An Electric Vehicle Power Battery Heating Method and Device

Abstract

An embodiment of the present application provides a method and device for heating a power battery of an electric vehicle. The method includes: first, obtaining the current battery temperature of the power battery; determining whether active battery heating of the power battery is required according to the current battery temperature; if so, adjusting the D-axis current of the motor and the PWM switching frequency of each phase of the motor so that the heat generated by the motor winding and the power module heats the battery coolant; and finally, actively heating the power battery through the heated battery coolant, which can realize the active battery heating function without increasing additional hardware costs and ensure the service life of the battery.

Description

Technical Field

[0001] The present application relates to the technical field of electric vehicles, and more particularly, to a method and device for heating a power battery of an electric vehicle. Background Art

[0002] Currently, the field of electric vehicles is developing rapidly. To make up for the shortcoming of the chemical characteristics of the power battery, it is necessary to effectively control the working temperature of the power battery so that the power battery works within a relatively ideal working temperature range and reduce the influence of temperature on the working performance of the power battery. The existing electric vehicle power battery heating methods usually use multi-stage PTC heating, which requires multiple different PTC modules to switch between different PTC heating gears to achieve multi-stage heating. However, in practice, it is found that the existing methods require the setting of multiple different PTC modules, which increases the cost of the whole vehicle. At the same time, the multi-stage switching is prone to generate impact current, which affects the service life of the battery. Summary of the Invention

[0003] The purpose of the embodiments of the present application is to provide a method and device for heating a power battery of an electric vehicle, which can realize the active battery heating function without increasing additional hardware costs and ensure the service life of the battery.

[0004] The first aspect of the embodiments of the present application provides a method for heating a power battery of an electric vehicle, including:

[0005] Obtain the current battery temperature of the power battery;

[0006] Judge whether it is necessary to actively heat the power battery according to the current battery temperature;

[0007] If so, adjust the D-axis current of the motor and the PWM switching frequency of each phase of the motor so that the heat generated by the motor winding and the power module heats the battery coolant;

[0008] Actively heat the power battery through the heated battery coolant.

[0009] In the above implementation process, first obtain the current battery temperature of the power battery; judge whether it is necessary to actively heat the power battery according to the current battery temperature; if so, adjust the D-axis current of the motor and the PWM switching frequency of each phase of the motor so that the heat generated by the motor winding and the power module heats the battery coolant; finally, actively heat the power battery through the heated battery coolant, which can realize the active battery heating function without increasing additional hardware costs and ensure the service life of the battery.

[0010] Further, the judging whether it is necessary to actively heat the power battery according to the current battery temperature includes:

[0011] Determine whether the current battery temperature is greater than a preset battery temperature threshold;

[0012] If not, determine that active battery heating of the power battery is required, and perform the adjustment of the D-axis current of the motor and the PWM switching frequency of each phase of the motor.

[0013] Further, the adjustment of the D-axis current of the motor and the PWM switching frequency of each phase of the motor includes:

[0014] Detect the first real-time temperature of the battery coolant;

[0015] Determine the target junction temperature of each phase of the motor and the target current to be adjusted according to the first real-time temperature;

[0016] Adjust the D-axis current of the motor to the target current, and control the PWM switching frequency of each phase of the motor so that the junction temperature of each phase of the motor reaches the target junction temperature.

[0017] Further, determining the target junction temperature of each phase of the motor and the target current to be adjusted according to the first real-time temperature includes:

[0018] When the first real-time temperature is within a preset first temperature range, determine that the target junction temperature of each phase of the motor is the first target junction temperature corresponding to the first temperature range, and determine that the target current to be adjusted is the first target current corresponding to the first temperature range;

[0019] When the first real-time temperature is within a preset second temperature range, determine that the target junction temperature of each phase of the motor is the second target junction temperature corresponding to the second temperature range, and determine that the target current to be adjusted is the second target current corresponding to the second temperature range;

[0020] When the first real-time temperature is within a preset third temperature range, determine that the target junction temperature of each phase of the motor is the third target junction temperature corresponding to the third temperature range, and determine that the target current to be adjusted is the third target current corresponding to the third temperature range.

[0021] Further, after actively heating the power battery with the heated battery coolant, the method further includes:

[0022] Detect the current second real-time temperature of the battery coolant;

[0023] Determine whether the second real-time temperature is greater than a preset maximum temperature threshold;

[0024] If so, turn off the active heating system and adjust the D-axis current of the motor to 0.

[0025] In a second aspect of the embodiments of the present application, a power battery heating device for an electric vehicle is provided. The power battery heating device for an electric vehicle includes:

[0026] An acquisition unit for acquiring the current battery temperature of the power battery;

[0027] A judgment unit for judging whether active battery heating of the power battery is required according to the current battery temperature;

[0028] An adjustment unit for, when it is judged that active battery heating of the power battery is required, adjusting the D-axis current of the motor and the PWM switching frequency of each phase of the motor, so that the heat generated by the motor winding and the power module heats the battery coolant;

[0029] An active heating unit for actively heating the power battery through the heated battery coolant.

[0030] In the above implementation process, the acquisition unit first acquires the current battery temperature of the power battery; the judgment unit judges whether active battery heating of the power battery is required according to the current battery temperature; the adjustment unit, when it is judged that active battery heating of the power battery is required, adjusts the D-axis current of the motor and the PWM switching frequency of each phase of the motor, so that the heat generated by the motor winding and the power module heats the battery coolant; finally, the active heating unit actively heats the power battery through the heated battery coolant, which can realize the active battery heating function without increasing additional hardware costs and ensure the service life of the battery.

[0031] Further, the judgment unit includes:

[0032] A judgment subunit for judging whether the current battery temperature is greater than a preset battery temperature threshold;

[0033] A first determination subunit for, when it is judged that the current battery temperature is not greater than the battery temperature threshold, determining that active battery heating of the power battery is required.

[0034] Further, the adjustment unit includes:

[0035] A detection subunit for detecting the first real-time temperature of the battery coolant;

[0036] A second determination subunit for determining the target junction temperature of each phase of the motor and the target current to be adjusted according to the first real-time temperature;

[0037] An adjustment subunit for adjusting the D-axis current of the motor to the target current and controlling the PWM switching frequency of each phase of the motor, so that the junction temperature of each phase of the motor reaches the target junction temperature.

[0038] In a third aspect of the embodiments of the present application, an electronic device is provided, including a memory and a processor. The memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to execute the electric vehicle power battery heating method according to any one of the first aspects of the embodiments of the present application.

[0039] In a fourth aspect of the embodiments of the present application, a computer-readable storage medium is provided, which stores computer program instructions. When the computer program instructions are read and run by a processor, the electric vehicle power battery heating method according to any one of the first aspects of the embodiments of the present application is executed. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0041] Figure 1 It is a schematic flowchart of an electric vehicle power battery heating method provided by the embodiments of the present application;

[0042] Figure 2 It is a schematic structural diagram of an electric vehicle power battery heating device provided by the embodiments of the present application;

[0043] Figure 3 It is a schematic diagram of the liquid circuit of a battery active heating system provided by the embodiments of the present application;

[0044] Figure 4 It is a schematic diagram of the target junction temperature and set current at different coolant temperatures provided by the embodiments of the present application;

[0045] Figure 5 It is a schematic diagram of controlling the PWM switching frequency to increase the heat generation of the power module provided by the embodiments of the present application;

[0046] Figure 6 It is a schematic diagram of the control strategy of a battery active heating system provided by the embodiments of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0047] The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application.

[0048] It should be noted that similar reference numerals and letters indicate similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of the present application, terms such as "first" and "second" are only used for distinguishing descriptions and cannot be construed as indicating or implying relative importance.

[0049] Embodiment 1

[0050] Please refer to Figure 1 , Figure 1 , which is a schematic flowchart of a method for heating an electric vehicle power battery provided by an embodiment of the present application. Among them, the method for heating the electric vehicle power battery includes:

[0051] S101. Obtain the current battery temperature of the power battery.

[0052] In the embodiment of the present application, obtaining the current battery temperature of the power battery means monitoring the true current battery temperature T of the power battery battery .

[0053] S102. Determine whether the current battery temperature is greater than a preset battery temperature threshold. If not, execute step S103; if so, end this process.

[0054] In the embodiment of the present application, the preset battery temperature threshold may specifically be 0°C, and the embodiment of the present application does not limit this.

[0055] In the embodiment of the present application, this method can be applied to a battery active heating system. Please also refer to Figure 3 , Figure 3 , which is a schematic diagram of a liquid circuit of a battery active heating system provided by an embodiment of the present application. As shown in Figure 3 , the active heating system includes a power module, a motor controller, a drive motor, a temperature sensor, a water pump, a power battery, a battery management system, and a cooling pipeline, etc. It can be determined whether the current battery temperature is greater than a preset battery temperature threshold through the battery management system. When the current battery temperature is less than or equal to 0°C, the power battery needs to be actively heated.

[0056] S103. Determine that battery active heating of the power battery is required.

[0057] In the embodiment of the present application, when it is determined that battery active heating of the power battery is required, the motor controller can increase the motor d-axis current Id to generate a large amount of heat in the motor winding to heat the coolant.

[0058] S104. Detect the first real-time temperature of the battery coolant.

[0059] S105. Determine the target junction temperature of each phase of the motor and the target current to be adjusted according to the first real-time temperature.

[0060] As an optional implementation, determining the target junction temperature of each phase of the motor and the target current to be adjusted according to the first real-time temperature includes:

[0061] When the first real-time temperature is within the preset first temperature range, determine that the target junction temperature of each phase of the motor is the first target junction temperature corresponding to the first temperature range, and determine that the target current to be adjusted is the first target current corresponding to the first temperature range;

[0062] When the first real-time temperature is within the preset second temperature range, determine that the target junction temperature of each phase of the motor is the second target junction temperature corresponding to the second temperature range, and determine that the target current to be adjusted is the second target current corresponding to the second temperature range;

[0063] When the first real-time temperature is within the preset third temperature range, determine that the target junction temperature of each phase of the motor is the third target junction temperature corresponding to the third temperature range, and determine that the target current to be adjusted is the third target current corresponding to the third temperature range.

[0064] In the above implementation, the target value T of the power module junction temperature can be adjusted according to the first real-time temperature T of the battery coolant coolant , and the specific strategy is as j shown. Figure 4 shown.

[0065] In the above implementation, the first temperature range can specifically be lower than 20°C, and the first target junction temperature corresponding to the first temperature range can specifically be 140°C. When the first real-time temperature T coolant is lower than 20°C, the target junction temperature of each phase of the motor can be determined to be 140°C, and at this time, the active heating system enters the rapid heating stage. According to the suitable current data calibrated by the experiment, the target current Id is set as the first target current Id1 at this time. According to the formula of the junction temperature, T j = R * f SW * (E on + E off + U * I * t s ), where t s is the conduction time, U is the effective value of the voltage, I is the effective value of the current, and R is the thermal resistance. It can be seen from the above formula that the switching frequency f SW is in a proportional relationship with the junction temperature T j .

[0066] In the above implementation, the switching frequency f can be controlled through the PI controller in Figure 5 , SWThe junction temperature of each phase can reach or approach the target junction temperature. When the current junction temperature is higher than the target junction temperature, the switching frequency is reduced; when the current junction temperature is lower than the target junction temperature, the switching frequency is increased.

[0067] In the above embodiment, the second temperature range can specifically be 20°C to 40°C. At this time, the second target junction temperature corresponding to the second temperature range can be 120°C, and the active heating system slows down the heating speed. At this time, the target current Id is set to the second target current Id2. The switching frequency of each phase is adjusted by a PI controller according to the target junction temperature.

[0068] In the above embodiment, the third temperature range can specifically be 40°C - 50°C. At this time, the third target junction temperature corresponding to the third temperature range can be 100°C, and the active heating system further slows down the heating speed. At this time, the target current Id is set to the third target current Id3, and the switching frequency of each phase is adjusted by a PI controller according to the target junction temperature.

[0069] After step S105, the following steps are further included:

[0070] S106. Adjust the D-axis current of the motor to the target current, and control the PWM switching frequency of each phase of the motor so that the junction temperature of each phase of the motor reaches the target junction temperature.

[0071] In the embodiment of the present application, it is necessary to monitor the first real-time temperature Tcoolant of the battery coolant. Since the battery heating efficiency is low when the battery coolant temperature is lower than 40°C and the energy consumption is large when it is higher than 50°C, therefore, when active heating of the battery is required, the optimal temperature of the battery coolant is 40°C - 45°C. The current value of the target current Id and the target junction temperature of each phase of the motor can be adjusted in real time according to this optimal temperature, and then the corresponding switching frequency f can be controlled. SW 。

[0072] Please refer to Figure 6 , Figure 6 which is a schematic diagram of a control strategy for a battery active heating system provided by an embodiment of the present application. As Figure 6 shown, when it is determined that the electric battery needs to be actively heated, the motor controller increases the motor d-axis current Id to convert electrical energy into the required heat energy to heat the battery coolant. Generally, the same PWM switching frequency is used for each phase of the power module. Given the Is amplitude, angle, and rotor position, the currents passing through the three phases in the power module are different. Therefore, the heat generated by the three chip modules is different. In extreme cases, the temperature of a certain phase chip approaches the high temperature upper limit of the module, and the temperatures of the other two phase chips are still very low. According to the switching loss formula: P SW =f SW *(E on +E off ), it can be known that the switching loss P of the power moduleSW is proportional to the corresponding switching frequency f SW and the switching loss P SW exists in the system in the form of heat. To further increase the heat energy generated by the power module, by dynamically adjusting the switching frequency f SW of each phase, it is possible to make each chip work at a higher target junction temperature, thereby shortening the time required for battery heating.

[0073] S107. Actively heat the power battery through the heated battery coolant.

[0074] In the embodiment of the present application, at the current current Id, the motor controller can judge the junction temperatures corresponding to the three phases in the power module, and then control the PWM switching frequency of each phase of the motor through the PI controller, thereby increasing the heat generation of the power module, and the generated heat heats the coolant.

[0075] In the embodiment of the present application, the heated battery coolant is transported to the power battery through a water pump, thereby realizing the active heating of the power battery.

[0076] S108. Detect the current second real-time temperature of the battery coolant.

[0077] S109. Judge whether the second real-time temperature is greater than a preset maximum temperature threshold. If so, execute step S110; if not, execute steps S108 to S109.

[0078] In the embodiment of the present application, the preset maximum temperature threshold can specifically be 50°C, and the embodiment of the present application does not make any limitation on this.

[0079] S110. Turn off the active heating system and adjust the D-axis current of the motor to 0.

[0080] In the embodiment of the present application, when the temperature Tcoolant of the battery coolant is higher than 50°C, the active heating system is turned off, and at this time, the D-axis current Id of the motor is 0.

[0081] In the embodiment of the present application, the execution subject of this method can be a main controller or other devices of an electric vehicle, and no limitation is made in this embodiment.

[0082] In the embodiment of the present application, this method can, on the basis of actively heating the battery by generating heat through the motor, also make full use of the heat energy generated by the power module. By separately controlling the PWM switching frequency of the three phases, each phase chip module works at a higher junction temperature, generating more heat, thereby accelerating the battery heating process, and thus realizing the battery active heating function without increasing additional hardware costs.

[0083] It can be seen that implementing the electric vehicle power battery heating method described in this embodiment can achieve the battery active heating function without increasing additional hardware costs and ensure the service life of the battery.

[0084] Embodiment 2

[0085] Please refer to Figure 2 , Figure 2 , which is a schematic structural diagram of an electric vehicle power battery heating device provided by an embodiment of this application. As Figure 2 shown, the electric vehicle power battery heating device includes:

[0086] An acquisition unit 210, configured to acquire the current battery temperature of the power battery;

[0087] A judgment unit 220, configured to judge whether active battery heating of the power battery is required according to the current battery temperature;

[0088] An adjustment unit 230, configured to adjust the D-axis current of the motor and the PWM switching frequency of each phase of the motor when it is determined that active battery heating of the power battery is required, so that the heat generated by the motor winding and the power module heats the battery coolant;

[0089] An active heating unit 240, configured to actively heat the power battery through the heated battery coolant.

[0090] As an optional implementation manner, the judgment unit 220 includes:

[0091] A judgment subunit 221, configured to judge whether the current battery temperature is greater than a preset battery temperature threshold;

[0092] A first determination subunit 222, configured to determine that active battery heating of the power battery is required when it is determined that the current battery temperature is not greater than the battery temperature threshold.

[0093] As an optional implementation manner, the adjustment unit 230 includes:

[0094] A detection subunit 231, configured to detect the first real-time temperature of the battery coolant;

[0095] A second determination subunit 232, configured to determine the target junction temperature of each phase of the motor and the target current to be adjusted according to the first real-time temperature;

[0096] An adjustment subunit 233, configured to adjust the D-axis current of the motor to the target current and control the PWM switching frequency of each phase of the motor, so that the junction temperature of each phase of the motor reaches the target junction temperature.

[0097] As an alternative implementation manner, the second determination subunit 232 is specifically configured to: when the first real-time temperature is within a preset first temperature range, determine that the target junction temperature of each phase of the motor is the first target junction temperature corresponding to the first temperature range, and determine that the target current to be adjusted is the first target current corresponding to the first temperature range; when the first real-time temperature is within a preset second temperature range, determine that the target junction temperature of each phase of the motor is the second target junction temperature corresponding to the second temperature range, and determine that the target current to be adjusted is the second target current corresponding to the second temperature range; and when the first real-time temperature is within a preset third temperature range, determine that the target junction temperature of each phase of the motor is the third target junction temperature corresponding to the third temperature range, and determine that the target current to be adjusted is the third target current corresponding to the third temperature range.

[0098] As an alternative implementation manner, the electric vehicle power battery heating device further includes:

[0099] A detection unit 250, configured to detect the current second real-time temperature of the battery coolant after actively heating the power battery with the heated battery coolant;

[0100] A temperature judgment unit 260, configured to judge whether the second real-time temperature is greater than a preset highest temperature threshold;

[0101] A shutdown unit 270, configured to, when it is judged that the second real-time temperature is greater than the preset highest temperature threshold, shut down the active heating system and adjust the D-axis current of the motor to 0.

[0102] In the embodiment of the present application, for the problem that the heating speed is slow due to only considering a single heat source in the active heating technology, this method can utilize the heat energy generated by the power module, and by adjusting the switching frequencies of the power modules of different motor phases, increase the generation of heat energy in the system, thereby shortening the time required for battery heating.

[0103] In the embodiment of the present application, the explanation of the electric vehicle power battery heating device can refer to the description in Embodiment 1, and details will not be repeated herein.

[0104] It can be seen that implementing the electric vehicle power battery heating device described in this embodiment can achieve the battery active heating function without increasing additional hardware costs and ensure the service life of the battery.

[0105] The embodiment of the present application provides an electronic device, including a memory and a processor, where the memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to execute the electric vehicle power battery heating method in Embodiment 1 of the present application.

[0106] An embodiment of the present application provides a computer-readable storage medium storing computer program instructions, which, when read and executed by a processor, execute the electric vehicle power battery heating method in Embodiment 1 of the present application.

[0107] In several embodiments provided by the present application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architectures, functions, and operations of devices, methods, and computer program products according to multiple embodiments of the present application. In this regard, each block in the flowchart or block diagram may represent a module, a program segment, or a part of code, and the module, program segment, or part of code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than marked in the accompanying drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, as well as the combination of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system for performing the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions.

[0108] In addition, in each embodiment of the present application, the various functional modules may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0109] If the function is implemented in the form of a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present application. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs that can store program codes.

[0110] The above are only embodiments of the present application and are not intended to limit the protection scope of the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application. It should be noted that similar reference numerals and letters indicate similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0111] As described above, these are only the specific implementation manners of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, and all of them should be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

[0112] It should be noted that in this text, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the said element.

Claims

1. A method for heating a power battery of an electric vehicle, characterized in that, Including: Obtain the current battery temperature of the power battery; Judge whether active battery heating of the power battery is required according to the current battery temperature; If so, adjust the D-axis current of the motor and the PWM switching frequency of each phase of the motor so that the heat generated by the motor winding and the power module heats the battery coolant; Actively heat the power battery through the heated battery coolant; Wherein, the adjusting the D-axis current of the motor and the PWM switching frequency of each phase of the motor includes: Detect the first real-time temperature of the battery coolant; Determine the target junction temperature of each phase of the motor and the target current to be adjusted according to the first real-time temperature; Adjust the D-axis current of the motor to the target current and control the PWM switching frequency of each phase of the motor so that the junction temperature of each phase of the motor reaches the target junction temperature.

2. The method for heating an electric vehicle power battery according to claim 1, wherein, The judging whether active battery heating of the power battery is required according to the current battery temperature includes: Judge whether the current battery temperature is greater than a preset battery temperature threshold; If not, determine that active battery heating of the power battery is required and perform the adjustment of the D-axis current of the motor and the PWM switching frequency of each phase of the motor.

3. The method for heating an electric vehicle power battery according to claim 1, wherein Determining the target junction temperature of each phase of the motor and the target current to be adjusted according to the first real-time temperature includes: When the first real-time temperature is within a preset first temperature range, determine that the target junction temperature of each phase of the motor is the first target junction temperature corresponding to the first temperature range, and determine that the target current to be adjusted is the first target current corresponding to the first temperature range; When the first real-time temperature is within a preset second temperature range, determine that the target junction temperature of each phase of the motor is the second target junction temperature corresponding to the second temperature range, and determine that the target current to be adjusted is the second target current corresponding to the second temperature range; When the first real-time temperature is within a preset third temperature range, determine that the target junction temperature of each phase of the motor is the third target junction temperature corresponding to the third temperature range, and determine that the target current to be adjusted is the third target current corresponding to the third temperature range.

4. The method for heating an electric vehicle power battery according to claim 1, wherein After actively heating the power battery through the heated battery coolant, the method further includes: Detect the current second real-time temperature of the battery coolant; Judge whether the second real-time temperature is greater than a preset maximum temperature threshold; If so, turn off the active heating system and adjust the D-axis current of the motor to 0.

5. An electric vehicle power battery heating device, characterized in that, The electric vehicle power battery heating device includes: [[ID= ​ ​ ​ ​ A detection subunit, configured to detect the first real-time temperature of the battery coolant; A second determination subunit, configured to determine the target junction temperature of each phase of the motor and the target current to be adjusted according to the first real-time temperature; An adjustment subunit, configured to adjust the D-axis current of the motor to the target current and control the PWM switching frequency of each phase of the motor, so that the junction temperature of each phase of the motor reaches the target junction temperature.

6. The electric vehicle power battery heating device according to claim 5, wherein The judgment unit includes: A judgment subunit, configured to judge whether the current battery temperature is greater than a preset battery temperature threshold; A first determination subunit, configured to determine that active battery heating of the power battery is required when it is determined that the current battery temperature is not greater than the battery temperature threshold.

7. An electronic device, characterized in that, The electronic device includes a memory and a processor, the memory is configured to store a computer program, and the processor runs the computer program so that the electronic device executes the electric vehicle power battery heating method according to any one of claims 1 to 4.

8. A readable storage medium, characterized in that, Computer program instructions are stored in the readable storage medium, and when the computer program instructions are read and run by a processor, the electric vehicle power battery heating method according to any one of claims 1 to 4 is executed.

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