Motor control method and device, electronic equipment and readable medium

Abstract

This application provides a motor control method, apparatus, electronic device, and readable medium. The method includes: acquiring the initial voltage and target heat generation of a vehicle's drive motor and determining the operating torque of the drive motor, wherein the initial voltage is lower than or equal to the voltage of the vehicle's power battery; if the target heat generation is higher than a heat generation threshold, determining the step-up voltage of the drive motor based on the drive motor's operating torque, the vehicle speed, and a step-up voltage relationship table, wherein the step-up voltage is higher than the power battery voltage, and the step-up voltage relationship table contains the correspondence between vehicle speed, motor torque, and step-up voltage; determining the target operating voltage based on the drive motor's step-up voltage and the target heat generation; and outputting the target operating voltage to the drive motor. This method can ensure the operating temperature of the power battery and improve the user experience of the vehicle.

Description

Technical Field

[0001] This application relates to the field of new energy vehicles, and in particular to a motor control method, device, electronic device, and readable medium. Background Technology

[0002] The performance degradation of batteries in new energy vehicles at low temperatures has always been a challenge in the field. Therefore, maintaining the temperature of power batteries in new energy vehicles at low temperatures has become a crucial problem to be solved.

[0003] In related technologies, the thermal management water circuit is connected in series with the water circuit of the drive motor, and the heat energy generated by the drive motor during parking and driving is recovered through the thermal management integrated module, thereby heating the power battery or passenger compartment.

[0004] However, in such solutions, the drive motor has limited heat generation capacity. In low-temperature environments, it may generate insufficient heat, resulting in reduced heating effect. Consequently, the battery may not be heated to the predetermined temperature, leading to performance degradation and affecting the user experience of the vehicle. Summary of the Invention

[0005] In view of the above-mentioned technical problems, this application provides a motor control method, device, electronic device and readable medium to ensure the operating temperature of the power battery and improve the user experience of the vehicle.

[0006] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0007] According to one aspect of the embodiments of this application, a motor control method is provided, comprising:

[0008] The initial voltage and target heat generation of the vehicle's drive motor are obtained, and the operating torque of the drive motor is determined, wherein the initial voltage is lower than or equal to the voltage of the vehicle's power battery.

[0009] If the target heat generation is higher than the heat generation threshold, the boost voltage of the drive motor is determined according to the working torque of the drive motor, the vehicle speed, and the boost voltage relationship table. The boost voltage is higher than the voltage of the power battery. The boost voltage relationship table contains the correspondence between vehicle speed, motor torque, and boost voltage.

[0010] The target operating voltage is determined based on the step-up voltage of the drive motor and the target heat generation;

[0011] The target operating voltage is output to the drive motor.

[0012] According to one aspect of the embodiments of this application, a motor control device is provided, comprising:

[0013] The data acquisition module is configured to acquire the initial voltage and target heat generation of the vehicle's drive motor and determine the operating torque of the drive motor, wherein the initial voltage is lower than or equal to the voltage of the vehicle's power battery.

[0014] The boost module is configured to determine the boost voltage of the drive motor based on the operating torque of the drive motor, the vehicle speed, and a boost voltage relationship table if the target heat generation is higher than the heat generation threshold. The boost voltage is higher than the voltage of the power battery. The boost voltage relationship table contains the correspondence between vehicle speed, motor torque, and boost voltage.

[0015] The voltage determination module is configured to determine the target operating voltage based on the step-up voltage of the drive motor and the target heat generation;

[0016] A voltage output module is configured to output the target operating voltage to the drive motor.

[0017] In some embodiments of this application, based on the above technical solutions, the voltage determination module is specifically configured to: determine the quadrature-axis current and direct-axis current under the step-up voltage according to the step-up voltage and the motor speed of the drive motor; determine the target operating voltage according to the current-torque curve and the mapping relationship between the quadrature-axis current and the direct-axis current under the step-up voltage, wherein the current-torque curve is used to indicate the mapping relationship between the quadrature-axis current and the direct-axis current of the drive motor at the operating torque.

[0018] In some embodiments of this application, based on the above technical solutions, the data acquisition module is specifically configured to: acquire the current vehicle speed and accelerator pedal opening of the vehicle; acquire the wheel-end torque requirement corresponding to the current vehicle speed and the accelerator pedal opening according to the pedal characteristic mapping, wherein the pedal characteristic mapping is used to represent the mapping relationship between the wheel-end torque requirement and the accelerator pedal opening; and determine the operating torque of the drive motor according to the wheel-end torque requirement and the transmission efficiency of the vehicle.

[0019] In some embodiments of this application, based on the above technical solutions, the voltage determination module is specifically configured to: determine the current-torque curve of the drive motor according to the operating torque of the drive motor, wherein the current-torque curve is used to indicate the mapping relationship between the quadrature-axis current and the direct-axis current of the drive motor at the operating torque; determine the voltage limit curve of the vehicle according to the step-up voltage and the motor speed of the drive motor, wherein the voltage limit curve is used to represent the mapping relationship between the quadrature-axis current and the direct-axis current under the step-up voltage; and determine the target operating voltage according to the voltage limit curve and the current-torque curve of the drive motor.

[0020] In some embodiments of this application, based on the above technical solutions, the voltage limit curve is an elliptical curve, and the voltage determination module is specifically configured to: determine the current limit curve of the vehicle according to the maximum allowable current of the drive motor, wherein the current limit curve is a circular curve and is used to represent the mapping relationship between the quadrature axis current and the direct axis current of the drive motor at the maximum allowable current; if the voltage limit curve and the current limit curve intersect, then the target operating voltage is determined according to the current limit curve and the current-torque curve of the drive motor.

[0021] In some embodiments of this application, based on the above technical solutions, the voltage determination module is further configured to: if the current limit curve contains the voltage limit curve, then in the current coordinate system of the quadrature axis current and direct axis current of the drive motor, determine the target operating current of the drive motor according to the intersection point of the voltage limit curve and the current torque curve in the current coordinate system; and determine the voltage corresponding to the target operating current as the target operating voltage.

[0022] In some embodiments of this application, based on the above technical solutions, the voltage determination module is specifically configured to: determine the target operating current of the drive motor in the current coordinate system of the quadrature-axis current and direct-axis current of the drive motor, according to the intersection point of the current limit curve and the current torque curve in the current coordinate system; and determine the voltage corresponding to the target operating current as the target operating voltage.

[0023] According to one aspect of the embodiments of this application, an electronic device is provided, the electronic device comprising: a processor; and a memory for storing executable instructions of the processor; wherein the processor is configured to perform a motor control method as described above by executing the executable instructions.

[0024] According to one aspect of the embodiments of this application, a computer-readable storage medium is provided, on which a computer program is stored, which, when executed by a processor, implements the motor control method as described above.

[0025] In the embodiments of this application, by stepping up the voltage of the drive motor, the operating voltage of the drive motor is increased, thereby widening the range of heat generation of the drive motor and improving the heat generation capacity of the drive motor. This avoids insufficient heat generation in low-temperature environments, which would reduce the heating effect and help ensure the operating temperature of the power battery and improve the user experience of the vehicle.

[0026] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0028] In the attached diagram:

[0029] Figure 1 This is a system architecture for a motor control scheme applied to a drive motor system according to an embodiment of this application.

[0030] Figure 2 The diagram shows a schematic of the energy flow relationships in this architecture.

[0031] Figure 3 A flowchart of a motor control method according to an embodiment of this application is shown.

[0032] Figure 4 This is a schematic diagram of the current curve before voltage boost in an embodiment of this application.

[0033] Figure 5 This is a schematic diagram of the current curve after voltage boosting in an embodiment of this application.

[0034] Figure 6 A schematic block diagram of the motor control device in an embodiment of this application is shown.

[0035] Figure 7 A schematic diagram of the structure of a computer system suitable for implementing the electronic device of the present application is shown. Detailed Implementation

[0036] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0037] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0038] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0039] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0040] It should be understood that the solution proposed in this application can be applied to the field of thermal management for new energy vehicles, and specifically to the development of electric drive self-heating control strategies. Electric drive self-heating refers to a function aimed at controlling the drive motor to generate more heat during parking and driving, used to increase the heat generation of the electric drive at low temperatures, and connecting the thermal management water circuit and the electric drive water circuit in series, recovering the heat energy generated by the drive motor through the thermal management integrated module, which can be used to heat the battery pack or passenger compartment.

[0041] The performance degradation of batteries in new energy vehicles at low temperatures has always been a challenge in the field. Therefore, maintaining the temperature of the power batteries in low-temperature environments is a crucial problem to be solved. One related technology connects the thermal management water circuit in series with the drive motor's water circuit, using an integrated thermal management module to recover heat generated by the drive motor during parking and driving, thereby heating the power battery or passenger compartment. However, in this approach, the drive motor's heating capacity is limited, and insufficient heat generation may occur at low temperatures, resulting in reduced heating effectiveness. This can prevent the battery from reaching the predetermined temperature, leading to performance degradation and impacting the vehicle's user experience.

[0042] Based on this, the technical solution of this application proposes a motor control scheme. In this scheme, when the vehicle needs to heat the battery in a low-temperature environment, the boost converter circuit is controlled to output a corresponding voltage. By increasing the boost converter control, the operating voltage of the motor is increased, allowing the vehicle to select a larger operating current as needed. This further reduces motor efficiency to improve the motor's heating capacity, thereby broadening the power range of electric drive heating. Overall, this application first determines the wheel-end torque requirement based on the current vehicle speed and accelerator pedal opening by looking up a table. Then, it determines whether there is a heating requirement. If there is no heating requirement, the dual-motor high-efficiency drive mode or sport mode is selected based on the driver's operation; otherwise, the electric drive heating mode is selected. Based on the heat generated, the current motor operating point is selected, and the boost converter circuit is controlled to output a corresponding voltage. Please refer to [link to relevant documentation]. Figure 1The system architecture of the motor control scheme applied to the drive motor system according to the embodiments of this application can generally include two drive motors, a corresponding motor controller (Inv), a transformer, and a power battery (Battery). The two drive motors, powered by the power battery, drive their respective tires to propel the vehicle. Figure 2 The diagram illustrates the energy flow relationships within this architecture. (For example...) Figure 2 As shown, the battery supplies power to two motor controllers (Inv) through a boost converter circuit. The motor controllers then drive their respective drive motors, which in turn drive the wheels through a transmission device.

[0043] The implementation details of the technical solutions in the embodiments of this application are described below: Please refer to Figure 3 , Figure 3 A flowchart of a motor control method according to an embodiment of this application is shown. This motor control method can be executed by an automotive control system, such as a computer, in-vehicle terminal, or controller within the automotive control system. (Refer to...) Figure 1 As shown, the motor control method includes at least steps S310 to S360, which are described in detail below:

[0044] Step S310: Obtain the initial voltage and target heat generation of the vehicle's drive motor and determine the operating torque of the drive motor, wherein the initial voltage is lower than or equal to the voltage of the vehicle's power battery.

[0045] In this embodiment, the vehicle is in an activated state, which can be either parked or in motion. The initial voltage of the drive motor is the current voltage of the drive motor at the time the scheme is executed. The target heat output is the heat output that the drive motor is required to achieve, as determined by the vehicle's control system. This target heat output can be determined based on the current ambient temperature and the required heat output. For example, the required heat output can be determined as the target heat output based on data such as the current ambient temperature, the target temperature to be achieved, thermal conductivity, and heating rate. The operating torque of the drive motor refers to the torque required by the drive motor in the current or target operating state, which is affected by factors such as vehicle speed and transmission efficiency. In this application, during the process of controlling the motor heat output, this operating torque is generally considered to be constant or approximately constant. The initial voltage of the drive motor is lower than or equal to the voltage of the vehicle's power battery. The voltage of the power battery is the maximum voltage that the power battery itself can output.

[0046] In some optional embodiments of this application, during the process of determining the operating torque of the drive motor, the vehicle acquires the wheel-end torque requirement and then determines the operating torque of the drive motor based on the wheel-end torque requirement and the vehicle's transmission efficiency. Specifically, during the process of acquiring the wheel-end torque requirement, the vehicle first acquires the vehicle's current speed and accelerator pedal opening, and then acquires the wheel-end torque requirement corresponding to the current speed and the accelerator pedal opening based on a pedal characteristic mapping. The pedal characteristic mapping is used to represent the mapping relationship between the torque of the drive motor and the accelerator pedal opening.

[0047] Step S320: If the target heat generation is higher than the heat generation threshold, the boost voltage of the drive motor is determined according to the working torque of the drive motor, the vehicle speed, and the boost voltage relationship table. The boost voltage is higher than the voltage of the power battery. The boost voltage relationship table contains the correspondence between vehicle speed, motor torque, and boost voltage.

[0048] Specifically, the heat generation threshold is based on the heat generated by the drive motor at its maximum current when the power battery outputs its maximum voltage to the drive motor. If the target heat generation exceeds the heat generation threshold, it means that even the maximum output capacity of the power battery cannot meet the current vehicle's heat generation requirements. In this case, the vehicle needs to further boost the voltage of the drive motor to allow it to operate at a higher current. The boosted voltage becomes the step-up voltage, which is higher than the voltage of the power battery. The step-up voltage relationship table contains the correspondence between vehicle speed, motor torque, and step-up voltage. This table is usually pre-determined and installed in the vehicle. When needed, the vehicle can directly access the table and look up the corresponding step-up voltage based on the vehicle speed and operating torque.

[0049] Step S330: Determine the target operating voltage based on the step-up voltage of the drive motor and the target heat generation.

[0050] Specifically, based on the step-up voltage and the target heat output, the operating voltage required for the motor to reach the target heat output can be determined. This operating voltage is typically less than or equal to the step-up voltage and is usually also constrained by the maximum operating current of the drive motor. Based on this constraint information, the vehicle can determine the voltage required for actual operation. This determination process can be performed using pre-configured function calculations or directly determined through pre-stored correspondences on the vehicle.

[0051] In some embodiments, during the process of determining the target operating voltage based on the step-up voltage of the drive motor and the target heat generation, the vehicle can determine the quadrature-axis current and direct-axis current under the step-up voltage based on the step-up voltage and the motor speed of the drive motor. Then, based on the current-torque curve and the mapping relationship between the quadrature-axis current and direct-axis current under the step-up voltage, the target operating voltage is determined. The current-torque curve is used to indicate the mapping relationship between the quadrature-axis current and direct-axis current of the drive motor at the operating torque. In this embodiment, the operating torque is considered constant; therefore, the current-torque curve is a constant torque curve, and its curve data is mainly related to data such as the inductance parameters of the motor itself.

[0052] In some embodiments, during the process of determining the target operating voltage based on the step-up voltage of the drive motor and the target heat generation, the vehicle determines the current-torque curve of the drive motor based on the operating torque of the drive motor. The current-torque curve is used to indicate the mapping relationship between the quadrature-axis current and the direct-axis current of the drive motor at the operating torque. Then, based on the step-up voltage and the motor speed of the drive motor, the vehicle determines the voltage limit curve. The voltage limit curve is used to represent the mapping relationship between the quadrature-axis current and the direct-axis current under the step-up voltage. Finally, based on the voltage limit curve and the current-torque curve of the drive motor, the target operating voltage is determined.

[0053] The voltage limit curve represents the mapping relationship between the quadrature-axis current and the direct-axis current under a step-up voltage. For this curve, with a constant step-up voltage, the higher the motor speed, the smaller the selectable range of the quadrature-axis and direct-axis currents. Taking an elliptical voltage limit curve as an example, when the step-up voltage is constant, the higher the motor speed, the smaller the area of ​​the ellipse. The motor speed of a vehicle is usually determined based on parameters such as the vehicle's speed and tire radius.

[0054] The portion where the voltage limit curve intersects the current-torque curve can be considered as the selectable range of the drive motor's operating current. Within this range, the operating voltage can be correspondingly determined for each determined current operating point. The magnitude of the operating current determines the heat generated by the drive motor; therefore, based on the target heat generation, the corresponding current operating point can be determined within the intersection of the voltage limit curve and the current-torque curve, and then the corresponding target operating voltage can be determined based on the current operating point.

[0055] In an optional embodiment of this application, the voltage limit curve is an elliptic curve. The above step of determining the target operating voltage based on the voltage limit curve and the current-torque curve of the drive motor includes:

[0056] Based on the maximum allowable current of the drive motor, the current limit curve of the vehicle is determined, wherein the current limit curve is a circular curve and is used to represent the mapping relationship between the quadrature axis current and the direct axis current of the drive motor at the maximum allowable current.

[0057] If the voltage limit curve and the current limit curve intersect, the target operating voltage is determined based on the current limit curve and the current-torque curve of the drive motor.

[0058] The current limiting curve is a circular curve representing the mapping between the quadrature-axis and direct-axis currents of the drive motor at the maximum permissible current. When mapping the voltage and current limiting curves onto a coordinate system based on the quadrature-axis and direct-axis currents, two relationships typically exist: intersection and inclusion. Generally, without voltage boosting, the current limiting curve includes the voltage limiting curve; therefore, the selection of the operating current is primarily constrained by the voltage limiting curve, meaning it can only be selected within the voltage limiting ellipse. However, after voltage boosting, the area of ​​the voltage limiting ellipse increases with voltage, leading to intersection with the current limiting curve. In this case, the maximum current value of the voltage limiting curve exceeds the maximum permissible current of the drive motor, and the operating current becomes constrained by the current limiting curve. Therefore, the vehicle determines the target operating voltage based on the current limiting curve and the drive motor's current-torque curve. The determination method is similar to the process of determining the target operating voltage based on the voltage limiting curve and the current-torque curve.

[0059] In some optional embodiments of this application, if the current limit curve contains the voltage limit curve, it indicates that although the drive motor has been boosted and the voltage after boosting has a greater constraint on the current selection range than the maximum output voltage of the power battery, it is still less than the maximum allowable current constraint range. Therefore, in the current coordinate system of the quadrature-axis current and direct-axis current of the drive motor, the vehicle still determines the target operating current of the drive motor based on the intersection of the voltage limit curve and the current-torque curve in the current coordinate system, and determines the voltage corresponding to the target operating current as the target operating voltage. However, it should be noted that the current value range of the voltage limit curve after boosting is greater than the current value range of the voltage limit curve of the maximum output voltage of the power battery. The area of ​​the voltage limit ellipse after boosting will be greater than the area of ​​the voltage limit ellipse of the maximum output voltage of the power battery. For the current value in the area exceeding this range, the heat generation of the drive motor can be further increased compared to the heat generation of the maximum output voltage of the power battery, thereby obtaining higher heat generation and heating effect.

[0060] In some optional embodiments, during the process of determining the target operating voltage based on the current limiting curve and the current-torque curve of the drive motor, the vehicle determines the target operating current of the drive motor in a current coordinate system of the quadrature-axis current and direct-axis current, based on the intersection of the current limiting curve and the current-torque curve in the current coordinate system. The voltage corresponding to the target operating current is then determined as the target operating voltage. Specifically, the intersection of the current limiting curve and the current-torque curve in the current coordinate system is typically the maximum current selectable under the current torque, thus obtaining the maximum current achievable under the current operating torque.

[0061] Step S340: Output the target operating voltage to the drive motor.

[0062] The output terminal of the power battery is connected to a step-up transformer, such as a transformer. The vehicle controls this transformer to increase the voltage output from the power point to the target operating voltage before outputting it to the drive motor, thereby enabling the drive motor to draw the current required to generate the target heat.

[0063] In the embodiments of this application, by stepping up the voltage of the drive motor, the operating voltage of the drive motor is increased, thereby widening the range of heat generation of the drive motor and improving the heat generation capacity of the drive motor. This avoids insufficient heat generation in low-temperature environments, which would reduce the heating effect and help ensure the operating temperature of the power battery and improve the user experience of the vehicle.

[0064] In the embodiments of this application, by stepping up the voltage of the drive motor, the operating voltage of the drive motor is increased, thereby widening the range of heat generation of the drive motor and improving the heat generation capacity of the drive motor. This avoids insufficient heat generation in low-temperature environments, which would reduce the heating effect and help ensure the operating temperature of the power battery and improve the user experience of the vehicle.

[0065] The solution of this application will be described below with reference to specific embodiments. In the solution of this application, the vehicle determines the working voltage through the following steps: Step 1: Based on the accelerator pedal opening and the actual vehicle speed, the required torque at the driver's wheel end is obtained by querying a pre-stored table; Step 2: Based on the current temperature, the heat generated by the current motor required for thermal management is determined; Step 3: Based on the heat generated, it is selected whether to increase the voltage and the working current point of the motor after the voltage increase is calculated; Step 4: Based on the calculation results, the current working point is selected, and the transformer outputs the corresponding voltage.

[0066] Specifically, during operation, the motor controller controls the electrical power input, converting electrical energy into mechanical energy to drive the transmission system. During this process, the motor generates heat, and the copper loss varies quadratically with the stator current. The ohmic loss formula is given by the following equation: W c =mI 2 Rc Where m is the number of phases of the permanent magnet synchronous motor; I is the effective value of the coil current, in A; R c This represents the resistance value of each phase winding, in Ω. The vehicle will then determine if there is a heating requirement. If not, it will select either the dual-motor high-efficiency drive mode or the sport mode based on the driver's needs; otherwise, it will select the electric drive heating mode. In the electric drive heating mode, the first step is for the vehicle to obtain the required wheel-end torque as T. DrvReq The vehicle speed is V Spd The tire radius is r. Assume the vehicle's transmission efficiency is η. Trans The transmission ratio is i Motor Then the total torque required by the motor Torque required for a single motor motor speed The constant torque curve T of the motor Motor =P×[ψ f ×I q +(L d -L q )×I q ×I d ], where I d I q These are the d-axis and q-axis currents, respectively, I max This is the maximum allowable current for the electronic control system. L d L q Inductance along the d-axis and q-axis, respectively, ψ f Let P be the permanent magnet flux linkage and P be the number of pole pairs in the permanent magnet synchronous motor. The constant torque curve of the motor is shown below. Figure 4 As shown, in high-efficiency mode, the current at the high-efficiency point is selected. To be the smallest, that is Figure 4 The high-efficiency point in the process. Second step: When there is a heating requirement at low temperatures, the intersection region of the voltage limit ellipse and the current limit circle is denoted as the current selectable region. Assuming the motor is a built-in permanent magnet synchronous motor and the battery pack voltage is U... dc Before the voltage is boosted, the current and voltage constraint equations are:

[0067] Current limiting circle:

[0068] Voltage limit ellipse:

[0069] Before boosting the voltage, at a certain speed, the maximum selectable current is: Figure 4 The optional inefficiency points. According to Figure 4 It is evident that the current is constrained by the voltage limit ellipse.

[0070] Step 3: When heat generation is insufficient, increase the area of ​​the voltage limit ellipse by boosting the voltage. Assume the battery pack voltage after boosting is U. dc_upThe voltage limit ellipse after boosting is as follows:

[0071] Voltage limit ellipse (after boost):

[0072] This method can increase the effective operating current of the motor and increase heat generation. The maximum selectable current is... Figure 5 The optional inefficient point shows that after voltage boosting, the current is not constrained by the voltage limit ellipse, but by the current limit circle. The maximum current is greater than before voltage boosting, so the heat generated by the motor will increase.

[0073] Finally, in practical applications, the boost point can be calibrated based on specific vehicle speed, torque, and heat generation to improve the speed of heating response. For example, the calibration table can be as follows:

[0074] 1000-3000 3000-5000 5000-7000 7000-9000 9000-11000 10-30 <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> 30-50 <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> 50-70 <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> 70-90 <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> 90-110 <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> 110-130 <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> 130-150 <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]> <![CDATA[U dc_up ]]>

[0075] It should be noted that although the steps of the method in this application are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps may be omitted, multiple steps may be combined into one step, and / or a step may be broken down into multiple steps.

[0076] The following describes the implementation of the apparatus of this application, which can be used to execute the motor control method in the above embodiments of this application. Figure 6 A schematic block diagram illustrating the composition of the motor control device in an embodiment of this application is shown. For example... Figure 6 As shown, the motor control device 600 mainly includes:

[0077] The data acquisition module 610 is configured to acquire the initial voltage and target heat generation of the vehicle's drive motor and determine the operating torque of the drive motor, wherein the initial voltage is lower than or equal to the voltage of the vehicle's power battery.

[0078] The boost module 620 is configured to determine the boost voltage of the drive motor based on the working torque of the drive motor, the vehicle speed, and a boost voltage relationship table if the target heat generation is higher than the heat generation threshold. The boost voltage is higher than the voltage of the power battery. The boost voltage relationship table contains the correspondence between vehicle speed, motor torque, and boost voltage.

[0079] The voltage determination module 630 is configured to determine the target operating voltage based on the step-up voltage of the drive motor and the target heat generation;

[0080] The voltage output module 640 is configured to output the target operating voltage to the drive motor.

[0081] In some embodiments of this application, based on the above technical solutions, the voltage determination module 630 is specifically configured to: determine the quadrature-axis current and direct-axis current under the step-up voltage according to the step-up voltage and the motor speed of the drive motor; determine the target operating voltage according to the current-torque curve and the mapping relationship between the quadrature-axis current and the direct-axis current under the step-up voltage, wherein the current-torque curve is used to indicate the mapping relationship between the quadrature-axis current and the direct-axis current of the drive motor at the operating torque.

[0082] In some embodiments of this application, based on the above technical solutions, the data acquisition module 610 is specifically configured to: acquire the current vehicle speed and accelerator pedal opening of the vehicle; acquire the wheel end demand torque corresponding to the current vehicle speed and the accelerator pedal opening according to the pedal characteristic mapping, wherein the pedal characteristic mapping is used to represent the mapping relationship between the wheel end demand torque and the accelerator pedal opening; and determine the working torque of the drive motor according to the wheel end demand torque and the transmission efficiency of the vehicle.

[0083] In some embodiments of this application, based on the above technical solutions, the voltage determination module 630 is specifically configured to: determine the current-torque curve of the drive motor according to the operating torque of the drive motor, wherein the current-torque curve is used to indicate the mapping relationship between the quadrature-axis current and the direct-axis current of the drive motor at the operating torque; determine the voltage limit curve of the vehicle according to the step-up voltage and the motor speed of the drive motor, wherein the voltage limit curve is used to represent the mapping relationship between the quadrature-axis current and the direct-axis current under the step-up voltage; and determine the target operating voltage according to the voltage limit curve and the current-torque curve of the drive motor.

[0084] In some embodiments of this application, based on the above technical solutions, the voltage limit curve is an elliptical curve, and the voltage determination module 630 is specifically configured to: determine the current limit curve of the vehicle according to the maximum allowable current of the drive motor, wherein the current limit curve is a circular curve and is used to represent the mapping relationship between the quadrature axis current and the direct axis current of the drive motor at the maximum allowable current; if the voltage limit curve and the current limit curve intersect, then the target operating voltage is determined according to the current limit curve and the current-torque curve of the drive motor.

[0085] In some embodiments of this application, based on the above technical solutions, the voltage determination module 630 is further configured to: if the current limit curve contains the voltage limit curve, then in the current coordinate system of the quadrature axis current and direct axis current of the drive motor, determine the target operating current of the drive motor according to the intersection point of the voltage limit curve and the current torque curve in the current coordinate system; and determine the voltage corresponding to the target operating current as the target operating voltage.

[0086] In some embodiments of this application, based on the above technical solutions, the voltage determination module 630 is specifically configured to: determine the target operating current of the drive motor in the current coordinate system of the quadrature axis current and the direct axis current of the drive motor according to the intersection point of the current limit curve and the current torque curve in the current coordinate system; and determine the voltage corresponding to the target operating current as the target operating voltage.

[0087] It should be noted that the apparatus provided in the above embodiments and the method provided in the above embodiments belong to the same concept, and the specific way in which each module performs the operation has been described in detail in the method embodiments, and will not be repeated here.

[0088] Figure 7 A schematic diagram of the structure of a computer system suitable for implementing the electronic device of the present application is shown.

[0089] It should be noted that, Figure 7 The computer system 700 of the electronic device shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of this application.

[0090] like Figure 7 As shown, the computer system 700 includes a Central Processing Unit (CPU) 701, which can perform various appropriate actions and processes based on programs stored in Read-Only Memory (ROM) 702 or programs loaded from storage section 708 into Random Access Memory (RAM) 703. The RAM 703 also stores various programs and data required for system operation. The CPU 701, ROM 702, and RAM 703 are interconnected via a bus 704. An Input / Output (I / O) interface 705 is also connected to the bus 704.

[0091] The following components are connected to the I / O interface 705: an input section 706 including a keyboard, mouse, etc.; an output section 707 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and speakers, etc.; a storage section 708 including a hard disk, etc.; and a communication section 709 including a network interface card such as a LAN (Local Area Network) card, modem, etc. The communication section 709 performs communication processing via a network such as the Internet. A drive 710 is also connected to the I / O interface 705 as needed. A removable medium 711, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on the drive 710 as needed so that computer programs read from it can be installed into the storage section 708 as needed.

[0092] Specifically, according to embodiments of this application, the processes described in the various method flowcharts can be implemented as computer software programs. For example, embodiments of this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication section 709, and / or installed from removable medium 711. When the computer program is executed by central processing unit (CPU) 701, it performs various functions defined in the system of this application.

[0093] It should be noted that the computer-readable medium shown in the embodiments of this application can be a computer-readable signal medium or a computer-readable storage medium, or any combination of the two. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), flash memory, optical fiber, portable compact disc read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this application, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such transmitted data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. The computer-readable signal medium can also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to wireless, wired, etc., or any suitable combination thereof.

[0094] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0095] It should be noted that although several modules or units for the device used to perform actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to the embodiments of this application, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0096] Through the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, touch terminal, or network device, etc.) to execute the method according to the embodiments of this application.

[0097] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.

[0098] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A method of controlling an electric machine, characterized by, include: The initial voltage and target heat generation of the vehicle's drive motor are obtained, and the operating torque of the drive motor is determined. The initial voltage is lower than or equal to the voltage of the vehicle's power battery, and the target heat generation is the heat generation that the drive motor is to achieve. If the target heat generation is higher than the heat generation threshold, the boost voltage of the drive motor is determined according to the working torque of the drive motor, the vehicle speed, and the boost voltage relationship table. The boost voltage is higher than the voltage of the power battery. The boost voltage relationship table contains the correspondence between vehicle speed, motor torque, and boost voltage. The heat generation threshold is the heat generation that the drive motor can achieve at the maximum current when the power battery outputs the maximum voltage to the drive motor. The target operating voltage is determined based on the step-up voltage of the drive motor and the target heat generation; The target operating voltage is output to the drive motor.

2. The motor control method according to claim 1, characterized by, Determining the target operating voltage based on the step-up voltage of the drive motor and the target heat generation includes: Based on the step-up voltage and the motor speed of the drive motor, determine the quadrature-axis current and direct-axis current under the step-up voltage; The target operating voltage is determined based on the current-torque curve and the mapping relationship between the quadrature-axis current and the direct-axis current under the step-up voltage. The current-torque curve is used to indicate the mapping relationship between the quadrature-axis current and the direct-axis current of the drive motor at the operating torque.

3. The method of claim 1, wherein, Determining the operating torque of the drive motor includes: Obtain the current vehicle speed and accelerator pedal opening; Based on the pedal characteristic mapping, the wheel end torque required corresponding to the current vehicle speed and the accelerator pedal opening is obtained. The pedal characteristic mapping is used to represent the mapping relationship between the wheel end torque required and the accelerator pedal opening. The operating torque of the drive motor is determined based on the required torque at the wheel end and the transmission efficiency of the vehicle.

4. The method of claim 1, wherein, Determining the target operating voltage based on the step-up voltage of the drive motor and the target heat generation includes: Based on the operating torque of the drive motor, the current-torque curve of the drive motor is determined. The current-torque curve is used to indicate the mapping relationship between the quadrature axis current and the direct axis current of the drive motor at the operating torque. Based on the step-up voltage and the motor speed of the drive motor, the voltage limit curve of the vehicle is determined. The voltage limit curve is used to represent the mapping relationship between the quadrature axis current and the direct axis current under the step-up voltage. The target operating voltage is determined based on the voltage limit curve and the current-torque curve of the drive motor.

5. The method of claim 4, wherein, The voltage limit curve is an elliptic curve. Determining the target operating voltage based on the voltage limit curve and the current-torque curve of the drive motor includes: Based on the maximum allowable current of the drive motor, the current limit curve of the vehicle is determined, wherein the current limit curve is a circular curve and is used to represent the mapping relationship between the quadrature axis current and the direct axis current of the drive motor at the maximum allowable current. If the voltage limit curve and the current limit curve intersect, the target operating voltage is determined based on the current limit curve and the current-torque curve of the drive motor.

6. The method of claim 5, wherein, The method further includes: If the current limit curve contains the voltage limit curve, then in the current coordinate system of the quadrature axis current and direct axis current of the drive motor, the target operating current of the drive motor is determined according to the intersection point of the voltage limit curve and the current torque curve in the current coordinate system. The voltage corresponding to the target operating current is determined as the target operating voltage.

7. The method of claim 5, wherein, Determining the target operating voltage based on the current limit curve and the current-torque curve of the drive motor includes: In the current coordinate system of the quadrature axis current and direct axis current of the drive motor, the target operating current of the drive motor is determined according to the intersection of the current limit curve and the current torque curve in the current coordinate system. The voltage corresponding to the target operating current is determined as the target operating voltage.

8. A motor control device, characterized in that, include: The data acquisition module is configured to acquire the initial voltage and target heat generation of the vehicle's drive motor and determine the operating torque of the drive motor, wherein the initial voltage is lower than or equal to the voltage of the vehicle's power battery. The boost module is configured to determine the boost voltage of the drive motor based on the operating torque of the drive motor, the vehicle speed, and a boost voltage relationship table if the target heat generation is higher than the heat generation threshold. The boost voltage is higher than the voltage of the power battery. The boost voltage relationship table contains the correspondence between vehicle speed, motor torque, and boost voltage. The heat generation threshold is the heat generation that the drive motor can achieve at the maximum current when the power battery outputs the maximum voltage to the drive motor. The voltage determination module is configured to determine the target operating voltage based on the step-up voltage of the drive motor and the target heat generation; A voltage output module is configured to output the target operating voltage to the drive motor.

9. An electronic device, characterized in that, include: processor; Memory for storing the executable instructions of the processor; The processor is configured to execute the motor control method of any one of claims 1 to 7 by executing the executable instructions.

10. A computer-readable medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the motor control method as described in any one of claims 1 to 7.

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