A vehicle drive motor stall protection control system and method

Abstract

This invention discloses a vehicle drive motor stall protection control system and method, comprising: when the motor speed is less than a preset speed threshold, calculating the square difference between the actual motor current value and the current value corresponding to a preset first torque, and obtaining the integral value of the square difference between the real-time current and the current value corresponding to the preset first torque; calculating the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque, and performing a fixed-time integration on the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque to obtain the fixed-time integral value of the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque; when the integral value of the square difference between the real-time current and the current value corresponding to the preset first torque is greater than or equal to the fixed-time integral value of the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque, determining that the current motor stall fault state is mature, and implementing fault protection measures.

Description

Technical Field

[0001] This invention relates to the field of motor control for new energy vehicles, specifically to a stall protection control system and method for vehicle drive motors. Background Technology

[0002] With the development of new energy vehicle technologies and the popularization of new energy vehicles, the safety and reliability of these vehicles have received considerable attention. In the design of electric vehicle drive systems, there is a performance indicator called maximum gradeability. During maximum gradeability testing, electric vehicles may experience tire lock-up, causing the motor speed to approach zero, resulting in motor stall. When the motor stalls, the drive module in the motor controller stops switching, causing one phase IGBT to overheat rapidly, potentially burning out and damaging the motor controller.

[0003] When an electric vehicle is accelerating uphill or stuck in a stall, the motor control strategy becomes particularly important. Generally, the motor is required to output peak torque, resulting in low motor speed and peak current. At this time, the Insulated Gate Bipolar Transistor (IGBT) operates at a high switching frequency, leading to significant switching losses and a rapid rise in IGBT temperature. Especially during repeated uphill climbs, prolonged acceleration uphill, or stalling, this can even cause the IGBT to burn out, posing a safety hazard and reducing vehicle safety. Currently, when a car is in these conditions, the motor control strategy is to maintain a constant frequency; therefore, the overall vehicle system safety cannot be guaranteed.

[0004] In existing technologies, a three-phase drive bridge of a motor controller is used to drive the motor according to torque command requirements, and the motor speed and output torque are detected in real time. When the motor stops, a timer is started. If the duration of the motor stoppage under the same torque is greater than or equal to the predetermined time corresponding to that torque, it is determined that the motor has stalled, and the motor torque is unloaded until the motor is detected to be in a non-stalled state. This stalling method protects the IGBT drive module.

[0005] Existing technologies also involve collecting motor drive data and operating data; calculating the motor input power based on the drive data and operating data; calculating the motor's theoretical output power according to preset controller parameters, the motor's given frequency value, and operating data; and determining whether the motor is stalled based on the operating data, motor input power, and motor theoretical output power. By acquiring the motor's operating data, motor input power, and theoretical output power, motor stall detection is performed from the perspective of motor power balance, directly determining whether the motor is stalled, ensuring that the motor stall protection logic can be correctly activated, and guaranteeing the safe operation of the drive module.

[0006] The above-mentioned technical solutions, which rely on reducing torque to protect the motor, cannot reduce the temperature in the shortest time, nor can they achieve the same temperature reduction effect under the same torque, thus failing to maximize the motor's performance; or they require estimation of input and input power, resulting in numerous calculations with insufficient accuracy, making it impossible to accurately determine stall conditions. Summary of the Invention

[0007] The purpose of this invention is to provide a vehicle drive motor stall protection control system and a vehicle drive motor stall protection control method. This system and method can solve the problems of the current motor stall control process being unable to reduce the controller temperature as quickly as possible, and the stall heat recalculation when stall monitoring is frequently activated.

[0008] To achieve this objective, the present invention provides a vehicle drive motor stall protection control system, comprising:

[0009] The parameter acquisition module is used to acquire motor speed, direct-axis current and quadrature-axis current in real time;

[0010] The first integral calculation module is used to calculate the integral value of the squared difference between the real-time current and the current value corresponding to the preset first torque.

[0011] The second integral calculation module is used to calculate the fixed-time integral value of the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque.

[0012] The fault response module is used to determine that the current motor stall fault state is mature and to implement fault protection measures when the integral value of the square difference between the real-time current and the current value corresponding to the preset first torque is greater than or equal to the fixed-time integral value of the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque.

[0013] Furthermore, the method for calculating the integral value of the square difference between the real-time current and the current value corresponding to the preset first torque includes: when the motor speed is less than the preset speed threshold, calculating the actual motor current value based on the direct-axis current value and the quadrature-axis current value, calculating the square difference between the actual motor current value and the current value corresponding to the preset first torque, and integrating the square difference between the real-time current and the current value corresponding to the preset first torque.

[0014] Furthermore, the method for calculating the fixed-time integral value of the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque includes: calculating the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque, and performing a fixed-time integral on the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque.

[0015] Furthermore, the method for calculating the actual motor current value based on the direct-axis current value and the quadrature-axis current value, calculating the square difference between the actual motor current value and the current value corresponding to the preset first torque, and integrating the square difference between the real-time current and the current value corresponding to the preset first torque to obtain the integral value of the square difference between the real-time current and the current value corresponding to the preset first torque includes:

[0016] ;

[0017] ;

[0018] Where is is the actual current value of the motor, id is the direct-axis current, and iq is the quadrature-axis current. ib is the square difference between the real-time current and the current value corresponding to the preset first torque B. The preset first torque B is the motor torque corresponding to the IGBT junction temperature balance when it is below the set value of the maximum tolerable temperature point. ib is the current value corresponding to the motor torque when it is the preset first torque B.

[0019] Integrating the squared difference between the real-time current and the current value corresponding to the preset first torque yields the result. =Q1, where Q1 is the integral of the squared difference between the real-time current and the current value corresponding to the preset first torque, and t is the duration after the motor speed is less than the preset speed threshold.

[0020] Furthermore, the method for calculating the squared difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque, and integrating the squared difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque over a fixed time, to obtain the fixed-time integral value of the squared difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque, includes: ;

[0021] in, The difference between the square of the current value corresponding to the preset first torque and the current value corresponding to the preset second torque A is the motor torque corresponding to the IGBT junction temperature balance at the highest tolerable temperature point. ib is the current value corresponding to the motor torque when it is the preset first torque B, and ic is the current value corresponding to the motor torque when it is the preset second torque A.

[0022] The squared difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque is obtained by integrating over a fixed time. =Q,t1 is the maximum stall time of the motor obtained by the dynamometer test, andQ is the motor stall integral energy value within the maximum stall time.

[0023] Furthermore, methods for determining whether the current motor stall fault condition is mature include:

[0024] =Q1, =Q, when If the motor stall fault condition is mature, then the motor stall fault condition is considered mature; otherwise, the motor stall fault condition is not mature.

[0025] 7. A vehicle drive motor stall protection control system according to claim 6, characterized in that: after determining that the current motor stall fault state is mature, the method for implementing fault protection measures includes: reducing the IGBT switching frequency to a preset value and limiting the maximum torque of the motor to below a preset value.

[0026] Furthermore, while implementing the fault protection measures, the square difference between the real-time current and the current value corresponding to the preset first torque is continuously integrated. When the integral value Q1 of the square difference between the real-time current and the current value corresponding to the preset first torque is less than the integral value Q of the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque, and the motor speed is greater than the preset speed, the motor exits the fault state.

[0027] Furthermore, a vehicle drive motor stall protection control method based on the aforementioned system includes:

[0028] Real-time acquisition of motor speed, direct-axis current, and quadrature-axis current;

[0029] The integral value of the squared difference between the real-time current and the current value corresponding to the preset first torque is calculated.

[0030] The fixed-time integral value of the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque is calculated.

[0031] When the integral value of the square difference between the real-time current and the current value corresponding to the preset first torque is greater than or equal to the fixed-time integral value of the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque, the current motor stall fault state is judged to be mature, and fault protection measures are implemented.

[0032] The beneficial effects of this invention are as follows: Introducing current integration calculation in motor stall fault diagnosis is more accurate than directly using torque. After confirming the motor stall state, adding response control to the IGBT turn-on frequency helps to rapidly reduce the IGBT temperature. When the stall monitoring conditions are not met, the energy of the current integration decays to 0 at a certain rate. When the stall monitoring conditions are frequently met, the judgment is re-evaluated based on the integrated energy, allowing for faster and more accurate determination of the stall state. Attached Figure Description

[0033] Figure 1 This is a flowchart illustrating the stall control principle of the present invention.

[0034] Figure 2 This is a schematic diagram of the structure of the present invention. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0037] Example 1

[0038] like Figure 2 As shown, a vehicle drive motor stall protection control system includes:

[0039] The parameter acquisition module is used to acquire motor speed, direct-axis current and quadrature-axis current in real time;

[0040] The first integral calculation module is used to calculate the integral value of the squared difference between the real-time current and the current value corresponding to the preset first torque.

[0041] The second integral calculation module is used to calculate the fixed-time integral value of the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque.

[0042] The fault response module is used to determine that the current motor stall fault state is mature and to implement fault protection measures when the integral value of the square difference between the real-time current and the current value corresponding to the preset first torque is greater than or equal to the fixed-time integral value of the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque.

[0043] In some technical solutions, the method for calculating the integral value of the square difference between the real-time current and the current value corresponding to the preset first torque includes: when the motor speed is less than the preset speed threshold, calculating the actual motor current value based on the direct axis current value and the quadrature axis current value, calculating the square difference between the actual motor current value and the current value corresponding to the preset first torque, and integrating the square difference between the real-time current and the current value corresponding to the preset first torque.

[0044] The preset speed threshold is set according to the actual situation. In some embodiments, the preset speed threshold is 200 rpm.

[0045] When a motor stalls, its speed is extremely low, but the corresponding current reaches its peak. The drive module in the motor controller stops switching, and the motor remains stationary at a certain angle for an extended period. During this time, one phase of the three-phase current will be higher than the other two for a prolonged period, leading to uneven heating. The bridge arm with the higher current will heat up rapidly, causing the IGBT to overheat and burn out, ultimately damaging the motor controller. Therefore, this motor stall protection solution primarily achieves motor stall protection by detecting and adjusting the IGBT temperature.

[0046] In some technical solutions, the method for calculating the fixed-time integral value of the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque includes: calculating the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque, and performing a fixed-time integral on the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque.

[0047] The preset second torque A is the motor torque corresponding to the junction temperature balance of the motor controller IGBT module at the highest tolerable temperature point. The highest tolerable temperature point of the IGBT module junction temperature is provided by the supplier. In some embodiments, the highest tolerable temperature point of the IGBT module junction temperature balance is 150°C. Therefore, the preset second torque A is the motor torque corresponding to the junction temperature balance of the motor controller IGBT module at 150°C.

[0048] The preset first torque B is the motor torque corresponding to the IGBT junction temperature balance being below the set value of the maximum tolerable temperature point. In some embodiments, the maximum tolerable temperature point of the IGBT module junction temperature balance is 150°C. The preset first torque B can be set to the motor torque corresponding to the IGBT junction temperature balance being 147°C. The junction temperature of the IGBT module corresponding to the preset first torque B is slightly lower than the junction temperature of the IGBT module corresponding to the preset second torque A. The purpose is to leave a temperature safety margin of 3°C, ensuring that when the IGBT junction temperature balance is 147°C, the motor controller quickly reports a fault and performs cooling protection on the IGBT module, preventing the IGBT module from being burned out due to untimely cooling when the junction temperature balance is only at the maximum tolerable junction temperature (150°C).

[0049] In some technical solutions, the method of calculating the actual motor current value based on the direct-axis current value and the quadrature-axis current value, calculating the square difference between the actual motor current value and the current value corresponding to the preset first torque, and integrating the square difference between the real-time current and the current value corresponding to the preset first torque to obtain the integral value of the square difference between the real-time current and the current value corresponding to the preset first torque includes:

[0050] ;

[0051] ;

[0052] Where is is the actual current value of the motor, id is the direct-axis current, and iq is the quadrature-axis current. ib is the square difference between the real-time current and the current value corresponding to the preset first torque B. The preset first torque B is the motor torque corresponding to the IGBT junction temperature balance when it is below the set value of the maximum tolerable temperature point. ib is the current value corresponding to the motor torque when it is the preset first torque B.

[0053] Integrating the squared difference between the real-time current and the current value corresponding to the preset first torque yields the result. =Q1, where Q1 is the integral of the squared difference between the real-time current and the current value corresponding to the preset first torque, and t is the duration after the motor speed is less than the preset speed threshold.

[0054] The direct-axis and quadrature-axis current values ​​are automatically calculated by the motor controller using three-phase AC power. In practical applications, the motor controller adjusts the current through closed-loop control. The direct-axis current (id) and quadrature-axis current (iq) in a two-phase rotating coordinate system are calculated based on the three-phase current collected by the closed-loop control. The real-time current value is then calculated using the direct-axis current (id) and quadrature-axis current (iq). The real-time current value calculated using the direct-axis current (id) and quadrature-axis current (iq) directly reflects the actual load state of the motor and is more suitable for protection-related logic judgments compared to the target current value in closed-loop control (the current value required for the target torque calculated by the motor controller based on the target torque).

[0055] The preset first torque B is the torque that allows the IGBT junction temperature to balance at a safe value during long-term operation, which is the set value (such as 147°C) that is lower than the maximum tolerable temperature point mentioned above. When the actual motor current value (is) corresponding to the actual motor torque exceeds the current value corresponding to the preset first torque B, it indicates that the IGBT module temperature may exceed the safe threshold. At this time, the heat value of the IGBT module is calculated by integration.

[0056] In some technical solutions, the method of calculating the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque, and then integrating the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque over a fixed time, to obtain the fixed-time integral value of the square difference between the current values ​​corresponding to the preset first torque and the current value corresponding to the preset second torque includes: ;

[0057] in, The difference between the square of the current value corresponding to the preset first torque and the current value corresponding to the preset second torque A is the motor torque corresponding to the IGBT junction temperature balance at the highest tolerable temperature point. ib is the current value corresponding to the motor torque when it is the preset first torque B, and ic is the current value corresponding to the motor torque when it is the preset second torque A.

[0058] The squared difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque is obtained by integrating over a fixed time. =Q,t1 is the maximum stall time of the motor obtained by the dynamometer test, andQ is the motor stall integral energy value within the maximum stall time.

[0059] After the motor torque exceeds the first preset torque B and the integral heat calculation begins, it indicates that the current temperature of the IGBT module of the motor controller may exceed the safe value (147°C). The preset second torque A is the torque corresponding to the highest temperature that the IGBT module can withstand. The purpose of setting the preset second torque A is to determine a specific heat target threshold. The determined specific heat target threshold is the motor stall integral energy value Q during the maximum stall time of the motor. Q is obtained by integrating the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque over a fixed time. The maximum temperature that the IGBT module can withstand is generally provided by the IGBT module supplier. In some embodiments, the longest time that the IGBT module can withstand when the junction temperature is above 150°C is 10 seconds, that is, the maximum stall time of the motor is 10 seconds. The fixed time t1 can be set to 5 seconds or 7 seconds (less than 10 seconds is acceptable). The heat generated by integrating the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque over a fixed time t1 is obtained to obtain the heat generated by the maximum junction temperature that the IGBT module can withstand within the fixed time t1. The purpose is to ensure that the actual heat generation Q1 of the IGBT module is less than the maximum tolerable heat generation Q, so that the motor controller can report the fault in advance for protection.

[0060] Some technical solutions include methods for determining whether the current motor stall fault state is mature, such as:

[0061] =Q1, =Q, when If the motor stall fault condition is mature, then the motor stall fault condition is considered mature; otherwise, the motor stall fault condition is not mature.

[0062] Q1 represents the actual heat generated by the IGBT module as the temperature rises when the real-time current of the motor exceeds the current value corresponding to the preset first torque. Q represents the heat generated by the IGBT module at the maximum junction temperature it can withstand. When Q1 is greater than or equal to Q, the actual heat generated by the IGBT module is greater than or equal to the heat generated by the maximum junction temperature it can withstand, indicating that the motor stall fault condition is mature. At this time, fault protection measures are implemented to reduce the junction temperature of the IGBT module.

[0063] In some technical solutions, after determining that the current motor stall fault state is mature, the methods for implementing fault protection measures include: reducing the IGBT switching frequency to a preset value and limiting the maximum torque of the motor to below a preset value.

[0064] In some embodiments, after determining that the motor stall fault condition has matured, the method for implementing fault response measures includes: the motor controller immediately reducing the IGBT switching frequency to 2K / s. Simultaneously, the maximum torque of the motor controller is limited to a preset value of 220NM at a set rate. The preset maximum torque limit value can be set according to actual conditions, and the preset maximum torque limit value can be a torque value that can maintain the IGBT junction temperature balance at a suitable and safe temperature.

[0065] In some technical solutions, while implementing fault protection measures, the square difference between the real-time current and the current value corresponding to the preset first torque is continuously integrated. When the integral value Q1 of the square difference between the real-time current and the current value corresponding to the preset first torque is less than the integral value Q of the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque, and the motor speed is greater than the preset speed, the motor exits the fault state.

[0066] During the fault protection response phase after the motor stall confirmation is complete, the current energy is continuously integrated on the square difference between the real-time current and the current value corresponding to the preset first torque. After the motor torque and IGBT switching frequency decrease, the actual motor current is and the motor speed decrease. At this time, the current energy is integrated on the square difference between the real-time current and the current value corresponding to the preset first torque, causing the integrated current energy to begin to decrease. When the integral value Q1 of the square difference between the real-time current and the current value corresponding to the preset first torque decreases to less than the integral value Q of the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque, and the motor speed is greater than the preset speed, it indicates that the motor has exited the stall state, and the torque limit and IGBT switching frequency have returned to normal.

[0067] When the motor stall detection process fails and the stall integral calculation is terminated due to the speed threshold not being met, the motor torque limit and IGBT switching frequency are executed according to normal torque control, while the integral energy Q decays at a preset rate. If it has not decayed to 0 before the next integral calculation is completed, the stall fault is determined directly based on this energy level.

[0068] By implementing this stall control method, it is possible to effectively and accurately monitor when the motor is in a stalled state, and take timely measures to reduce the heat generation of the motor controller, effectively protect the motor, and improve the reliability of vehicle operation.

[0069] Figure 1 The stall control principle flow of this invention is as follows:

[0070] Step 1. The motor controller detects the motor speed and current. When the real-time motor speed is greater than or equal to 200 rpm, the motor controller performs normal torque control. When the real-time motor speed is less than 200 rpm, proceed to step 2.

[0071] Step 2. Enter the stall monitoring process and determine whether the motor is entering stall monitoring for the first time. If so, start the current integration calculation from zero; if not, calculate the real-time current integration value when re-entering stall monitoring plus the residual value of the previous current integration.

[0072] Step 3. Determine if the current integration operation conditions are met. If so, reduce the torque limit and reduce the IGBT switching frequency to reduce the real-time motor current. At this time, perform the reverse current integration operation (i.e., the integration result is negative). If not, the motor controller performs normal torque control.

[0073] Step 4. Determine if the fault exit condition is met under the motor stall fault state. Specifically, determine if the integral value Q1 of the difference between the real-time current and the square of the current corresponding to the preset first torque is less than the integral value Q of the difference between the square of the current corresponding to the preset first torque and the current corresponding to the preset second torque, and if the motor speed is greater than 200 rpm. If the integral value Q1 of the difference between the real-time current and the square of the current corresponding to the preset first torque is less than the integral value Q of the difference between the square of the current corresponding to the preset first torque and the current corresponding to the preset second torque, but the motor speed is less than or equal to 200 rpm, then re-execute the stall monitoring process. If the integral value Q1 of the difference between the real-time current and the square of the current corresponding to the preset first torque is less than the integral value Q of the difference between the square of the current corresponding to the preset first torque and the current corresponding to the preset second torque, and the motor speed is greater than 200 rpm, then exit the stall detection process. The current integral at the moment before exiting stall monitoring decays at a preset rate.

[0074] Example 2

[0075] A vehicle drive motor stall protection control method based on the system includes:

[0076] Real-time acquisition of motor speed, direct-axis current, and quadrature-axis current;

[0077] The integral value of the squared difference between the real-time current and the current value corresponding to the preset first torque is calculated.

[0078] The fixed-time integral value of the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque is calculated.

[0079] When the integral value of the square difference between the real-time current and the current value corresponding to the preset first torque is greater than or equal to the fixed-time integral value of the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque, the current motor stall fault state is judged to be mature, and fault protection measures are implemented.

[0080] Example 3

[0081] A computer program product includes a computer program that, when executed by a processor, implements the steps of the method described in Embodiment 2.

[0082] This invention can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented in whole or in part as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this invention are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)).

[0083] It will be readily understood by those skilled in the art that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, combinations, substitutions, improvements, etc., made under the spirit and principles of the present invention are included within the protection scope of the present invention.

[0084] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. A kind of vehicle drive motor locked-rotor protection control system, it is characterized in that, include: The parameter acquisition module is used to acquire motor speed, direct-axis current and quadrature-axis current in real time; The first integral calculation module is used to calculate the integral value of the squared difference between the real-time current and the current value corresponding to the preset first torque. The method for calculating the integral value of the square difference between the real-time current and the current value corresponding to the preset first torque includes: when the motor speed is less than the preset speed threshold, calculating the actual motor current value based on the direct axis current value and the quadrature axis current value, calculating the square difference between the actual motor current value and the current value corresponding to the preset first torque, and integrating the square difference between the real-time current and the current value corresponding to the preset first torque; The second integral calculation module is used to calculate the fixed-time integral value of the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque. The method for calculating the fixed-time integral value of the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque includes: calculating the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque, and performing a fixed-time integral on the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque; calculating the actual motor current value based on the direct-axis current value and the quadrature-axis current value, calculating the square difference between the actual motor current value and the current value corresponding to the preset first torque, and integrating the square difference between the real-time current and the current value corresponding to the preset first torque to obtain the integral value of the square difference between the real-time current and the current value corresponding to the preset first torque includes: ； ； Where is is the actual current value of the motor, id is the direct-axis current, and iq is the quadrature-axis current. ib is the square difference between the real-time current and the current value corresponding to the preset first torque B. The preset first torque B is the motor torque corresponding to the IGBT junction temperature balance when it is below the set value of the maximum tolerable temperature point. ib is the current value corresponding to the motor torque when it is the preset first torque B. Integrating the squared difference between the real-time current and the current value corresponding to the preset first torque yields the result. =Q1, where Q1 is the integral of the squared difference between the real-time current and the current value corresponding to the preset first torque, and t is the duration after the motor speed is less than the preset speed threshold. The method for calculating the squared difference between the current value corresponding to a preset first torque and the current value corresponding to a preset second torque, and then integrating the squared difference between the two values ​​over a fixed time to obtain the fixed-time integral value of the squared difference between the two values, includes: ; in, The difference between the square of the current value corresponding to the preset first torque and the current value corresponding to the preset second torque A is the motor torque corresponding to the IGBT junction temperature balance at the highest tolerable temperature point. ib is the current value corresponding to the motor torque when it is the preset first torque B, and ic is the current value corresponding to the motor torque when it is the preset second torque A. The squared difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque is obtained by integrating over a fixed time. =Q,t1 is the maximum stall time of the motor obtained by the dynamometer test, andQ is the stall integral energy value of the motor during the maximum stall time. The fault response module is used to determine that the current motor stall fault state is mature and to implement fault protection measures when the integral value of the square difference between the real-time current and the current value corresponding to the preset first torque is greater than or equal to the fixed-time integral value of the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque.

2. The vehicle drive motor stall protection control system according to claim 1, characterized in that: Methods for determining whether the current motor stall fault condition is mature include: =Q1, =Q, when If the motor stall fault condition is mature, then the motor stall fault condition is considered mature; otherwise, the motor stall fault condition is not mature.

3. The vehicle drive motor stall protection control system according to claim 2, characterized in that: Once the current motor stall fault condition is deemed mature, the methods for implementing fault protection measures include: reducing the IGBT switching frequency to a preset value and limiting the maximum motor torque to below a preset value.

4. A vehicle drive motor stall protection control system according to claim 3, characterized in that: While implementing fault protection measures, the square difference between the real-time current and the current value corresponding to the preset first torque is continuously integrated. When the integral value Q1 of the square difference between the real-time current and the current value corresponding to the preset first torque is less than the integral value Q of the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque, and the motor speed is greater than the preset speed, the motor exits the fault state.

5. A method for controlling stall protection of a vehicle drive motor based on the system described in claim 1, characterized in that, include: Real-time acquisition of motor speed, direct-axis current, and quadrature-axis current; The integral value of the squared difference between the real-time current and the current value corresponding to the preset first torque is calculated. The fixed-time integral value of the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque is calculated. When the integral value of the square difference between the real-time current and the current value corresponding to the preset first torque is greater than or equal to the fixed-time integral value of the square difference between the current value corresponding to the preset first torque and the current value corresponding to the preset second torque, the current motor stall fault state is judged to be mature, and fault protection measures are implemented.

6. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method described in claim 5.

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