehicle.

[0010] Optionally, activating the differential protection function of the differential and / or the gravity control system of the electric vehicle includes: within the first torque range, if the gravity control system is not activated, activating the differential protection function when the duration for which the output torque is greater than the minimum value of the first torque range meets a preset duration; otherwise, activating the differential protection function when it is determined that the speed difference is still greater than or equal to the first preset value after the gravity control system has finished executing; and activating the differential protection function and the gravity control system within the second torque range.

[0011] According to the above technical means, in the first torque range, if the gravity control system is not activated, the differential protection function is activated when the duration of the output torque being greater than the minimum value of the first torque range meets the preset time. Otherwise, after the gravity control system finishes execution, if it is determined that the speed difference is still greater than or equal to the preset value, the differential protection function is activated. In the second torque range, the differential protection function and the gravity control system are activated to achieve dual protection for the differential, avoid differential failure, improve the reliability and lifespan of pure electric vehicles, and enhance the user's driving experience.

[0012] Optionally, the differential protection function includes: if the speed difference is greater than or equal to the first preset value and less than the second preset value, then reducing the output torque of the drive motor to a first target torque; if the speed difference is greater than or equal to the second preset value, then reducing the output torque of the drive motor to a first preset torque, wherein the first target torque is greater than the first preset torque.

[0013] According to the above technical means, in the embodiment of this application, the differential protection function reduces the output torque of the drive motor to the first target torque when the speed difference is greater than or equal to the first preset value and less than the second preset value. If the speed difference is greater than or equal to the second preset value, the output torque of the drive motor is reduced to the first preset torque, thereby reducing the speed difference between the left and right wheels, increasing the braking force of the wheels, and realizing stable vehicle driving.

[0014] Optionally, reducing the output torque of the drive motor to the first target torque further includes: identifying whether the gravity control system is activated; if the gravity control system is not activated, the first target torque is a second preset torque; if the gravity control system is activated, the first target torque is the minimum value between the second preset torque and the corresponding limiting torque of the gravity control system.

[0015] Based on the above technical means, the embodiments of this application identify whether the gravity control system is activated. If it is not activated, the first target torque is the second preset torque. If it is activated, the first target torque is the minimum value in the constraint matrix corresponding to the second preset torque and the gravity control system, thereby minimizing the wear of the electric drive differential on the electric vehicle and improving the reliability of the electric vehicle.

[0016] A second aspect of this application provides a protection device for a differential, comprising: an acquisition module for acquiring the output torque of a drive motor in an electric vehicle; an activation module for activating a differential protection function of the differential and / or a gravity control system of the electric vehicle if the output torque is within a preset torque range, wherein the gravity control system and the differential protection function have different execution priorities; and a processing module for reducing the output torque of the drive motor using the differential protection function and / or the gravity control system to reduce the speed difference between the half-shafts in the differential until the speed difference is less than a first preset value.

[0017] Optionally, the preset torque range includes a first torque range or a second torque range, wherein in the first torque range, the execution priority of the gravity control system is higher than the execution priority of the differential protection function, and in the second torque range, the execution priority of the differential protection function is higher than the execution priority of the gravity control system, and the minimum value of the second torque range is greater than the maximum value of the first torque range.

[0018] Optionally, the activation module is further configured to: within the first torque range, if the gravity control system is not activated, activate the differential protection function when the duration for which the output torque is greater than the minimum value of the first torque range meets a preset duration; otherwise, after the gravity control system has finished executing, activate the differential protection function when it is determined that the speed difference is still greater than or equal to the first preset value; within the second torque range, activate the differential protection function and the gravity control system.

[0019] Optionally, the differential protection function includes: if the speed difference is greater than or equal to the first preset value and less than the second preset value, then reducing the output torque of the drive motor to a first target torque; if the speed difference is greater than or equal to the second preset value, then reducing the output torque of the drive motor to a first preset torque, wherein the first target torque is greater than the first preset torque.

[0020] Optionally, the processing module is further configured to: identify whether the gravity control system is activated; if the gravity control system is not activated, the first target torque is the second preset torque; if the gravity control system is activated, the first target torque is the minimum value between the second preset torque and the corresponding limiting torque of the gravity control system.

[0021] A third aspect of this application provides an electric vehicle, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the differential protection method as described in the above embodiments.

[0022] A fourth aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the differential protection method as described in the above embodiments.

[0023] Therefore, this application has at least the following beneficial effects:

[0024] (1) The embodiment of this application can activate the differential protection function of the differential when the output torque of the drive motor is large, and can be linked with the gravity control system to protect the differential, so as to avoid damage to the differential due to excessive torque without differential protection. Thus, the timing of activation is determined by the motor torque. This not only avoids frequent start-stop or false triggering of the differential protection function, but also greatly reduces the wear and tear on the electric drive differential of electric vehicles, improves the life of electric vehicles, reduces the failure rate, and improves the user experience.

[0025] (2) In the first torque range of this application embodiment, the execution priority of the gravity control system is higher than the execution priority of the differential protection function, while in the second torque range, the execution priority of the differential protection function is higher than the execution priority of the gravity control system, thereby reducing the impact on chassis performance and reducing the wear of electric drive differential in electric vehicles.

[0026] (3) In the first torque range of this application embodiment, if the gravity control system is not activated, the differential protection function is activated when the duration of the output torque being greater than the minimum value of the first torque range meets the preset duration. Otherwise, after the gravity control system is executed, if it is determined that the speed difference is still greater than or equal to the preset value, the differential protection function is activated. In the second torque range, the differential protection function and the gravity control system are activated to achieve dual protection of the differential, avoid differential failure, improve the reliability and life of pure electric vehicles, and improve the user's driving experience.

[0027] (4) In this embodiment of the application, the differential protection function reduces the output torque of the drive motor to the first target torque when the speed difference is greater than or equal to the first preset value and less than the second preset value. If the speed difference is greater than or equal to the second preset value, the output torque of the drive motor is reduced to the first preset torque, thereby reducing the speed difference between the left and right wheels, increasing the braking force of the wheels, and realizing the smooth driving of the vehicle.

[0028] (5) In this embodiment of the application, the gravity control system is identified as activated. If it is not activated, the first target torque is the second preset torque. If it is activated, the first target torque is the minimum value in the constraint matrix corresponding to the second preset torque and the gravity control system, thereby minimizing the wear of the electric drive differential on the electric vehicle and improving the reliability of the electric vehicle.

[0029] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0030] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0031] Figure 1 This is a flowchart of a differential protection method provided according to an embodiment of this application;

[0032] Figure 2 This is a schematic diagram of a differential speed failure caused by TCS failure according to an embodiment of this application;

[0033] Figure 3 The differential protection boundary curve provided according to the embodiments of this application;

[0034] Figure 4This is a schematic diagram illustrating the layered and zoned protection of the differential protection function provided in the embodiments of this application;

[0035] Figure 5 This is a diagram illustrating the differential protection function strategy provided according to an embodiment of this application.

[0036] Figure 6 This is a block diagram of a protection device for a differential according to an embodiment of this application;

[0037] Figure 7 This is a schematic diagram of the structure of an electric vehicle according to an embodiment of this application. Detailed Implementation

[0038] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0039] The following description, with reference to the accompanying drawings, outlines a differential protection method, apparatus, electric vehicle, and storage medium according to embodiments of this application. Addressing the issue mentioned in the background art where prolonged wear exceeding the differential's design limits during traction conditions can easily lead to differential failure, vehicle malfunction, reduced electric vehicle lifespan, and a poor user experience, this application provides a differential protection method. This method activates the differential protection function when the drive motor's output torque is high. Furthermore, it can be linked with a traction control system to provide differential protection, preventing damage caused by excessive torque without differential protection. The motor torque determines the activation timing, avoiding frequent start-stop or false triggering of the differential protection function. This significantly reduces wear on the electric drive differential, extending the electric vehicle's lifespan, lowering the failure rate, and improving the user experience. Therefore, this method solves the problems in related technologies where prolonged wear of the differential easily exceeds design limits, leading to differential failure, vehicle malfunction, reduced electric vehicle lifespan, and a poor user experience.

[0040] Specifically, Figure 1 This is a flowchart illustrating a differential protection method provided in an embodiment of this application.

[0041] like Figure 1 As shown, the protection method for this differential includes the following steps:

[0042] In step S101, the output torque of the drive motor in the electric vehicle is obtained.

[0043] It is understood that the embodiments of this application obtain the output torque of the drive motor in the electric vehicle in order to subsequently activate the differential protection function of the differential and / or the gravity control system of the electric vehicle.

[0044] In step S102, if the output torque is within a preset torque range, the differential protection function of the differential and / or the gravity control system of the electric vehicle are activated, wherein the execution priority of the gravity control system and the differential protection function is different.

[0045] The preset torque range includes either a first torque range or a second torque range.

[0046] Among them, the first torque range; the second torque range

[0047] In this embodiment, within the first torque range, the execution priority of the gravity control system is higher than that of the differential protection function; within the second torque range, the execution priority of the differential protection function is higher than that of the gravity control system; and the minimum value of the second torque range is greater than the maximum value of the first torque range.

[0048] In this embodiment, activating the differential protection function of the differential and / or the gravity control system of the electric vehicle includes: within a first torque range, if the gravity control system is not activated, then when the duration for which the output torque is greater than the minimum value of the first torque range meets a preset duration, the differential protection function is activated; otherwise, after the gravity control system has finished executing, when it is determined that the speed difference is still greater than or equal to a first preset value, the differential protection function is activated; within a second torque range, the differential protection function and the gravity control system are activated.

[0049] In this embodiment of the application, the differential protection function includes: if the speed difference is greater than or equal to a first preset value and less than a second preset value, then reducing the output torque of the drive motor to a first target torque; if the speed difference is greater than or equal to the second preset value, then reducing the output torque of the drive motor to a first preset torque, wherein the first target torque is greater than the first preset torque.

[0050] In step S103, the output torque of the drive motor is reduced by using the differential protection function and / or the gravity control system to reduce the speed difference between the half shafts in the differential until the speed difference is less than the first preset value.

[0051] In this embodiment of the application, reducing the output torque of the drive motor to the first target torque further includes: identifying whether the gravity control system is activated; if the gravity control system is not activated, the first target torque is the second preset torque; if the gravity control system is activated, the first target torque is the minimum value between the second preset torque and the corresponding limiting torque of the gravity control system.

[0052] According to the differential protection method proposed in this application embodiment, the differential protection function of the differential can be activated when the output torque of the drive motor is large. It can also be linked with the gravity control system to protect the differential, avoiding damage to the differential due to excessive torque without differential protection. The timing of activation is determined by the motor torque, which not only avoids frequent start-stop or false triggering of the differential protection function, but also greatly reduces the wear and tear on the electric drive differential of electric vehicles, improves the lifespan of electric vehicles, reduces the failure rate, and enhances the user experience.

[0053] The following will combine Figures 2 to 5 The protection methods for differentials are explained in detail, and the specific steps are as follows:

[0054] Step 1: Assess the capabilities of the differential:

[0055] Differential tests were conducted based on the developed differential, with the differential nearing failure as the evaluation criterion, to determine the differential's ultimate capabilities and define its usage boundary.

[0056] Step 2: Based on the wheel speed signal status, adopt the "protection strategy based on the hierarchical and zoned principle":

[0057] (1) The speed difference between the left and right wheels is less than the differential use boundary △n1, which is located in the non-differential protection boundary area: no protection strategy is implemented;

[0058] (2) When the speed difference between the left and right wheels is located at the differential operating boundary △n1-△n2, it belongs to the differential protection strategy area: At this time, the motor requests a torque reduction of **% (calibrated) and compares it with the TCS torque reduction request. The minimum value is taken and the maximum gradient is executed, and then it is gradually restored to the torque requested by the VCU; the protection information is reported.

[0059] (3) When the speed difference between the left and right wheels is greater than the differential use boundary △n2, the motor drops to 0 with the maximum response gradient and reports protection information.

[0060] Step 3: The differential protection function is linked to the TCS function to reduce the impact on chassis performance.

[0061] (1) TCS is normal. Within the forced zone: TCS is not activated. If the operating point crosses the first layer boundary of differential protection by ≥0.3S, differential protection is activated. After TCS is activated, TCS is executed first. Outside the forced zone: differential protection takes priority, and TCS is forcibly activated.

[0062] (2) TCS abnormal, wheel speed signal valid: differential protection function is valid.

[0063] (3) TCS malfunction, wheel speed signal invalid: differential protection function is invalid.

[0064] Implementation conditions: The chassis TCS activation point should be within the differential boundary range as much as possible, and the control point should also be within the differential boundary range as much as possible.

[0065] In summary, this application develops an electric drive differential protection function based on the differential's usage boundary. This function is integrated with the vehicle's TCS function and interconnected to minimize the wear and tear on the electric drive differential caused by pure electric vehicles, improve the reliability and lifespan of pure electric vehicles, reduce after-sales failure rates, and enhance the customer's user experience.

[0066] Next, the protective device for the differential proposed according to the embodiments of this application is described with reference to the accompanying drawings.

[0067] Figure 6 This is a block diagram of the protection device for the differential in an embodiment of this application.

[0068] like Figure 6 As shown, the differential protection device 10 includes: an acquisition module 100, an activation module 200, and a processing module 300.

[0069] The acquisition module 100 is used to acquire the output torque of the drive motor in the electric vehicle; the activation module 200 is used to activate the differential protection function of the differential and / or the gravity control system of the electric vehicle if the output torque is within a preset torque range, wherein the execution priority between the gravity control system and the differential protection function is different; the processing module 300 is used to reduce the output torque of the drive motor by utilizing the differential protection function and / or the gravity control system to reduce the speed difference between the half shafts in the differential until the speed difference is less than a first preset value.

[0070] In this embodiment of the application, the preset torque range includes a first torque range or a second torque range. In the first torque range, the execution priority of the gravity control system is higher than the execution priority of the differential protection function. In the second torque range, the execution priority of the differential protection function is higher than the execution priority of the gravity control system. The minimum value of the second torque range is greater than the maximum value of the first torque range.

[0071] In this embodiment, the activation module 200 is further configured to: activate the differential protection function when the output torque is greater than the minimum value of the first torque range for a preset duration if the gravity control system is not activated within the first torque range; otherwise, activate the differential protection function when the speed difference is determined to be greater than or equal to the first preset value after the gravity control system has been executed; and activate the differential protection function and the gravity control system within the second torque range.

[0072] It should be noted that the foregoing explanation of the differential protection method embodiment also applies to the differential protection device of this embodiment, and will not be repeated here.

[0073] According to the differential protection device proposed in the embodiments of this application, the differential protection function of the differential can be activated when the output torque of the drive motor is large. It can also be linked with the gravity control system to protect the differential, avoiding damage to the differential due to excessive torque without differential protection. The timing of activation is determined by the motor torque, which not only avoids frequent start-stop or false triggering of the differential protection function, but also greatly reduces the wear and tear on the electric drive differential of electric vehicles, improves the lifespan of electric vehicles, reduces the failure rate, and enhances the user experience.

[0074] Figure 7 A schematic diagram of the structure of an electric vehicle provided in an embodiment of this application. The electric vehicle may include:

[0075] The memory 701, the processor 702, and the computer program stored on the memory 701 and executable on the processor 702.

[0076] When the processor 702 executes the program, it implements the differential protection method provided in the above embodiments.

[0077] Furthermore, electric vehicles also include:

[0078] Communication interface 703 is used for communication between memory 701 and processor 702.

[0079] The memory 701 is used to store computer programs that can run on the processor 702.

[0080] The memory 701 may include high-speed RAM (Random Access Memory) memory, and may also include non-volatile memory, such as at least one disk storage.

[0081] If the memory 701, processor 702, and communication interface 703 are implemented independently, then the communication interface 703, memory 701, and processor 702 can be interconnected via a bus to complete communication between them. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 7 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0082] Optionally, in a specific implementation, if the memory 701, processor 702, and communication interface 703 are integrated on a single chip, then the memory 701, processor 702, and communication interface 703 can communicate with each other through an internal interface.

[0083] The processor 702 may be a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of this application.

[0084] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the above-described differential protection method.

[0085] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0086] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0087] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0088] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (FPGAs), field-programmable gate arrays (FPGAs), etc.

[0089] Those skilled in the art will understand that all or part of the steps of the methods described in the above embodiments can be implemented by a program instructing related hardware, and the program can be stored in a computer-readable storage medium. When executed, the program includes one or a combination of the steps of the method embodiments.

[0090] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method of protecting a differential, characterized in that, Includes the following steps: Obtain the output torque of the drive motor in an electric vehicle; If the output torque is within a preset torque range, the differential protection function of the differential and / or the gravity control system of the electric vehicle are activated, wherein the execution priority of the gravity control system and the differential protection function is different. The differential protection function and / or gravity control system are used to reduce the output torque of the drive motor, thereby reducing the speed difference between the half-shafts in the differential until the speed difference is less than a first preset value. The preset torque range includes a first torque range or a second torque range. In the first torque range, the execution priority of the gravity control system is higher than the execution priority of the differential protection function. In the second torque range, the execution priority of the differential protection function is higher than the execution priority of the gravity control system. The minimum value of the second torque range is greater than the maximum value of the first torque range. The activation of the differential protection function of the differential and / or the gravity control system of the electric vehicle includes: If the gravity control system is not activated within the first torque range, the differential protection function is activated when the duration of the output torque being greater than the minimum value of the first torque range meets the preset duration; otherwise, the differential protection function is activated when the rotational speed difference is determined to be greater than or equal to the first preset value after the gravity control system has finished executing. Within the second torque range, the differential protection function and the gravity control system are activated.

2. The method of claim 1, wherein, The differential protection function includes: If the speed difference is greater than or equal to the first preset value and less than the second preset value, then the output torque of the drive motor is reduced to the first target torque; If the speed difference is greater than or equal to the second preset value, the output torque of the drive motor is reduced to the first preset torque, wherein the first target torque is greater than the first preset torque.

3. The method of claim 2, wherein, The step of reducing the output torque of the drive motor to the first target torque further includes: Identify whether the gravity control system is activated; If the gravity control system is not activated, the first target torque is the second preset torque; If the gravity control system is activated, the first target torque is the minimum value between the second preset torque and the corresponding limiting torque of the gravity control system.

4. A device for protecting a differential, implementing the method for protecting a differential according to any one of claims 1 to 3, characterized in that, include: The acquisition module is used to acquire the output torque of the drive motor in an electric vehicle; An activation module is used to activate the differential protection function of the differential and / or the gravity control system of the electric vehicle if the output torque is within a preset torque range, wherein the execution priority of the gravity control system and the differential protection function is different. The processing module is used to reduce the output torque of the drive motor by utilizing the differential protection function and / or the gravity control system, so as to reduce the speed difference between the half shafts in the differential until the speed difference is less than a first preset value. The preset torque range includes a first torque range or a second torque range, wherein, in the first torque range, the execution priority of the attraction control system is higher than the execution priority of the differential protection function, in the second torque range, the execution priority of the differential protection function is higher than the execution priority of the attraction control system, and the minimum value of the second torque range is greater than the maximum value of the first torque range.

5. The apparatus of claim 4, wherein, The activation module is further used for: in the first torque range, if the attraction control system is not activated, when the duration that the output torque is greater than the minimum value of the first torque range satisfies a preset time length, the differential protection function is activated, otherwise, when the attraction control system is executed and completed, if the rotational speed difference is still greater than or equal to the first preset value, the differential protection function is activated; in the second torque range, the differential protection function and the attraction control system are activated.

6. An electric vehicle, characterized by comprise: a memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executes the program to implement the differential protection method according to any one of claims 1-3.

7. A computer readable storage medium having stored thereon a computer program, characterized in that, The program is executed by the processor to implement the differential protection method according to any one of claims 1-3.

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