Battery heating method, device and system, motor controller and vehicle

Abstract

The embodiment of the invention discloses a battery heating method, device and system, a motor controller and a vehicle, the method is applied to the motor controller of the vehicle, the motor controller is used for controlling at least two motors, and the method comprises the steps that in response to a heating request from a battery control unit of the vehicle, target angles of control parameters of the at least two motors are determined, according to the target value of the carrier phase interleaving control angle, the carrier frequency of one of the at least two motors is adjusted, so that ripple currents on buses of the at least two motors are overlapped to heat a power battery of the vehicle, and according to the target mapping relation of the torque and current mapping relation, the current mapped by the torque request value is increased to heat the power battery of the vehicle. Cooling liquid of a vehicle heat exchange system is heated, and the power battery is heated through the cooling liquid. And the heating efficiency of the power battery is improved.

Description

Technical Field

[0001] The present invention relates to the technology of power batteries in vehicles, and particularly to a battery heating method, device, system, motor controller and vehicle. Background Art

[0002] Currently, in new energy vehicles, the performance of power batteries is significantly affected by temperature. In a low-temperature environment, the internal chemical reaction rate of the power battery decreases, resulting in capacity attenuation, decreased charge and discharge efficiency, and increased internal resistance, seriously affecting the vehicle's cruising range and the life of the power battery.

[0003] In related technologies, the heating of power batteries can be achieved by positive temperature coefficient (PTC) heating, blocked-rotor heating or pulse heating. However, the heating efficiency of this method is not high. Summary of the Invention

[0004] Embodiments of the present invention provide a battery heating method, device, system, motor controller and vehicle, which can improve the heating efficiency of the power battery.

[0005] The technical solution of the present invention is implemented as follows: Embodiments of the present invention provide a battery heating method, which is applied to a motor controller of a vehicle. The motor controller is used to control at least two motors, and includes: In response to a heating request from the battery control unit of the vehicle, determining target values of control parameters of the at least two motors; wherein, the control parameters include at least one of the following: carrier phase interleaving control angle, torque-current mapping relationship; According to the target angle of the carrier phase interleaving control angle, adjusting the carrier frequency of one of the at least two motors, so that the ripple currents on the buses of the at least two motors are superimposed on each other to heat the power battery of the vehicle; According to the target mapping relationship of the torque-current mapping relationship, increasing the current mapped by the torque request value to heat the coolant of the vehicle's heat exchange system, and heating the power battery through the coolant; Wherein, the target values include: the target angle and the target mapping relationship.

[0006] In this way, by responding to a heating request to determine the target angles of the carrier phase interleaving control angles of at least two motors, the carrier frequency of one motor can be adjusted. By adjusting the carrier frequency of one motor, the ripple currents on the bus of at least two motors are superimposed on each other, and the superimposed ripple currents are used to directly heat the power battery. In this way, through the direct heating method, the rapid temperature rise of the power battery can be achieved without an additional heating device, improving the heating efficiency of the power battery. By responding to a heating request to determine the target mapping relationship of the mapping relationship between torque and current, the current mapped by the torque request value can be increased using the target mapping relationship. After increasing the motor current, the heat of the increased motor current can be used to heat the coolant in the heat exchange system, and then the power battery can be heated through the circulation of the coolant. In this way, by reusing the electric drive hardware in the vehicle, the power battery can be heated through the indirect heating method, improving the heating efficiency of the power battery.

[0007] Further, the determining the target angles of the control parameters of the at least two motors in response to a heating request from the battery control unit of the vehicle includes: In response to a heating request from the battery control unit of the vehicle, according to the heating gear parameter in the heating request or the state parameter of the power battery, the target angle of the carrier phase interleaving control angle is determined from a preset carrier phase interleaving control angle range; Wherein, the preset carrier phase interleaving control angle range is greater than or equal to 0 degrees and less than 90 degrees.

[0008] In this way, by using the heating gear parameter or the state parameter of the power battery to determine the target angle, the determined target angle is related to the heating gear parameter or the state parameter of the power battery, and a target angle matching the heating gear parameter or the state parameter of the power battery can be determined, improving the adaptability of the target angle.

[0009] Further, the heating intensity indicated by the heating gear parameter is negatively correlated with the target angle; the state parameters at least include: cell temperature, SOC; the magnitude of the cell temperature is positively correlated with the magnitude of the target angle; the magnitude of the SOC is negatively correlated with the magnitude of the target angle.

[0010] In this way, by determining the magnitude of the target angle through the above correlations, the magnitude of the determined target angle changes with the heating intensity indicated by the heating gear parameter or with the magnitude of the state parameter, which is beneficial to determining a more accurate target angle in combination with the heating gear parameter of the vehicle or the state parameter of the power battery. While improving the accuracy of the target angle, it is beneficial to delay the life attenuation of the power battery.

[0011] Further, determining the target values of the control parameters of the at least two motors in response to a heating request from the battery control unit of the vehicle includes: In response to a heating request from the battery control unit of the vehicle, determine the target mapping relationship from the preset set of torque-current mapping relationships according to the heating level parameter in the heating request or the state parameter of the power battery.

[0012] In this way, determining the target mapping relationship through the heating level parameter or the state parameter of the power battery makes the determined target mapping relationship related to the heating level parameter or the state parameter of the power battery, and can determine a target mapping relationship that matches the heating level parameter or the state parameter of the power battery, improving the adaptability of the target mapping relationship.

[0013] Further, the heating intensity indicated by the heating level parameter is positively correlated with the magnitude of the current value in the target mapping relationship at the same torque; the state parameters at least include: cell temperature, SOC; the magnitude of the cell temperature is negatively correlated with the magnitude of the current value in the target mapping relationship at the same torque; the magnitude of the SOC is positively correlated with the magnitude of the current value in the target mapping relationship at the same torque.

[0014] In this way, determining the magnitude of the target mapping relationship through the above correlations makes the magnitude of the current value in the determined target mapping relationship change with the heating intensity indicated by the heating level parameter or with the magnitude of the state parameter, which is beneficial to realizing a more accurate target mapping relationship determined in combination with the heating level parameter or the state parameter of the power battery, improving the accuracy of the target mapping relationship and at the same time being beneficial to delaying the life attenuation of the power battery.

[0015] Further, the method further includes: Determine the upper limit value and the lower limit value of the current of the motor at different torques according to the equal torque curve at different torques, the MTPA curve of the motor, and the intersection points of the preset current limit circle of the motor; Determine the preset set of torque-current mapping relationships according to the upper limit value and the lower limit value of the current of the motor at different torques.

[0016] In this way, the preset set of torque-current mapping relationships can be determined through the above method, and thus the target mapping relationship that matches the heating level parameter or the state parameter of the power battery can be determined from it, which is beneficial to determining a more accurate target mapping relationship.

[0017] Further, adjusting the carrier frequency of one of the at least two motors according to the target value of the carrier phase interleaving control angle, so that the ripple currents on the bus of the at least two motors are superimposed on each other to heat the power battery of the vehicle, includes: Performing PI control on the difference between the target angle of the carrier phase interleaving control angle and the carrier frequencies of the at least two motors to obtain the carrier frequency of one of the at least two motors; Controlling one of the at least two motors according to the carrier frequency of one of the at least two motors, so that the ripple currents on the bus of the at least two motors are superimposed on each other to heat the power battery.

[0018] In this way, through the above PI control method, the difference between the carrier frequencies of at least two motors is close to the target angle of the carrier phase interleaving control angle. The smaller the target angle, the smaller the difference, and the greater the loss caused by the superimposition of the ripple currents on the motor bus, which helps to directly heat the power battery, thereby improving the heating efficiency.

[0019] Further, determining the target value of the control parameter of the at least two motors in response to a heating request from the battery control unit of the vehicle includes: In response to a heating request from the battery control unit of the vehicle, obtaining the carrier frequencies of the at least two motors and the operating modes of the at least two motors; When the operating modes of the at least two motors are the same, the difference between the carrier frequencies of the at least two motors is within a preset frequency difference range, and the random PWM enabling of the at least two motors is in a prohibited state, determining the target angle of the carrier phase interleaving control angle in the control parameters of the at least two motors.

[0020] In this way, by judging the operating modes of at least two motors, the difference between the carrier frequencies of at least two motors, and the random PWM enabling of at least two motors, the target value of the carrier phase interleaving control angle of at least two motors is determined, so that the operating parameters of the motor controller use carrier phase interleaving control to heat the power battery only when certain conditions are met. In this way, direct heating of the power battery is achieved while ensuring the stable operation of the motor.

[0021] Further, the method further includes: In response to a heating request from the battery control unit of the vehicle, determining the maximum torque of the motor according to the maximum available driving power of the motor in the heating request; Send the maximum torque of the motor to the vehicle's vehicle controller, so that the torque request value sent by the vehicle controller to the motor controller is less than or equal to the maximum torque of the motor.

[0022] In this way, by determining the maximum torque of the motor in the above manner, the magnitude of the torque request value sent by the vehicle controller to the motor controller can be restricted, thereby avoiding over-discharge of the power battery caused by excessive driving torque consuming a large amount of battery power in a low-temperature environment, which is beneficial to delaying the life attenuation of the power battery.

[0023] Furthermore, the method further includes: When the power battery supplies power to the motor controller, the motor controller is in a preset fault-free state, and the vehicle is in a drivable state, send an allow heating signal to the battery control unit, so that the battery control unit sends a heating request to the motor controller when the power battery meets the preset heating conditions.

[0024] In this way, by sending the allow heating signal to the battery control unit in the above manner, it can be ensured that the battery control unit sends a heating request to the motor controller only when heating is allowed, setting certain conditions for heating the power battery, so as to ensure that the power battery can be heated only when the motor, the battery, and the vehicle are in a normal working state, improving the safety of heating the power battery.

[0025] An embodiment of the present invention provides a battery heating device, which is arranged in the motor controller of a vehicle and is used to control at least two motors, including: A determination module, configured to respond to a heating request from the battery control unit of the vehicle and determine target values of control parameters of the at least two motors; wherein, the control parameters at least include one of the following: carrier phase interleaving control angle, torque-current mapping relationship; A first heating module, configured to adjust the carrier frequency of one of the at least two motors according to the target angle of the carrier phase interleaving control angle, so that the ripple currents on the bus of the at least two motors are superimposed on each other to heat the power battery of the vehicle; A second heating module, configured to increase the current corresponding to the torque request value according to the target mapping relationship of the torque-current mapping relationship to heat the coolant of the vehicle's heat exchange system, and heat the power battery through the coolant; Wherein, the target values include: the target angle and the target mapping relationship.

[0026] An embodiment of the present invention provides a motor controller, including: a processor and a storage medium storing executable instructions of the processor. The storage medium depends on the processor to execute operations through a communication bus. When the instructions are executed by the processor, the battery heating method described in one or more of the above embodiments is executed.

[0027] An embodiment of the present invention provides a battery heating system, including: a motor controller as described in one or more of the above embodiments, at least two motors, a battery control unit, a power battery, a heat exchange system, and a vehicle controller.

[0028] An embodiment of the present invention provides a vehicle, including: a battery heating system as described in one or more of the above embodiments.

[0029] An embodiment of the present invention further provides a computer program product, including a computer program or instructions, characterized in that when the computer program or instructions are executed by a processor, the steps of the battery heating method described in one or more of the above embodiments are implemented.

[0030] Advantages of the present invention: (1) By responding to a heating request, determining the target angle of the carrier phase interleaving control angle of at least two motors, the carrier frequency of one motor can be adjusted. By adjusting the carrier frequency of one motor, the ripple currents on the bus of at least two motors are superimposed on each other, and the superimposed ripple is used to directly heat the power battery. In this way, through the direct heating method, the rapid heating of the power battery can be achieved without an additional heating device, improving the heating efficiency of the power battery; (2) By responding to a heating request, determining the target mapping relationship of the mapping relationship between torque and current, the current mapped by the torque request value can be increased using the target mapping relationship. After increasing the motor current, the heat of the increased motor current can be used to heat the coolant in the heat exchange system, and then the power battery can be heated through the circulation of the coolant. In this way, by reusing the electric drive hardware in the vehicle, the power battery can be heated through the indirect heating method, improving the heating efficiency of the power battery. Description of the Drawings

[0031] Figure 1 It is a schematic flow chart of an optional battery heating method provided by an embodiment of the present invention; Figure 2 It is a schematic diagram of a curve related to a motor in a dq-axis current coordinate system provided by an embodiment of the present invention; Figure 3 It is a schematic structural diagram of an example of an optional battery heating system provided by an embodiment of the present invention; Figure 4Schematic flowchart of Example 1 of an optional battery heating method provided by an embodiment of the present invention; Figure 5 Schematic flowchart of Example 2 of an optional battery heating method provided by an embodiment of the present invention; Figure 6 Schematic structural diagram of an optional battery heating device provided by an embodiment of the present invention; Figure 7 Schematic structural diagram of an optional motor controller provided by an embodiment of the present invention; Figure 8 Schematic structural diagram of an optional battery heating system provided by an embodiment of the present invention; Figure 9 Schematic structural diagram of an optional vehicle provided by an embodiment of the present invention. Detailed implementation manners

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0033] In view of the problem of low heating efficiency of power batteries in the related art, an embodiment of the present invention provides a battery heating method, which is applied to a motor controller of a vehicle, and the motor controller is used to control at least two motors. Figure 1 Schematic flowchart of an optional battery heating method provided by an embodiment of the present invention, as Figure 1 shown, the battery heating method may include: S101: In response to a heating request from a battery control unit of the vehicle, determine target values of control parameters of at least two motors; In an embodiment of the present invention, in order to heat the power battery, when heating the power battery is allowed and the power battery reaches a preset heating condition, the battery control unit sends a heating request to the motor controller, and the motor controller responds to the heating request and determines target values of control parameters of at least two motors, where the control parameters include at least one of the following: carrier phase interleaving control angle, torque-current mapping relationship, and the target value may be a target angle or a target mapping relationship.

[0034] That is to say, the motor controller responds to the heating request and determines the target angle of the carrier phase interleaving control angle of at least two motors and / or the target mapping relationship of the torque-current mapping relationship. The target angle of the carrier phase interleaving control angle and / or the target mapping relationship of the torque-current mapping relationship can also be referred to as the value of the control parameter of the motor in the heating mode of the power battery.

[0035] Among them, the target angle of the carrier phase interleaved control angle and / or the target mapping relationship of the torque-current mapping relationship can be preset in the motor controller or determined by the motor controller in real time. Here, the embodiments of the present invention do not make specific limitations on this.

[0036] For the real-time determination of the target angle of the carrier phase interleaved control angle and / or the target mapping relationship, for example, the target angle of the carrier phase interleaved control angle can be determined based on the cell temperature of the power battery. Among them, the lower the cell temperature, the smaller the target angle of the carrier phase interleaved control angle; the target mapping relationship can determine the target mapping relationship according to the state of charge (SOC) of the battery. Among them, the smaller the SOC of the battery, the smaller the current mapped by the same torque in the target mapping relationship.

[0037] In addition, before the battery control unit sends a heating request, it needs to set its own allowable heating flag bit. Only when the allowable heating flag bit is set, when the power battery reaches the preset heating condition, it will send a heating request to the motor controller. Here, in order to set the allowable heating flag bit, the motor controller needs to send an allowable heating signal to the battery control unit when both its own state and the state of the whole vehicle meet the preset allowable heating conditions, so as to set the allowable heating flag bit in the battery control unit.

[0038] S102: Adjust the carrier frequency of one of the at least two motors according to the target angle of the carrier phase interleaved control angle, so that the ripple currents on the bus of the at least two motors are superimposed on each other to heat the power battery of the vehicle; After determining the target angle of the carrier phase interleaved control angle of the at least two motors through the above S101, in S102, adjust the carrier frequency of one motor according to the target angle of the carrier phase interleaved control angle, so that the ripple currents on the bus of the at least two motors are superimposed on each other to directly heat the power battery.

[0039] Among them, after knowing the target angle of the carrier phase interleaved control angle, the carrier frequency of one motor can be adjusted based on this, so that the difference between the carrier phases of the two motors is close to the target angle of the carrier phase interleaved control angle. Here, the smaller the target angle of the carrier phase interleaved control angle, the closer the carrier phases of the two motors, then the more the ripple currents on the bus of the at least two motors are superimposed, and the superimposition of the ripple currents will cause losses. Here, this loss can be directly used to heat the power battery.

[0040] It should be noted that whether to adjust the carrier frequency of one motor according to the target angle of the carrier phase interleaving control angle needs to be combined with the operating modes of at least two motors and the difference in the carrier frequencies of at least two motors. Only when the operating modes of at least two motors and the difference in the carrier frequencies of at least two motors meet the conditions, will the carrier frequency of one motor be adjusted according to the target angle of the carrier phase interleaving control angle, so that the ripple currents on the busbars of at least two motors are superimposed on each other to heat the power battery of the vehicle.

[0041] Among them, for the difference in the carrier frequencies of at least two motors, for two motors, it is the difference in the carrier frequencies of the two motors, and for more than two motors, it is the difference in the carrier frequencies of any two of the at least two motors. The operating modes of at least two motors refer to the operating modes of all the motors among the at least two motors.

[0042] In addition, the difference in the carrier phases of the at least two motors can be determined by using the difference in the carrier phase timestamp signals of the at least two motors. The carrier phase timestamp signal of each motor among the at least two motors can be: during the generation of the carrier signal, the time count value of the crystal oscillator counter converted when passing through the same position to the motor controller.

[0043] For different target angles of the above carrier phase interleaving control angle, the adjustment of the carrier frequency of one motor is different, so that the degree of superposition of the ripple currents on the busbars of at least two motors is different, and then the heating of the power battery is different. Among them, the smaller the target angle of the carrier phase interleaving control angle, the greater the heating intensity of the power battery.

[0044] It should be pointed out that for the carrier phase interleaving control, it can be applied to two motors. Among them, it can be realized by controlling the carrier frequency of one motor while keeping the carrier frequency of the other motor operating normally. When it is applied to more than two motors, it can be realized by controlling the carrier frequency of one motor while keeping the carrier frequencies of the other motors operating normally.

[0045] In this way, through this method, there is no need to add a heating device, and direct heating of the power battery can be realized, and driving heating can also be realized.

[0046] S103: According to the target mapping relationship of the torque-current mapping relationship, increase the current mapped by the torque request value to heat the coolant of the vehicle heat exchange system, and heat the power battery through the coolant.

[0047] After determining the target mapping relationship of the torque-current mapping relationship through the above S101, in S103, according to the target mapping relationship, increase the current mapped by the torque request value to heat the coolant of the vehicle heat exchange system, and heat the power battery through the coolant.

[0048] Among them, after obtaining the target mapping relationship, the motor controller maps to obtain the dq-axis current value according to the torque request value sent by the vehicle controller, and uses this current value as the command value for controlling the motor current.

[0049] The above target mapping relationship can be called the mapping of the torque and current of the motor under the heating mode of the power battery. After receiving the torque request value, the motor controller maps to obtain the current mapped by the torque request value according to the target mapping relationship. Compared with the mapping under the non-heating mode of the torque and current mapping relationship, the current value mapped by the torque request value is increased. The increase in the motor current causes the windings of the motor to heat up, which can be used to heat the coolant. The heated coolant flows to the power battery side, and the power battery can be heated.

[0050] For the differences in the above target mapping relationships, the magnitudes of the currents mapped by the torque request values are different, so the heating degrees of the coolant are different, and then the heating of the power battery is different. Among them, the larger the current mapped by the same torque in the target mapping relationship, the greater the heating intensity of the coolant, and thus the greater the heating intensity of the power battery.

[0051] It should be noted that for heating the power battery through the above target mapping relationship, it can be applied to two motors. Among them, a corresponding target mapping relationship is determined for each motor, and the corresponding target mapping relationship is used to map a larger current to heat the coolant, and then heat the power battery.

[0052] In this way, through this method, indirect heating of the power battery can be realized without adding a heating device, and driving heating can be realized at the same time.

[0053] In an optional embodiment, to determine the target value of the carrier phase interleaving control angle, S101 may include: In response to a heating request from the battery control unit of the vehicle, obtain the carrier frequencies of at least two motors and the operating modes of at least two motors; When the operating modes of at least two motors are the same, the difference between the carrier frequencies of at least two motors is within a preset frequency difference range, and the random pulse width modulation (PWM) enabling of at least two motors is in a prohibited state, determine the target angle of the carrier phase interleaving control angle in the control parameters of at least two motors.

[0054] It can be understood that after the motor controller receives the heating request, in response to the heating request, it obtains the carrier frequencies of at least two motors and the operating modes of at least two motors. Among them, the operating mode may include a driving mode and a generating mode.

[0055] Taking two motors as an example, after obtaining the carrier frequency of each of the two motors and the operating mode of each motor, compare whether the operating modes of the two motors are the same, calculate the difference between the carrier frequencies of the two motors, and determine whether the difference is within a preset frequency difference range. Also, check whether the random PWM enable of each of the two motors is in the disabled state. Here, when the operating modes of each of the two motors are the same, the above difference is within the preset frequency difference range, and the random PWM enable of each of the two motors is in the disabled state, determine the target angle of the carrier phase interleaving control angle in the control parameters of the two motors.

[0056] In this way, by judging the operating modes of at least two motors, the difference in the carrier frequencies of at least two motors, and the random PWM enable of at least two motors, determine the target value of the carrier phase interleaving control angle of at least two motors, so that the operating parameters of the motor controller use carrier phase interleaving control to heat the power battery only when certain conditions are met. In this way, while ensuring the stable operation of the motor, directly heat the power battery.

[0057] In order to determine the target angle of the carrier phase interleaving control angle, in an optional embodiment, S101 may include: In response to a heating request from the battery control unit of the vehicle, according to the heating gear parameter or the state parameter of the power battery in the heating request, determine the target angle of the carrier phase interleaving control angle from the preset range of the carrier phase interleaving control angle of the motor.

[0058] It can be understood that after the motor controller receives the heating request and responds to the heating request, it can determine the target angle of the carrier phase interleaving control angle from the preset carrier phase interleaving control angle range according to the heating gear parameter, or it can determine the target angle of the carrier phase interleaving control angle from the preset carrier phase interleaving control angle range according to the state parameter of the power battery.

[0059] Among them, the above battery heating gear parameter can be a number, a letter, or others. The heating gear parameter is divided according to the heating intensity. For example, the heating gear parameter includes: low gear, medium gear, and high gear. The heating intensity of the low gear is lower than that of the medium gear, and the heating intensity of the medium gear is lower than that of the high gear. The above state parameters of the power battery may include: cell temperature, SOC.

[0060] Among them, the preset carrier phase interleaved control angle range is greater than or equal to 0 degrees and less than 90 degrees. That is to say, for the value of the carrier phase interleaved control angle, it is generally set to 90 degrees in the non-heating state, so that the loss generated by the superposition of the ripple current on the motor bus is minimized. Here, in order to increase the superposition of the ripple current, the target value of the carrier phase interleaved control angle can be set to be greater than or equal to 0 degrees and less than 90 degrees. In this way, different target angles of the carrier phase interleaved control angle can be set according to different required heating degrees, so as to realize the heating of the power battery according to different required heating degrees.

[0061] It should be noted that when the target angle of the carrier phase interleaved control angle is equal to 0 degrees, the loss generated by the superposition of the ripple currents on the motor bus is the largest. It can be seen that the smaller the target angle of the carrier phase interleaved control angle, the greater the direct heating force.

[0062] In this way, by determining the target angle through the heating gear parameter or the state parameter of the power battery, the determined target angle is related to the heating gear parameter or the state parameter of the power battery, and a target angle matching the heating gear parameter or the state parameter of the power battery can be determined, improving the adaptability of the target angle.

[0063] In order to improve the accuracy of the target angle, in an optional embodiment, the heating force indicated by the heating gear parameter is negatively correlated with the target angle; the state parameter at least includes: cell temperature, SOC; the magnitude of the cell temperature is positively correlated with the magnitude of the target angle; the magnitude of the SOC is negatively correlated with the magnitude of the target angle.

[0064] It can be understood that when the heating force indicated by the heating gear parameter is negatively correlated with the target angle, the greater the heating force indicated by the heating gear parameter, the smaller the target angle. When the magnitude of the cell temperature is positively correlated with the magnitude of the target angle, it means that the greater the cell temperature, the greater the target angle; when the magnitude of the SOC is negatively correlated with the magnitude of the target angle, it means that the smaller the SOC, the greater the target angle. For example, when the heating force indicated by the heating gear parameter is relatively large, the target angle is closer to 0. When the cell temperature is lower, the target angle is smaller. When the SOC is smaller, the target angle is larger.

[0065] In this way, by determining the magnitude of the target angle through the above correlations, the magnitude of the determined target angle changes with the magnitude of the heating gear parameter, cell temperature or SOC, which is beneficial to determining a more accurate target angle in combination with the heating gear parameter or the state parameter of the power battery. While improving the accuracy of the target angle, it is beneficial to delay the life attenuation of the power battery.

[0066] In order to determine the target mapping relationship, in an optional embodiment, S101 may include: In response to a heating request from the battery control unit of the vehicle, a target mapping relationship is determined from a set of preset torque-current mapping relationships according to the heating gear parameter or the state parameter of the power battery.

[0067] It can be understood that after receiving the heating request, the motor controller, in response to the heating request, can determine the target mapping relationship from the set of preset torque-current mapping relationships according to the heating gear parameter, or can determine the target mapping relationship from the set of preset torque-current mapping relationships according to the state parameter of the power battery.

[0068] In this way, the target mapping relationship is determined by the heating gear parameter or the state parameter of the power battery, so that the determined target mapping relationship is related to the heating gear parameter or the state parameter of the power battery, and a target mapping relationship matching the heating gear parameter or the state parameter of the power battery can be determined, improving the adaptability of the target mapping relationship.

[0069] In order to improve the accuracy of the target mapping relationship, in an optional embodiment, the heating intensity indicated by the heating gear parameter is positively correlated with the magnitude of the current value in the target mapping relationship under the same torque; the state parameter at least includes: cell temperature, SOC; the magnitude of the cell temperature is negatively correlated with the magnitude of the current value in the target mapping relationship under the same torque; the magnitude of the SOC is positively correlated with the magnitude of the current value in the target mapping relationship under the same torque.

[0070] It can be understood that when the heating intensity indicated by the heating gear parameter is positively correlated with the magnitude of the current value in the target mapping relationship under the same torque, the greater the heating intensity indicated by the heating gear parameter, the greater the current value in the target mapping relationship under the same torque; when the magnitude of the cell temperature is negatively correlated with the magnitude of the current value in the target mapping relationship under the same torque, it means that the greater the magnitude of the cell temperature, the smaller the current value in the target mapping relationship under the same torque; when the magnitude of the SOC is positively correlated with the magnitude of the current value in the target mapping relationship under the same torque, it means that the smaller the SOC, the smaller the current value in the target mapping relationship under the same torque.

[0071] For example, when the heating intensity indicated by the heating gear parameter increases, the current value in the target mapping relationship under the same torque is closer to the maximum value of the current value; when the cell temperature is lower, the current value in the target mapping relationship under the same torque is closer to the maximum value of the current value; when the SOC is larger, the current value in the target mapping relationship under the same torque is closer to the maximum value of the current value.

[0072] In this way, the size of the target mapping relationship is determined through the above-mentioned correlation, so that the magnitude of the current value in the determined target mapping relationship changes with the magnitude of the heating gear parameter or the state parameter, which is beneficial to realizing a more accurate target mapping relationship determined by combining the heating gear parameter or the state parameter of the power battery. While improving the accuracy of the target mapping relationship, it is beneficial to delay the life attenuation of the power battery.

[0073] In order to determine the mapping relationship set between the preset torque and the current, in an alternative embodiment, the above method may further include: According to the intersection points of the constant torque curves at different torques, the Maximum Torque Per Ampere Curve (MTPA) curve of the motor, and the preset current limit circle of the motor, determine the upper limit value and the lower limit value of the current of the motor at different torques; According to the upper limit value and the lower limit value of the current of the motor at different torques, determine the mapping relationship set between the preset torque and the current.

[0074] Figure 2 FIG. is a schematic diagram of a curve related to the motor in an optional dq-axis current coordinate system provided by an embodiment of the present invention. As Figure 2 shown, the dq-axis current coordinate system of the motor may include: the voltage limit circle 21 of the motor when the speed is less than the transition speed, the current limit circle 22 of the motor, the current limit circle 23 of the motor, the MTPA curve 24, the constant torque curve 25, and the constant torque curve 26.

[0075] Among them, the current limit circle 23 of the motor is the rated current when the motor operates at normal efficiency. The current limit circle 22 of the motor is a circle inside the current limit circle 23 of the motor. In order to obtain the upper limit value and the lower limit value of the current of the motor at different torques, taking the constant torque curve 25 as an example, determine the intersection point B of the constant torque curve 25 and the MTPA curve, and determine the point C with a smaller d-axis among the intersection points of the constant torque curve 25 and the current limit circle 22 of the motor. Take point B as the upper limit value of the current of the motor at the torque of the constant torque curve 25, and take point C as the lower limit value of the current of the motor at the torque of the constant torque curve 25. Then, based on the upper limit value and the lower limit value, select different current values on the constant torque curve BC to form the mapping relationship set between the preset torque and the current.

[0076] It should be noted that the above-mentioned transition speed refers to the critical speed point at which the motor switches from the constant torque operation mode to the field weakening operation mode. The current limit circle 22 of the motor is the set allowable degrading heating peak current. In Figure 2 it, the degrading heating peak current is equal to the rated current value when the motor operates at normal efficiency. This peak current is less than the peak current under the normal efficiency Map operation condition (the peak current under the normal efficiency Map operation condition is equivalent to Figure 2the current limit circle 23) of the motor in

[0077] During the derating heating calibration, let the d-axis current change from 0 to the negative derating heating peak current, with a total of N current values, and the q-axis current change from 0 to the positive derating heating peak current, also with a total of N current values. A total of N×N different torque values corresponding to dq-axis current combinations can be obtained.

[0078] In the above torque and current combinations, there are multiple dq-axis current combinations for the same torque. In the dq current coordinate system, an equal torque curve is formed. Select the dq-axis combinations with the maximum and minimum motor phase currents (motor phase current Is = sqrt(id*id + iq*iq)). Then, the dq-axis with the minimum motor phase current is the point on the MTPA curve (for example, points A and B), and the point with the maximum motor phase current is the current point with the maximum derating heating power (for example, points C and D); the current point combinations between the two points can be configured according to different heating gear parameters or different battery state parameters (the phase currents of other points on the equal torque curve 26 are between the phase currents of points A and D), forming a complete low-efficiency torque-dq current Map for different gears, thereby forming a set of target mapping relationships between the preset torque and current.

[0079] In this way, the set of mapping relationships between the preset torque and current can be determined through the above method, and then the target mapping relationship matching the current gear parameters or the state parameters of the power battery can be determined from it, which is beneficial to determining a more accurate target mapping relationship.

[0080] In order to achieve the heating of the power battery through carrier phase interleaving control, in an optional embodiment, S102 may include: Perform proportional-integral (PI) control on the target angle of the carrier phase interleaving control angle and the difference in carrier frequencies of at least two motors to obtain the carrier frequency of one of the at least two motors; According to the carrier frequency of one of the at least two motors, control one of the at least two motors so that the ripple currents on the busbars of the at least two motors are superimposed on each other to heat the power battery.

[0081] It can be understood that in addition to determining the target angle of the carrier phase interleaving control angle, the difference in carrier frequencies of at least two motors is also calculated. These two values are used as inputs and input into the carrier phase interleaving closed-loop adjustment module in the motor controller for PI closed-loop control, and a frequency adjustment signal for one motor is output. This frequency adjustment signal is the carrier frequency of this motor. Using this carrier frequency to control the operation of this motor, so that the ripple currents on the busbars of at least two motors are superimposed on each other. The loss after superposition increases, and the heat generated by this loss is used to directly heat the power battery.

[0082] Here, it should be noted that for at least two motors, one motor adjusts the carrier frequency of one motor using the target angle of the carrier phase interleaving control angle, and the carrier frequencies of the remaining motors remain unchanged. In this way, by adjusting the carrier frequency of one motor, the difference between the carrier frequencies of at least two motors approaches the target angle of the carrier phase interleaving control angle, thereby increasing the loss caused by the superposition of the ripple current to directly heat the power battery.

[0083] In this way, through the above PI control method, the difference between the carrier frequencies of at least two motors approaches the target angle of the carrier phase interleaving control angle. The smaller the target angle, the smaller the difference, and the greater the loss caused by the superposition of the ripple current on the motor bus, which helps to directly heat the power battery, thereby improving the heating efficiency.

[0084] In addition, to prevent the problem of over-discharging of the power battery at low temperatures caused by excessive motor torque, in an optional embodiment, the above method may further include: In response to a heating request from the battery control unit of the vehicle, determine the maximum torque of the motor according to the maximum available driving power of the motor in the heating request; Send the maximum torque of the motor to the vehicle's vehicle controller so that the torque request value sent by the vehicle controller to the motor controller is less than or equal to the maximum torque of the motor.

[0085] It can be understood that after receiving the heating request, the motor controller responds to the heating request and determines the maximum torque of the motor according to the maximum available driving power of the motor in the heating request, where the maximum available driving power of the motor is determined by the battery control unit according to the cell temperature.

[0086] Among them, after determining the cell temperature, the battery control unit can determine the maximum output power of the power battery according to the cell temperature. In addition, the non-driving power can be obtained from the vehicle controller. Here, the non-driving power is the sum of the powers of the non-driving devices of the vehicle. The non-driving devices send their own powers to the vehicle controller, and then the vehicle controller adds them up to obtain the sum value, which is the non-driving power and is sent to the battery control unit. After obtaining the maximum output power and non-driving power of the power battery, the difference between the maximum output power and non-driving power of the power battery is determined as the maximum available driving power of the motor.

[0087] Here, the above non-driving devices may include: a DC-to-DC Converter (DCDC) device, a compressor, a PTC, etc. Here, the embodiments of the present invention do not make specific limitations on this.

[0088] After obtaining the maximum available driving power of the motor, the motor controller can determine the maximum torque of the motor according to the preset correspondence between power and torque, or can call a preset calculation formula to determine the maximum torque of the motor. The calculation formula can be as follows: (1) Wherein, represents the maximum torque of the motor, represents the maximum available driving power of the motor, represents the rotational speed of the motor, is the efficiency of the current operating point of the motor, for example, the efficiency at the current rotational speed and the current torque, represents the torque conversion coefficient.

[0089] After obtaining the torque of the motor, the motor controller sends the maximum torque of the motor to the vehicle controller, so that the vehicle controller can limit the torque request value within the maximum torque of the motor when sending the torque request value to the motor controller.

[0090] In this way, by determining the maximum torque of the motor in the above manner, the magnitude of the torque request value sent by the vehicle controller to the motor controller can be limited, thereby avoiding over-discharge of the power battery caused by excessive driving torque consuming a large amount of battery power in a low-temperature environment, which is beneficial to delaying the life attenuation of the power battery.

[0091] In order to enable the battery control unit to send a heating request to the motor controller when the power battery meets the preset heating conditions, in an optional embodiment, the above method may further include: When the power battery supplies power to the motor controller, the motor controller is in a preset fault-free state, and the vehicle is in a drivable state, send an allowable heating signal to the battery control unit, so that the battery control unit can send a heating request to the motor controller when the power battery meets the preset heating conditions.

[0092] It can be understood that the motor controller first determines whether the power battery supplies power to the motor controller, and also determines whether the motor controller is in a preset fault-free state, and also determines whether the vehicle is in a drivable state.

[0093] Among them, to determine whether the power battery supplies power to the motor controller, when the motor controller is in the powered-on state, it indicates that the power battery supplies power to the motor controller; to determine whether the obtained motor controller is in a preset fault-free state, here, the operation log of the motor controller can be obtained, and it can be determined whether the motor controller is in a preset fault-free state according to the operation log. The fault information of the motor controller can also be obtained. If the fault information is empty, it indicates that the motor controller is in a preset fault-free state; to determine whether the vehicle is in a drivable state, the gear information of the vehicle can be obtained. For example, if the gear is in the drive (D) gear, it indicates that the vehicle is in a drivable state. When the vehicle controller receives a driving instruction for driving and can execute the driving instruction, it indicates that the vehicle is in a drivable state.

[0094] When the above three conditions are all satisfied, the motor controller sends an allow heating signal to the battery control unit. After receiving this signal, the battery control unit sets its own allow heating flag bit to indicate that the power battery is in an allow heating state.

[0095] After the power battery is in the allow heating state, when the power battery meets the preset heating conditions, the battery control unit sends a heating request to the motor controller, and the motor controller uses one or more of the above embodiments to perform heating on the above-mentioned power battery.

[0096] Among them, the above-mentioned power battery meeting the preset heating conditions can be: the core temperature of the power battery is less than the first preset temperature threshold and the SOC of the power battery is greater than the first preset SOC threshold.

[0097] In this way, by sending an allow heating signal to the battery control unit in the above manner, it can be ensured that the battery control unit sends a heating request to the motor controller only when heating is allowed, setting certain conditions for heating the power battery, so as to ensure that the power battery can be heated only when the motor, the battery, and the vehicle are in a normal working state, improving the safety of heating the power battery.

[0098] In addition, to be able to exit the heating mode of the power battery, in an optional embodiment, the above method may further include: Responding to the exit heating request from the battery control unit, determining the value of the control parameter of the motor in the non-heating state.

[0099] It can be understood that when the battery control unit detects that the power battery has a fault, or the power battery does not meet the heating conditions, at this time, the battery control unit can send an exit heating request to the motor controller, and the motor controller responds to the exit heating request to determine the value of the control parameter of the motor in the non-heating state.

[0100] Among them, the above power battery not meeting the heating condition may include: the core temperature of the power battery is greater than or equal to the second preset temperature threshold, or the SOC of the power battery is less than or equal to the second preset SOC threshold; the above first preset temperature threshold is less than the second preset temperature threshold, and the first preset SOC threshold is greater than the second preset SOC threshold.

[0101] Here, the control parameters of the motor are divided into values in the heating state and values in the non-heating state. Then, the values of the control parameters of the motor in the non-heating state can be the values of the control parameters of the motor except for the values in the heating state. Here, the embodiments of the present invention do not make specific limitations on this.

[0102] For example, the values of the control parameters of the motor in the non-heating state can be determined according to the requirements of the vehicle. For example, the values of the control parameters of the motor determined when the state parameters of the power battery of the vehicle are not passed are different.

[0103] In this way, by the above method of exiting the heating request to exit the heating mode of the power battery, it is possible to prevent the problem of overheating of the power battery caused by overheating the power battery, which is beneficial to delaying the life attenuation of the power battery.

[0104] The following gives an example to describe the heating method of the power battery described in the above one or more embodiments.

[0105] In order to propose an efficient, energy-saving and driving-condition-adaptive battery heating technology, this example proposes a dual-motor cooperative control strategy under driving conditions to achieve two-way battery heating. Through the carrier phase interleaved control of the dual-motor controller on the power battery side, the bus ripple current is increased to directly heat the battery, and the motor controller on the dual-motor side operates with reduced efficiency to increase the waste heat of the motor to heat the coolant, so as to achieve intermittent heating of the power battery. The two work together to achieve efficient driving heating of the power battery in a low-temperature environment and improve the performance and driving range of the power battery.

[0106] Figure 3 For an example of the structure diagram of an optional battery heating system provided by the embodiments of the present invention, as Figure 3 shown, the battery heating system 300 may include: a vehicle controller 31, a power battery 32, a battery control unit 33, a dual-motor controller 34, a dual-motor 35, and a heat exchange system 36; among them, the vehicle controller 31 is respectively connected to the battery control unit 33 and the dual-motor controller 34, the battery control unit 33 is respectively connected to the power battery 32 and the dual-motor controller 34, the dual-motor controller 34 is further connected to the dual-motor 35, and the heat exchange system 36 is respectively connected to the power battery 32 and the dual-motor 35. Among them, the dual-motor controller 34 is equivalent to the above-mentioned motor controller.

[0107] Among them, the dual-motor controller 34 is used to control the basic operation of the dual-motor 35, and at the same time, it performs signal interaction with the vehicle controller 31 and the battery control unit 33, is used to respond to the heating request and the heating cancellation request of the driving power battery 32, and simultaneously synchronously executes the heating logic of the driving power battery 32 on the driving power battery 32 side and the dual-motor 35 side respectively.

[0108] The battery control unit 33 is mainly used to monitor the battery state of the driving power battery 32 and send it to the vehicle controller 31, and apply for heating of the driving power battery 32 and cancellation of heating of the driving power battery 32 according to the vehicle state and the electric control state sent by the vehicle controller 31. Among them, the dual-motor controller 34 sends the electric control state to the vehicle controller 31.

[0109] The main function of the vehicle controller 31 is to send a torque command to the dual-motor controller 34 according to the maximum torque value allowed by the vehicle controller (Vehicle Control Unit, VCU) requested by the feedback of the dual-motor controller 34 and the driver's request, and at the same time send the vehicle state to the battery control unit 33 and the dual-motor controller 34.

[0110] The dual-motor controller 34 is used to perform carrier phase interleaving control and derating control on the dual-motor 35 after receiving the motor state of the dual-motor 35.

[0111] The heat exchange system 36 is used to absorb the heat generated by the dual-motor 35 for interval heating of the driving power battery 32. Mainly through derating control, the motor winding generates heat to heat the coolant, and the coolant heats the battery. At the same time, it cools the dual-motor 35 and the driving power battery 32 under non-battery heating conditions.

[0112] Based on the above Figure 3 , Figure 4 is a schematic flowchart of Example 1 of an optional battery heating method provided by an embodiment of the present invention. As Figure 4 shown, the heating method of the driving power battery may include: S401: The dual-motor controller 34 sends a driving heating permission signal to the battery control unit 33 according to the electric control preparation state and the vehicle preparation state. The battery control unit 33 sends a heating request and the maximum available driving power limit value of the driving power battery 32 to the dual-motor controller 34 according to the battery state and the driving heating permission signal; S402: The dual-motor controller 34 receives the heating request, configures the control parameters of the motor, calculates the maximum torque limit value allowed for driving electric heating according to the maximum available driving power limit value, and sends it to the vehicle controller 31; S403: The dual - motor controller 34 performs carrier - phase interleaved control to cause superimposed ripple current to be generated on the bus side of the dual - motor 35, directly heating the power battery 32. The dual - motor controller 34 performs derating control to cause the windings of the dual - motor 35 to generate heat for heating the coolant, and indirectly heats the power battery 32 through the heat - exchange system 36; S404: When the heating termination condition of the power battery 32 is met, the dual - motor controller 34 stops heating the power battery 32 and controls the dual - motor 35 to operate in the normal mode.

[0113] Figure 5 As shown in the schematic flow diagram of the second example of an optional battery heating method provided by the embodiment of the present invention, Figure 5 The battery heating method may include: S501: Start the vehicle with the gear in the D - gear; Among them, in a low - temperature environment, the discharge capacity of the power battery 32 is limited. When the driver starts the vehicle with the gear in the D - gear, the vehicle is in a ready - to - drive condition; S502: The dual - motor controller 34 sends a driving - allowed heating signal to the battery control unit 33 according to the electronic - control ready state and the vehicle - whole ready state; Among them, the electronic - control ready state means that when the power battery 32 supplies power to the dual - motor controller 34 and the dual - motor controller 34 has no fault, and the vehicle - whole ready state is that the vehicle gear is in the D - gear. When both conditions are met, the dual - motor controller 34 sends a driving - allowed heating signal to the battery control unit 33, so that the heating - allowed flag bit in the battery control unit 33 is 1. Here, by judging the states of the vehicle and the dual - motor controller 34, the purpose of determining whether the vehicle has the basic conditions for driving - related heating is achieved.

[0114] S503: The battery control unit 33 monitors the cell temperature of the power battery 32, the SOC of the power battery, and the driving - allowed heating flag bit in real - time; Among them, here, by monitoring the status signals of the power battery 32, preparations are made for whether the battery control unit 33 will send a heating request in the next step.

[0115] S504: Determine whether the cell temperature of the power battery 32 is less than the set threshold T1, whether the SOC of the power battery 32 is greater than the set threshold X1%, and whether the driving - allowed heating flag bit is 1? If all are yes, execute S505; otherwise, execute S506; S505: The battery control unit 33 sends a heating request for the power battery 32 to the dual - motor controller 34, and sends the maximum available driving - power limit value to the dual - motor controller 34 according to the current cell temperature of the power battery 32 and the SOC of the power battery 32; Among them, to avoid a large amount of power consumption of the driving battery 32 during driving in a low-temperature environment, causing over-discharge of the power battery 32 and accelerating the life attenuation of the power battery 32, the maximum available driving power limit value is sent here.

[0116] The above-mentioned maximum available driving power limit value refers to the value obtained by subtracting the vehicle non-driving power from the maximum power that the power battery 32 can output at the current cell temperature. The non-driving power is mainly the sum of the powers of the DCDC device, the compressor, and the PTC.

[0117] S506: The dual-motor controller 34 controls the operation of the dual motors 35 in the normal mode and executes S515; S507: The dual-motor controller 34 configures the control parameters of the motor according to the heating request of the power battery 32; calculates the maximum allowable heating torque limit of the driving battery according to the maximum available driving power limit value and sends it to the vehicle controller 31; Among them, after receiving the heating request of the power battery 32, the dual-motor controller 34 configures control parameters such as the carrier phase interleaving control angle and the derated torque-current Map.

[0118] Here, the maximum motor torque limit Tmax is calculated according to the maximum available driving power limit value Pmax, the motor speed Spd, and the efficiency η% of the current operating point. The above formula (1) can be used, and k can generally be 0.9. By converting the maximum available driving power into the maximum torque value that the vehicle controller 31 can apply to the dual-motor controller 34, the maximum torque for heating the driving battery is limited.

[0119] S508: The dual-motor controller 34 executes carrier phase interleaving control to generate superimposed ripple current on the bus side of the dual motors 35 to directly heat the power battery 32; the dual-motor controller 34 executes derating control to make the windings of the dual motors 35 generate heat to heat the coolant, and indirectly heat the power battery 32 through the heat exchange system 36; Among them, in this step, the carrier phase interleaving control angle can be determined to be 0 degrees. Obtain the carrier frequencies and operating modes of the two motors, and determine that the operating modes of the two motors are the same as the enabling condition 1 for executing carrier phase interleaving control; according to the carrier frequency of motor 1 and the carrier frequency of motor 2, the frequency difference between the two is within the first frequency difference threshold as the enabling condition 2 for executing carrier phase interleaving control; the random PWM enabling of motor 1 and the random PWM enabling signal of motor 2 are both not enabled as the enabling condition 3 for executing carrier phase interleaving control; when conditions 1, 2, and 3 are all satisfied, execute the carrier phase interleaving control of motor 1; among them, only motor 1 executes the carrier phase interleaving control, and motor 2 does not execute.

[0120] Among them, for the carrier phase interleaved control of the motor 1, the carrier phase timestamp signals of the dual motors 35 are obtained in real time and the difference is calculated. The carrier frequency of the motor 1 is dynamically adjusted by using the carrier phase interleaved closed-loop adjustment module, so that the carrier phase difference of the dual motors 35 reaches the first carrier phase interleaved control angle. Among them, the carrier phase timestamp signal is the time count value converted to the controller crystal oscillator counter when passing through the same position during the generation of the carrier signal. The carrier phase difference between the motor 1 and the motor 2 can be calculated from the difference between the carrier phase timestamp signals of the motor 1 and the motor 2.

[0121] The difference between the above first carrier phase interleaved control angle and the carrier phase timestamp difference signal of the motor 1 and the motor 2 is calculated, and the result is input into the carrier phase interleaved closed-loop adjustment module for PI closed-loop control, and the frequency adjustment signal of the motor 1 is output to control the motor 1.

[0122] The above first carrier phase interleaved control angle is set to 0 degrees, so as to achieve the purpose that the ripple currents generated by the dual motors on the bus are superimposed on each other to directly heat the power battery. At the same time, by setting different first carrier phase interleaved control angles, the purpose of adjusting the heating on the power battery side is achieved.

[0123] Among them, the dual-motor controller 34 switches the normal torque-current Map to an inefficient torque-current Map for current control. The normal torque-current Map is calibrated according to the MTPA curve and the Maximum Torque Per Voltage Curve (MTPV) curve. The inefficient torque-current Map is a set of current points between the intersection points of the torque command and the region enclosed by the MTPA and the derating heating peak current limit circle below the transition speed. When taking the current point with a smaller d-axis current, the determined mapping relationship between torque and current is the lowest inefficient torque-current Map.

[0124] Here, through derating control, in the current low-temperature environment, without affecting vehicle driving and ensuring the safety of the power battery, the dual-motor windings are heated to the maximum extent, the temperature of the coolant is increased, and the heat indirectly heats the power battery 32 through the heat exchange system 36, so as to achieve the purpose of heating the power battery 32.

[0125] Among them, the derating torque-current Map is obtained through calibration, and different efficiency torque-current Maps can be used according to different gears to achieve the purpose of adjusting the heating power.

[0126] S509: Determine whether the power battery 32 has a fault? If yes, execute S510; if no, execute S511; S510: The battery control unit 33 requests the dual-motor controller 34 to stop heating the battery, or the dual-motor controller 34 actively stops heating the power battery. S511: Determine whether the core temperature of the power battery 32 is greater than or equal to T1, or whether the SOC is less than or equal to X2%? If yes, execute S512; if no, execute S513. S512: The battery control unit 33 requests the dual-motor controller 34 to stop the dual-motor 35 from heating the power battery. During the heating process of the power battery 32, since the power battery is continuously consumed by being driven by the motor and heating with reduced efficiency, when the capacity is lower than the set value, the heating operation needs to be stopped to enable the vehicle to drive to the charging station for recharging; generally, the SOC threshold X2% is set to 20%.

[0127] When the dual-motor controller 34 receives a request to stop heating the power battery 32, it controls the dual-motor 35 to exit the carrier phase interleaved control and the reduced-efficiency control.

[0128] S513: Continuously heat the power battery 32. S514: The dual-motor controller 34 exits the heating mode of the power battery 32 and executes S506. S515: End.

[0129] In this example, when the dual-motor controller executes the carrier phase interleaved control to generate ripple current on the bus side to directly heat the battery, and when the dual-motor controller executes the reduced-efficiency control, the motor winding generates heat to heat the coolant, and indirectly heats the battery through the heat exchange system, which has the following advantages: Heating from both the battery side and the motor side greatly shortens the heating time of the power battery, effectively improves the temperature rise rate of the power battery, and realizes efficient heating; reusing the existing electric drive hardware without adding additional heating devices to realize in-vehicle heating, with high system integration; according to the heating requirements, selecting the appropriate carrier phase interleaved control angle and different low-efficiency torque-current Maps to realize dynamic adjustment of the heating rate and dynamic control.

[0130] An embodiment of the present invention provides a battery heating method. By responding to a heating request, the target angles of the carrier phase interleaving control angles of at least two motors are determined, and the carrier frequency of one motor can be adjusted. By adjusting the carrier frequency of one motor, the ripple currents on the bus of at least two motors are superimposed on each other, and the superimposed ripple currents are used to directly heat the power battery. In this way, through the direct heating method, the rapid temperature rise of the power battery can be achieved without an additional heating device, and the heating efficiency of the power battery is improved. By responding to a heating request, the target mapping relationship of the mapping relationship between torque and current is determined, and the current mapped by the torque request value can be increased by using the target mapping relationship. After increasing the motor current, the heat of the increased motor current can be used to heat the coolant in the heat exchange system, and then the power battery can be heated through the circulation of the coolant. In this way, the electric drive hardware in the vehicle is reused, and the power battery can be heated through the indirect heating method, and the heating efficiency of the power battery is improved.

[0131] Based on the same inventive concept as the foregoing embodiment, an embodiment of the present invention provides a battery heating device, which is disposed in a motor controller of a vehicle and is used to control at least two motors. Figure 6 As a schematic structural diagram of an optional battery heating device provided by an embodiment of the present invention, as Figure 6 shown, the battery heating device 600 may include: A determination module 61, configured to determine target values of control parameters of at least two motors in response to a heating request from a battery control unit of the vehicle; wherein, the control parameters at least include one of the following: carrier phase interleaving control angle, mapping relationship between torque and current; A first heating module 62, configured to adjust the carrier frequency of one of at least two motors according to the target angle of the carrier phase interleaving control angle, so that the ripple currents on the bus of at least two motors are superimposed on each other to heat the power battery of the vehicle; A second heating module 63, configured to increase the current corresponding to the torque request value according to the target mapping relationship of the mapping relationship between torque and current, so as to heat the coolant in the vehicle heat exchange system, and heat the power battery through the coolant; wherein, the target values include: target angle and target mapping relationship.

[0132] In an optional embodiment, the determination module 61 is configured to: in response to a heating request from a battery control unit of the vehicle, determine the target angle of the carrier phase interleaving control angle from a preset carrier phase interleaving control angle range according to the heating gear parameter or the state parameter of the power battery; wherein, the preset carrier phase interleaving control angle range is greater than or equal to 0 degrees and less than 90 degrees.

[0133] In an alternative embodiment, the heating intensity indicated by the heating gear parameter is negatively correlated with the target angle; the state parameters at least include: the cell temperature, SOC; the magnitude of the cell temperature is positively correlated with the magnitude of the target angle; the magnitude of the SOC is negatively correlated with the magnitude of the target angle.

[0134] In an alternative embodiment, the determining module 61 is configured to: in response to a heating request from the battery control unit of the vehicle, determine a target mapping relationship from a preset set of mapping relationships between torque and current according to the heating gear parameter in the heating request or the state parameters of the power battery.

[0135] In an alternative embodiment, the heating intensity indicated by the heating gear parameter is positively correlated with the magnitude of the current value in the target mapping relationship at the same torque; the state parameters at least include: the cell temperature, SOC; the magnitude of the cell temperature is negatively correlated with the magnitude of the current value in the target mapping relationship at the same torque; the magnitude of the SOC is positively correlated with the magnitude of the current value in the target mapping relationship at the same torque.

[0136] In an alternative embodiment, the device is further configured to: determine the upper limit value and the lower limit value of the current of the motor at different torques according to the intersection points of the equal torque curves at different torques, the MTPA curve of the motor, and the preset current limit circle of the motor; determine the preset set of mapping relationships between torque and current according to the upper limit value and the lower limit value of the current of the motor at different torques.

[0137] In an alternative embodiment, the first heating module 62 is configured to: perform PI control on the target angle of the carrier phase interleaving control angle and the difference between the carrier frequencies of at least two motors to obtain the carrier frequency of one of the at least two motors; control one of the at least two motors according to the carrier frequency of one of the at least two motors, so that the ripple currents on the bus of the at least two motors are superimposed on each other to heat the power battery.

[0138] In an alternative embodiment, the determining module 61 is configured to: in response to a heating request from the battery control unit of the vehicle, obtain the carrier frequencies of at least two motors and the operating modes of at least two motors; determine the target angle of the carrier phase interleaving control angle in the control parameters of at least two motors when the operating modes of at least two motors are the same, the difference between the carrier frequencies of at least two motors is within a preset frequency difference range, and the random PWM enabling of at least two motors is in a prohibited state.

[0139] In an alternative embodiment, the device is further configured to: in response to a heating request from the battery control unit of the vehicle, determine the maximum torque of the motor according to the maximum available driving power of the motor in the heating request; send the maximum torque of the motor to the vehicle's vehicle controller, so that the torque request value sent by the vehicle controller to the motor controller is less than or equal to the maximum torque of the motor.

[0140] In an alternative embodiment, the device is further configured to: when the power battery supplies power to the motor controller, the motor controller is in a preset fault-free state, and the vehicle is in a drivable state, send an allow heating signal to the battery control unit, so that the battery control unit sends a heating request to the motor controller when the power battery meets the preset heating conditions.

[0141] In practical applications, the above-mentioned determination module 61, the first heating conversion module 62, and the second heating module 63 can be implemented by a processor located on the battery heating device 600, specifically a central processing unit (CPU, Central Processing Unit), a microprocessor (MPU, Microprocessor Unit), a digital signal processor (DSP, Digital Signal Processing), or a field programmable gate array (FPGA, Field Programmable Gate Array), etc.

[0142] An embodiment of the present invention further provides a motor controller. Figure 7 As a schematic structural diagram of an alternative motor controller provided by an embodiment of the present invention, as Figure 7 shown, an embodiment of the present invention provides a motor controller 700, including: a processor 71 and a storage medium 72 storing instructions executable by the processor 71, the storage medium 72 depends on the processor 71 to execute operations through a communication bus 73, and when the instructions are executed by the processor 71, the battery heating method described in the above one or more embodiments is executed.

[0143] It should be noted that in practical applications, each component in the motor controller 700 is coupled together through the communication bus 73. It can be understood that the communication bus 73 is used to realize the connection and communication between these components. The communication bus 73 includes not only a data bus, but also a power bus, a control bus, and a status signal bus. However, for the sake of clear description, in Figure 7 all kinds of buses are labeled as the communication bus 73.

[0144] An embodiment of the present invention further provides a battery heating system. Figure 8 As a schematic structural diagram of an alternative battery heating system provided by an embodiment of the present invention, asFigure 8 As shown in Figure 8 , the battery heating system 800 may include: the motor controller 700 as described in one or more of the above embodiments, at least two motors 81, a battery control unit 82, a power battery 83, a heat exchange system 84, and a vehicle controller 85.

[0145] An embodiment of the present invention further provides a vehicle. Figure 9 As shown in , which is a schematic structural diagram of an optional vehicle provided by an embodiment of the present invention, Figure 9 As shown in Figure 9 , the vehicle 900 may include: the battery heating system 800 as described in one or more of the above embodiments.

[0146] An embodiment of the present invention provides a computer storage medium storing executable instructions. When the executable instructions are executed by one or more processors, the processors execute the battery heating method as described in one or more of the above embodiments.

[0147] An embodiment of the present invention provides a computer program product including a computer program or instructions. When the computer program or instructions are executed by a processor, the steps of the battery heating method as described in one or more of the above embodiments are implemented.

[0148] Among them, the computer-readable storage medium may be a ferromagnetic random access memory (FRAM), a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory, a magnetic surface memory, an optical disc, or a compact disc read-only memory (CD-ROM), etc.

[0149] Those skilled in the art should understand that the embodiments of the present invention may be provided as a method, a system, or a computer program product. Therefore, the present invention may take the form of a hardware embodiment, a software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories and optical memories, etc.) containing computer-usable program code.

[0150] The present invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each flow and / or block in the flowchart illustrations and / or block diagrams, and combinations of flows and / or blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine, such that the instructions executed by the processor of the computer or other programmable data processing device create means for implementing the functions specified in the flow Figure 1 one or more flows and / or blocks Figure 1 or means for implementing the functions specified in one or more blocks.

[0151] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means that implement the functions specified in the flow Figure 1 one or more flows and / or blocks Figure 1 or means for implementing the functions specified in one or more blocks.

[0152] These computer program instructions may also be loaded onto a computer or other programmable data processing device, such that a series of operational steps are performed on the computer or other programmable device to produce a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in the flow Figure 1 one or more flows and / or blocks Figure 1 or means for implementing the functions specified in one or more blocks.

[0153] The above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention.

Claims

1. A battery heating method, characterized in that, The method is applied to a motor controller of a vehicle, and the motor controller is used to control at least two motors, including: Responding to a heating request from a battery control unit of the vehicle, determining target values of control parameters of the at least two motors; wherein, the control parameters at least include one of the following: carrier phase interleaving control angle, torque-current mapping relationship; According to the target angle of the carrier phase interleaving control angle, adjusting the carrier frequency of one of the at least two motors, so that the ripple currents on the bus of the at least two motors are superimposed on each other to heat the power battery of the vehicle; According to the target mapping relationship of the torque-current mapping relationship, increasing the current mapped by the torque request value to heat the coolant of the vehicle's heat exchange system, and heating the power battery through the coolant; Wherein, the target values include: the target angle and the target mapping relationship.

2. The method according to claim 1, characterized in that The responding to a heating request from a battery control unit of the vehicle and determining the target angle of the control parameters of the at least two motors includes: Responding to a heating request from a battery control unit of the vehicle, and determining the target angle of the carrier phase interleaving control angle from a preset carrier phase interleaving control angle range according to the heating gear parameter in the heating request or the state parameter of the power battery; Wherein, the preset carrier phase interleaving control angle range is greater than or equal to 0 degrees and less than 90 degrees.

3. The method according to claim 2, wherein: The heating intensity indicated by the heating gear parameter is negatively correlated with the target angle; The state parameter at least includes: cell temperature, SOC; The magnitude of the cell temperature is positively correlated with the magnitude of the target angle; The magnitude of the SOC is negatively correlated with the magnitude of the target angle.

4. The method according to claim 1, wherein The responding to a heating request from a battery control unit of the vehicle and determining the target values of the control parameters of the at least two motors includes: Responding to a heating request from a battery control unit of the vehicle, and determining the target mapping relationship from a preset set of torque-current mapping relationships according to the heating gear parameter in the heating request or the state parameter of the power battery.

5. The method according to claim 4, wherein: The heating intensity indicated by the heating gear parameter is positively correlated with the magnitude of the current value in the target mapping relationship at the same torque; The state parameter at least includes: cell temperature, SOC; The magnitude of the state parameter cell temperature is negatively correlated with the magnitude of the current value in the target mapping relationship at the same torque; The magnitude of the SOC is positively correlated with the magnitude of the current value in the target mapping relationship at the same torque.

6. The method according to claim 4, characterized in that, The method further includes: Determining upper and lower limit values of the current of the motor at different torques according to the equal torque curves at different torques, the MTPA curve of the motor, and the intersection points of a preset current limit circle of the motor; Determining the preset set of torque-current mapping relationships according to the upper and lower limit values of the current of the motor at different torques.

7. The method according to any one of claims 1 to 6, characterized in that Adjusting the carrier frequency of one of the at least two motors according to the target value of the carrier phase interleaving control angle, so that the ripple currents on the bus of the at least two motors are superimposed on each other to heat the power battery of the vehicle, includes: Performing PI control on the difference between the target angle of the carrier phase interleaving control angle and the carrier frequencies of the at least two motors to obtain the carrier frequency of one of the at least two motors; Controlling one of the at least two motors according to the carrier frequency of one of the at least two motors, so that the ripple currents on the bus of the at least two motors are superimposed on each other to heat the power battery.

8. The method according to any one of claims 1 to 6, characterized in that Responding to a heating request from the battery control unit of the vehicle to determine the target value of the control parameters of the at least two motors, includes: Responding to a heating request from the battery control unit of the vehicle to obtain the carrier frequencies of the at least two motors and the operating modes of the at least two motors; When the operating modes of the at least two motors are the same, the difference between the carrier frequencies of the at least two motors is within a preset frequency difference range, and the random PWM enabling of the at least two motors is in a prohibited state, determining the target angle of the carrier phase interleaving control angle in the control parameters of the at least two motors.

9. The method according to any one of claims 1 to 6, characterized in that, The method further includes: Responding to a heating request from the battery control unit of the vehicle, determining the maximum torque of the motor according to the maximum available driving power of the motor in the heating request; Sending the maximum torque of the motor to the vehicle's vehicle controller, so that the torque request value sent by the vehicle controller to the motor controller is less than or equal to the maximum torque of the motor.

10. The method according to any one of claims 1 to 6, characterized in that The method further includes: When the power battery supplies power to the motor controller, the motor controller is in a preset fault-free state, and the vehicle is in a drivable state, sending an allow heating signal to the battery control unit, so that the battery control unit sends a heating request to the motor controller when the power battery meets the preset heating conditions.

11. A battery heating device, characterized in that: The device is arranged in the motor controller of the vehicle and is used to control at least two motors, includes: A determination module, configured to respond to a heating request from the battery control unit of the vehicle and determine the target value of the control parameters of the at least two motors; wherein, the control parameters at least include one of the following: carrier phase interleaving control angle, torque-current mapping relationship; A first heating module, configured to adjust the carrier frequency of one of the at least two motors according to the target angle of the carrier phase interleaving control angle, so that the ripple currents on the bus of the at least two motors are superimposed on each other to heat the power battery of the vehicle; A second heating module, configured to increase the current corresponding to the torque request value according to the target mapping relationship of the torque-current mapping relationship to heat the coolant of the vehicle's heat exchange system, and heat the power battery through the coolant; Wherein, the target value includes: the target angle and the target mapping relationship.

12. A motor controller, characterized in that, Includes: A processor and a storage medium storing instructions executable by the processor, wherein the storage medium relies on the processor to perform operations via a communication bus, and when the instructions are executed by the processor, the battery heating method according to any one of claims 1 to 10 is executed.

13. A battery heating system, characterized in that: include: The motor controller, at least two motors, a battery control unit, a power battery, a heat exchange system and a vehicle controller as described in claim 12.

14. A vehicle, characterized in that, include: The battery heating system as claimed in claim 13.

15. A computer program product, comprising a computer program or instructions, characterized in that, When the computer program or instruction is executed by a processor, the steps of the battery heating method according to any one of claims 1 to 10 are implemented.

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