Motor control method and device, vehicle and storage medium

Abstract

The invention provides a motor control method and device, a vehicle and a storage medium, and relates to the technical field of vehicles. The method comprises the following steps: when a relay used for connecting a power battery and an inverter in the electric driving system is disconnected, performing first preset control on a motor through the inverter according to an operation mode and operation parameters of the motor in the electric driving system; when it is detected that the relay is disconnected, the current operation mode and operation parameters of the motor in the electric drive system are obtained, corresponding first preset control is carried out on operation of the motor according to the current operation mode and operation parameters of the motor, the operation state of the motor after the relay is disconnected can be effectively managed, and the operation efficiency of the motor is improved. Therefore, serious over-voltage, over-current, under-voltage and the like in a loop separated from the power battery are avoided, torque impact caused by unstable torque output of the motor is avoided, and an electric drive system where the motor is located is protected under the fault working condition such as load throwing.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and in particular to a motor control method, device, vehicle and storage medium. Background Art

[0002] In the vehicle's electric drive system, power batteries, relays, inverters, motors and other components are electrically connected to form a current loop. The inverter is used to achieve the conversion of electrical energy between the power battery and the motor, and the relay is used to control the on and off of the circuit between the power battery and the inverter. Depending on the operating conditions of the motor, when the motor is in the driving state, the power battery serves as the power supply; when the motor is in the power generation state, the power battery serves as the load.

[0003] When the power battery has a corresponding fault, the power controller of the electric drive system controls the relay to disconnect the power battery from the circuit to avoid serious secondary disasters (such as fire, short circuit, thermal runaway, explosion, etc.) of the power battery and the electric drive system. This working condition is called load dumping. Since the power battery may fail at any time and under any working condition and cause the relay to disconnect, the motor may be in the maximum power generation condition or the maximum drive condition at this time, and the motor speed may be at any speed between 0 speed and the maximum speed. This means that when load dumping occurs, the motor may still continue to operate without the participation of the power battery, which may cause serious overvoltage, overcurrent, undervoltage, etc. in the circuit that is separated from the power battery, thereby causing damage to capacitors, power devices and other devices in the circuit. Summary of the invention

[0004] The problem solved by the present invention is: how to realize load dump protection for an electric drive system where a motor is located.

[0005] To solve the above problems, the present invention provides a motor control method, device, vehicle and storage medium.

[0006] In a first aspect, the present invention provides a motor control method, comprising:

[0007] When a relay for connecting a power battery and an inverter in an electric drive system is disconnected, the motor is subjected to a first preset control through the inverter according to an operating mode and operating parameters of the motor in the electric drive system; wherein the first preset control includes one of active short-circuit control, inertial gliding control and zero torque control.

[0008] Optionally, the operating parameters include current, voltage and speed; when the relay for connecting the power battery and the inverter in the electric drive system is disconnected, performing a first preset control on the motor through the inverter according to the operating mode and operating parameters of the motor in the electric drive system includes:

[0009] When the relay is disconnected, if the operation mode is the torque mode, and the current is less than the first preset limit, the voltage is less than the second preset limit, and the speed is less than the third preset limit, the motor is coasted by the inverter;

[0010] When the relay is disconnected, if the operating mode is the torque mode, and at least one of the current is greater than or equal to the first preset limit, the voltage is greater than or equal to the second preset limit, and the speed is greater than or equal to the third preset limit, the active short-circuit control of the motor is performed through the inverter.

[0011] Optionally, the operating parameter includes a rotation speed; when a relay for connecting a power battery and an inverter in the electric drive system is disconnected, performing a first preset control on the motor through the inverter according to an operating mode and operating parameters of the motor in the electric drive system includes:

[0012] When the relay is disconnected, if the operation mode is the initialization mode or the standby mode, and the rotation speed is greater than a seventh preset limit value, the active short-circuit control is performed on the motor through the inverter;

[0013] When the relay is disconnected, if the operation mode is the initialization mode or the standby mode, and the rotation speed is less than or equal to the seventh preset limit, the motor is subjected to the inertial gliding control through the inverter.

[0014] Optionally, the operating parameter includes a rotation speed; when the relay for connecting the power battery and the inverter in the electric drive system is disconnected, before performing a first preset control on the motor through the inverter according to the operating mode and operating parameters of the motor in the electric drive system, the motor control method further includes:

[0015] When the operation mode is a fault mode, the active short-circuit control, the coasting control or the zero-torque control is performed on the motor through the inverter;

[0016] When the relay for connecting the power battery and the inverter in the electric drive system is disconnected, performing a first preset control on the motor through the inverter according to the operation mode and operation parameters of the motor in the electric drive system includes:

[0017] When the relay is disconnected, if the rotation speed is greater than a seventh preset limit value, the motor is actively short-circuited through the inverter;

[0018] When the relay is disconnected, if the rotation speed is less than or equal to the seventh preset limit value, the motor is subjected to the coasting control through the inverter.

[0019] Optionally, the motor control method further includes:

[0020] When the relay is closed, the motor is subjected to a second preset control through the inverter according to at least one of the acquired operation mode and operation parameters of the motor.

[0021] Optionally, the operating parameter includes a back electromotive force; when the relay is closed, according to at least one of the acquired operating mode and operating parameter of the motor, performing a second preset control on the motor through the inverter includes:

[0022] When the operation mode is the torque mode, if the relay is closed, the motor is controlled by the inverter to maintain the current operation mode, and when an operation mode request is received, the motor is controlled to operate according to the operation mode request;

[0023] Or, when the operating mode is the initialization mode or the standby mode, if the relay is closed and the back electromotive force is greater than the DC bus voltage of the inverter, the inverter is used to perform the active short-circuit control or the zero-torque control on the motor; when the operating mode is the initialization mode or the standby mode, if the relay is closed and the back electromotive force is less than or equal to the DC bus voltage of the inverter, the inverter is used to perform the inertial gliding control or the zero-torque control on the motor.

[0024] Optionally, the operating parameter includes a back electromotive force; when the relay is closed, before performing a second preset control on the motor through the inverter according to at least one of the acquired operating mode and operating parameter of the motor, the motor control method further includes:

[0025] When the operation mode is a fault mode, the active short-circuit control, the coasting control or the zero-torque control is performed on the motor through the inverter;

[0026] When the relay is closed, performing a second preset control on the motor through the inverter according to at least one of the acquired operation mode and operation parameters of the motor includes:

[0027] When the relay is closed, if the back electromotive force is greater than the DC bus voltage of the inverter, the motor is actively short-circuited or zero-torque controlled through the inverter;

[0028] When the relay is closed, if the back electromotive force is less than or equal to the DC bus voltage of the inverter, the motor is subjected to the inertial gliding control or the zero torque control through the inverter.

[0029] Optionally, after the motor is subjected to the coasting control by the inverter, the motor control method further includes:

[0030] When receiving an operation mode request, determining whether the relay is closed;

[0031] If the relay is closed, the motor is controlled to operate according to the operation mode request;

[0032] If the relay is not closed, and at least one of the current is greater than or equal to the first preset limit, the voltage is greater than or equal to the second preset limit, and the speed is greater than or equal to the third preset limit is satisfied, the active short-circuit control is performed on the motor through the inverter;

[0033] If the relay is not closed, and the current is less than the first preset limit, the voltage is less than the second preset limit, and the speed is less than the third preset limit, the motor is controlled by the inverter to maintain the inertial gliding control.

[0034] Optionally, after the active short-circuit control is performed on the motor by the inverter, the motor control method further includes:

[0035] If the relay continues to be disconnected, and the current is less than the fourth preset limit, the voltage is less than the fifth preset limit, and the speed is less than the sixth preset limit, the motor is subjected to the inertial gliding control through the inverter;

[0036] If the relay continues to be disconnected and at least one of the current is greater than or equal to the fourth preset limit, the voltage is greater than or equal to the fifth preset limit, and the speed is greater than or equal to the sixth preset limit is satisfied, the motor is controlled by the inverter to remain in the active short-circuit control;

[0037] If the relay is closed again, the motor is controlled to operate according to the operation mode request when an operation mode request is received.

[0038] In a second aspect, the present invention provides a motor control device, comprising:

[0039] A motor control unit is used to control the motor through the inverter according to the motor control method as described above, based on the operating mode and operating parameters of the motor in the electric drive system when the relay used to connect the power battery and the inverter in the electric drive system is disconnected.

[0040] In a third aspect, the present invention provides a vehicle, comprising a memory and a processor;

[0041] The memory is used to store computer programs;

[0042] The processor is used to implement the motor control method as described in the first aspect when executing the computer program.

[0043] In a fourth aspect, the present invention provides a computer-readable storage medium storing a computer program. When the computer program is read and executed by a processor, the motor control method as described in the first aspect is implemented.

[0044] Compared with the prior art, the present invention has the following beneficial effects: the present invention detects the switch state of the relay used to connect the power battery and the inverter in the electric drive system, so as to take corresponding measures for the motor in time when the relay is disconnected, so as to avoid that after the relay is disconnected, the energy output by the motor in the maximum power generation condition, the maximum driving condition and the like has nowhere to be released, resulting in serious overvoltage, overcurrent, undervoltage and the like in the circuit separated from the power battery, thereby causing damage to the capacitor, power device and other devices in the circuit, and avoiding the torque shock caused by the motor (i.e., the impact of the unstable torque output of the motor on the mechanical parts). Specifically, when it is detected that the relay used to connect the power battery and the inverter in the electric drive system is disconnected, the current operation mode and operation parameters of the motor in the electric drive system are obtained, so as to perform the corresponding first preset control on the operation of the motor according to the current operation mode and operation parameters of the motor, so that the operation state of the motor after the relay is disconnected can be effectively managed, thereby avoiding serious overvoltage, overcurrent, undervoltage and the like in the circuit separated from the power battery, and avoiding the situation that the torque shock is caused by the unstable torque output of the motor, so as to realize the protection of the electric drive system where the motor is located under the fault condition such as load dumping. Among them, the first preset control includes active short-circuit control, coasting control or zero torque control and other motor control modes for effectively limiting the motor output, aiming to ensure that the motor is still in a controllable state when it is disconnected from the power battery. In this way, the various components in the circuit that is disconnected from the power battery are protected from the influence of power battery failure and the corresponding operating conditions of the motor, and the safety, stability and reliability of the motor and the electric drive system in the face of corresponding emergencies are improved, reducing the serious losses that may be caused. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A schematic diagram of a portion of the structure of an electric drive system in an embodiment of the present invention;

[0046] Figure 2 A schematic diagram of a flow chart of a motor control method according to an embodiment of the present invention;

[0047] Figure 3 A schematic diagram of a flow chart of a motor control method according to an embodiment of the present invention;

[0048] Figure 4 A schematic diagram of a flow chart of a motor control method according to an embodiment of the present invention;

[0049] Figure 5 A schematic diagram of a flow chart of a motor control method according to an embodiment of the present invention;

[0050] Figure 6 is a structural block diagram of a motor control device in an embodiment of the present invention;

[0051] Figure 7 Schematic diagram of the structure of the memory and processor of the vehicle in an embodiment of the present invention. DETAILED DESCRIPTION

[0052] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0053] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein.

[0054] Combination Figure 1 As shown, an embodiment of the present invention provides a motor control method, including:

[0055] When the relay used to connect the power battery and the inverter in the electric drive system is disconnected, the motor is subjected to a first preset control through the inverter according to the operating mode and operating parameters of the motor in the electric drive system; wherein the first preset control includes one of active short-circuit control, inertial gliding control and zero torque control.

[0056] In this embodiment, the electric drive system includes components such as a power battery, a relay, an inverter, and a motor that are electrically connected in sequence. The inverter is used to realize the conversion of electric energy between the power battery and the motor. For example, when the power battery supplies power to the motor through the inverter, the inverter is used to convert the direct current output by the power battery into the alternating current required by the motor; when the motor reversely charges the power battery through the inverter, the inverter is used to convert the alternating current output by the motor into the direct current required by the power battery. The relay is used to connect the power battery and the inverter, and the on and off of the relay realizes the on and off of the electrical connection between the power battery and the inverter.

[0057] Considering that when the electric drive system encounters a condition such as load dumping due to a power battery failure, the relay will be disconnected to avoid serious secondary disasters in the power battery and the electric drive system, which will cause more serious losses. Therefore, by directly obtaining the switch state of the relay, corresponding measures can be taken for the motor in time when the relay is disconnected to avoid that after the relay is disconnected, the energy output by the motor in the maximum power generation condition, the maximum drive condition, etc. has nowhere to be released, resulting in serious overvoltage, overcurrent, undervoltage, etc. in the circuit separated from the power battery, which may cause damage to capacitors, power devices, etc. in the circuit, and avoid the torque shock caused by the motor (that is, the shock caused by the unstable torque output of the motor to the mechanical parts).

[0058] Specifically, when it is detected that the relay used to connect the power battery and the inverter in the electric drive system is disconnected, the current operating mode and operating parameters of the motor in the electric drive system are obtained, so as to control the operation of the motor accordingly according to the current operating mode and operating parameters of the motor (i.e., the first preset control), so that the operating state of the motor after the relay is disconnected can be effectively managed, thereby avoiding serious overvoltage, overcurrent, undervoltage and the like in the circuit separated from the power battery, and avoiding torque shock caused by unstable motor torque output, so as to protect the electric drive system where the motor is located under fault conditions such as load dumping. Among them, the first preset control includes one of active short circuit control, coasting control and zero torque control. Active short-circuit control (ASC), when the relay is disconnected, the inverter short-circuits the motor winding (such as by turning on the upper three bridges or the lower three bridges of the inverter's three-phase bridge rectifier circuit) to generate a reaction force to limit the increase in the motor's speed and avoid overspeed or overvoltage problems caused by motor inertia or external loads; Free Wheeling control (FW), when the motor's operating state is relatively stable and no additional braking force is required, the motor is allowed to coast freely (such as by turning off all the upper three bridges and the lower three bridges of the inverter's three-phase bridge rectifier circuit, so that the motor does not generate active driving force or braking force, allowing the motor to rotate freely under the action of external forces such as inertia and gravity), maintaining the inertial motion state, thereby avoiding torque shock caused by excessive braking; Zero torque control (0nm control), in certain circumstances, through inverter adjustment, the torque output by the motor is made zero, thereby stabilizing the operation of the motor and preventing any form of mechanical or electrical stress from being aggravated.

[0059] In this way, the method of this embodiment detects the switch state of the relay used to connect the power battery and the inverter in the electric drive system, so as to take corresponding measures for the motor in time when the relay is disconnected, so as to avoid that after the relay is disconnected, the energy output by the motor in the maximum power generation condition, the maximum driving condition and the like has nowhere to be released, resulting in serious overvoltage, overcurrent, undervoltage and the like in the circuit separated from the power battery, and causing damage to the capacitor, power device and other devices in the circuit, and avoiding the torque shock caused by the motor (i.e., the impact of the unstable torque output of the motor on the mechanical parts). Specifically, when it is detected that the relay used to connect the power battery and the inverter in the electric drive system is disconnected, the current operation mode and operation parameters of the motor in the electric drive system are obtained, so as to perform the corresponding first preset control on the operation of the motor according to the current operation mode and operation parameters of the motor, so that the operation state of the motor after the relay is disconnected can be effectively managed, thereby avoiding serious overvoltage, overcurrent, undervoltage and the like in the circuit separated from the power battery, and avoiding the situation of torque shock caused by unstable torque output of the motor, so as to realize the protection of the electric drive system where the motor is located under fault conditions such as load dumping. Among them, the first preset control includes active short-circuit control, coasting control or zero torque control and other motor control modes for effectively limiting the motor output, aiming to ensure that the motor is still in a controllable state when it is disconnected from the power battery. In this way, the various components in the circuit that is disconnected from the power battery are protected from the influence of power battery failure and the corresponding operating conditions of the motor, and the safety, stability and reliability of the motor and the electric drive system in the face of corresponding emergencies are improved, reducing the serious losses that may be caused.

[0060] In addition, in the prior art, the load dumping condition is determined and protection is performed by determining whether the bus voltage of the inverter is overvoltage or undervoltage. Although this can prevent damage to the electric drive system to a certain extent, since the bus voltage will fluctuate violently at the moment of load dumping, this protection mechanism often reacts with lag, which can easily lead to repeated overvoltage or overcurrent problems of the bus, and may further damage capacitors, power devices and other devices in the electric drive system. In the method of this embodiment, based on the real-time relay switch state and the motor operation mode, operation parameters and other information, the operation state or fault state of the motor and the electric drive system is accurately identified and responded in time, that is, the motor and the electric drive system are protected in time through the first preset control, and the control strategy can be adjusted in real time, which significantly reduces the risk of overvoltage and overcurrent, and improves the stability and reliability of the electric drive system.

[0061] Optionally, combined Figure 1-Figure 3 As shown, the operating parameters include current, voltage and speed; when the relay for connecting the power battery and the inverter in the electric drive system is disconnected, according to the operating mode and operating parameters of the motor in the electric drive system, the first preset control of the motor through the inverter includes:

[0062] When the relay is disconnected, if the operation mode is the torque mode, and the current is less than the first preset limit, the voltage is less than the second preset limit, and the speed is less than the third preset limit, the motor is coasted by the inverter;

[0063] When the relay is disconnected, if the operating mode is the torque mode, and at least one of the current is greater than or equal to the first preset limit, the voltage is greater than or equal to the second preset limit, and the speed is greater than or equal to the third preset limit, the motor is actively short-circuited through the inverter.

[0064] Specifically, when the relay is disconnected, if the current operating mode of the motor is a torque mode (i.e., a motor control mode in which torque is used as the output of the motor, such as by controlling the magnitude and phase of the motor current and voltage to achieve precise control of the motor output torque and obtain the required target torque), and the motor current is less than the first preset limit, the motor voltage is less than the second preset limit, and the motor speed is less than the third preset limit, it means that the motor is in a low load or low speed state at this time. At this time, the motor is inertial gliding control through the inverter, such as by turning off the upper three bridges and the lower three bridges of the three-phase bridge rectifier circuit of the inverter to achieve free rotation (inertial gliding) of the motor to reduce energy loss and avoid unnecessary power consumption or electrical stress caused by active control of the motor when it is not necessary to provide driving or braking force.

[0065] When the relay is disconnected, if the operation mode is the torque mode, and at least one of the current is greater than or equal to the first preset limit, the voltage is greater than or equal to the second preset limit, and the speed is greater than or equal to the third preset limit is satisfied, it means that the motor is in a high load or high speed state at this time. At this time, if no corresponding measures are taken for the motor, the motor may generate too high back electromotive force or other overvoltage and overcurrent phenomena, causing damage to the corresponding components in the electric drive system. Therefore, when the relay is disconnected, the operation mode is the torque mode, and at least one of the current is greater than or equal to the first preset limit, the voltage is greater than or equal to the second preset limit, and the speed is greater than or equal to the third preset limit is satisfied, the motor is actively short-circuited through the inverter, that is, the three-phase winding of the motor is short-circuited through the inverter to form a closed loop. In this closed loop, due to the interaction between the back electromotive force of the motor and the inductance of the motor winding (or electromagnetic damping effect), a reaction torque (braking torque) is generated, thereby limiting the further increase of the motor speed, reducing the motor voltage, and reducing the motor current, and finally playing a protective role for the motor and the electric drive system.

[0066] Optionally, the first preset limit, the second preset limit and the third preset limit can be set according to demand. Among them, the first preset limit is a preset current limit (or threshold value). When the motor current is greater than or equal to the first preset limit, it is considered that the current is too large, which may cause the motor to overheat or damage. The second preset limit is a preset voltage limit. When the motor voltage is greater than or equal to the second preset limit, it is considered that the voltage is too large, which may cause the motor to be damaged. The third preset limit is a preset speed limit. When the motor speed is greater than or equal to the third preset limit, it is considered that the speed is high; for example, considering that when the motor is actively short-circuited, the torque is large when the motor rotates at a low speed (such as the speed is less than the third preset limit), a large braking torque will be generated, affecting the comfort of the vehicle, etc. Therefore, when the motor rotates at a low speed, the motor is open-circuited (i.e., coasting, Free Wheeling, FW). At this time, the motor speed is low, and the motor is in an open-circuit state. The motor will not actively generate braking torque to ensure the smooth operation of the motor. In some embodiments, the current in the motor operating parameters may be the input current of the motor, or the current of the motor winding; correspondingly, the voltage in the motor operating parameters may be the input voltage of the motor, or the voltage of the motor winding.

[0067] Optionally, under the premise of actively short-circuiting the motor through the inverter, if the relay remains disconnected and at least one of the current is greater than or equal to a first preset limit, the voltage is greater than or equal to a second preset limit, and the speed is greater than or equal to a third preset limit is satisfied, it is necessary to continue to actively short-circuit control the motor until the current of the motor is less than the first preset limit, the voltage is less than the second preset limit, and the speed is less than the third preset limit are simultaneously satisfied, and then the motor is controlled by inertia gliding through the inverter.

[0068] Optionally, combined Figure 1 , Figure 2 and Figure 4 As shown, the operating parameters include the rotational speed; when the relay for connecting the power battery and the inverter in the electric drive system is disconnected, according to the operating mode and operating parameters of the motor in the electric drive system, the first preset control of the motor through the inverter includes:

[0069] When the relay is disconnected, if the operation mode is the initialization mode or the standby mode and the speed is greater than the seventh preset limit, the motor is actively short-circuited through the inverter.

[0070] Specifically, when the relay is disconnected, if the current operating mode of the motor is initialization mode (such as the mode when the motor is not started or not fully started) or standby mode (such as the mode when the motor is in low power consumption or inactive state), it means that the current workload of the motor is low and the speed of the motor is relatively low or close to zero. At this time, if the speed of the motor is greater than the seventh preset limit, the motor will generate a relatively large back electromotive force. When the back electromotive force is greater than the DC bus voltage (UDC) of the inverter to a certain extent, it means that the motor is in a power generation condition and the speed is high (because the back electromotive force of the motor is proportional to the speed). The motor may feed energy back to the power battery (reverse charging). To avoid If the voltage or current of reverse charging from the motor to the power battery is too high (for example, it exceeds the threshold value for ensuring the safety and normal operation of components such as the power battery and inverter), the motor can be actively short-circuited or zero-torque controlled through the inverter to absorb or consume excess energy output by the motor. This prevents the reverse charging voltage or current from being too high, which may cause adverse effects such as damage to corresponding components of the high-voltage system (which is a high-voltage electrical system, with the electric drive system as part of the high-voltage system; the high-voltage system also includes other high-voltage electrical components, such as an air-conditioning compressor, an electric braking system, etc.; in some embodiments, the various electrical components of the high-voltage system are mainly powered by the power battery of the electric drive system), thereby protecting the high-voltage system. Among them, in the active short-circuit control mode, the inverter short-circuit the motor winding through its switching elements (such as IGBT or MOSFET). The short circuit allows the motor winding current to flow inside the motor winding, thereby generating a large reverse current inside the motor. This reverse current helps to absorb or consume the back electromotive force generated by the motor, that is, the back electromotive force generated by the motor is consumed in the short-circuit current, so as to effectively consume the excess energy output by the motor and prevent the back electromotive force of the motor from being too high, thereby protecting the electrical devices in the high-voltage system.

[0071] When the relay is disconnected, if the operation mode is the initialization mode or the standby mode, and the speed is less than or equal to the seventh preset limit, the motor is coasted by the inverter.

[0072] Specifically, when the relay is disconnected, if the current operation mode of the motor is the initialization mode or the standby mode, at this time, if the speed of the motor is less than or equal to the seventh preset limit, the back electromotive force generated by the motor is small, and will not cause serious overvoltage, overcurrent, undervoltage in the circuit separated from the power battery, and the motor will not cause torque shock, etc., and the motor can be controlled by inertial glide through the inverter to reduce energy loss, avoid unnecessary power consumption or electrical stress caused by active control when the motor does not need to provide driving or braking force, and improve the driving comfort of the vehicle. Among them, in the inertial glide control mode, the inverter adjusts the current flow direction of the motor through its switching elements (such as IGBT or MOSFET), so that the motor can rotate freely by its own inertia without additional driving force; in this mode, the current of the motor is close to zero, so that the motor can naturally decelerate without consuming excess energy.

[0073] In some embodiments, the seventh preset limit is used as a preset motor speed limit (or threshold value). When the motor speed is less than or equal to the seventh preset limit, it is considered that the back electromotive force generated by the motor is small, and the impact on the electrical load of the electric drive system is small or no impact; when the motor speed is higher than the seventh preset limit, it is considered that the back electromotive force of the motor is high, which may cause the electrical components of the electric drive system to face a large load. The seventh preset limit can be set according to demand.

[0074] Optionally, combined Figure 1 , Figure 2 and Figure 5 As shown, the operating parameters include the rotational speed; when the relay for connecting the power battery and the inverter in the electric drive system is disconnected, according to the operating mode and operating parameters of the motor in the electric drive system, before the first preset control is performed on the motor by the inverter, the motor control method also includes:

[0075] When the operation mode is the fault mode, the motor is actively short-circuited, coasted or zero-torque controlled through the inverter.

[0076] Specifically, when there is no operating condition such as load dumping that causes the relay to disconnect, the relay is in a closed state and the motor operates normally. At this time, if the motor or the electric drive system has a corresponding abnormality or fault, the motor enters the fault mode. In the fault mode, in order to prevent the corresponding operating conditions of the motor from affecting the circuit where the motor is located (such as a circuit including the motor, inverter, power battery, etc.), the motor is actively short-circuited, coasted, or controlled by zero torque through the inverter. Among them, according to the actual situation of the fault, the motor can be actively short-circuited, coasted, or controlled by zero torque through the inverter to prevent the fault from worsening and reduce the impact of the fault on the corresponding components. For example, if the motor suddenly loses its electrical load, overspeeds, or the motor still rotates at high speed after the relay is disconnected, or the motor is in a high-speed operation state when the corresponding fault occurs, the motor may generate a high back electromotive force at this time. Too high back electromotive force may cause problems such as overvoltage or overcurrent, and then damage the corresponding components of the electric drive system. In this case, it is necessary to actively short-circuit the motor to quickly consume the excess kinetic energy of the motor, thereby reducing the back electromotive force and avoiding damage to the corresponding electrical components; when the corresponding fault occurs, the motor speed is low or the load has been greatly reduced, the back electromotive force generated by the motor is low, and no excessive electrical stress is generated. At this time, there is no need to actively brake or decelerate, and only the motor needs to be coasted to allow the motor to naturally decelerate and glide under the action of inertia, reduce unnecessary energy loss, and avoid applying additional electrical stress to the motor and the electrical system; when the motor fails and needs to maintain the stability of the motor, but does not want the motor to continue to generate any output torque, the motor can be controlled by zero torque to keep the motor running stably, without generating driving force or braking force, etc., and ensure that the motor does not affect the stability of the vehicle under the corresponding fault, and avoid unnecessary torque fluctuations.

[0077] When a relay for connecting a power battery and an inverter in the electric drive system is disconnected, performing a first preset control on the motor through the inverter according to an operation mode and operation parameters of the motor in the electric drive system includes:

[0078] When the relay is disconnected, if the speed is greater than the seventh preset limit, the motor is actively short-circuited through the inverter;

[0079] When the relay is disconnected, if the speed is less than or equal to the seventh preset limit, the motor is coasted by the inverter.

[0080] Under the premise that the motor operation mode is a fault mode and the motor is actively short-circuited, coasted or zero-torque controlled through the inverter, according to the switch state of the relay monitored in real time, when the relay is disconnected, if the motor speed is greater than the seventh preset limit, it means that the kinetic energy of the motor is large. At this time, a high back electromotive force may be generated, which may easily lead to overvoltage, overcurrent and other problems of the inverter and other electrical components. In this case, the motor is actively short-circuited through the inverter to short-circuit the motor winding, and the reverse current generated inside the winding is used to consume excess kinetic energy and voltage, thereby effectively suppressing overvoltage, overcurrent and other problems; and if the motor speed is less than or equal to the seventh preset limit, it means that the kinetic energy of the motor is small, and the generated back electromotive force will not cause significant overvoltage, overcurrent and other problems. In this case, the motor is coasted through the inverter to decelerate the motor naturally, reduce unnecessary energy consumption, and avoid the motor from generating excess electrical stress in this state, while improving the efficiency of the electric drive system and the driving stability and comfort of the vehicle in which the electric drive system is located.

[0081] In this way, according to the motor speed, the motor control mode suitable for the current motor and electric drive system is selected to adapt to the actual operating state of the motor and the electric drive system, avoid generating a large braking torque that affects the comfort and stability of the vehicle, and avoid unnecessary energy consumption or electrical stress, and prevent the overvoltage or overcurrent generated by the motor from damaging the electrical components in the circuit disconnected from the power battery, thereby improving the safety and reliability of the electric drive system and extending the service life of the motor and the electric drive system.

[0082] Optionally, combined Figure 1 and Figure 2 As shown, the motor control method also includes:

[0083] When the relay is closed, the motor is subjected to a second preset control through the inverter according to at least one of the acquired operation mode and operation parameters of the motor.

[0084] In order to improve the motor control method, enrich the application scenarios of the motor control method, and enhance the applicability of the motor control method, in this embodiment, the motor control method also includes: when the relay is closed, the motor is subjected to a second preset control through the inverter according to at least one of the acquired operating mode and operating parameters of the motor.

[0085] Specifically, when there is no operating condition such as load dumping that causes the relay to disconnect, the relay is in a closed state, and an electrical connection is formed between the power battery, the inverter, and the motor, so that electric energy can flow bidirectionally between the power battery and the motor. At this time, based on at least one of the current operating mode (such as torque mode, speed mode, etc.) and operating parameters (such as current, voltage, speed, etc.) of the motor obtained, the motor can be controlled more suitable for the current operating mode / current operating parameters (i.e., the second preset control), such as optimizing the output torque, speed or power of the motor to ensure that the motor can achieve the expected performance and efficiency. In some embodiments, the second preset control includes maintaining the current operating mode, active short-circuit control, coasting control, or zero torque control.

[0086] Optionally, combined Figure 1 , Figure 2 As shown, the operating parameters include back electromotive force; when the relay is closed, according to at least one of the acquired operating mode and operating parameters of the motor, performing a second preset control on the motor through the inverter includes:

[0087] When the operation mode is the torque mode, if the relay is closed, the motor is controlled by the inverter to maintain the current operation mode, and the motor is controlled to operate according to the operation mode request when an operation mode request is received.

[0088] Specifically, when there is no operating condition such as load dumping that causes the relay to disconnect, the relay is in a closed state. At this time, if the motor's operating mode is a torque mode, it means that the motor is already executing a specific torque command, and the motor is kept running in the current operating mode (i.e., torque mode) through the inverter to ensure that the motor continues to provide the required torque output, thereby meeting the power requirements of the electric drive system. In addition, when a request for an operating mode (recorded as an operating mode request) is received, the request is responded to, that is, the motor is controlled to operate in the operating mode corresponding to the request according to the request. For example, the vehicle may need to switch to different modes (such as economic mode, sports mode, etc.) during normal driving, or switch to different modes (such as standby mode, torque mode) according to the gear state. At this time, the electric drive system will adjust the motor's operating mode according to the operating mode request from the VCU (vehicle control unit) to meet the new driving requirements. In this way, the motor and the electric drive system can quickly respond to the mode switching request of the driver or VCU to meet the personalized driving needs of the user (or driver) or meet the automatic control needs of the vehicle.

[0089] Or, when the operating mode is initialization mode or standby mode, if the relay is closed and the back electromotive force is greater than the DC bus voltage of the inverter, the motor is actively short-circuited or controlled by zero torque through the inverter; when the operating mode is initialization mode or standby mode, if the relay is closed and the back electromotive force is less than or equal to the DC bus voltage of the inverter, the motor is coasted or controlled by zero torque through the inverter.

[0090] Specifically, when there is no working condition such as load dumping that causes the relay to disconnect, the relay is in a closed state. At this time, if the motor's operating mode is initialization mode or standby mode, and the motor's back electromotive force is greater than the DC bus voltage of the inverter, the motor may reverse charge the power battery, which may cause the risk of overvoltage or overcurrent. The inverter is used to actively short-circuit the motor or control it to zero torque to absorb or consume the excess energy generated by the motor, prevent the voltage or current in the circuit where the motor is located from being too high, and protect the electrical components in the electric drive system. Among them, the motor is actively short-circuited to short-circuit the motor winding, and the excess energy is consumed by the current, so as to avoid the motor from generating a high back electromotive force and protect the electric drive system from damage; if the motor needs to be kept running stably without output torque, the motor is controlled to zero torque to prevent the motor from further accelerating and generating excessive back electromotive force.

[0091] When there is no operating condition such as load dumping that causes the relay to disconnect, the relay is in a closed state. At this time, if the motor's operating mode is initialization mode or standby mode, and the motor's back electromotive force is less than or equal to the DC bus voltage of the inverter, it means that the motor's current speed is low and the energy generated by the motor is insufficient to cause risks such as overvoltage or overcurrent in the electric drive system. In this case, the motor is controlled by inertia coasting through the inverter so that the motor can rotate freely without consuming unnecessary energy or causing additional stress on the electrical system. Among them, when the vehicle does not need to provide driving force or braking force, the motor is controlled by inertia coasting so that the motor can use inertia to glide naturally and reduce unnecessary energy consumption; if the motor needs to be kept running stably without output torque, the motor is controlled by zero torque to prevent the motor from further accelerating and generating excessive back electromotive force.

[0092] In this way, by selecting the appropriate motor control mode according to the operating mode and / or operating parameters of the motor when the relay is closed, the real-time operating status of the motor and the electric drive system can be effectively adapted to avoid potential electrical risks. The energy management and operating efficiency of the electric drive system can also be optimized, the service life of the electrical device in the electric drive system can be extended, and the driving quality and safety of vehicles using the electric drive system can be improved.

[0093] Optionally, combined Figure 1 , Figure 2As shown, the operating parameters include back electromotive force; when the relay is closed, according to at least one of the acquired operating mode and operating parameters of the motor, before the second preset control is performed on the motor by the inverter, the motor control method also includes:

[0094] When the operation mode is the fault mode, the motor is actively short-circuited, coasted or zero-torque controlled through the inverter.

[0095] Specifically, when there is no operating condition such as load dumping that causes the relay to disconnect, the relay is in a closed state and the motor operates normally. At this time, if the motor or the electric drive system has a corresponding abnormality or fault, the motor enters the fault mode. In the fault mode, in order to prevent the corresponding operating conditions of the motor from affecting the circuit where the motor is located (such as a circuit including the motor, inverter, power battery, etc.), the motor is actively short-circuited, coasted, or controlled by zero torque through the inverter. Among them, according to the actual situation of the fault, the motor can be actively short-circuited, coasted, or controlled by zero torque through the inverter to prevent the fault from worsening and reduce the impact of the fault on the corresponding components.

[0096] When the relay is closed, according to at least one of the acquired operation mode and operation parameters of the motor, performing a second preset control on the motor through the inverter includes:

[0097] When the relay is closed, if the back EMF is greater than the DC bus voltage of the inverter, the motor is actively short-circuited or zero-torque controlled through the inverter;

[0098] When the relay is closed, if the back electromotive force is less than or equal to the DC bus voltage of the inverter, the motor is subjected to coasting control or zero torque control through the inverter.

[0099] Specifically, when the motor operation mode is a fault mode, and the inverter is used to actively short-circuit control, coast control, or zero-torque control the motor, based on the switching state of the relay and the real-time monitoring of the motor's back electromotive force, if the relay is closed and the motor's back electromotive force is greater than the DC bus voltage of the inverter, the motor may reverse charge the power battery, which may cause the risk of overvoltage or overcurrent. In this case, the inverter is used to actively short-circuit control or zero-torque control the motor to absorb or consume excess energy generated by the motor, prevent excessive voltage or current in the circuit where the high-voltage system is located, and protect electrical devices in the high-voltage system.

[0100] When the motor operation mode is a fault mode and the inverter is used to actively short-circuit control or coast control the motor, based on the switch state of the relay and the real-time monitoring of the motor's back electromotive force, if the relay is closed and the motor's back electromotive force is less than or equal to the inverter's DC bus voltage, it means that the motor's current speed is low and the energy generated by the motor is insufficient to cause risks such as overvoltage or overcurrent in the high-voltage system. In this case, the inverter is used to coast the motor so that the motor can rotate freely without consuming unnecessary energy or generating additional stress on the electrical system. Alternatively, the inverter is used to perform zero-torque control on the motor so that the motor maintains a stable operating state without generating any additional torque output, or to prevent the motor from continuing to accelerate and generating excessive back electromotive force.

[0101] Optionally, combined Figure 1 , Figure 2 As shown, after the motor is coasted by the inverter, the motor control method further includes:

[0102] When receiving an operation mode request, determining whether the relay is closed;

[0103] If the relay is closed, the motor is controlled to run according to the operation mode request;

[0104] If the relay is not closed, and at least one of the current is greater than or equal to the first preset limit, the voltage is greater than or equal to the second preset limit, and the speed is greater than or equal to the third preset limit is satisfied, actively short-circuit the motor through the inverter;

[0105] If the relay is not closed, and the current is less than the first preset limit, the voltage is less than the second preset limit, and the speed is less than the third preset limit, the motor is controlled by the inverter to maintain inertial gliding control.

[0106] Considering that the switch state of the relay may change, such as disconnecting the relay when a power battery fault is detected, and the relay may close again or remain disconnected for other reasons after the power battery fault is eliminated; and because the switch state of the relay directly affects the electrical connection between the motor and the battery, and thus affects the operation mode of the motor and the protection requirements for the motor and the electric drive system. Therefore, the control mode used for the motor also needs to be adaptively adjusted according to the change of the switch state of the relay.

[0107] Under the premise of coasting the motor through the inverter, when a request for an operating mode (referred to as an operating mode request) is received, the current switching state of the relay is obtained to determine whether to respond to the request based on the current switching state of the relay.

[0108] Specifically, under the premise of coasting control of the motor through the inverter, when a request for the operating mode (referred to as the operating mode request) is received, if the relay is closed again (i.e., changed from the open state to the closed state), the request is responded to, and the motor is controlled to operate in the operating mode corresponding to the request according to the request. In this way, by adjusting the motor operating mode according to actual needs after coasting control, unnecessary energy loss can be avoided, and the motor can be ensured to operate in a suitable mode, thereby optimizing the overall energy efficiency of the vehicle. And the operating mode request response based on the coasting control with a low motor speed can, on the one hand, quickly and smoothly switch the motor from the coasting state to other modes, avoiding driving experience fluctuations caused by the sudden application or cancellation of torque by the motor; on the other hand, it can effectively reduce the electrical stress during the change of motor speed, reduce the mechanical and electrical loads on the inverter and the motor itself, thereby improving the reliability and service life of the electric drive system.

[0109] Under the premise of inertial gliding control of the motor through the inverter, when a request for the operating mode is received (recorded as the operating mode request), if the relay is not closed (continues to be disconnected), and at least one of the current is greater than or equal to the first preset limit, the voltage is greater than or equal to the second preset limit, and the speed is greater than or equal to the third preset limit, it means that the motor is in a high load or high speed state at this time. At this time, it is necessary to continue to take active short-circuit control of the motor to limit the further increase of the motor speed, reduce the motor voltage, and reduce the motor current, so as to protect the motor, the electric drive system, and the high-voltage system.

[0110] Under the premise of inertial gliding control of the motor through the inverter, when a request for the operating mode is received (recorded as the operating mode request), if the relay is not closed (continues to be disconnected), and the current current of the motor is less than the first preset limit, the voltage is less than the second preset limit, and the speed is less than the third preset limit, it means that the motor is in a low load or low speed state at this time. The energy generated by the motor is relatively small and its operating conditions are relatively stable. Therefore, there is no need to continue to take active short-circuit control of the motor at this time, but inertial gliding control of the motor is taken to avoid unnecessary energy consumption and braking torque generation, thereby improving the driving comfort of the vehicle.

[0111] In this way, based on the real-time monitoring of the switching state of the relay and the operating parameters of the motor, such as the current, voltage and speed, the motor control mode suitable for the current motor and electric drive system is dynamically selected to adapt to the actual operating state of the motor and the electric drive system. The motor control method can adapt to the dynamic changes of the switching state of the relay, the operating parameters of the motor, etc., and can achieve the best operating effect and system protection under various working conditions, thereby improving the stability, reliability and safety of the operation of the motor and the electric drive system, and improving the applicability of the motor control method; or adapting to user needs and improving user experience.

[0112] Optionally, combined Figure 1 , Figure 2 As shown, after the motor is actively short-circuited by the inverter, the motor control method further includes:

[0113] If the relay continues to be disconnected, and the current is less than the fourth preset limit, the voltage is less than the fifth preset limit, and the speed is less than the sixth preset limit, the motor is coasted by the inverter;

[0114] If the relay continues to be disconnected and at least one of the current is greater than or equal to the fourth preset limit, the voltage is greater than or equal to the fifth preset limit, and the speed is greater than or equal to the sixth preset limit is satisfied, the motor is controlled by the inverter to maintain active short-circuit control;

[0115] If the relay is closed again, the motor is controlled to operate according to the operating mode request when the operating mode request is received.

[0116] Considering that the switch state of the relay may change, such as disconnecting the relay when a power battery fault is detected, and the relay may close again or remain disconnected for other reasons after the power battery fault is eliminated; and because the switch state of the relay directly affects the electrical connection between the motor and the battery, and thus affects the operation mode of the motor and the protection requirements for the motor and the electric drive system. Therefore, the control mode used for the motor also needs to be adaptively adjusted according to the change of the switch state of the relay.

[0117] Specifically, after the motor is actively short-circuited through the inverter, according to the switching state of the relay monitored in real time, when the relay continues to be disconnected, and the current current of the motor is less than the fourth preset limit, the voltage is less than the fifth preset limit, and the speed is less than the sixth preset limit, it means that the motor is in a low load or low speed state at this time. The energy generated by the motor is relatively small and its operating conditions are relatively stable. Therefore, there is no need to continue to take active short-circuit control of the motor at this time. Instead, the motor is controlled by inertia gliding to avoid unnecessary energy consumption and the generation of braking torque, thereby improving the driving comfort of the vehicle.

[0118] After the motor is actively short-circuited through the inverter, according to the real-time monitoring of the switching state of the relay, when the relay continues to be disconnected and at least one of the current is greater than or equal to the fourth preset limit, the voltage is greater than or equal to the fifth preset limit, and the speed is greater than or equal to the sixth preset limit, it means that the motor is in a high load or high speed state. At this time, it is necessary to continue to take active short-circuit control of the motor to limit the further increase in the motor speed, reduce the motor voltage, reduce the motor current, and play a protective role in the motor and the electric drive system.

[0119] After the inverter actively short-circuit controls the motor, based on the real-time monitoring of the switch state of the relay, when the relay is closed again (i.e., changes from an open state to a closed state), it indicates that the fault that previously disconnected the relay may have been eliminated, and the electrical connection between the power battery and the inverter and the motor is restored. At this point, the motor regains the power supply required for normal operation and can respond to operating mode requests.

[0120] In this way, according to the real-time monitoring of the switching state of the relay and the operating parameters of the motor such as the current, voltage and speed, the motor control mode suitable for the current motor and electric drive system is dynamically selected to adapt to the actual operating state of the motor and the electric drive system, that is, the motor control method can adapt to the dynamic changes of the switching state of the relay and the operating parameters of the motor, and can achieve the best operating effect and system protection under various working conditions, thereby improving the stability, reliability and safety of the operation of the motor and the electric drive system, and improving the applicability of the motor control method. Moreover, it avoids the problem that the motor is always kept in the same mode, which is easy to cause the motor or the corresponding device to fail, such as the problem that the motor is actively short-circuited for a long time when the relay is in the open state, which is easy to cause the motor to overheat, demagnetize or even ablate, and the problem that when the motor speed drops to a low level, a large braking torque will be generated, which will affect the comfort and stability of the vehicle.

[0121] Optionally, the fourth preset limit, the fifth preset limit and the sixth preset limit can be set according to demand. Among them, the fourth preset limit is a preset current limit (or threshold value). When the motor current is greater than or equal to the fourth preset limit, it is considered that the current is too large, which may cause the motor to overheat or damage. The fifth preset limit is a preset voltage limit. When the motor voltage is greater than or equal to the fifth preset limit, it is considered that the voltage is too large, which may cause the motor to be damaged. The sixth preset limit is a preset speed limit. When the motor speed is greater than or equal to the sixth preset limit, it is considered that the speed is high. In some embodiments, considering that during active short-circuit control, the motor winding is short-circuited, which will cause the motor current, voltage and speed to change accordingly, therefore, in order to ensure that when the current, voltage and speed of the motor change to meet the corresponding conditions, the motor can be controlled accordingly in time to better adapt to the actual operating state of the motor and ensure the safety and stability of the motor and the electric drive system, it can be achieved by setting a fourth preset limit that is different from the first preset limit, a fifth preset limit that is different from the second preset limit, and a sixth preset limit that is different from the third preset limit.

[0122] Combination Figure 6 As shown, another embodiment of the present invention provides a motor control device, comprising:

[0123] The motor control unit is used to control the motor according to the above-mentioned motor control method through the inverter according to the operating mode and operating parameters of the motor in the electric drive system when the relay used to connect the power battery and the inverter in the electric drive system is disconnected.

[0124] Specifically, the motor control unit is used to perform a first preset control of the motor through the inverter according to the operating mode and operating parameters of the motor in the electric drive system when the relay used to connect the power battery and the inverter in the electric drive system is disconnected; wherein the first preset control includes one of active short-circuit control, inertial gliding control and zero torque control.

[0125] The motor control device of this embodiment is used to implement the above-mentioned motor control method. Its advantages over the prior art are the same as the advantages of the above-mentioned motor control method over the prior art, which will not be repeated here.

[0126] Optionally, the motor control device is specifically used for: when the relay is disconnected, if the operating mode is a torque mode, and the current is less than a first preset limit, the voltage is less than a second preset limit, and the speed is less than a third preset limit, the motor is controlled to coast through the inverter; when the relay is disconnected, if the operating mode is a torque mode, and at least one of the current is greater than or equal to the first preset limit, the voltage is greater than or equal to the second preset limit, and the speed is greater than or equal to the third preset limit is satisfied, the motor is actively short-circuited through the inverter.

[0127] Optionally, the motor control device is specifically used to: after actively short-circuiting the motor through the inverter, if the relay continues to be disconnected, and the current is less than a first preset limit, the voltage is less than a second preset limit, and the speed is less than a third preset limit, the motor is coasted through the inverter; if the relay continues to be disconnected, and at least one of the current is greater than or equal to the first preset limit, the voltage is greater than or equal to the second preset limit, and the speed is greater than or equal to the third preset limit is satisfied, the motor is actively short-circuited through the inverter; if the relay is reopened, and the back electromotive force is greater than the DC bus voltage of the inverter, the motor is actively short-circuited or zero-torque controlled through the inverter; if the relay is reopened, and the back electromotive force is less than or equal to the DC bus voltage of the inverter, the motor is coasted through the inverter.

[0128] Optionally, the motor control device is specifically used for: when the relay is disconnected, if the operating mode is initialization mode or standby mode, and the speed is greater than the seventh preset limit, actively short-circuiting the motor through the inverter; if the operating mode is initialization mode or standby mode, and the speed is less than or equal to the seventh preset limit, inertia gliding control of the motor is performed through the inverter.

[0129] Optionally, the motor control device is specifically used for: when the operating mode is a fault mode, after the motor is actively short-circuited or coasted through the inverter, when the relay is disconnected, if the speed is greater than a seventh preset limit, the motor is actively short-circuited through the inverter; if the speed is less than or equal to the seventh preset limit, the motor is coasted through the inverter.

[0130] Optionally, the motor control device is further used to: when the relay is closed, perform a second preset control on the motor through the inverter according to at least one of the acquired operating mode and operating parameters of the motor.

[0131] Optionally, the motor control device is specifically used for: when the operating mode is the torque mode, if the relay is closed, the operating mode of the motor is maintained in the torque mode through the inverter; or, when the operating mode is the initialization mode or the standby mode, if the relay is closed and the back electromotive force is greater than the DC bus voltage of the inverter, the motor is actively short-circuited or zero-torque controlled through the inverter; when the operating mode is the initialization mode or the standby mode, if the relay is closed and the back electromotive force is less than or equal to the DC bus voltage of the inverter, the motor is inertial gliding controlled through the inverter.

[0132] Optionally, the motor control device is specifically used for: when the operating mode is a fault mode, after the motor is actively short-circuited or coasted through the inverter, when the relay is closed, if the back electromotive force is greater than the DC bus voltage of the inverter, the motor is actively short-circuited or zero-torque controlled through the inverter; if the back electromotive force is less than or equal to the DC bus voltage of the inverter, the motor is coasted through the inverter.

[0133] Optionally, the motor control device is specifically configured to: after controlling the operation mode of the motor to be maintained in the torque mode through the inverter, when receiving an operation mode request, control the operation of the motor according to the operation mode request.

[0134] Optionally, the motor control device is specifically used for: after performing coasting control on the motor through the inverter, when receiving an operation mode request, controlling the motor to operate according to the operation mode request.

[0135] Combination Figure 7 As shown, another embodiment of the present invention provides a vehicle, including a memory 701 and a processor 702;

[0136] Memory 701, used for storing computer programs;

[0137] The processor 702 is used to implement the above motor control method when executing the computer program.

[0138] In other words, a vehicle includes a memory 701 and a processor 702 coupled to the memory 701; the memory 701 is configured to store a computer program; and the processor 702 is configured to perform the following operations when executing the computer program:

[0139] When the relay used to connect the power battery and the inverter in the electric drive system is disconnected, the motor is subjected to a first preset control through the inverter according to the operating mode and operating parameters of the motor in the electric drive system; wherein the first preset control includes one of active short-circuit control, inertial gliding control and zero torque control.

[0140] The vehicle of this embodiment can be used to implement the above-mentioned motor control method. Its advantages over the prior art are the same as the advantages of the above-mentioned motor control method over the prior art, which will not be repeated here.

[0141] Another embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is read and executed by a processor, the above-mentioned motor control method is implemented.

[0142] In other words, a non-volatile computer-readable storage medium stores a computer program, which, when executed by a processor, causes the processor to perform the following operations:

[0143] When the relay used to connect the power battery and the inverter in the electric drive system is disconnected, the motor is subjected to a first preset control through the inverter according to the operating mode and operating parameters of the motor in the electric drive system; wherein the first preset control includes one of active short-circuit control, inertial gliding control and zero torque control.

[0144] The technical solution of the embodiment of the present invention, in essence or in other words, the part that contributes to the prior art, or the whole or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for making a computer device (which can be a personal computer, server, or network device, etc.) or a processor perform all or part of the steps of the method of the embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

[0145] The computer-readable storage medium of this embodiment can be used to implement the above-mentioned motor control method. Its advantages over the prior art are the same as the advantages of the above-mentioned motor control method over the prior art, which will not be repeated here.

[0146] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A motor control method, characterized in that: include: When a relay for connecting a power battery and an inverter in an electric drive system is disconnected, the motor is subjected to a first preset control through the inverter according to an operating mode and operating parameters of the motor in the electric drive system; wherein the first preset control includes one of active short-circuit control, inertial gliding control and zero torque control.

2. The motor control method according to claim 1, characterized in that: The operating parameters include current, voltage and speed; when the relay for connecting the power battery and the inverter in the electric drive system is disconnected, performing a first preset control on the motor through the inverter according to the operating mode and operating parameters of the motor in the electric drive system includes: When the relay is disconnected, if the operation mode is the torque mode, and the current is less than the first preset limit, the voltage is less than the second preset limit, and the speed is less than the third preset limit, the motor is coasted by the inverter; When the relay is disconnected, if the operating mode is the torque mode, and at least one of the current is greater than or equal to the first preset limit, the voltage is greater than or equal to the second preset limit, and the speed is greater than or equal to the third preset limit, the active short-circuit control of the motor is performed through the inverter.

3. The motor control method according to claim 1, characterized in that: The operating parameter includes a rotation speed; when a relay for connecting a power battery and an inverter in the electric drive system is disconnected, performing a first preset control on the motor through the inverter according to an operating mode and operating parameters of the motor in the electric drive system includes: When the relay is disconnected, if the operation mode is the initialization mode or the standby mode, and the rotation speed is greater than a seventh preset limit value, the active short-circuit control is performed on the motor through the inverter; When the relay is disconnected, if the operation mode is the initialization mode or the standby mode, and the rotation speed is less than or equal to the seventh preset limit, the motor is subjected to the inertial gliding control through the inverter.

4. The motor control method according to claim 1, characterized in that: The operating parameter includes a rotation speed; when the relay for connecting the power battery and the inverter in the electric drive system is disconnected, before the first preset control is performed on the motor by the inverter according to the operating mode and operating parameters of the motor in the electric drive system, the motor control method further includes: When the operation mode is a fault mode, the active short-circuit control, the coasting control or the zero-torque control is performed on the motor through the inverter; When the relay for connecting the power battery and the inverter in the electric drive system is disconnected, performing a first preset control on the motor through the inverter according to the operation mode and operation parameters of the motor in the electric drive system includes: When the relay is disconnected, if the rotation speed is greater than a seventh preset limit value, the motor is actively short-circuited through the inverter; When the relay is disconnected, if the rotation speed is less than or equal to the seventh preset limit value, the motor is subjected to the coasting control through the inverter.

5. The motor control method according to any one of claims 1 to 4, characterized in that: Also includes: When the relay is closed, the motor is subjected to a second preset control through the inverter according to at least one of the acquired operation mode and operation parameters of the motor.

6. The motor control method according to claim 5, characterized in that: The operating parameter includes a back electromotive force; when the relay is closed, according to at least one of the acquired operating mode and operating parameter of the motor, performing a second preset control on the motor through the inverter includes: When the operation mode is the torque mode, if the relay is closed, the motor is controlled by the inverter to maintain the current operation mode, and when an operation mode request is received, the motor is controlled to operate according to the operation mode request; Or, when the operating mode is the initialization mode or the standby mode, if the relay is closed and the back electromotive force is greater than the DC bus voltage of the inverter, the inverter is used to perform the active short-circuit control or the zero-torque control on the motor; when the operating mode is the initialization mode or the standby mode, if the relay is closed and the back electromotive force is less than or equal to the DC bus voltage of the inverter, the inverter is used to perform the inertial gliding control or the zero-torque control on the motor.

7. The motor control method according to claim 5, characterized in that: The operating parameter includes a back electromotive force; when the relay is closed, before the motor is subjected to a second preset control by the inverter according to at least one of the acquired operating mode and operating parameter of the motor, the motor control method further includes: When the operation mode is a fault mode, the active short-circuit control, the coasting control or the zero-torque control is performed on the motor through the inverter; When the relay is closed, performing a second preset control on the motor through the inverter according to at least one of the acquired operation mode and operation parameters of the motor includes: When the relay is closed, if the back electromotive force is greater than the DC bus voltage of the inverter, the motor is subjected to the active short-circuit control or the zero-torque control through the inverter; When the relay is closed, if the back electromotive force is less than or equal to the DC bus voltage of the inverter, the motor is subjected to the inertial gliding control or the zero torque control through the inverter.

8. The motor control method according to any one of claims 2 to 4, characterized in that: After the inverter performs the coasting control on the motor, the motor control method further includes: When receiving an operation mode request, determining whether the relay is closed; If the relay is closed, the motor is controlled to operate according to the operation mode request; If the relay is not closed, and at least one of the current is greater than or equal to the first preset limit, the voltage is greater than or equal to the second preset limit, and the speed is greater than or equal to the third preset limit is satisfied, the active short-circuit control is performed on the motor through the inverter; If the relay is not closed, and the current is less than the first preset limit, the voltage is less than the second preset limit, and the speed is less than the third preset limit, the motor is controlled by the inverter to maintain the inertial gliding control.

9. The motor control method according to any one of claims 2 to 4, characterized in that: After the active short-circuit control is performed on the motor by the inverter, the motor control method further includes: If the relay continues to be disconnected, and the current is less than the fourth preset limit, the voltage is less than the fifth preset limit, and the speed is less than the sixth preset limit, the motor is subjected to the inertial gliding control through the inverter; If the relay continues to be disconnected and at least one of the current is greater than or equal to the fourth preset limit, the voltage is greater than or equal to the fifth preset limit, and the speed is greater than or equal to the sixth preset limit is satisfied, the motor is controlled by the inverter to remain in the active short-circuit control; If the relay is closed again, the motor is controlled to operate according to the operation mode request when an operation mode request is received.

10. A motor control device, characterized in that: include: A motor control unit, used to control the motor through the inverter according to the motor control method described in any one of claims 1 to 9 according to the operating mode and operating parameters of the motor in the electric drive system when the relay used to connect the power battery and the inverter in the electric drive system is disconnected.

11. A vehicle, characterized in that: including memory and processor; The memory is used to store computer programs; The processor is used to implement the motor control method according to any one of claims 1 to 9 when executing the computer program.

12. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is read and executed by a processor, the motor control method according to any one of claims 1 to 9 is implemented.

Images