Control method of motor of electric vehicle and electric vehicle
By obtaining the mapping relationship between the temperature and the upper limit of the motor stator, the motor torque output is dynamically adjusted, which solves the problem of motor overheating and damage in electric vehicles under high load conditions, and realizes the reliability of the motor and the stability of power output.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHEJIANG GEELY HLDG GRP CO LTD
- Filing Date
- 2023-08-07
- Publication Date
- 2026-06-26
AI Technical Summary
When electric vehicles are driven under conditions such as continuous rapid acceleration and deceleration, the motor is prone to overheating, leading to irreversible damage and power loss.
By obtaining the mapping relationship between the temperature of the motor stator and the upper limit of torque, the torque output of the motor is dynamically adjusted to slowly reduce the upper limit of torque and prevent the motor from being damaged by overload. This includes controlling the torque output by using different attenuation rates in different temperature ranges.
It effectively prevents irreversible damage to the motor due to overheating, maintains the power output of the electric vehicle, and avoids loss of power for the entire vehicle.
Smart Images
Figure CN117104017B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of electric vehicles, and more particularly to a method for controlling the motor of an electric vehicle and the electric vehicle itself. Background Technology
[0002] When electric vehicles are driven under conditions such as continuous rapid acceleration and deceleration, or continuous uphill driving, the motor will be under high load, which can cause irreversible damage such as overheating, reduced power, and demagnetization.
[0003] When some electric vehicles are overloaded, the motor may rapidly reduce its torque to avoid damage, resulting in zero torque output and loss of power for the entire vehicle. Summary of the Invention
[0004] This application provides a motor control method for an electric vehicle and an electric vehicle.
[0005] This application provides a method for controlling the motor of an electric vehicle, including:
[0006] Get the current requested torque of the motor and the current temperature of the motor stator;
[0007] Based on the mapping relationship between the temperature of the motor stator and the upper limit of the motor torque, determine the current upper limit of the motor torque corresponding to the current temperature;
[0008] The current output torque is determined based on the currently requested torque and the current torque limit; and
[0009] Control the motor according to the current output torque;
[0010] The mapping relationship between the temperature of the motor stator and the upper limit of the motor torque includes:
[0011] If the temperature of the stator of the motor is less than or equal to the critical temperature, the upper limit of the torque of the motor is equal to the peak torque;
[0012] If the temperature of the stator of the motor is greater than the critical temperature but less than or equal to the first equilibrium temperature, the upper limit of the motor torque decreases linearly from the peak torque to the first torque at a first decay rate.
[0013] If the temperature of the stator of the motor is greater than the first equilibrium temperature and less than or equal to the limit temperature, the upper limit of the motor torque decreases from the first torque to the valley torque at a second decay rate; wherein the valley torque is less than the first torque and less than the peak torque; and the second decay rate is greater than the first decay rate.
[0014] Furthermore, the critical temperature is obtained by the following method:
[0015] During the testing of electric vehicles, the electric vehicle is accelerated from zero to a set speed, then braked to zero, and this operation is repeated a set number of times.
[0016] The first temperature of the stator of the motor is obtained when the motor accelerates to the set speed after the set number of accelerations; if the total attenuation of the power performance of the electric vehicle is less than the set attenuation value, the first temperature is taken as the critical temperature.
[0017] Furthermore, the first equilibrium temperature is obtained by the following method:
[0018] During the testing of electric vehicles, the electric vehicle is accelerated from zero to a set speed and then braked to zero, and this operation is repeated more than a set number of times.
[0019] When the torque of the motor decreases from the peak torque by less than 50%, if the temperature of the stator of the motor remains at a second temperature for a first set time and the second temperature is less than the limit temperature, then the second temperature is taken as the first equilibrium temperature.
[0020] When the torque of the motor decreases by less than 50% from the peak torque, if the temperature of the stator of the motor continues to rise to the limit temperature, the limit temperature minus the set temperature is taken as the first equilibrium temperature.
[0021] Furthermore, the limiting temperature range is between 160°C and 200°C; and / or
[0022] The set temperature range is between 15°C and 25°C.
[0023] Further, the second attenuation rate includes a third attenuation rate and a fourth attenuation rate; if the temperature of the motor stator is greater than the first equilibrium temperature and less than or equal to the limit temperature, the upper limit torque of the motor attenuates from the first torque to the valley torque at the second attenuation rate, including:
[0024] If the temperature of the stator of the motor is greater than the first equilibrium temperature and less than or equal to the second equilibrium temperature, the upper limit of the motor torque decreases linearly from the first torque to the second torque at the third decay rate.
[0025] If the temperature of the stator of the motor is greater than the second equilibrium temperature and less than or equal to the limit temperature, the upper limit of the motor torque decreases from the second torque to the valley torque at the fourth decay rate.
[0026] Furthermore, the second torque is less than 50% of the peak torque.
[0027] Furthermore, the second equilibrium temperature is obtained by the following method:
[0028] During the testing of electric vehicles, the electric vehicle is accelerated from zero to a set speed and then braked to zero, and this operation is repeated more than a set number of times.
[0029] When the torque of the motor decreases by more than 50% from the peak torque, if the temperature of the stator of the motor remains at a third temperature for a second set time and the third temperature is less than the limit temperature, then the third temperature is taken as the second equilibrium temperature.
[0030] Furthermore, the third decay rate is greater than the fourth decay rate.
[0031] Furthermore, the first torque is greater than 50% of the peak torque.
[0032] This application provides an electric vehicle, including a controller and a motor, wherein the controller is electrically connected to the motor; the controller is used to execute the motor control method as described in any of the above embodiments.
[0033] The electric vehicle motor control method provided in this application reduces the upper limit of the motor torque at a first decay rate as the stator temperature rises from a critical temperature to a first equilibrium temperature. As the stator temperature rises from the first equilibrium temperature to a maximum temperature, the upper limit of the motor torque decreases from the first torque to a valley torque at a second decay rate, where the second decay rate is greater than the first decay rate. When the stator temperature is between the critical temperature and the first equilibrium temperature, the rate of decrease in the upper limit of the motor torque is relatively slow, maintaining a certain upper limit value. This prevents the output torque from dropping too low due to a lower upper limit, thus maintaining a certain level of motor power and preventing power loss in the electric vehicle.
[0034] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description
[0035] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.
[0036] Figure 1 The diagram shown is a flowchart of a motor control method for an electric vehicle according to an embodiment of this application;
[0037] Figure 2 The diagram shown is a mapping relationship between the temperature of the stator of an electric motor and the upper limit of the motor torque according to an embodiment of this application.
[0038] Figure 3 The diagram shown is a mapping relationship between the temperature of the stator of the motor and the upper limit of the motor torque according to another embodiment of this application. Detailed Implementation
[0039] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.
[0040] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit the application. Unless otherwise defined, the technical or scientific terms used in this application should be understood in their ordinary sense by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms "a" or "one," etc., do not indicate a quantity limitation, but rather indicate the presence of at least one. "A plurality" or "several" indicates two or more. Unless otherwise indicated, the terms "front," "rear," "lower," and / or "upper," etc., are for ease of description only and are not limited to a location or spatial orientation. The terms "comprising" or "including," etc., mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. The terms "connected," "linked," etc., are not limited to physical or mechanical connections and can include electrical connections, whether direct or indirect.
[0041] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.
[0042] This application provides an electric vehicle. The electric vehicle can be water-cooled or oil-cooled, and this application is not limited to either. The electric vehicle includes a controller and a motor. The controller is electrically connected to the motor. The motor provides power for the electric vehicle's movement. The controller is used to execute control methods for the motor.
[0043] Figure 1 The diagram shown is a flowchart of a motor control method for an electric vehicle according to an embodiment of this application; Figure 2 The diagram shown illustrates the mapping relationship between the stator temperature and the upper limit of the motor torque in one embodiment of this application. See also... Figure 1 and Figure 2 As shown, the control method for the motor of an electric vehicle includes steps S101 to S104:
[0044] In step S101, the current requested torque of the motor and the current temperature of the motor stator are obtained. The current requested torque of the motor can be obtained based on the signal from at least one of the accelerator pedal, brake pedal, and gear shift switch. The current temperature of the motor stator can be obtained using a temperature sensor installed on the motor stator.
[0045] In step S102, the current upper limit of the motor's torque corresponding to the current temperature is determined based on the mapping relationship between the motor's stator temperature and the motor's torque limit. The motor's torque limit can refer to the maximum torque value the motor can provide during operation. Determining the current upper limit of the motor's torque corresponding to the current temperature ensures that the output torque at the current temperature will not exceed its torque limit, thus preventing motor overload damage. The mapping relationship between the motor's stator temperature and the motor's torque limit includes:
[0046] If the temperature of the motor stator is less than or equal to the critical temperature T3, the upper limit of the motor torque is equal to the peak torque N. max Peak torque N max It can refer to the maximum torque that the motor can achieve.
[0047] If the stator temperature of the motor is greater than the critical temperature T3 and less than or equal to the first equilibrium temperature T2, the upper limit of the motor's torque decreases from the peak torque N at a first decay rate. max It decreases linearly to the first torque N1.
[0048] If the temperature of the motor stator is greater than the first equilibrium temperature T2 and less than or equal to the limit temperature T max The upper limit of the motor's torque decreases from the first torque N1 to the valley torque N3 at a second decay rate. The valley torque N3 can be greater than or equal to 0. Specifically, the valley torque N3 is less than the first torque N1 and less than the peak torque N. max The valley torque N3 is less than the first torque N1, and the first torque N1 is less than the peak torque N. max In some embodiments, the first torque N1 is greater than the peak torque N. max50%. During the process of the motor stator temperature rising from the critical temperature T3 to the first equilibrium temperature T2, the upper limit of the motor torque decreases at a first decay rate. When the motor stator temperature reaches the first equilibrium temperature T2, the upper limit of the motor torque decreases to the first torque N1, and the motor can output torque at the first torque N1. The first torque N1 is greater than the peak torque N. max The torque is 50% of the maximum torque of the motor. Therefore, even after the maximum torque of the motor decreases with increasing temperature, the motor can still output a relatively large initial torque N1, ensuring strong power output even after the maximum torque of the motor decreases. The second attenuation rate is greater than the first attenuation rate.
[0049] In step S103, the current output torque is determined based on the current requested torque and the current torque limit. If the current requested torque is greater than or equal to the current torque limit, the current output torque is determined to be equal to the current torque limit. If the current requested torque is less than the current torque limit, the current output torque is determined to be equal to the current requested torque.
[0050] In step S104, the motor is controlled according to the current output torque.
[0051] In related technologies, if the stator temperature of an electric vehicle motor continues to rise after reaching a critical temperature, the stator temperature may rapidly reach or even exceed the limit temperature. This causes the motor's maximum torque to rapidly decrease to zero as the temperature rises, resulting in zero torque output and a loss of power for the entire vehicle. The electric vehicle motor control method provided in this application controls the motor's maximum torque to decrease at a first decay rate as the stator temperature rises from the critical temperature T3 to the first equilibrium temperature T2. As the stator temperature rises from the first equilibrium temperature T2 to the limit temperature T... max During the process, the upper limit of the motor's torque decreases from the first torque N1 to the valley torque N3 at a second decay rate, which is greater than the first decay rate. When the temperature of the motor stator is between the critical temperature T3 and the first equilibrium temperature T2, the rate of decay of the upper limit of the motor's torque is relatively slow, and the upper limit of the torque remains at a certain value. This prevents the output torque from dropping too low due to a lower upper limit of torque, thus maintaining a certain level of power for the motor and preventing the loss of power in the electric vehicle. Simultaneously, when the temperature of the motor stator reaches the first equilibrium temperature T2, the temperature of the motor stator will not continue to rise for a certain period of time, thereby prolonging the time it takes for the motor stator temperature to reach the limit temperature T. max This timeframe can prevent the motor's torque from rapidly decreasing to zero.
[0052] In some embodiments, the critical temperature T3 is obtained by the following method: during the testing of the electric vehicle, the electric vehicle is accelerated from zero to a set speed, then braked to zero, and this operation is repeated a set number of times. The set speed can be 100 km / h. The set number of times can be eight, nine, ten, etc., and this application does not impose any limitation. The electric vehicle can be accelerated from zero to 100 km / h, then rapidly braked to zero, and this operation can be repeated eight times consecutively.
[0053] The first temperature of the motor stator is obtained when the vehicle accelerates to a set speed after a set number of accelerations. If the total degradation of the electric vehicle's power performance is less than or equal to a set degradation value, the first temperature is taken as the critical temperature T3. In this embodiment, the first temperature of the motor stator can be obtained when the vehicle accelerates to 100 km / h for the eighth time. If, during the above operation, the total degradation of the electric vehicle's power performance is less than or equal to the set degradation value, the first temperature is taken as the critical temperature T3. The set degradation value is between 15% and 25% of the initial power performance of the electric vehicle. If the total degradation of the electric vehicle's power performance exceeds the set degradation value, the electric vehicle's thermal management system needs to be optimized to improve its heat exchange capacity.
[0054] In some embodiments, the first equilibrium temperature is obtained by accelerating the electric vehicle from zero to a set speed and then braking it to zero during testing, repeating this operation more than a set number of times. This operation can be repeated more than a set number of times until the remaining capacity of the electric vehicle's power battery is reduced to below 5% of its total capacity.
[0055] The motor torque is from the peak torque N max The attenuation was less than the peak torque N. max When the temperature of the motor stator is maintained at the second temperature for a first set time, and the second temperature is less than the limit temperature T, the motor stator temperature is 50% of the limit temperature. max Then, the second temperature is taken as the first equilibrium temperature T2. As the number of operations exceeds the set number and gradually increases, the temperature of the motor stator will gradually rise. The motor torque will increase from the peak torque N. max The torque begins to decrease, and the magnitude of the decrease is less than the peak torque N. max Within 50% of the range, and during the decay process, if the temperature of the motor stator can be maintained at the second temperature for a first set time, and the second temperature is less than the limit temperature T max The second temperature is then taken as the first equilibrium temperature T2. At the first equilibrium temperature T2, the heat generated by the motor stator and the heat dissipation of the electric vehicle's thermal management system can be balanced, allowing the temperature of the motor stator to remain stable for a certain period of time.
[0056] When the motor torque decreases by less than 50% from its peak torque, if the stator temperature of the motor continues to rise to the limit temperature T... max Then the limiting temperature T max Subtract the set temperature to obtain the first equilibrium temperature T2. The motor torque is calculated from the peak torque N. max The torque begins to decrease, and the magnitude of the decrease is less than the peak torque N. max When the temperature is within 50% of the maximum value, and during the decay process, if the temperature of the motor stator continues to rise to the limit temperature T... max This indicates that the equilibrium temperature was not reached during the decay process, and the limiting temperature T can be set as follows. max Subtract the set temperature to obtain the first equilibrium temperature T2. In some embodiments, the extreme temperature T... max The temperature range is between 160°C and 200°C. In some embodiments, the set temperature range is between 15°C and 25°C. In this embodiment, the set temperature is 20°C. The first equilibrium temperature T2 thus obtained ensures that when the temperature of the motor stator rises to the first equilibrium temperature T2, the temperature of the motor stator will not continue to rise for a certain period of time, thereby preventing the motor from reaching the limit temperature T. max This prevents the motor's torque from rapidly decreasing to zero. Simultaneously, it allows the output of the first torque N1 at the initial thermal equilibrium temperature T2, ensuring that the motor stator temperature does not continue to rise and cause overheating, while also guaranteeing that the motor can output a certain torque.
[0057] Figure 3 The diagram shown illustrates the mapping relationship between the stator temperature and the upper limit of the motor torque in another embodiment of this application. See also... Figure 3 As shown, in some embodiments, the second decay rate includes a third decay rate and a fourth decay rate. The third decay rate is greater than the first decay rate, and the fourth decay rate is greater than the first decay rate. If the stator temperature of the motor is greater than the first equilibrium temperature T2 and less than or equal to the limiting temperature T... max The upper limit of the motor torque decreases from the first torque N1 to the valley torque N3 at a second decay rate, including:
[0058] If the stator temperature of the motor is greater than the first equilibrium temperature T2 and less than or equal to the second equilibrium temperature T1, the upper limit of the motor torque decreases linearly from the first torque N1 to the second torque N2 at a third decay rate. In some embodiments, the second torque N2 is less than the peak torque N. max 50%. Thus, when the upper limit of the motor torque decreases to the second torque N2, the motor can output at the second torque N2, thereby maintaining a relatively large output torque after the upper limit of the motor torque decreases from the first torque N1 to the second torque N2.
[0059] If the temperature of the motor stator is greater than the second equilibrium temperature T1, but less than or equal to the limit temperature T max The upper limit of the motor torque decays from the second torque N2 to the valley torque N3 at a fourth decay rate. This further prevents the upper limit of the motor torque from rapidly decaying to zero, resulting in higher reliability. In some embodiments, the third decay rate is greater than the fourth decay rate. The torque can decay from the second torque N2 to the valley torque N3 at a relatively slower rate, thereby preventing the upper limit of the motor torque from rapidly decaying to zero.
[0060] In some other embodiments, the fourth decay rate includes a fifth decay rate and a sixth decay rate. If the temperature of the motor stator is greater than the second equilibrium temperature T1 and less than or equal to the limiting temperature T... max The upper limit of the motor's torque decreases from the second torque N2 to the valley torque N3 at a fourth decay rate, including:
[0061] If the temperature of the motor stator is greater than the second equilibrium temperature T1 and less than or equal to the third equilibrium temperature, the upper limit of the motor torque decreases linearly from the second torque N2 to the third torque at the fifth decay rate.
[0062] If the temperature of the motor stator is greater than the third equilibrium temperature but less than or equal to the limit temperature T max The upper limit of the motor torque decreases from the third torque to the valley torque N3 at a sixth decay rate. The sixth decay rate may also include a seventh decay rate and an eighth decay rate, etc., which are not limited in this application.
[0063] In some embodiments, the second equilibrium temperature T1 is obtained by accelerating the electric vehicle from zero to a set speed and then braking it to zero during the testing of the electric vehicle, and repeating the above operation more than a set number of times.
[0064] The motor torque is from the peak torque N max The attenuation was greater than the peak torque N. max When the temperature of the motor stator is maintained at 50% of the set value for a second set time, and the third temperature is less than the limit temperature T, max Then, the third temperature is taken as the second equilibrium temperature T1. As the number of operations exceeds the set number and gradually increases, the temperature of the motor stator will gradually rise. The motor torque will increase from the peak torque N. max The torque begins to decrease, and the magnitude of the decrease is greater than the peak torque N. max When the temperature is within 50% of the set value, and during the decay process, if the stator temperature of the motor remains at the third temperature for a second set time, and the third temperature is less than the limit temperature T... maxThe third temperature is then taken as the second equilibrium temperature T1. The first set time can be equal to or different from the second set time. At the second equilibrium temperature T1, a balance is achieved between the heat generated by the motor stator and the heat dissipation of the electric vehicle's thermal management system, allowing the motor stator temperature to remain stable for a certain period. Thus, when the motor stator temperature rises to the second equilibrium temperature T1, the stator temperature will not continue to rise for a certain period, preventing the motor from reaching its limit temperature T. max This prevents the motor's torque from rapidly decreasing to zero. Simultaneously, it allows for the output of a second torque N2 at the second equilibrium temperature T1, ensuring that the motor stator temperature does not continue to rise and cause overheating, while also guaranteeing that the motor can output a certain torque.
[0065] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.
[0066] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.
Claims
1. A control method for the motor of an electric vehicle, characterized in that, include: Get the current requested torque of the motor and the current temperature of the motor stator; Based on the mapping relationship between the temperature of the motor stator and the upper limit of the motor torque, determine the current upper limit of the motor torque corresponding to the current temperature; The current output torque is determined based on the current requested torque and the current torque limit. and Control the motor according to the current output torque; The mapping relationship between the temperature of the motor stator and the upper limit of the motor torque includes: If the temperature of the stator of the motor is less than or equal to the critical temperature, the upper limit of the torque of the motor is equal to the peak torque; If the temperature of the stator of the motor is greater than the critical temperature but less than or equal to the first equilibrium temperature, the upper limit of the motor torque decreases linearly from the peak torque to the first torque at a first decay rate. If the temperature of the stator of the motor is greater than the first equilibrium temperature and less than or equal to the limit temperature, the upper limit of the motor torque decreases from the first torque to the valley torque at a second decay rate; wherein the valley torque is less than the first torque and less than the peak torque; and the second decay rate is greater than the first decay rate.
2. The control method for the motor of an electric vehicle according to claim 1, characterized in that, The critical temperature was obtained by the following method: During the testing of electric vehicles, the electric vehicle is accelerated from zero to a set speed, then braked to zero, and this operation is repeated a set number of times. The first temperature of the stator of the motor is obtained when the motor accelerates to the set speed after the set number of accelerations; if the total attenuation of the power performance of the electric vehicle is less than the set attenuation value, the first temperature is taken as the critical temperature.
3. The control method for the motor of an electric vehicle according to claim 1, characterized in that, The first equilibrium temperature was obtained by the following method: During the testing of electric vehicles, the electric vehicle is accelerated from zero to a set speed and then braked to zero, and this operation is repeated more than a set number of times. When the torque of the motor decreases from the peak torque by less than 50%, if the temperature of the stator of the motor remains at a second temperature for a first set time and the second temperature is less than the limit temperature, then the second temperature is taken as the first equilibrium temperature. When the torque of the motor decreases by less than 50% from the peak torque, if the temperature of the stator of the motor continues to rise to the limit temperature, the limit temperature minus the set temperature is taken as the first equilibrium temperature.
4. The control method for the motor of an electric vehicle according to claim 3, characterized in that, The extreme temperature range is between 160°C and 200°C; and / or The set temperature range is between 15°C and 25°C.
5. The control method for the motor of an electric vehicle according to claim 1, characterized in that, The second decay rate includes a third decay rate and a fourth decay rate; if the temperature of the motor stator is greater than the first equilibrium temperature and less than or equal to the limit temperature, the upper limit torque of the motor decays from the first torque to the valley torque at the second decay rate, including: If the temperature of the stator of the motor is greater than the first equilibrium temperature and less than or equal to the second equilibrium temperature, the upper limit of the motor torque decreases linearly from the first torque to the second torque at the third decay rate. If the temperature of the stator of the motor is greater than the second equilibrium temperature and less than or equal to the limit temperature, the upper limit of the motor torque decreases from the second torque to the valley torque at the fourth decay rate.
6. The control method for the motor of an electric vehicle according to claim 5, characterized in that, The second torque is less than 50% of the peak torque.
7. The control method for the motor of an electric vehicle according to claim 5, characterized in that, The second equilibrium temperature was obtained by the following method: During the testing of electric vehicles, the electric vehicle is accelerated from zero to a set speed and then braked to zero, and this operation is repeated more than a set number of times. When the torque of the motor decreases by more than 50% from the peak torque, if the temperature of the stator of the motor remains at a third temperature for a second set time and the third temperature is less than the limit temperature, then the third temperature is taken as the second equilibrium temperature.
8. The control method for the motor of an electric vehicle according to claim 5, characterized in that, The third decay rate is greater than the fourth decay rate.
9. The control method for the motor of an electric vehicle according to claim 1, characterized in that, The first torque is greater than 50% of the peak torque.
10. An electric vehicle, characterized in that, It includes a controller and a motor, the controller being electrically connected to the motor; the controller is used to perform the motor control method as described in any one of claims 1-9.