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

Abstract

Embodiments of the present invention disclose a battery heating method, device, system, motor controller, and vehicle. The method is applied to a motor controller of a vehicle, which is used to control at least two motors. The method includes: determining a target angle for control parameters of the at least two motors in response to a heating request from the vehicle's battery control unit; adjusting the carrier frequency of one of the at least two motors based on a target value of the carrier phase staggered control angle so that the ripple currents on the busbars of the at least two motors are superimposed on each other to heat the vehicle's power battery; and increasing the current mapped to the torque request value based on a target mapping relationship between torque and current to heat the coolant of the vehicle's heat exchange system, thereby heating the power battery through the coolant. This improves the heating efficiency of the power battery.

Description

Technical Field

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

[0002] Currently, the performance of power batteries in new energy vehicles is significantly affected by temperature. At low temperatures, the chemical reaction rate within the battery slows, leading to capacity decay, decreased charge and discharge efficiency, and increased internal resistance, seriously impacting vehicle range and battery life.

[0003] In related technologies, power batteries can be heated using positive temperature coefficient (PTC) heating, locked-rotor heating, or pulse heating. However, the heating efficiency of these methods is low. 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 a power battery.

[0005] The technical solution of the present invention is achieved as follows:

[0006] An embodiment of the present invention provides 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, including:

[0007] In response to a heating request from a battery control unit of the vehicle, target values ​​of control parameters of the at least two motors are determined; wherein the control parameters include at least one of the following: a carrier phase interleaving control angle, and a mapping relationship between torque and current;

[0008] adjusting 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 ripple currents on busbars of the at least two motors are superimposed on each other to heat the power battery of the vehicle;

[0009] increasing the current mapped by the torque request value according to the target mapping relationship of the torque and current, so as to heat the coolant of the vehicle heat exchange system, thereby heating the power battery through the coolant;

[0010] Wherein, the target value includes: the target angle and the target mapping relationship.

[0011] In this way, by responding to the heating request and determining the target angle of the carrier phase staggered 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 busbars of at least two motors are superimposed on each other, and the superimposed ripple current is used to directly heat the power battery. In this way, direct heating allows the power battery to be rapidly heated without the need for an additional heating device, thereby improving the heating efficiency of the power battery. By responding to the 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 by circulating the coolant. In this way, the electric drive hardware in the vehicle is reused, and the power battery can be heated by indirect heating, thereby improving the heating efficiency of the power battery.

[0012] Furthermore, determining target angles of control parameters of the at least two motors in response to a heating request from a battery control unit of the vehicle includes:

[0013] In response to a heating request from a battery control unit of the vehicle, determining a target angle of the carrier phase interleaving control angle from a preset carrier phase interleaving control angle range according to a heating gear parameter in the heating request or a state parameter of the power battery;

[0014] The preset carrier phase staggered control angle range is greater than or equal to 0 degrees and less than 90 degrees.

[0015] In this way, the target angle is determined by the heating gear parameters or the state parameters of the power battery, so that the determined target angle is related to the heating gear parameters or the state parameters of the power battery. The target angle that matches the heating gear parameters or the state parameters of the power battery can be determined, thereby improving the adaptability of the target angle.

[0016] Furthermore, the heating intensity indicated by the heating gear parameter is negatively correlated with the target angle; the state parameters include at least: battery cell temperature, SOC; the size of the battery cell temperature is positively correlated with the size of the target angle; the size of the SOC is negatively correlated with the size of the target angle.

[0017] In this way, the size of the target angle is determined by the above-mentioned correlation, so that the size of the determined target angle changes with the heating intensity indicated by the heating gear parameter, or changes with the size of the state parameter. This is conducive to determining a more accurate target angle in combination with the vehicle's heating gear parameter or the state parameter of the power battery, which improves the accuracy of the target angle and helps to delay the life attenuation of the power battery.

[0018] Furthermore, determining target values ​​of control parameters of the at least two motors in response to a heating request from a battery control unit of the vehicle includes:

[0019] In response to a heating request from a battery control unit of the vehicle, the target mapping relationship is determined from a set of preset torque-current mapping relationships according to a heating gear parameter in the heating request or a state parameter of the power battery.

[0020] In this way, the target mapping relationship is determined by the heating gear parameters or the state parameters of the power battery, so that the determined target mapping relationship is related to the heating gear parameters or the state parameters of the power battery. The target mapping relationship that matches the heating gear parameters or the state parameters of the power battery can be determined, thereby improving the adaptability of the target mapping relationship.

[0021] Furthermore, 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 parameters include at least: battery cell temperature, SOC; the magnitude of the battery 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.

[0022] In this way, the size of the target mapping relationship is determined by the above-mentioned correlation, so that the size of the current value in the determined target mapping relationship changes with the heating intensity indicated by the heating gear parameter, or changes with the size of the state parameter. This is conducive to determining a more accurate target mapping relationship in combination with the heating gear parameter or the state parameter of the power battery, which improves the accuracy of the target mapping relationship and helps to delay the life attenuation of the power battery.

[0023] Furthermore, the method further comprises:

[0024] Determining upper and lower limits of the current of the motor at different torques according to the intersection of the equal torque curve at different torques, the MTPA curve of the motor, and a preset current limit circle of the motor;

[0025] The mapping relationship set between the preset torque and the current is determined according to the upper limit value and the lower limit value of the current of the motor under different torques.

[0026] In this way, a preset torque and current mapping relationship set can be determined in the above manner, so that a target mapping relationship matching the heating gear parameters or the power battery status parameters can be determined, which is conducive to determining a more accurate target mapping relationship.

[0027] Furthermore, the adjusting the carrier frequency of one of the at least two motors according to the target value of the carrier phase staggered control angle so that the ripple currents on the busbars of the at least two motors are superimposed on each other to heat the power battery of the vehicle includes:

[0028] Performing PI control on a difference between a target angle of the carrier phase interleaving control angle and the carrier frequencies of the at least two motors to obtain a carrier frequency of one of the at least two motors;

[0029] According to the carrier frequency of one of the at least two motors, one of the at least two motors is controlled so that ripple currents on the busbars of the at least two motors are superimposed on each other to heat the power battery.

[0030] In this way, through the above-mentioned PI control method, the difference in carrier frequency 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 superposition of ripple current on the motor bus, which helps to achieve direct heating of the power battery, thereby improving the heating efficiency.

[0031] Furthermore, determining target values ​​of control parameters of the at least two motors in response to a heating request from a battery control unit of the vehicle includes:

[0032] acquiring, in response to a heating request from a battery control unit of the vehicle, carrier frequencies of the at least two motors and operating modes of the at least two motors;

[0033] When the operating modes of the at least two motors are the same, the difference in carrier frequencies of the at least two motors is within a preset frequency difference range, and the random PWM enable of the at least two motors is in a disabled state, the target angle of the carrier phase interleaving control angle in the control parameters of the at least two motors is determined.

[0034] In this way, the target value of the carrier phase interleaving control angle of at least two motors is determined by judging the operating mode 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. This ensures that the operating parameters of the motor controller are only used to heat the power battery by using the carrier phase interleaving control when certain conditions are met. In this way, direct heating of the power battery is achieved while ensuring stable operation of the motor.

[0035] Furthermore, the method further comprises:

[0036] In response to a heating request from a battery control unit of the vehicle, determining a maximum torque of the motor according to a maximum available driving power of the motor in the heating request;

[0037] The maximum torque of the motor is sent to a vehicle controller of the vehicle, so that a torque request value sent by the vehicle controller to the motor controller is less than or equal to the maximum torque of the motor.

[0038] In this way, by determining the maximum torque of the motor in the above manner, the size 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.

[0039] Furthermore, the method further comprises:

[0040] 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, a heating permission signal is sent 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.

[0041] In this way, by sending a heating permission signal to the battery control unit in the above manner, the battery control unit can send a heating request to the motor controller only when heating is allowed, setting certain conditions for the heating of the power battery, thereby ensuring that the power battery can be heated when the motor, battery, and vehicle are in normal working conditions, thereby improving the safety of heating the power battery.

[0042] An embodiment of the present invention provides a battery heating device, which is provided in a motor controller of a vehicle and is used to control at least two motors, including:

[0043] a determination module, configured to determine target values ​​of control parameters of the at least two motors in response to a heating request from a battery control unit of the vehicle; wherein the control parameters include at least one of the following: a carrier phase interleaving control angle, and a mapping relationship between torque and current;

[0044] a first heating module, configured to adjust a carrier frequency of one of the at least two motors according to a target angle of the carrier phase staggered control angle, so that ripple currents on busbars of the at least two motors are superimposed on each other to heat a power battery of the vehicle;

[0045] a second heating module, configured to increase a current corresponding to a torque request value according to a target mapping relationship of the torque and current mapping relationship, so as to heat a coolant of the vehicle heat exchange system, thereby heating the power battery through the coolant;

[0046] Wherein, the target value includes: the target angle and the target mapping relationship.

[0047] An embodiment of the present invention provides a motor controller, comprising: 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 described in one or more of the above embodiments is executed.

[0048] An embodiment of the present invention provides a battery heating system, comprising: 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.

[0049] An embodiment of the present invention provides a vehicle, comprising: a battery heating system according to one or more of the above embodiments.

[0050] An embodiment of the present invention further provides a computer program product, including a computer program or instructions, wherein 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.

[0051] Beneficial effects of the present invention:

[0052] (1) By responding to a heating request, the target angle of the carrier phase interleaving control angle of at least two motors is determined, and the carrier frequency of one motor can be adjusted. By adjusting the carrier frequency of one motor, the ripple currents on the busbars 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, the power battery can be quickly heated without an additional heating device through direct heating, thereby improving the heating efficiency of the power battery;

[0053] (2) By responding to the heating request, a target mapping relationship of the mapping relationship between torque and current is determined. The target mapping relationship can be used to increase the current mapped by the torque request value. After the motor current is increased, the heat of the increased motor current can be used to heat the coolant in the heat exchange system, and then the power battery is heated by circulating the coolant. In this way, the electric drive hardware in the vehicle can be reused, and the power battery can be heated by indirect heating, thereby improving the heating efficiency of the power battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 A schematic flow chart of an optional battery heating method provided in an embodiment of the present invention;

[0055] Figure 2 A schematic diagram of a curve related to a motor in an optional dq-axis current coordinate system provided in an embodiment of the present invention;

[0056] Figure 3 A schematic structural diagram of an example of an optional battery heating system provided in an embodiment of the present invention;

[0057] Figure 4 A schematic flow chart of Example 1 of an optional battery heating method provided in an embodiment of the present invention;

[0058] Figure 5 A schematic flow chart of a second example of an optional battery heating method provided in an embodiment of the present invention;

[0059] Figure 6 A schematic structural diagram of an optional battery heating device provided in an embodiment of the present invention;

[0060] Figure 7 A schematic diagram of the structure of an optional motor controller provided in an embodiment of the present invention;

[0061] Figure 8 A schematic structural diagram of an optional battery heating system provided in an embodiment of the present invention;

[0062] Figure 9 A schematic structural diagram of an optional vehicle provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0063] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0064] In view of the problem of low heating efficiency of power batteries in related technologies, an embodiment of the present invention provides a battery heating method, which is applied to a motor controller of a vehicle, wherein the motor controller is used to control at least two motors. Figure 1 A schematic flow chart of an optional battery heating method provided in an embodiment of the present invention is shown as follows: Figure 1 As shown, the battery heating method may include:

[0065] S101: In response to a heating request from a battery control unit of a vehicle, determining target values ​​of control parameters of at least two motors;

[0066] In an embodiment of the present invention, in order to achieve heating of the power battery, when heating of 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 determines the target values ​​of the control parameters of at least two motors in response to the heating request, wherein the control parameters include at least one of the following: a carrier phase interleaving control angle, a mapping relationship between torque and current, and the target value can be a target angle or a target mapping relationship.

[0067] That is to say, in response to the heating request, the motor controller determines the target angle of the carrier phase interleaving control angle and / or the target mapping relationship of the mapping relationship between torque and current of at least two motors. The target angle of the carrier phase interleaving control angle and / or the target mapping relationship of the mapping relationship between torque and current can also be referred to as the value of the control parameter of the motor of the power battery in the heating mode.

[0068] The target angle of the carrier phase staggered control angle and / or the target mapping relationship between torque and current may be pre-set in the motor controller or determined in real time by the motor controller.

[0069] Regarding the real-time determination of the target angle and / or target mapping relationship of the carrier phase interleaving control angle, for example, the target angle of the carrier phase interleaving control angle can be determined based on the battery cell temperature of the power battery, wherein the lower the battery cell temperature, the smaller the target angle of the carrier phase interleaving control angle; the target mapping relationship can be determined according to the battery state of charge (SOC), wherein the smaller the battery SOC, the smaller the current mapped by the same torque in the target mapping relationship.

[0070] In addition, before sending a heating request, the battery control unit needs to set its own heating permission flag. Only when the heating permission flag is set and the power battery meets the preset heating conditions will it send a heating request to the motor controller. Here, in order to set the heating permission flag, the motor controller needs to send a heating permission signal to the battery control unit when both its own status and the status of the entire vehicle meet the preset heating permission conditions, thereby setting the heating permission flag in the battery control unit.

[0071] S102: adjusting the carrier frequency of one of the at least two motors according to a target angle of the carrier phase interleaving control angle so that ripple currents on the busbars of the at least two motors are superimposed on each other to heat a power battery of the vehicle;

[0072] After determining the target angle of the carrier phase interleaving control angle of at least two motors through the above S101, in S102, the carrier frequency of one motor is adjusted 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 directly heat the power battery.

[0073] After knowing the target angle of the carrier phase interleaving control angle, the carrier frequency of one motor can be adjusted based on this, so that the difference in the carrier phases of the two motors approaches the target angle of the carrier phase interleaving control angle. Here, the smaller the target angle of the carrier phase interleaving control angle and the closer the carrier phases of the two motors are, the more ripple currents on the busbars of at least two motors will be superimposed. The superposition of ripple currents will cause losses, which can be directly used to heat the power battery.

[0074] It should be noted that whether the carrier frequency of a motor is adjusted according to the target angle of the carrier phase interleaving control angle needs to be combined with the operating mode of at least two motors and the difference between the carrier frequencies of at least two motors. Only when the operating mode of at least two motors and the difference between the carrier frequencies of at least two motors meet the conditions, the carrier frequency of a motor is adjusted 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.

[0075] The difference in carrier frequencies of at least two motors is the difference in carrier frequencies of the two motors for two motors, and the difference in carrier frequencies of any two motors of the at least two motors for more than two motors. The operating mode of the at least two motors refers to the operating mode of all the motors of the at least two motors.

[0076] In addition, the difference in the carrier phases of the at least two motors can be determined using the difference in the carrier phase timestamp signals of the at least two motors. The carrier phase timestamp signal of each of the at least two motors can be: the time count value converted to the crystal oscillator counter of the motor controller when passing through the same position during the carrier signal generation process.

[0077] Different target angles for the carrier phase interleaving control angles result in different adjustments to the carrier frequency of one motor, resulting in different degrees of superposition of ripple currents on the busbars of at least two motors. Consequently, different heating effects are exerted on the power battery. The smaller the target angle for the carrier phase interleaving control angle, the greater the heating effect on the power battery.

[0078] It should be pointed out that, for carrier phase interleaving control, it can be applied to two motors, wherein, it can be achieved by controlling the carrier frequency of one motor while allowing the carrier frequency of the other motor to operate normally. When it is applied to more than two motors, it can be achieved by controlling the carrier frequency of one motor while allowing the carrier frequencies of other motors to operate normally.

[0079] In this way, the power battery can be directly heated without adding a heating device, and driving heating can be achieved.

[0080] S103: According to the target mapping relationship of the mapping relationship between the torque and the current, the current mapped by the torque request value is increased to heat the coolant of the vehicle heat exchange system, thereby heating the power battery through the coolant.

[0081] After the target mapping relationship of the torque and current is determined in S101, in S103, the current mapped by the torque request value is increased according to the target mapping relationship to heat the coolant of the vehicle heat exchange system, thereby heating the power battery through the coolant.

[0082] Among them, after obtaining the target mapping relationship, the motor controller maps the dq axis current value according to the torque request value sent by the vehicle controller, and uses the current value as the instruction value for controlling the motor current.

[0083] The above-mentioned target mapping relationship can be called the mapping relationship between the torque and current of the motor in the heating mode of the power battery. After receiving the torque request value, the motor controller obtains the current mapped by the torque request value according to the target mapping relationship. Compared with the mapping in the non-heating mode in the mapping relationship between torque and current, the current value of the torque request value mapping is increased. The increase in motor current causes the motor winding to heat up, which can be used to heat the coolant. The heated coolant flows to the power battery side, which can achieve heating of the power battery.

[0084] Different target mappings result in different currents mapped to torque requests, leading to different degrees of coolant heating and, consequently, different heating of the power battery. The greater the current mapped to the same torque in the target mapping, the greater the coolant heating, and, consequently, the greater the power battery heating.

[0085] It should be pointed out that the above-mentioned target mapping relationship can be applied to two motors to achieve heating of the power battery, wherein a corresponding target mapping relationship is determined for each motor, and a larger current is mapped using the corresponding target mapping relationship to achieve heating of the coolant and thus heating of the power battery.

[0086] In this way, indirect heating of the power battery and driving heating can be achieved without adding a heating device.

[0087] In order to determine a target value of the carrier phase stagger control angle, in an optional embodiment, S101 may include:

[0088] acquiring carrier frequencies of at least two motors and operating modes of at least two motors in response to a heating request from a battery control unit of the vehicle;

[0089] When the operating modes of 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 pulse width modulation (PWM) enable of the at least two motors is in a disabled state, a target angle of the carrier phase staggered control angle in the control parameters of the at least two motors is determined.

[0090] It can be understood that after receiving the heating request, the motor controller obtains the carrier frequencies of at least two motors and the operating modes of at least two motors in response to the heating request, wherein the operating mode may include a driving mode and a power generation mode.

[0091] Taking two motors as an example, after obtaining the carrier frequency and operating mode of each of the two motors, 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 the preset frequency difference range. Also check whether the random PWM enable of each of the two motors is in a disabled state. Here, when the operating mode of each of the two motors is 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 a disabled state, determine the target angle of the carrier phase interleaving control angle in the control parameters of the two motors.

[0092] In this way, the target value of the carrier phase interleaving control angle of at least two motors is determined by judging the operating mode 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. This ensures that the operating parameters of the motor controller are only used to heat the power battery by using the carrier phase interleaving control when certain conditions are met. In this way, direct heating of the power battery is achieved while ensuring stable operation of the motor.

[0093] In order to determine the target angle of the carrier phase interleaving control angle, in an optional embodiment, S101 may include:

[0094] In response to a heating request from a battery control unit of the vehicle, a target angle of the carrier phase interleaving control angle is determined from a preset range of the motor's carrier phase interleaving control angle according to the heating gear parameter in the heating request or the state parameter of the power battery.

[0095] It can be understood that after receiving the heating request, the motor controller can respond to the heating request by determining the target angle of the carrier phase interleaving control angle from the preset carrier phase interleaving control angle range based on the heating gear parameters, or can determine the target angle of the carrier phase interleaving control angle from the preset carrier phase interleaving control angle range based on the state parameters of the power battery.

[0096] The battery heating gear parameter can be a number, a letter, or other type. The heating gear parameter is divided by 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 the heating intensity of the medium gear, and the heating intensity of the medium gear is lower than the heating intensity of the high gear. The power battery status parameter can include: battery cell temperature and SOC.

[0097] Among them, the preset carrier phase interleaving 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 interleaving control angle, it is generally set to 90 degrees in the non-heating state, so that the loss caused by the superposition of ripple current on the motor bus is minimized. Here, in order to increase the superposition of ripple current, the target value of the carrier phase interleaving control angle can be set to greater than or equal to 0 degrees and less than 90 degrees. In this way, different target angles of the carrier phase interleaving control angle can be set according to different required heating degrees, so that the power battery can be heated according to different required heating degrees.

[0098] It should be noted that when the target angle of the carrier phase interleaving control angle is equal to 0 degrees, the loss caused by the superposition of ripple currents on the motor bus is the largest. It can be seen that the smaller the target angle of the carrier phase interleaving control angle, the greater the direct heating intensity.

[0099] In this way, the target angle is determined by the heating gear parameters or the state parameters of the power battery, so that the determined target angle is related to the heating gear parameters or the state parameters of the power battery. The target angle that matches the heating gear parameters or the state parameters of the power battery can be determined, thereby improving the adaptability of the target angle.

[0100] In order to improve the accuracy of the target angle, in an optional embodiment, the heating intensity indicated by the heating gear parameter is negatively correlated with the target angle; the state parameters include at least: battery cell temperature, SOC; the size of the battery cell temperature is positively correlated with the size of the target angle; the size of the SOC is negatively correlated with the size of the target angle.

[0101] It can be understood that when the heating intensity indicated by the heating gear parameter is negatively correlated with the target angle, the greater the heating intensity indicated by the heating gear parameter, the smaller the target angle. When the battery cell temperature is positively correlated with the target angle, the higher the battery cell temperature, the larger the target angle. When the SOC is negatively correlated with the target angle, the lower the SOC, the larger the target angle. For example, when the heating intensity indicated by the heating gear parameter is greater, the target angle is closer to 0, the lower the battery cell temperature, the smaller the target angle, and the smaller the SOC, the larger the target angle.

[0102] In this way, the size of the target angle is determined by the above-mentioned correlation, so that the size of the determined target angle changes with the heating gear parameters, battery cell temperature or SOC, which is conducive to determining a more accurate target angle in combination with the heating gear parameters or the state parameters of the power battery, while improving the accuracy of the target angle and helping to delay the life attenuation of the power battery.

[0103] In order to determine the target mapping relationship, in an optional embodiment, S101 may include:

[0104] In response to a heating request from a battery control unit of the vehicle, a target mapping relationship is determined from a set of preset torque-current mapping relationships according to a heating gear parameter or a state parameter of the power battery.

[0105] It can be understood that after receiving the heating request, the motor controller can respond to the heating request by determining the target mapping relationship from the preset torque and current mapping relationship set based on the heating gear parameters, or it can determine the target mapping relationship from the preset torque and current mapping relationship set based on the state parameters of the power battery.

[0106] In this way, the target mapping relationship is determined by the heating gear parameters or the state parameters of the power battery, so that the determined target mapping relationship is related to the heating gear parameters or the state parameters of the power battery. The target mapping relationship that matches the heating gear parameters or the state parameters of the power battery can be determined, thereby improving the adaptability of the target mapping relationship.

[0107] 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 parameters include at least: battery cell temperature, SOC; the magnitude of the battery 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.

[0108] 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; the battery cell temperature is negatively correlated with the magnitude of the current value in the target mapping relationship under the same torque, indicating that the greater the battery cell temperature, the smaller the current value in the target mapping relationship under the same torque; the SOC is positively correlated with the magnitude of the current value in the target mapping relationship under the same torque, indicating that the smaller the SOC, the smaller the current value in the target mapping relationship under the same torque.

[0109] 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 current value; when the battery cell temperature is lower, the current value in the target mapping relationship under the same torque is closer to the maximum current value; when the SOC is larger, the current value in the target mapping relationship under the same torque is closer to the maximum current value.

[0110] In this way, the size of the target mapping relationship is determined by the above-mentioned correlation, so that the size of the current value in the determined target mapping relationship changes with the size of the heating gear parameter or the state parameter, which is conducive to determining a more accurate target mapping relationship in combination with the heating gear parameter or the state parameter of the power battery, improving the accuracy of the target mapping relationship while helping to delay the life attenuation of the power battery.

[0111] In order to determine a set of mapping relationships between preset torque and current, in an optional embodiment, the method may further include:

[0112] Determining upper and lower limits of the motor current at different torques based on the intersection of the equal torque curve at different torques, the maximum torque per ampere curve (MTPA) of the motor, and a preset current limit circle of the motor;

[0113] A set of mapping relationships between preset torques and currents is determined according to upper and lower limits of the current of the motor under different torques.

[0114] Figure 2 A schematic diagram of a curve related to a motor in an optional dq axis current coordinate system provided by an embodiment of the present invention, such as Figure 2 As 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 turning speed, the current limit circle 22 of the motor, the current limit circle 23 of the motor, the MTPA curve 24, the equal torque curve 25 and the equal torque curve 26.

[0115] Among them, the current limit circle 23 of the motor is the rated current when the motor is running at normal efficiency, and 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 and lower limit values ​​of the motor current under different torques, taking the equal torque curve 25 as an example, the intersection B of the equal torque curve 25 and the MTPA curve is determined, and the point C with the smaller d-axis at the intersection with the current limit circle 22 of the motor is determined. Point B is used as the upper limit value of the motor current under the torque of the equal torque curve 25, and point C is used as the lower limit value of the motor current under the torque of the equal torque curve 25. Then, based on the upper limit and lower limit values, different current values ​​are selected on the equal torque curve BC to form a preset torque and current mapping relationship set.

[0116] It should be noted that the above-mentioned turning speed refers to the critical speed point at which the motor switches from the constant torque operation mode to the weak magnetic operation mode. The current limit circle 22 of the motor is the set allowable derated heating peak current. Figure 2 The peak current of the reduced efficiency heating is equal to the rated current value when the motor is running at normal efficiency. This peak current is smaller than the peak current under normal efficiency Map operation (the peak current under normal efficiency Map operation is equivalent to Figure 2 The current limit of the motor in circle 23).

[0117] During the reduced efficiency heating calibration, the d-axis current is allowed to vary from 0 to the negative reduced efficiency heating peak current, with a total of N current values, and the q-axis current is allowed to vary from 0 to the positive reduced efficiency heating peak current, with a total of N current values. A total of N×N torque values ​​at different dq-axis current combination points can be obtained.

[0118] In the above-mentioned combinations of torque and current, there are multiple dq-axis current combinations for the same torque. In the dq current coordinate system, an equal torque curve is formed, and the dq-axis combination with the maximum and minimum motor phase current is selected (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 reduced-efficiency heating power (for example, points C and D). The current point combination between the two points can be configured according to different heating gear parameters or different battery status 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 preset target mapping relationship set between torque and current.

[0119] In this way, a preset torque and current mapping relationship set can be determined in the above manner, so that a target mapping relationship that matches the current gear parameters or power battery state parameters can be determined, which is conducive to determining a more accurate target mapping relationship.

[0120] In order to achieve heating of the power battery through carrier phase interleaving control, in an optional embodiment, S102 may include:

[0121] Performing proportional-integral (PI) control on a difference between a target angle of the carrier phase staggered control angle and the carrier frequencies of the at least two motors to obtain a carrier frequency of one of the at least two motors;

[0122] According to the carrier frequency of one of the at least two motors, one of the at least two motors is controlled so that the ripple currents on the busbars of the at least two motors are superimposed on each other to heat the power battery.

[0123] It can be understood that in addition to determining the target angle of the carrier phase interleaving control angle, the difference in the carrier frequencies of at least two motors is also calculated. These two values ​​are used as input and input into the carrier phase interleaving closed-loop adjustment module in the motor controller for PI closed-loop control. The output is a frequency adjustment signal for the motor, which is the carrier frequency of the motor. The carrier frequency is used to control the operation of the motor, so that the ripple currents on the busbars of at least two motors are superimposed on each other, and the loss after superposition increases. The heat generated by the loss is used to directly heat the power battery.

[0124] Here, it should be noted that, for at least two motors, one motor uses the target angle of the carrier phase interleaving control angle to adjust the carrier frequency of one motor, and the carrier frequencies of the other motors remain unchanged. In this way, by adjusting the carrier frequency of one motor, the difference in the carrier frequencies of at least two motors is made close to the target angle of the carrier phase interleaving control angle, thereby increasing the loss caused by the superposition of ripple current, so as to achieve direct heating of the power battery.

[0125] In this way, through the above-mentioned PI control method, the difference in carrier frequency 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 superposition of ripple current on the motor bus, which helps to achieve direct heating of the power battery, thereby improving the heating efficiency.

[0126] In addition, in order to prevent the problem of over-discharge of the power battery at low temperatures caused by excessive motor torque, in an optional embodiment, the method may further include:

[0127] In response to a heating request from a battery control unit of the vehicle, determining a maximum torque of the electric motor based on a maximum available drive power of the electric motor in the heating request;

[0128] The maximum torque of the motor is sent to the vehicle controller of the vehicle 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.

[0129] 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 based on the maximum available driving power of the motor in the heating request, wherein the maximum available driving power of the motor is determined by the battery control unit based on the battery cell temperature.

[0130] After determining the cell temperature, the battery control unit can determine the maximum output power of the power battery based on the cell temperature. Additionally, the vehicle controller can obtain non-drive power, which is the sum of the powers of the vehicle's non-drive components. The non-drive components send their own power to the vehicle controller, which then adds the sum to obtain the non-drive power. This sum is then sent to the battery control unit. After obtaining the maximum output power and non-drive power of the power battery, the difference between the maximum output power and the non-drive power is determined as the maximum available drive power of the motor.

[0131] Here, the non-driving device may include: a DC-to-DC converter (DCDC), a compressor, a PTC, etc., which is not specifically limited in the embodiment of the present invention.

[0132] After obtaining the maximum available driving power of the motor, the motor controller can determine the maximum torque of the motor according to a preset correspondence between power and torque, or call a preset calculation formula to determine the maximum torque of the motor, wherein the calculation formula can be as follows:

[0133] (1)

[0134] in, Indicates the maximum torque of the motor, Indicates the maximum available drive power of the motor, Indicates the motor speed, is the efficiency of the motor at the current operating point, for example, the efficiency at the current speed and current torque, Indicates the torque conversion factor.

[0135] 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 sent to the motor controller to be within the maximum torque of the motor.

[0136] In this way, by determining the maximum torque of the motor in the above manner, the size 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.

[0137] 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 method may further include:

[0138] 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, a heating permission signal is sent 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.

[0139] It can be understood that the motor controller first determines whether the power battery is supplying 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.

[0140] Among them, in order to determine whether the power battery supplies power to the motor controller, when the motor controller is in the power-on state, it means that the power battery supplies power to the motor controller; in order to determine whether the obtained motor controller is in the preset fault-free state, here, the operation log of the motor controller can be obtained, and whether the motor controller is in the preset fault-free state can be determined based on the operation log. The fault information of the motor controller can also be obtained. If the fault information is empty, it means that the motor controller is in the preset fault-free state; in order to determine whether the vehicle is in a drivable state, the gear information of the vehicle can be obtained. If the gear is in the drive (Drive, D) gear, it means that the vehicle is in a drivable state. When the vehicle controller receives the driving instruction for driving and is able to execute the driving instruction, it means that the vehicle is in a drivable state.

[0141] When all three of the above conditions are met, the motor controller sends a heating permission signal to the battery control unit. After receiving the signal, the battery control unit sets its own heating permission flag to indicate that the power battery is in a state where heating is permitted.

[0142] After the power battery is in a state where heating is allowed, the battery control unit sends a heating request to the motor controller if the power battery meets preset heating conditions. The motor controller uses one or more of the above embodiments to perform heating of the power battery.

[0143] The power battery meeting the preset heating condition may be that: the cell temperature of the power battery is lower than a first preset temperature threshold and the SOC of the power battery is higher than a first preset SOC threshold.

[0144] In this way, by sending a heating permission signal to the battery control unit in the above manner, the battery control unit can send a heating request to the motor controller only when heating is allowed, setting certain conditions for the heating of the power battery, thereby ensuring that the power battery can be heated when the motor, battery, and vehicle are in normal working conditions, thereby improving the safety of heating the power battery.

[0145] Furthermore, in order to exit the heating mode of the power battery, in an optional embodiment, the above method may further include:

[0146] In response to a request from the battery control unit to exit heating, a value of a control parameter of the motor in a non-heating state is determined.

[0147] It can be understood that when the battery control unit detects that the power battery has a fault or that the power battery does not meet the heating conditions, the battery control unit can send a request to exit heating to the motor controller. In response to the request to exit heating, the motor controller determines the value of the motor control parameters in the non-heating state.

[0148] Among them, the above-mentioned power battery does not meet the heating conditions may include: the cell 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-mentioned 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.

[0149] Here, the control parameters of the motor are divided into values ​​in the heating state and values ​​in the non-heating state. Then the value of the control parameters of the motor in the non-heating state can be the value of the control parameters of the motor except the value in the heating state. Here, the embodiment of the present invention does not make specific limitations on this.

[0150] For example, the values ​​of the motor control parameters in the non-heating state can be determined according to the needs of the vehicle. For example, when the state parameters of the vehicle's power battery do not pass, the values ​​of the motor control parameters in the non-heating state are different.

[0151] In this way, the heating mode of the power battery is exited by the above-mentioned method of exiting the heating request, so as to prevent the power battery from overheating due to excessive heating of the power battery, which is beneficial to delaying the life attenuation of the power battery.

[0152] The following describes the method for heating the power battery described in one or more of the above embodiments with reference to examples.

[0153] To develop an efficient, energy-saving, and driving-adaptable battery heating technology, this example proposes a dual-motor collaborative control strategy under driving conditions to achieve bidirectional battery heating. By staggering the carrier phases of the dual-motor controllers on the power battery side, the bus ripple current is increased to directly heat the battery. The motor controllers on the dual-motor side operate at reduced efficiency to increase the motor's waste heat to heat the coolant, thereby achieving intermittent heating of the power battery. The two work together to achieve efficient driving heating of the power battery in low-temperature environments, improving the performance and range of the power battery.

[0154] Figure 3A schematic structural diagram of an example of an optional battery heating system provided by an embodiment of the present invention, such as Figure 3 As 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, dual motors 35, and a heat exchange system 36. The vehicle controller 31 is connected to the battery control unit 33 and the dual-motor controller 34, respectively. The battery control unit 33 is connected to the power battery 32 and the dual-motor controller 34, respectively. The dual-motor controller 34 is also connected to the dual motors 35. The heat exchange system 36 is connected to the power battery 32 and the dual motors 35. The dual-motor controller 34 is equivalent to the motor controller described above.

[0155] Among them, the dual-motor controller 34 is used to control the basic operation of the dual motors 35, and at the same time interact with the vehicle controller 31 and the battery control unit 33 for signals, and is used to respond to the heating request and exit heating request of the driving power battery 32, and at the same time synchronously execute the heating logic of the power battery 32 on the power battery 32 side and the dual-motor 35 side respectively.

[0156] The battery control unit 33 is primarily used to monitor the battery status of the power battery 32 and transmit it to the vehicle controller 31. Based on the vehicle status and electrical control status transmitted by the vehicle controller 31, the battery control unit 33 requests heating of the power battery 32 for driving and requests heating of the power battery 32 for driving. The dual-motor controller 34 transmits the electrical control status to the vehicle controller 31.

[0157] The main function of the vehicle controller 31 is to send a torque command to the dual-motor controller 34 based on the maximum torque allowed to be requested by the vehicle control unit (VCU) and the driver's request fed back by the dual-motor controller 34, and at the same time send the vehicle status to the battery control unit 33 and the dual-motor controller 34.

[0158] The dual-motor controller 34 is configured to perform carrier phase interleaving control and efficiency reduction control on the dual-motor 35 after receiving the motor status of the dual-motor 35 .

[0159] The heat exchange system 36 is used to absorb the heat generated by the dual motors 35 for intermittent heating of the power battery 32, mainly through efficiency reduction control. The motor windings generate heat to heat the coolant, and the coolant heats the battery. At the same time, the dual motors 35 and the power battery 32 are cooled under non-battery heating conditions.

[0160] Based on the above Figure 3 , Figure 4 A flowchart of an example 1 of an optional battery heating method provided by an embodiment of the present invention is shown as follows: Figure 4 As shown, the power battery heating method may include:

[0161] S401: The dual-motor controller 34 sends a driving heating permission signal to the battery control unit 33 based on the electronic control preparation state and the vehicle preparation state. The battery control unit 33 sends a heating request and a maximum available driving power limit of the power battery 32 to the dual-motor controller 34 based on the battery state and the driving heating permission signal.

[0162] S402: The dual-motor controller 34 receives the heating request, configures the motor control parameters, calculates the maximum torque limit allowed for electric heating during driving based on the maximum available drive power limit, and sends it to the vehicle controller 31;

[0163] S403: The dual-motor controller 34 performs carrier phase interleaving control to generate superimposed ripple current on the bus side of the dual-motor 35, directly heating the power battery 32. The dual-motor controller 34 performs de-rating control to generate heat in the windings of the dual-motor 35 for heating the coolant, indirectly heating the power battery 32 through the heat exchange system 36.

[0164] 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 motors 35 to operate in a normal mode.

[0165] Figure 5 A flow chart of Example 2 of an optional battery heating method provided by an embodiment of the present invention is shown as follows: Figure 5 As shown, the battery heating method may include:

[0166] S501: Starting the vehicle, with the gear in D;

[0167] In a low-temperature environment, the discharge capacity of the power battery 32 is limited. The driver starts the vehicle, the vehicle gear is in the D gear, and the vehicle is in a ready-to-drive state.

[0168] S502: The dual-motor controller 34 sends a driving heating permission signal to the battery control unit 33 according to the electronic control preparation state and the vehicle preparation state;

[0169] The electronic control ready state refers to when the power battery 32 supplies power to the dual-motor controller 34 and the dual-motor controller 34 is fault-free, and the vehicle is in gear D. When both conditions are met, the dual-motor controller 34 sends a driving heating permission signal to the battery control unit 33, thereby setting the heating permission flag in the battery control unit 33 to 1. By determining the status of the vehicle and the dual-motor controller 34, the purpose of determining whether the basic conditions for driving heating are met is achieved.

[0170] S503: The battery control unit 33 monitors the cell temperature, SOC, and driving heating permission flag of the power battery 32 in real time;

[0171] Here, by monitoring the status signal of the power battery 32, preparation is made for whether the battery control unit 33 sends a heating request in the next step.

[0172] 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 heating flag is 1. If all are yes, execute S505; otherwise, execute S506;

[0173] S505: The battery control unit 33 sends a heating request for the power battery 32 to the dual-motor controller 34, and sends a maximum available driving power limit to the dual-motor controller 34 based on the current cell temperature and SOC of the power battery 32;

[0174] The maximum available driving power limit is sent here to avoid consuming a large amount of power of the power battery 32 during driving in a low temperature environment, causing over-discharge of the power battery 32 and accelerating the life of the power battery 32 .

[0175] The above-mentioned maximum available driving power limit refers to the maximum power that the power battery 32 can output at the current battery cell temperature minus the vehicle's non-driving power. The non-driving power is mainly the sum of the powers of the DCDC device, the compressor, and the PTC.

[0176] S506: The dual motor controller 34 controls the operation of the dual motors 35 in a normal mode, and then executes S515;

[0177] S507: The dual-motor controller 34 configures the control parameters of the motors according to the heating request of the power battery 32; calculates the maximum torque limit allowed for heating of the driving battery according to the maximum available driving power limit, and sends it to the vehicle controller 31;

[0178] After receiving the heating request from the power battery 32 , the dual-motor controller 34 configures control parameters such as the carrier phase interleaving control angle and the degraded torque-current map.

[0179] Here, the maximum motor torque limit Tmax is calculated based on the maximum available driving power limit 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 driving battery heating is limited.

[0180] S508: The dual-motor controller 34 performs carrier phase interleaving control to generate superimposed ripple current on the bus side of the dual-motor 35, directly heating the power battery 32. The dual-motor controller 34 performs de-rating control to heat the windings of the dual-motor 35 to heat the coolant, indirectly heating the power battery 32 through the heat exchange system 36.

[0181] Among them, in this step, it can be determined that the carrier phase interleaving control angle is 0 degrees. The carrier frequencies and operating modes of the two motors are obtained, and it is determined that the operating modes of the two motors are the same, which is used as the enabling condition 1 for executing the carrier phase interleaving control; according to the carrier frequencies of motor 1 and motor 2, the frequency difference between the two is within the first frequency difference threshold, which is used as the enabling condition 2 for executing the carrier phase interleaving control; the random PWM enable signal of motor 1 and the random PWM enable signal of motor 2 are both not turned on, which is used as the enabling condition 3 for executing the carrier phase interleaving control; if conditions 1, 2 and 3 are met at the same time, the carrier phase interleaving control of motor 1 is executed; wherein, the carrier phase interleaving control is only executed for motor 1, and not for motor 2.

[0182] Among them, for the carrier phase interleaving control of motor 1, the carrier phase timestamp signal of the dual motor 35 is obtained in real time and the difference is calculated, and the carrier frequency of motor 1 is dynamically adjusted using the carrier phase interleaving closed-loop adjustment module so that the carrier phase difference of the dual motor 35 reaches the first carrier phase interleaving control angle; wherein, 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 carrier signal generation process, and the carrier phase timestamp signal difference of motor 1 and motor 2 is calculated to obtain the carrier phase difference of motor 1 and motor 2.

[0183] The above-mentioned first carrier phase interleaving control angle is subtracted from the carrier phase timestamp difference signal of motor 1 and motor 2, and the difference is input into the carrier phase interleaving closed-loop adjustment module for PI closed-loop control, and the frequency adjustment signal of motor 1 is output to control motor 1.

[0184] The above-mentioned first carrier phase interleaving control angle is set to 0 degrees to achieve the purpose of superimposing the ripple currents generated by the dual motors on the bus to directly heat the power battery. At the same time, by setting different first carrier phase interleaving control angles, the purpose of adjusting the heating on the power battery side is achieved.

[0185] The dual-motor controller 34 switches the normal torque-current map to a low-efficiency torque-current map for current control. The normal torque-current map is calibrated using the MTPA curve and the Maximum Torque Per Voltage (MTPV) curve. The low-efficiency torque-current map is the set of current points below the breakover speed, where the torque command intersects the area enclosed by the MTPA and the derated heating peak current limit circle. The torque-current mapping relationship determined when the d-axis current is the lowest is the lowest-efficiency torque-current map.

[0186] Here, through efficiency reduction control, in the current low temperature environment, the dual motor windings will be heated to the maximum extent without affecting vehicle driving and ensuring the safety of the power battery. The temperature of the heating coolant is increased, and the heat is indirectly heated by the heat exchange system 36 to heat the power battery 32, thereby achieving the purpose of heating the power battery 32.

[0187] The reduced-efficiency torque-current map is obtained through calibration, and torque-current maps with different efficiencies can be used according to different gears to achieve the purpose of adjusting the heating power.

[0188] S509: Determine whether the power battery 32 is faulty. If yes, execute S510; if no, execute S511;

[0189] 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;

[0190] S511: Determine whether the cell 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;

[0191] S512: The battery control unit 33 requests the dual-motor controller 34 to stop the dual motors 35 from heating the power battery;

[0192] During the heating process of the power battery 32, since the power battery is continuously consumed by the motor drive and the reduced efficiency heating, when the capacity is lower than the set capacity, the heating operation needs to be stopped to meet the needs of the vehicle driving to the charging station for recharging; under normal circumstances, the SOC threshold X2% is set to 20%.

[0193] 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 interleaving control and the efficiency reduction control.

[0194] S513: Continue heating the power battery 32;

[0195] S514: The dual-motor controller 34 exits the power battery 32 heating mode and executes S506;

[0196] S515: End.

[0197] In this example, the dual-motor controller implements carrier phase interleaving control to generate ripple current on the bus side to directly heat the battery. The dual-motor controller implements reduced-efficiency control to generate heat in the motor windings to heat the coolant, indirectly heating the battery through a heat exchange system. This approach offers the following advantages:

[0198] Bidirectional heating from both the battery and motor sides significantly shortens the heating time of the power battery, effectively increasing the temperature rise rate of the power battery and achieving efficient heating. Existing electric drive hardware is reused, eliminating the need for additional heating devices to achieve on-the-go heating with a high level of system integration. Based on heating requirements, the appropriate carrier phase interleaving control angle and different low-efficiency torque-current maps can be selected to achieve dynamic adjustment of the heating rate and thus dynamic control.

[0199] An embodiment of the present invention provides a battery heating method, which determines the target angle of the carrier phase staggered control angle of at least two motors in response to a heating request, and can adjust the carrier frequency of one motor. By adjusting the carrier frequency of one motor, the ripple currents on the busbars of at least two motors are superimposed on each other, and the superimposed ripple current is used to directly heat the power battery. In this way, the power battery can be quickly heated up by direct heating without an additional heating device, thereby improving the heating efficiency of the power battery. By responding to the 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 the motor current is increased, the heat of the increased motor current can be used to heat the coolant in the heat exchange system, and then the power battery is heated by circulating the coolant. In this way, the electric drive hardware in the vehicle is reused, and the power battery can be heated by indirect heating, thereby improving the heating efficiency of the power battery.

[0200] Based on the same inventive concept as the above embodiments, an embodiment of the present invention provides a battery heating device, which is provided in a motor controller of a vehicle and is used to control at least two motors. Figure 6 A schematic structural diagram of an optional battery heating device provided in an embodiment of the present invention is shown in FIG. Figure 6 As shown, the battery heating device 600 may include:

[0201] a determination module 61 for determining 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 include at least one of the following: a carrier phase interleaving control angle, and a mapping relationship between torque and current;

[0202] a first heating module 62 for adjusting the carrier frequency of one of the at least two motors according to a target angle of the carrier phase staggered control angle so that ripple currents on the busbars of the at least two motors are superimposed on each other to heat the power battery of the vehicle;

[0203] a second heating module 63 for increasing the current corresponding to the torque request value according to a target mapping relationship of the torque and current, so as to heat the coolant of the vehicle heat exchange system, thereby heating the power battery through the coolant;

[0204] The target value includes: target angle and target mapping relationship.

[0205] In an optional embodiment, the determination module 61 is used to: respond 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 parameters in the heating request or the status parameters 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.

[0206] In an optional embodiment, the heating intensity indicated by the heating gear parameter is negatively correlated with the target angle; the state parameters include at least: battery cell temperature, SOC; the size of the battery cell temperature is positively correlated with the size of the target angle; the size of the SOC is negatively correlated with the size of the target angle.

[0207] In an optional embodiment, the determination module 61 is used to: respond to a heating request from a battery control unit of the vehicle, determine a target mapping relationship from a set of preset torque and current mapping relationships based on the heating gear parameters in the heating request or the state parameters of the power battery.

[0208] 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 parameters include at least: battery cell temperature, SOC; the magnitude of the battery 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.

[0209] In an optional embodiment, the device is also used to: determine the upper limit and lower limit values ​​of the motor current under different torques based on the intersection of the equal torque curve under different torques, the MTPA curve of the motor and the preset current limit circle of the motor; determine the preset torque and current mapping relationship set based on the upper limit and lower limit values ​​of the motor current under different torques.

[0210] In an optional embodiment, the first heating module 62 is used to: perform PI control on the difference between the target angle of the carrier phase staggered control angle and the carrier frequency of at least two motors to obtain the carrier frequency of one of the at least two motors; and control one of the at least two motors according to the carrier frequency 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.

[0211] In an optional embodiment, the determination module 61 is used to: obtain the carrier frequency of at least two motors and the operating mode of at least two motors in response to a heating request from a battery control unit of the vehicle; and determine the target angle of the carrier phase interleaving control angle in the control parameters of the at least two motors when the operating modes of the at least two motors are the same, the difference in the carrier frequencies of the at least two motors is within a preset frequency difference range, and the random PWM enable of the at least two motors is in a disabled state.

[0212] In an optional embodiment, the device is also used to: respond to a heating request from a battery control unit of the vehicle, determine the maximum torque of the motor based on the maximum available driving power of the motor in the heating request; send the maximum torque of the motor to the vehicle controller of the vehicle, 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.

[0213] In an optional embodiment, the device is also used 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 a heating permission 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.

[0214] 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), a microprocessor (MPU), a digital signal processor (DSP) or a field programmable gate array (FPGA).

[0215] An embodiment of the present invention further provides a motor controller, Figure 7 A schematic diagram of the structure of an optional motor controller provided by an embodiment of the present invention is shown in FIG. Figure 7 As shown, an embodiment of the present invention provides a motor controller 700, including:

[0216] A processor 71 and a storage medium 72 storing instructions executable by the processor 71 , wherein the storage medium 72 relies on the processor 71 to perform operations via a communication bus 73 , and when the instructions are executed by the processor 71 , the battery heating method described in one or more of the above embodiments is executed.

[0217] It should be noted that in actual application, the various components in the motor controller 700 are coupled together via the communication bus 73. It is understood that the communication bus 73 is used to achieve connection and communication between these components. In addition to the data bus, the communication bus 73 also includes a power bus, a control bus, and a status signal bus. However, for the sake of clarity, Figure 7 Various buses are labeled as communication buses 73.

[0218] The embodiment of the present invention further provides a battery heating system, Figure 8 A schematic structural diagram of an optional battery heating system provided in an embodiment of the present invention is shown in FIG. Figure 8 As shown, the battery heating system 800 may include: a 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.

[0219] An embodiment of the present invention further provides a vehicle, Figure 9 A schematic diagram of an optional vehicle structure provided by an embodiment of the present invention is shown in FIG. Figure 9 As shown, a vehicle 900 may include: a battery heating system 800 according to one or more embodiments described above.

[0220] 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.

[0221] 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 described in one or more embodiments are implemented.

[0222] Among them, the computer-readable storage medium can 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 storage device, an optical disc, or a compact disc read-only memory (CD-ROM).

[0223] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of hardware embodiments, software embodiments, or embodiments combining software and hardware. Furthermore, 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 magnetic disk storage and optical storage) containing computer-usable program code.

[0224] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0225] 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 work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0226] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0227] The above description is merely a preferred embodiment of the present invention and is 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, where the motor controller is used to control at least two motors, and includes: In response to a heating request from a battery control unit of the vehicle, target values ​​of control parameters of the at least two motors are determined; wherein the control parameters include at least one of the following: a carrier phase interleaving control angle, and a mapping relationship between torque and current; adjusting 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 ripple currents on busbars of the at least two motors are superimposed on each other to heat the power battery of the vehicle; increasing the current mapped by the torque request value according to the target mapping relationship of the torque and current, so as to heat the coolant of the vehicle heat exchange system, thereby heating the power battery through the coolant; Wherein, the target value includes: the target angle and the target mapping relationship.

2. The method according to claim 1, characterized in that The determining, 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 comprises: In response to a heating request from a battery control unit of the vehicle, determining a target angle of the carrier phase interleaving control angle from a preset carrier phase interleaving control angle range according to a heating gear parameter in the heating request or a state parameter of the power battery; The preset carrier phase staggered control angle range is greater than or equal to 0 degrees and less than 90 degrees.

3. The method according to claim 2, characterized in that The heating intensity indicated by the heating gear parameter is negatively correlated with the target angle; The state parameters include at least: battery cell temperature and SOC; The temperature of the battery cell is positively correlated with the target angle; The size of the SOC is negatively correlated with the size of the target angle.

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

5. The method according to claim 4, characterized in that The heating intensity indicated by the heating gear parameter is positively correlated with the current value in the target mapping relationship under the same torque; The state parameters include at least: battery cell temperature and SOC; The state parameter battery core temperature is negatively correlated with 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.

6. The method according to claim 4, characterized in that The method further comprises: Determining upper and lower limits of the current of the motor at different torques according to the intersection of the equal torque curve at different torques, the MTPA curve of the motor, and a preset current limit circle of the motor; The mapping relationship set between the preset torque and the current is determined according to the upper limit value and the lower limit value of the current of the motor under different torques.

7. The method according to any one of claims 1 to 6, characterized in that The method of 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 ripple currents on the busbars of the at least two motors are superimposed on each other to heat the power battery of the vehicle includes: Performing PI control on a difference between a target angle of the carrier phase interleaving control angle and the carrier frequencies of the at least two motors to obtain a carrier frequency of one of the at least two motors; According to the carrier frequency of one of the at least two motors, one of the at least two motors is controlled so that ripple currents on the busbars 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 The determining, in response to a heating request from a battery control unit of the vehicle, target values ​​of control parameters of the at least two motors comprises: acquiring, in response to a heating request from a battery control unit of the vehicle, carrier frequencies of the at least two motors and operating modes of the at least two motors; When the operating modes of the at least two motors are the same, the difference in carrier frequencies of the at least two motors is within a preset frequency difference range, and the random PWM enable of the at least two motors is in a disabled state, the target angle of the carrier phase interleaving control angle in the control parameters of the at least two motors is determined.

9. The method according to any one of claims 1 to 6, characterized in that The method further comprises: In response to a heating request from a battery control unit of the vehicle, determining a maximum torque of the motor according to a maximum available driving power of the motor in the heating request; The maximum torque of the motor is sent to a vehicle controller of the vehicle, so that a 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 comprises: 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, a heating permission signal is sent 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 provided in a motor controller of a vehicle and is used to control at least two motors, including: a determination module, configured to determine target values ​​of control parameters of the at least two motors in response to a heating request from a battery control unit of the vehicle; wherein the control parameters include at least one of the following: a carrier phase interleaving control angle, and a mapping relationship between torque and current; a first heating module, configured to adjust a carrier frequency of one of the at least two motors according to a target angle of the carrier phase staggered control angle, so that ripple currents on busbars of the at least two motors are superimposed on each other to heat a power battery of the vehicle; a second heating module, configured to increase a current corresponding to a torque request value according to a target mapping relationship of the torque and current mapping relationship, so as to heat a coolant of the vehicle heat exchange system, thereby heating 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: include: 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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