Motor control method and device, vehicle, storage medium and program product

Abstract

The invention discloses a motor control method and device, a vehicle, a storage medium and a program product. The method comprises the steps that under the condition that a motor controller of the vehicle is in a pulse width modulation mode, the rotating speed of a motor in the vehicle is obtained; determining back electromotive force voltage of the motor according to the rotating speed of the motor; and under the condition that the back electromotive force voltage is smaller than the power supply voltage of the vehicle and the actual torque output by the motor is larger than a first threshold value and smaller than a second threshold value, the control mode of the motor is switched from a pulse width modulation mode to a free sliding mode, the first threshold value is smaller than 0, and the second threshold value is larger than 0. According to the embodiment of the invention, the energy consumption of the motor can be reduced.

Description

Technical Field

[0001] The present application belongs to the technical field of electric vehicles, and in particular, relates to a method, device, vehicle, storage medium and program product for controlling a motor. Background Art

[0002] In electric vehicles that use motors as driving sources, motor control systems usually use pulse width modulation (PWM) mode to drive the electric vehicles.

[0003] Pulse width modulation mode is a working mode that controls the motor output torque and speed by adjusting the pulse width of the current. In pulse width modulation mode, the torque and speed of the motor output can be flexibly modulated by controlling the current size and frequency to meet the vehicle's needs for various working conditions. However, pulse width modulation mode requires a larger current to control the motor output torque, so it consumes higher energy. Summary of the invention

[0004] The embodiments of the present application provide a motor control method, device, vehicle, storage medium and program product, which can solve the problem of high energy consumption in existing motor control methods.

[0005] In a first aspect, an embodiment of the present application provides a method for controlling a motor, the method comprising:

[0006] When a motor controller of the vehicle is in a pulse width modulation mode, obtaining a rotation speed of a motor in the vehicle;

[0007] Determining a back electromotive force voltage of the motor according to a rotation speed of the motor;

[0008] When the back electromotive force voltage is less than the power supply voltage of the vehicle and the actual torque output by the motor is greater than a first threshold and less than a second threshold, the control mode of the motor is switched from the pulse width modulation mode to the free sliding mode, the first threshold is less than 0, and the second threshold is greater than 0.

[0009] In some embodiments, switching the control mode of the motor from the pulse width modulation mode to the free sliding mode includes:

[0010] Switching the three-phase rectifier circuit in the vehicle from an on state to an off state, so as to switch the control mode of the motor from the pulse width modulation mode to the free sliding mode;

[0011] The three-phase rectifier circuit is used to convert the direct current output by the power supply into three-phase alternating current, and drive the motor to operate through the three-phase alternating current.

[0012] In some embodiments, after switching the control mode of the motor from the pulse width modulation mode to the free sliding mode, the method further includes:

[0013] The vehicle controller and the motor controller in the vehicle are switched from a torque control state to a standby state.

[0014] In some embodiments, after switching the control mode of the motor from the pulse width modulation mode to the free sliding mode, the method further includes:

[0015] obtaining a target torque of the vehicle;

[0016] When the target torque is less than or equal to a third threshold value, or greater than or equal to a fourth threshold value, switching the control mode of the motor from the free sliding mode to the pulse modulation mode;

[0017] The third threshold is greater than the first threshold and less than 0, and the fourth threshold is less than the second threshold and greater than 0.

[0018] In some embodiments, before switching the control mode of the motor from the free sliding mode to the pulse modulation mode, the method further includes:

[0019] The vehicle controller and the motor controller in the vehicle are switched from a standby state to a torque control state.

[0020] In some embodiments, after switching the vehicle controller and the motor controller in the vehicle from a standby state to a torque control state, the method further includes:

[0021] The motor is controlled to output the target torque.

[0022] In a second aspect, an embodiment of the present application provides a control device for a motor, the device comprising:

[0023] A first acquisition module, configured to acquire a rotation speed of a motor in the vehicle when a motor controller of the vehicle is in a pulse width modulation mode;

[0024] A first determination module, used to determine the back electromotive force voltage of the motor according to the rotation speed of the motor;

[0025] The first switching module is used to switch the control mode of the motor from the pulse width modulation mode to the free sliding mode when the back electromotive force voltage is less than the power supply voltage of the vehicle and the actual torque output by the motor is greater than a first threshold and less than a second threshold, and the first threshold is less than 0 and the second threshold is greater than 0.

[0026] In a third aspect, an embodiment of the present application provides a vehicle, wherein the device includes: a processor and a memory storing computer program instructions;

[0027] When the processor executes the computer program instructions, the above motor control method is implemented.

[0028] In a fourth aspect, an embodiment of the present application provides a computer storage medium having computer program instructions stored thereon, and the computer program instructions implement the above-mentioned motor control method when executed by a processor.

[0029] In a fifth aspect, an embodiment of the present application provides a computer program product, which includes computer program instructions, and when the computer program instructions are executed by a processor, the above-mentioned motor control method is implemented.

[0030] In the present application, by monitoring the speed of the vehicle motor and calculating the corresponding back electromotive force voltage, when the back electromotive force voltage is lower than the power supply voltage of the vehicle and the torque actually output by the motor is between the first threshold and the second threshold, the control mode of the motor is switched from the pulse width modulation mode to the free sliding mode. Through this switching mechanism, when the motor is not required to be actively driven, the pulse width of the motor is no longer adjusted, but it is allowed to slide freely, thereby significantly reducing the resistance loss caused by the current in the motor winding and the dynamic loss caused by the frequent switching of pulse width modulation, avoiding unnecessary energy consumption, and improving overall energy efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 is a flow chart of a method for controlling a motor provided in one embodiment of the present application;

[0033] Figure 2 is a schematic structural diagram of a motor control device provided in one embodiment of the present application;

[0034] Figure 3 It is a schematic diagram of the hardware structure of a vehicle provided in one embodiment of the present application. DETAILED DESCRIPTION

[0035] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0036] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0037] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The embodiments will be described in detail below in conjunction with the accompanying drawings.

[0038] Specifically, in order to solve the problems of the prior art, the embodiments of the present application provide a motor control method, device, vehicle, storage medium and program product. The motor control method provided by the embodiments of the present application is first introduced below.

[0039] Figure 1 A flow chart of a method for controlling a motor provided by an embodiment of the present application is shown. The method comprises the following steps:

[0040] S110 , when a motor controller of the vehicle is in a pulse width modulation mode, obtaining a rotation speed of a motor in the vehicle.

[0041] In this embodiment, the vehicle includes a power supply, a motor controller and a motor. The PWM mode (PulseWidth Modulation) is a working mode that controls the motor output by a pulse width modulation signal. Among them, in the PWM mode, the power supply provides direct current, which is the energy source of the entire system, and its output voltage is to the DC bus of the motor controller. The motor controller receives instructions from the vehicle controller, converts the direct current output of the battery into three-phase alternating current according to the driver's needs (such as acceleration and braking), and adjusts the current frequency and amplitude to control the speed and torque of the motor. The motor receives the three-phase alternating current output by the motor controller, generates torque, drives the wheels through the transmission system, and achieves acceleration, deceleration or coasting.

[0042] When the motor controller is in pulse width modulation mode, the motor speed can be obtained. For example, the motor speed can be obtained through the motor's rotor position sensor, which detects the angle change of the rotor in real time and calculates the speed through the motor controller. In addition, the speed can also be calculated by detecting the back electromotive force of the motor and combining the motor parameters.

[0043] S120, determining the back electromotive force voltage of the motor according to the rotation speed of the motor.

[0044] In this embodiment, the back electromotive force voltage is the voltage induced in the stator winding due to the rotor cutting the magnetic lines of force when the motor rotates, and the direction is opposite to the bus voltage.

[0045] After obtaining the speed of the motor in the vehicle, the back electromotive force voltage of the motor can be determined according to the speed of the motor. Specifically, a mapping relationship table can be pre-set, and the mapping relationship between the speed and the back electromotive force voltage is stored in the mapping relationship table. Then, after obtaining the speed of the motor, the back electromotive force voltage corresponding to the current speed can be directly determined by querying the mapping relationship table.

[0046] S130, when the back electromotive force voltage is less than the power supply voltage of the vehicle and the actual torque output by the motor is greater than a first threshold and less than a second threshold, the control mode of the motor is switched from the pulse width modulation mode to the free sliding mode, the first threshold is less than 0, and the second threshold is greater than 0.

[0047] In this embodiment, the freewheeling mode (FM) is a low-energy operation mode in which the motor stops actively driving. In the FM mode, the motor controller no longer actively drives the motor, and only relies on inertia or external force to maintain the rotation of the motor.

[0048] After the back electromotive force voltage is obtained by querying, the back electromotive force voltage can be compared with the power supply voltage of the vehicle. If the back electromotive force voltage is less than the power supply voltage of the vehicle, the actual torque currently output by the motor can be further compared with the first threshold value and the second threshold value set in advance. If the actual torque is greater than the first threshold value but less than the second threshold value, the motor controller can be switched from the pulse width modulation mode to the FM mode.

[0049] Specifically, if the back EMF voltage is greater than or equal to the vehicle's power supply voltage, the current will flow in the opposite direction, from the motor through the freewheeling diode into the power supply, forming a current backflow, which is equivalent to charging the bus capacitor. However, long-term charging may cause the bus capacitor voltage to be too high, which may cause damage. Therefore, if the back EMF voltage is greater than or equal to the vehicle's power supply voltage, switching to FM mode may be risky, so the motor controller can maintain operation in PWM mode.

[0050] If the back electromotive force voltage is less than the vehicle's power supply voltage, the current will not flow back to the power supply through the freewheeling diode, and the system remains safe. Therefore, the actual torque output by the motor can be further compared with the preset first threshold and second threshold.

[0051] If the actual torque is between the first threshold and the second threshold, it can be considered that the vehicle has entered a condition such as cruise control or low-speed gliding, and the motor does not need to output too much traction. Therefore, in order to reduce power consumption, the vehicle can be switched from pulse width modulation mode to free gliding mode.

[0052] If the actual torque is less than or equal to the first threshold, or greater than or equal to the second threshold, it is considered that the vehicle still requires greater traction force, and the pulse width modulation mode is maintained.

[0053] For example, the first threshold and the second threshold can be determined based on a pre-calibrated torque hysteresis control value and a tolerance value. The torque hysteresis control value is obtained through actual vehicle test experience, which can ensure that the motor runs stably when switched to FW mode without affecting the driving experience. The tolerance value is the error range allowed based on the torque hysteresis control value. For example, the torque hysteresis control value can be 2Nm, and the tolerance value can be 0.2Nm.

[0054] Then, the first threshold value can be set to (-2+0.2)Nm, that is, -1.8Nm, and the second threshold value can be set to (2-0.2)Nm, that is, 1.8Nm.

[0055] As an optional embodiment, the above S130 may include:

[0056] Switching the three-phase rectifier circuit in the vehicle from an on state to an off state, so as to switch the control mode of the motor from the pulse width modulation mode to the free sliding mode;

[0057] The three-phase rectifier circuit is used to convert the direct current output by the power supply into three-phase alternating current, and drive the motor to operate through the three-phase alternating current.

[0058] In this embodiment, the three-phase rectifier circuit is a circuit that converts the direct current from the power supply into the three-phase alternating current required by the motor. It is composed of power switching elements and generates alternating current with correct frequency and phase according to the control of the pulse width modulation signal to drive the motor.

[0059] In the vehicle of this embodiment, the three-phase rectifier circuit is connected to the power supply, motor controller and motor in the vehicle respectively. In PWM mode, the power supply outputs DC power, which is connected to the three-phase rectifier circuit through the DC bus of the motor controller; the motor controller is responsible for generating PWM signals and dynamically adjusting the working state of the three-phase rectifier circuit; the three-phase rectifier circuit converts DC power into AC power and directly outputs it to the three-phase winding of the motor, driving the motor to generate torque and speed.

[0060] In PWM mode, the three-phase rectifier circuit is in the on state, converting DC power into three-phase AC power and outputting it to the motor to drive the motor to operate normally. After the vehicle switches from PWM mode to FM mode, the motor will not draw current from the power supply and is in a free-gliding state.

[0061] In this state, since the power switching elements are no longer frequently turned on and off, the switching loss and conduction loss are greatly reduced, thereby reducing the loss of the system.

[0062] In the above manner, by switching the three-phase rectifier circuit from the on state to the off state, the motor controller switches from the pulse width modulation mode to the free sliding mode, which can stop the active drive of the motor, effectively reduce the power loss of the system, and extend the vehicle's cruising range.

[0063] As an optional embodiment, after switching the control mode of the motor from the pulse width modulation mode to the free sliding mode, the method further includes:

[0064] The vehicle controller and the motor controller in the vehicle are switched from a torque control state to a standby state.

[0065] In this embodiment, the vehicle controller is the core control unit of the vehicle, responsible for coordinating and managing various subsystems of the vehicle.

[0066] When the motor controller is in pulse width modulation mode, both the vehicle controller and the motor controller are in torque control (Torque) state; in the torque control state, the vehicle controller can calculate the target torque value according to the driver's operating requirements and the current vehicle state, and send the target torque value to the motor controller. The motor controller is the power execution unit, which is responsible for receiving the target torque value issued by the vehicle controller and adjusting the current and voltage to drive the motor according to the target torque value.

[0067] After the motor controller switches from the pulse width modulation mode to the free sliding mode, the motor cannot obtain current from the power supply because the three-phase rectifier circuit switches from the on state to the off state. Accordingly, the vehicle controller and the motor controller can be switched from the torque control state to the standby state. In the standby state, the vehicle controller sends a command to the motor controller to stop the power output. The motor controller stops driving the motor, and the three-phase rectifier circuit is turned off or in standby state. The motor does not output torque, and it only maintains basic system monitoring functions to reduce energy consumption.

[0068] In the above scheme, the motor controller can be switched from pulse width modulation mode to free sliding mode, and the vehicle controller and the motor controller can be further switched from torque control state to standby state, thereby significantly reducing the power consumption of the system and improving the energy utilization efficiency of the vehicle in sliding or idling conditions.

[0069] As an optional embodiment, after switching the control mode of the motor from the pulse width modulation mode to the free sliding mode, the method further includes:

[0070] obtaining a target torque of the vehicle;

[0071] When the target torque is less than or equal to a third threshold value, or greater than or equal to a fourth threshold value, switching the control mode of the motor from the free sliding mode to the pulse modulation mode;

[0072] The third threshold is greater than the first threshold and less than 0, and the fourth threshold is less than the second threshold and greater than 0.

[0073] In this embodiment, when the motor controller is in the free-slip mode, it is necessary to monitor the target torque of the vehicle in real time and compare the target torque with the third threshold and the fourth threshold. If the target torque is continuously between the third threshold and the fourth threshold, it means that the motor does not need to output too much traction at this time, and the free-slip state of the motor controller can be maintained. If the target torque is less than or equal to the preset third threshold, or greater than or equal to the fourth threshold, it means that the motor needs to output a larger traction to achieve the target torque, so the motor controller needs to be switched back to the pulse modulation mode from the free-slip mode.

[0074] For example, the third threshold and the fourth threshold can be determined based on the pre-calibrated first value and the tolerance value. Since the vehicle controller has core strategies such as zero-crossing control to optimize drivability, the first value needs to be smaller than the torque hysteresis control value. The tolerance value is the error range allowed based on the first value. For example, the first value can be 0.5Nm and the tolerance value can be 0.2Nm.

[0075] Then, the third threshold value may be set to (-0.5+0.2)Nm, ie, -0.3Nm, and the fourth threshold value may be set to (0.5-0.2)Nm, ie, 0.3Nm.

[0076] In this way, by dynamically monitoring the target torque of the vehicle in the free-slip mode and switching back to the pulse modulation mode in time when the target torque exceeds the set third threshold or fourth threshold, the power demand of the driver can be quickly responded to and power delay can be avoided. At the same time, the method maintains the free-slip mode when the torque demand is low, reduces energy consumption, and improves the operating efficiency and driving smoothness of the vehicle.

[0077] As an optional embodiment, before switching the control mode of the motor from the free sliding mode to the pulse modulation mode, the method further includes:

[0078] The vehicle controller and the motor controller in the vehicle are switched from a standby state to a torque control state.

[0079] In this embodiment, before switching the motor controller from the free sliding mode to the pulse modulation mode, the vehicle controller and the motor controller need to be switched from the standby state to the torque control state, thereby ensuring that the motor can quickly output the required target torque and avoiding power response delay.

[0080] Specifically, in standby mode, the vehicle controller and motor controller only maintain monitoring and low-power operation, and the motor does not actively output torque. Therefore, it cannot respond to the target torque, and the controller may not be able to adjust the current in time, causing the vehicle to run unsteadily.

[0081] Therefore, it is necessary to switch the vehicle controller and the motor controller from the standby state to the torque control state in advance so that the motor controller and the motor can output torque at any time to avoid power response delay.

[0082] That is to say, entering the torque control state before switching to the pulse modulation mode can ensure the rapid response and operating stability of the power system, thereby improving the vehicle's driving experience and avoiding power delays or unevenness.

[0083] As an optional embodiment, after switching the vehicle controller and the motor controller in the vehicle from a standby state to a torque control state, the method further includes:

[0084] The motor is controlled to output the target torque.

[0085] In this embodiment, after the vehicle controller and the motor controller in the vehicle are switched from the standby state to the torque control state, and the motor controller is switched from the free sliding mode to the pulse modulation mode, the vehicle controller can send the target torque as a command to the motor controller, and the motor controller adjusts the current amplitude of the output three-phase alternating current according to the target torque in the command, thereby adjusting the actual torque output by the motor, and adjusting the actual torque output by the motor to the target torque, so as to control the motor to output the target torque.

[0086] In this way, the target torque can be calculated by the vehicle controller and the output current can be dynamically adjusted by the motor controller, thus achieving precise torque control of the motor. Before controlling the motor to output the target torque, the vehicle controller and the motor controller in the vehicle are switched from the standby state to the torque control state, and the motor controller is switched from the free sliding mode to the pulse modulation mode, which improves the response speed and power stability of the vehicle, optimizes the energy utilization efficiency, and provides the vehicle with a better driving experience and endurance performance.

[0087] Based on the motor control method provided in the above embodiment, the present application also provides a specific implementation of the motor control device. Please refer to the following embodiment.

[0088] See first Figure 2 The motor control device 200 provided in the embodiment of the present application includes the following modules:

[0089] A first acquisition module 201 is used to acquire the rotation speed of the motor in the vehicle when the motor controller of the vehicle is in a pulse width modulation mode;

[0090] A first determination module 202, configured to determine a back electromotive force voltage of the motor according to a rotation speed of the motor;

[0091] The first switching module 203 is used to switch the control mode of the motor from the pulse width modulation mode to the free sliding mode when the back electromotive force voltage is less than the power supply voltage of the vehicle and the actual torque output by the motor is greater than a first threshold and less than a second threshold, and the first threshold is less than 0 and the second threshold is greater than 0.

[0092] The device can monitor the speed of the vehicle's motor and calculate the corresponding back-EMF voltage. When the back-EMF voltage is lower than the vehicle's power supply voltage and the actual torque output by the motor is between the first threshold and the second threshold, the motor's control mode is switched from pulse width modulation mode to free-slip mode. Through this switching mechanism, when the motor does not need to be actively driven, the pulse width of the motor is no longer adjusted, but it is allowed to slide freely, thereby significantly reducing the resistance loss caused by the current in the motor winding and the dynamic loss caused by the frequent switching of pulse width modulation, avoiding unnecessary energy consumption, and improving overall energy efficiency.

[0093] As an implementation of the present application, the first switching module 203 may further include:

[0094] A switching unit, used to switch the three-phase rectifier circuit in the vehicle from an on state to an off state, so as to switch the control mode of the motor from the pulse width modulation mode to the free sliding mode;

[0095] The three-phase rectifier circuit is used to convert the direct current output by the power supply into three-phase alternating current, and drive the motor to operate through the three-phase alternating current.

[0096] As an implementation of the present application, the control device 200 of the motor may further include:

[0097] The second switching module is used to switch the vehicle controller and the motor controller in the vehicle from a torque control state to a standby state.

[0098] As an implementation of the present application, the control device 200 of the motor may further include:

[0099] A second acquisition module, used for acquiring a target torque of the vehicle;

[0100] a third switching module, configured to switch the control mode of the motor from the free sliding mode to the pulse modulation mode when the target torque is less than or equal to a third threshold, or greater than or equal to a fourth threshold;

[0101] The third threshold is greater than the first threshold and less than 0, and the fourth threshold is less than the second threshold and greater than 0.

[0102] As an implementation of the present application, the control device 200 of the motor may further include:

[0103] The fourth switching module is used to switch the vehicle controller and the motor controller in the vehicle from a standby state to a torque control state.

[0104] As an implementation of the present application, the control device 200 of the motor may further include:

[0105] An output module is used to control the motor to output the target torque.

[0106] The motor control device provided in the embodiment of the present invention can implement each step in the above method embodiment, and will not be described again here to avoid repetition.

[0107] Figure 3 A schematic diagram of the hardware structure of a vehicle provided in an embodiment of the present application is shown.

[0108] The vehicle may include a processor 1001 and a memory 1002 storing computer program instructions.

[0109] Specifically, the processor 1001 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.

[0110] The memory 1002 may include a large capacity memory for data or instructions. By way of example and not limitation, the memory 1002 may include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive or a combination of two or more of these. In appropriate cases, the memory 1002 may include a removable or non-removable (or fixed) medium. In appropriate cases, the memory 1002 may be inside or outside the integrated gateway disaster recovery device. In a specific embodiment, the memory 1002 is a non-volatile solid-state memory.

[0111] The memory may include read-only memory (ROM), random access memory (RAM), magnetic disk storage media devices, optical storage media devices, flash memory devices, electrical, optical or other physical / tangible memory storage devices. Thus, typically, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to an aspect of the present disclosure.

[0112] The processor 1001 implements any one of the motor control methods in the above embodiments by reading and executing computer program instructions stored in the memory 1002 .

[0113] In one example, the vehicle may further include a communication interface 1003 and a bus 1010. Figure 3 As shown, the processor 1001, the memory 1002, and the communication interface 1003 are connected via a bus 1010 and communicate with each other.

[0114] The communication interface 1003 is mainly used to implement communication between various modules, devices, units and / or equipment in the embodiments of the present application.

[0115] Bus 1010 includes hardware, software or both, and the components of the vehicle are coupled to each other. For example, but not limitation, the bus may include accelerated graphics port (AGP) or other graphics bus, enhanced industrial standard architecture (EISA) bus, front-side bus (FSB), hypertransport (HT) interconnection, industrial standard architecture (ISA) bus, infinite bandwidth interconnection, low pin count (LPC) bus, memory bus, micro channel architecture (MCA) bus, peripheral component interconnect (PCI) bus, PCI-Express (PCI-X) bus, serial advanced technology attachment (SATA) bus, video electronics standard association local (VLB) bus or other suitable bus or two or more of these combinations. In appropriate cases, bus 1010 may include one or more buses. Although the present application embodiment describes and shows a specific bus, the present application considers any suitable bus or interconnection.

[0116] The vehicle can be based on the above-mentioned embodiment, thereby realizing the control method and device combined with the above-mentioned motor.

[0117] In addition, in combination with the motor control method in the above-mentioned embodiment, the embodiment of the present application may provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when the computer program instructions are executed by the processor, any one of the motor control methods in the above-mentioned embodiments is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here. Among them, the above-mentioned computer-readable storage medium may include a non-transitory computer-readable storage medium, such as a read-only memory (Read-Only Memory, referred to as ROM), a random access memory (Random Access Memory, referred to as RAM), a disk or an optical disk, etc., which are not limited here.

[0118] In addition, an embodiment of the present application further provides a computer program product, including computer program instructions, which can implement the steps and corresponding contents of the aforementioned method embodiment when the computer program instructions are executed by a processor.

[0119] It should be clear that the present application is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present application is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present application.

[0120] The functional blocks shown in the above block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0121] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.

[0122] Aspects of the present disclosure are described above with reference to the flowchart and / or block diagram of the method, device and computer program product according to the embodiment of the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram 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, or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the implementation of the function / action specified in one or more boxes of the flowchart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field programmable logic circuit. It can also be understood that each box in the block diagram and / or flowchart and the combination of boxes in the block diagram and / or flowchart can also be implemented by dedicated hardware that performs a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0123] The above are only specific implementation methods of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.

Claims

1. A method for controlling a motor, characterized in that: The method comprises: When a motor controller of the vehicle is in a pulse width modulation mode, obtaining a rotation speed of a motor in the vehicle; Determining a back electromotive force voltage of the motor according to a rotation speed of the motor; When the back electromotive force voltage is less than the power supply voltage of the vehicle and the actual torque output by the motor is greater than a first threshold and less than a second threshold, the control mode of the motor is switched from the pulse width modulation mode to the free sliding mode, the first threshold is less than 0, and the second threshold is greater than 0.

2. The motor control method according to claim 1, characterized in that: The step of switching the control mode of the motor from the pulse width modulation mode to the free sliding mode includes: Switching the three-phase rectifier circuit in the vehicle from an on state to an off state, so as to switch the control mode of the motor from the pulse width modulation mode to the free sliding mode; The three-phase rectifier circuit is used to convert the direct current output by the power supply into three-phase alternating current, and drive the motor to operate through the three-phase alternating current.

3. The motor control method according to claim 1, characterized in that: After switching the control mode of the motor from the pulse width modulation mode to the free sliding mode, the method further includes: The vehicle controller and the motor controller in the vehicle are switched from a torque control state to a standby state.

4. The motor control method according to claim 1, characterized in that: After switching the control mode of the motor from the pulse width modulation mode to the free sliding mode, the method further includes: obtaining a target torque of the vehicle; When the target torque is less than or equal to a third threshold value, or greater than or equal to a fourth threshold value, switching the control mode of the motor from the free sliding mode to the pulse modulation mode; The third threshold is greater than the first threshold and less than 0, and the fourth threshold is less than the second threshold and greater than 0.

5. The motor control method according to claim 4, characterized in that: Before switching the control mode of the motor from the free sliding mode to the pulse modulation mode, the method further includes: The vehicle controller and the motor controller in the vehicle are switched from a standby state to a torque control state.

6. The motor control method according to claim 5, characterized in that: After switching the vehicle controller and the motor controller in the vehicle from a standby state to a torque control state, the method further includes: The motor is controlled to output the target torque.

7. A control device for a motor, characterized in that: The device comprises: A first acquisition module, configured to acquire a rotation speed of a motor in the vehicle when a motor controller of the vehicle is in a pulse width modulation mode; A first determination module, used to determine the back electromotive force voltage of the motor according to the rotation speed of the motor; The first switching module is used to switch the control mode of the motor from the pulse width modulation mode to the free sliding mode when the back electromotive force voltage is less than the power supply voltage of the vehicle and the actual torque output by the motor is greater than a first threshold and less than a second threshold, and the first threshold is less than 0 and the second threshold is greater than 0.

8. A vehicle, characterized in that: The vehicle comprises: a processor and a memory storing computer program instructions; when the processor executes the computer program instructions, the control method of the motor according to any one of claims 1 to 6 is implemented.

9. A computer storage medium, characterized in that: The computer storage medium stores computer program instructions, which, when executed by a processor, implement the method for controlling a motor according to any one of claims 1 to 6.

10. A computer program product, characterized in that The computer program product comprises computer program instructions, and when the computer program instructions are executed by a processor, the method for controlling the motor according to any one of claims 1 to 6 is implemented.

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