Electric vehicle asynchronous motor parking heating system and method based on flux linkage control

Abstract

The invention discloses an electric vehicle asynchronous motor parking heating method based on flux linkage control, which comprises the following steps: acquiring a heating electric power signal to a motor controller, and sending a control voltage to an asynchronous motor by the motor controller; and obtaining a flux linkage value according to the received heating electric power signal, obtaining a direct-axis current reference value and a quadrature-axis current reference value according to the flux linkage value, processing the direct-axis current reference value and the quadrature-axis current reference value to obtain a control voltage to control heating of the asynchronous motor, and carrying out flux linkage reduction protection on the motor according to the real-time state of the motor. The asynchronous motor heats the power battery through the heat exchange system after being heated. According to the invention, corresponding flux linkage values can be calibrated according to different electric power requirements, direct-axis and quadrature-axis current reference values are changed by controlling the flux linkage of the motor, and the purposes of rapidly heating the motor and further heating a power battery are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of automobile motor control, and in particular to a parking heating system and method for an asynchronous motor of an electric vehicle based on flux linkage control. Background Art

[0002] As one of the core components of new energy vehicles, the characteristics of power batteries directly affect the driving performance and driving experience of new energy vehicles. In low temperature environments, the performance of automotive power batteries is significantly affected. How to solve this problem has become a key and difficult issue in the industry.

[0003] One of the methods commonly used in the industry is to pass current through the motor controller to the motor stator to increase the motor temperature, and then transfer the heat to the power battery through the cooling water circulation system, thereby increasing the battery temperature in a low-temperature environment and achieving better working performance. Most of the existing materials introduce methods for increasing the temperature of permanent magnet synchronous motors, and very few discuss how to increase the temperature of asynchronous motors. Therefore, it is very important to propose a method for heating the temperature of asynchronous motors. Summary of the invention

[0004] The present invention provides, on one hand, a parking heating system for an asynchronous motor of an electric vehicle based on flux linkage control, and on the other hand, a parking heating method for an asynchronous motor of an electric vehicle based on flux linkage control. The system and method can rapidly increase the battery temperature in a low temperature environment, solving the problem of limited battery performance of the entire vehicle at low temperatures. To achieve this purpose, the present invention is designed to provide a parking heating method for an asynchronous motor of an electric vehicle based on flux linkage control, which is characterized in that it comprises the following steps:

[0005] Obtain heating electric power signal to the motor controller, and the motor controller sends control voltage to the asynchronous motor;

[0006] A flux linkage value is obtained according to the received heating electric power signal, a direct-axis current reference value and a quadrature-axis current reference value are obtained according to the flux linkage value, and a control voltage is obtained after processing the direct-axis current reference value and the quadrature-axis current reference value to control the heating of the asynchronous motor, and the motor is protected by flux reduction according to the real-time state of the motor.

[0007] After the asynchronous motor is heated, the power battery is heated through the heat exchange system.

[0008] Furthermore, during normal heating of the motor, the flux value is a first flux reference value obtained based on the power flux value. When the temperature and / or current exceeds the set threshold during motor heating, the motor control enters a flux reduction protection mode. The flux value in the flux reduction protection mode is a second flux reference value obtained based on the flux value after temperature reduction and derating.

[0009] Furthermore, during the motor heating process, when the temperature and / or current exceeds a set threshold, a corresponding flux reduction coefficient is obtained according to the temperature and current, and a second flux reference value is obtained according to the flux reduction coefficient.

[0010] Furthermore, the method for obtaining the power flux value includes: according to the heating electric power signal, the motor controller obtains the corresponding power flux value by querying the power and flux table, and the power and flux table is obtained by calibration.

[0011] Furthermore, the method for obtaining a direct-axis current reference value and a quadrature-axis current reference value according to a flux value includes: limiting the power flux value to obtain a first flux reference value, and calculating the direct-axis current reference value and the quadrature-axis current reference value according to the first flux reference value.

[0012] Furthermore, the method for performing magnetic flux reduction protection on the motor according to the real-time state of the motor includes: obtaining three magnetic flux reduction coefficients k1, k2, and k3 according to the real-time detected motor stator temperature, IGBT temperature, and amplitude of the sampling current, and performing magnetic flux reduction protection on the motor by using the magnetic flux reduction coefficients k1, k2, and k3.

[0013] Furthermore, the method for obtaining the magnetic flux reduction coefficients k1, k2, and k3 includes: the motor controller detects the motor stator temperature in real time, and calculates the corresponding magnetic flux reduction coefficient k1 from the relationship between the motor stator temperature and the coefficient; the motor controller detects the IGBT temperature in real time, and calculates the corresponding magnetic flux reduction coefficient k2 from the relationship between the IGBT temperature and the coefficient; the motor controller detects the amplitude of the sampling current in real time, and queries the corresponding magnetic flux reduction coefficient k3 from the current and coefficient table.

[0014] Furthermore, the method of performing magnetic flux reduction protection on the motor by using magnetic flux reduction coefficients k1, k2, and k3 includes: comparing k1, k2, and k3, taking the minimum value as k0, multiplying k0 by the power magnetic flux value to obtain the magnetic flux value after temperature reduction and derating, limiting the magnetic flux value after temperature reduction and derating to obtain a second magnetic flux reference value after temperature reduction and derating, recalculating the motor direct-axis current reference value and the quadrature-axis current reference value through the second magnetic flux reference value after temperature reduction and derating, and performing temperature reduction and derating control on the motor through the recalculated direct-axis current reference value and the quadrature-axis current reference value.

[0015] A parking heating system for an asynchronous motor of an electric vehicle based on flux linkage control is provided by applying the parking heating method for an asynchronous motor of an electric vehicle based on flux linkage control, and the parking heating system comprises an information transmission module, a flux linkage control module, and a heat exchange system;

[0016] The information transmission module is used to obtain the heating electric power signal to the motor controller, and the motor controller sends the control voltage to the asynchronous motor;

[0017] The flux control module is used to obtain the flux value according to the received heating electric power signal, obtain the direct-axis current reference value and the quadrature-axis current reference value according to the flux value, obtain the control voltage after processing the direct-axis current reference value and the quadrature-axis current reference value to control the heating of the asynchronous motor, and perform flux reduction protection on the motor according to the real-time state of the motor.

[0018] The heat exchange system is used to heat the asynchronous motor and then heat the power battery through the heat exchange system.

[0019] Beneficial effects of the present invention: When the vehicle is in parking mode, the present invention controls the motor stator current through the motor controller, so that the motor stator temperature rises, and then heats the cooling water, and the cooling water circulates to heat the power battery. Without changing the original motor controller software control scheme, the present invention calibrates the corresponding magnetic flux value for different electric power requirements, that is, the corresponding magnetic flux is obtained through the power signal sent by the vehicle controller, and the d-axis current reference value and the q-axis current reference value are changed by controlling the motor magnetic flux, so as to achieve the purpose of quickly heating the motor, and the motor heats up quickly and has a good heating effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the present invention;

[0021] Figure 2 This is a flow chart of motor heating of the present invention;

[0022] Figure 3 This is the reference flux calculation diagram of the present invention. DETAILED DESCRIPTION

[0023] The invention with publication number CN113948797A obtains a temperature difference by subtracting the obtained battery pack cell temperature from a preset cell temperature threshold, determines the required heating amount of the battery pack according to the temperature difference, determines the required torque, required quadrature-axis current, and required direct-axis current of the motor, and drives the motor to operate according to the required quadrature-axis current and required direct-axis current, and utilizes the heat generated by the operation of the motor to heat the battery pack through a heat exchange system. This method requires modifying the motor control algorithm to realize active heating of the power battery using the motor and has no motor protection measures. The present invention can realize active heating of the power battery using the motor without changing the original motor control algorithm, and protect the motor from over-temperature and over-current according to the real-time status of the motor, and the data of the present invention is easier to obtain. Please refer to Example 1 for details.

[0024] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0025] A specific embodiment of a parking heating method for an asynchronous motor of an electric vehicle based on flux linkage control designed by the present invention:

[0026] Example 1

[0027] like Figure 2 As shown, a method for parking heating of an asynchronous motor of an electric vehicle based on flux linkage control comprises the following steps:

[0028] Obtain heating electric power signal to the motor controller, and the motor controller sends control voltage to the asynchronous motor;

[0029] A flux linkage value is obtained according to the received heating electric power signal, a direct-axis current reference value and a quadrature-axis current reference value are obtained according to the flux linkage value, and a control voltage is obtained after processing the direct-axis current reference value and the quadrature-axis current reference value to control the heating of the asynchronous motor, and the motor is protected by flux reduction according to the real-time state of the motor.

[0030] After the asynchronous motor is heated, the power battery is heated through the heat exchange system.

[0031] The asynchronous motor is a driving motor of an electric vehicle. The direct-axis current reference value and the quadrature-axis current reference value are also referred to as the d-axis current reference value and the q-axis current reference value.

[0032] In the above technical solution, during the normal heating process of the motor, the flux linkage value is a first flux linkage reference value obtained based on the power flux linkage value. When the temperature and / or current exceed the set threshold value during the heating process of the motor, the motor control will enter the flux linkage reduction protection mode. The flux linkage value in the flux linkage reduction protection mode is a second flux linkage reference value obtained based on the flux linkage value after temperature reduction and derating.

[0033] There is a close interaction between the flux and the asynchronous motor. The flux drives the motor through the principle of electromagnetic induction and affects the performance characteristics of the motor. In the design and operation of the asynchronous motor, the flux needs to be strictly controlled and managed to ensure the stable operation and excellent performance of the motor.

[0034] In the above technical solution, the method for obtaining the second flux reference value includes: when the temperature and / or current exceeds the set threshold during the motor heating process, the corresponding flux reduction coefficient is obtained according to the temperature and current, and the second flux reference value is obtained according to the flux reduction coefficient.

[0035] In the above technical solution, the method for obtaining the power flux value includes: according to the heating electric power signal, the motor controller obtains the corresponding power flux value by querying the power and flux table, and the power and flux table is obtained by calibration.

[0036] Heating power signal p owre The heating power value of f is obtained by the vehicle control strategy. When the car is in parking mode, the vehicle controller sends the motor heating power signal p through CAN communication. owre f is given to the motor controller, and the motor controller starts working at this time and operates in torque control mode.

[0037] In the above technical solution, the method for obtaining the direct-axis current reference value and the quadrature-axis current reference value according to the flux value includes: limiting the power flux value to obtain the first flux reference value, and calculating the direct-axis current reference value and the quadrature-axis current reference value according to the first flux reference value.

[0038] The formula for calculating the direct-axis current reference value and the quadrature-axis current reference value according to the first flux reference value is as follows:

[0039] The specific method for calculating the direct-axis current reference value is:

[0040] λ ref =L m *i dref ,λ ref is the flux reference value, L m is the motor mutual inductance value, L m Through calibration, i dref is the direct axis reference current.

[0041] The specific method for calculating the quadrature-axis current reference value is:

[0042]

[0043] i qref is the quadrature axis reference current, T e is the motor torque, L r is the rotor inductance, L r Through calibration, λ ref is the flux reference value, n is the motor speed, L m is the motor mutual inductance value, L m Obtained through calibration.

[0044] After obtaining the d-axis current reference value and the q-axis current reference value, the current sensor needs to sample the three-phase current, and obtain the feedback d-axis current reference value and q-axis current reference value through clark and park changes, and then obtain the d-axis voltage and q-axis voltage through the current loop PI regulator. Finally, the SVPWM modulation method is used to process the d-axis voltage and q-axis voltage, and then the output control voltage is used to control the operation of the asynchronous motor. It should be noted that when giving the asynchronous motor stator current, a suitable frequency value, such as 100Hz, needs to be added to avoid DC voltage, and the slip is set to 0 to avoid the motor output torque.

[0045] In motor control, d-axis and q-axis currents are important parameters in the motor control strategy. The d-axis current mainly affects the magnetic flux of the motor, while the q-axis current mainly affects the torque output of the motor. By adjusting the d-axis and q-axis currents, precise control of the motor performance can be achieved. The q-axis current is directly related to the torque output of the motor. Under normal circumstances, in order to generate torque, the q-axis current needs to have a certain value. However, in certain circumstances, such as when the motor is in standby, preheating or fault state, the q-axis current can be set to 0 to reduce energy consumption or avoid unnecessary torque output. For example, when the parking motor heating function is turned on, the main purpose of the motor is to provide heat rather than generate torque. In order to save energy and reduce unnecessary mechanical stress, the torque T e The command is 0, so the q-axis current is 0, so the motor does not produce actual torque output, so the quadrature-axis current reference value i qref Always 0.

[0046] Limiting the flux value is to prevent the flux value from exceeding the motor flux boundary [λ min ,λ max ], the maximum value of flux linkage is obtained through the motor no-load stall test, and the minimum value is allowed to be zero. The so-called limiting processing is to limit the maximum and minimum values ​​of the flux linkage value, such as the flux linkage value λ after temperature reduction and derating. table After the temperature is reduced and the rated value is reduced, the magnetic flux value λ table Within the limiting range, the flux reference value λ ref The value is the magnetic flux value after temperature reduction and derating λ table The magnetic flux value λ after temperature reduction and derating table Greater than λ max , then the reference value of magnetic flux is λ max , when the temperature is reduced and the magnetic flux value is λ table Less than λ min , then the reference value of magnetic flux is λ min . Flux reference value λ ref Exceeding the motor flux boundary will lead to unknown and uncertain consequences. For example, if the motor inductance is saturated and the flux continues to provide a large value, the d-axis current will not change and the asynchronous motor cannot be controlled.

[0047] The cooling water circulation system flows through the asynchronous motor and the power battery. When the asynchronous motor is heated, the cooling water circulation system is also heated. After the cooling water circulation system exchanges heat with the asynchronous motor, it exchanges heat with the power battery, ultimately achieving the purpose of heating the power battery.

[0048] like Figure 3As shown, in the above technical scheme, the method for performing magnetic flux reduction protection on the motor according to the real-time state of the motor includes: obtaining three magnetic flux reduction coefficients k1, k2, and k3 according to the real-time detected motor stator temperature, IGBT temperature, and amplitude of the sampling current, and performing magnetic flux reduction protection on the motor by using the magnetic flux reduction coefficients k1, k2, and k3.

[0049] The motor stator temperature, IGBT temperature, and sampling current amplitude are three important factors for the safe operation of the motor. The motor stator temperature, IGBT temperature, sampling current amplitude and their corresponding magnetic flux reduction coefficient are easy to obtain and the data is relatively accurate. In order to detect whether the motor is running safely, there are three solutions:

[0050] 1. Select any one of the motor stator temperature, IGBT temperature, and sampling current amplitude as the parameter for motor safe operation detection. The data is easy to obtain and has a high accuracy rate.

[0051] 2. Select any two of the motor stator temperature, IGBT temperature, and sampling current amplitude as parameters for motor safety operation detection. The data is easy to obtain and has a high accuracy rate. Compared with Solution 1, the detection of motor faults is more comprehensive, and the motor operation status can be effectively monitored with high reliability.

[0052] 3. The motor stator temperature, IGBT temperature, and sampling current amplitude are used together as parameters for motor safe operation detection. The data is easy to obtain and has a high accuracy rate. It can relatively comprehensively detect possible faults during motor operation and has high reliability. Therefore, using Scheme 3 to detect whether the motor is running safely can maximize the safety of the motor's operation.

[0053] In the above technical scheme, the specific method for obtaining the magnetic flux reduction coefficients k1, k2, and k3 is: the motor controller detects the motor stator temperature in real time, and calculates the corresponding magnetic flux reduction coefficient k1 from the relationship between the motor stator temperature and the coefficient; the motor controller detects the IGBT temperature in real time, and calculates the corresponding magnetic flux reduction coefficient k2 from the relationship between the IGBT temperature and the coefficient; the motor controller detects the amplitude of the sampling current in real time, and queries the corresponding magnetic flux reduction coefficient k3 from the current and coefficient table.

[0054] k1 is obtained through the relationship between motor temperature and coefficient, and the calculation method is: k1∈[0,1], where x is the real-time detected motor stator temperature. Here, the motor temperature threshold is set to 120 degrees Celsius. When the motor temperature is less than or equal to 120 degrees Celsius, the calculated value of k1 is greater than or equal to 1. At this time, the actual value of k1 is 1, which does not affect the normal heating of the motor. When the motor temperature exceeds 120 degrees Celsius, the value of k1 will gradually decrease until it reaches 0, and the motor will enter the cooling and derating mode.

[0055] k2 is obtained through the relationship between IGBT temperature and coefficient, and the calculation method is: k2∈[0,1], where x is the real-time detected IGBT temperature. Here, the IGBT temperature threshold is set to 90 degrees Celsius. When the IGBT temperature is less than or equal to 90 degrees Celsius, the calculated value of k2 is greater than or equal to 1, and the actual value of k2 is 1, which does not affect the normal heating of the motor. When the IGBT temperature exceeds 90 degrees Celsius, the value of k2 will gradually decrease until it reaches 0, and the motor will enter the temperature reduction and derating mode.

[0056] k3 is obtained through the relationship between the stator current amplitude and the coefficient. When the stator current amplitude is less than a certain threshold, such as the current amplitude threshold is 650A, when the current amplitude threshold is less than 650A, k3 is 1. When the current amplitude threshold is greater than or equal to 650A, k3 is 0. This threshold is obtained based on the vehicle test.

[0057] Taking the minimum value among k1, k2 and k3 can maximize the safety of motor operation.

[0058] In the above technical scheme, the method for reducing the magnetic flux of the motor for protection by reducing the magnetic flux coefficients k1, k2, and k3 includes: comparing k1, k2, and k3, taking the minimum value as k0, multiplying k0 by the power magnetic flux value to obtain the magnetic flux value after temperature reduction and derating, limiting the magnetic flux value after temperature reduction and derating to obtain a second magnetic flux reference value after temperature reduction and derating, calculating the motor direct-axis current reference value and the quadrature-axis current reference value again through the second magnetic flux reference value after temperature reduction and derating, and controlling the motor temperature reduction and derating through the recalculated direct-axis current reference value and the quadrature-axis current reference value.

[0059] The formula for obtaining the flux value after temperature reduction and derating by multiplying k0 by the power flux value is: table =λ table0 *k0,λ table is the magnetic flux value after temperature reduction and derating, λ table0 is the power flux value.

[0060] k0 is the coefficient after temperature reduction and derating. The purpose of this is to reduce the power flux value λ by a factor less than the power flux value λ when the motor temperature, IGBT temperature or current amplitude is detected to be greater than the corresponding threshold value during the motor heating process. table0 Magnetic flux value after temperature reduction and derating λ table , calculate the direct axis current, and then reduce the direct axis current to slow down the temperature rise of the motor, or reduce the motor temperature, or reduce the IGBT temperature, or reduce the stator current amplitude, so as to achieve the purpose of protecting the motor and IGBT. If this is not done, when the temperature is too high, the device will be burned out by continuing to heat with a large current.

[0061] Example 2

[0062] like Figure 1 As shown, the electric vehicle asynchronous motor parking heating system based on flux linkage control using the above-mentioned electric vehicle asynchronous motor parking heating method based on flux linkage control includes an information transmission module, a flux linkage control module, and a heat exchange system;

[0063] The information transmission module is used to obtain the heating electric power signal to the motor controller, and the motor controller sends the control voltage to the asynchronous motor;

[0064] The flux control module is used to obtain the flux value according to the received heating electric power signal, obtain the direct-axis current reference value and the quadrature-axis current reference value according to the flux value, obtain the control voltage after processing the direct-axis current reference value and the quadrature-axis current reference value to control the heating of the asynchronous motor, and perform flux reduction protection on the motor according to the real-time status of the motor.

[0065] The heat exchange system is used to heat the asynchronous motor and then heat the power battery through the heat exchange system.

[0066] Example 3

[0067] The present invention also includes a computer program product, including a computer program / instruction, which, when executed by a processor, implements the steps of the above-mentioned method for parking heating of an asynchronous motor of an electric vehicle based on flux linkage control.

[0068] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. A parking heating method for an asynchronous motor of an electric vehicle based on flux control, characterized in that: It includes: Obtain heating electric power signal to the motor controller, and the motor controller sends control voltage to the asynchronous motor; A flux linkage value is obtained according to the received heating electric power signal, a direct-axis current reference value and a quadrature-axis current reference value are obtained according to the flux linkage value, and a control voltage is obtained after processing the direct-axis current reference value and the quadrature-axis current reference value to control the heating of the asynchronous motor, and the motor is protected by flux reduction according to the real-time state of the motor. After the asynchronous motor is heated, the power battery is heated through the heat exchange system.

2. The method for parking heating of an asynchronous motor of an electric vehicle based on flux linkage control according to claim 1, characterized in that: During normal heating of the motor, the flux linkage value is a first flux linkage reference value obtained based on the power flux linkage value. During heating of the motor, when the temperature and / or current exceeds the set threshold, the motor control will enter a flux linkage reduction protection mode. The flux linkage value in the flux linkage reduction protection mode is a second flux linkage reference value obtained based on the flux linkage value after temperature reduction and derating.

3. The method for parking heating of an asynchronous motor of an electric vehicle based on flux linkage control according to claim 2 is characterized in that: The method for obtaining the second flux reference value includes: when the temperature and / or current exceeds a set threshold during the motor heating process, obtaining a corresponding flux reduction coefficient according to the temperature and current, and obtaining the second flux reference value according to the flux reduction coefficient.

4. The method for parking heating of an asynchronous motor of an electric vehicle based on flux linkage control according to claim 2, characterized in that: The method for obtaining the power flux value includes: according to the heating electric power signal, the motor controller obtains the corresponding power flux value through the power and flux table query, and the power and flux table is obtained through calibration.

5. The method for parking heating of an asynchronous motor of an electric vehicle based on flux linkage control according to claim 1 or 2, characterized in that: The method for obtaining a direct-axis current reference value and a quadrature-axis current reference value according to a flux value includes: performing amplitude limiting processing on a power flux value to obtain a first flux reference value, and calculating a direct-axis current reference value and a quadrature-axis current reference value according to the first flux reference value.

6. The method for parking heating of an asynchronous motor of an electric vehicle based on flux linkage control according to claim 1, characterized in that: The method for performing magnetic flux reduction protection on a motor according to the real-time state of the motor includes: obtaining three magnetic flux reduction coefficients k1, k2, and k3 according to the real-time detected motor stator temperature, IGBT temperature, and amplitude of the sampling current, and performing magnetic flux reduction protection on the motor through the magnetic flux reduction coefficients k1, k2, and k3.

7. The method for parking heating of an asynchronous motor of an electric vehicle based on flux linkage control according to claim 6, characterized in that: The method for obtaining the magnetic flux reduction coefficients k1, k2, and k3 includes: the specific method for obtaining the magnetic flux reduction coefficients k1, k2, and k3 is: the motor controller detects the motor stator temperature in real time, and calculates the corresponding magnetic flux reduction coefficient k1 from the relationship between the motor stator temperature and the coefficient; the motor controller detects the IGBT temperature in real time, and calculates the corresponding magnetic flux reduction coefficient k2 from the relationship between the IGBT temperature and the coefficient; the motor controller detects the amplitude of the sampling current in real time, and queries the corresponding magnetic flux reduction coefficient k3 from the current and coefficient table.

8. The method for parking heating of an asynchronous motor of an electric vehicle based on flux linkage control according to claim 6 or 7, characterized in that: The method for performing magnetic flux reduction protection on a motor by using magnetic flux reduction coefficients k1, k2, and k3 includes: comparing k1, k2, and k3, taking the minimum value as k0, multiplying k0 by the power magnetic flux value to obtain a magnetic flux value after temperature reduction and derating, limiting the magnetic flux value after temperature reduction and derating to obtain a second magnetic flux reference value after temperature reduction and derating, recalculating the motor direct-axis current reference value and the quadrature-axis current reference value by using the magnetic flux reference value after temperature reduction and derating, and performing temperature reduction and derating control on the motor by using the recalculated direct-axis current reference value and the quadrature-axis current reference value.

9. An electric vehicle asynchronous motor parking heating system based on flux control, characterized in that: It includes information transmission module, magnetic link control module and heat exchange system; The information transmission module is used to obtain the heating electric power signal to the motor controller, and the motor controller sends the control voltage to the asynchronous motor; The flux control module is used to obtain the flux value according to the received heating electric power signal, obtain the direct-axis current reference value and the quadrature-axis current reference value according to the flux value, obtain the control voltage after processing the direct-axis current reference value and the quadrature-axis current reference value to control the heating of the asynchronous motor, and perform flux reduction protection on the motor according to the real-time state of the motor. The heat exchange system is used to heat the asynchronous motor and then heat the power battery through the heat exchange system.

10. A computer program product, comprising a computer program / instruction, which implements the steps of the method according to claim 1 when executed by a processor.

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