Drive motor failure protection method, device, equipment and readable storage medium

Abstract

A drive motor failure protection method, device, equipment, and readable storage medium. The drive motor failure protection method includes: when a vehicle's drive motor experiences a power loss fault, controlling the drive motor to shut down; if the drive motor speed is greater than or equal to a preset intervention speed, controlling the generator to output electric torque to consume the back electromotive force feedback energy generated by the drive motor. This application is passed. When a vehicle's drive motor experiences a power loss fault, controlling the drive motor to shut down. If the drive motor speed is greater than or equal to the preset intervention speed, it means that there is a risk that the back electromotive force amplitude generated by the drive motor is higher than the bus capacitor voltage. Therefore, by controlling the generator to output electric torque to consume the back electromotive force feedback energy generated by the high-speed operation of the drive motor, the risk of current backflow caused by the back electromotive force amplitude being higher than the bus capacitor voltage is avoided, thereby providing effective protection for the drive motor system.

Description

Technical Field

[0001] The present application relates to the field of motor control technology, and in particular to a method, device, equipment and readable storage medium for failure protection of a drive motor. Background Art

[0002] With the popularization of new energy vehicles, plug-in hybrid vehicles are becoming more and more popular among consumers. Their power systems usually include drive motors, generators, dual-motor controllers (including drive motor controller units and generator control units), gearboxes and engines, among which the drive motors usually adopt high-efficiency and high-power-density permanent magnet synchronous motors.

[0003] When a vehicle is traveling at high speed, if the drive motor system experiences a serious power loss fault, such as overcurrent, overvoltage, resolver fault, or IGBT (Insulated Gate Bipolar Transistor) module fault, a large back-electromotive force (BEMF) will be generated. The higher the vehicle speed and the higher the drive motor speed, the greater the back-electromotive force. When the back-electromotive force voltage amplitude is higher than the bus capacitor voltage, current backflow will occur, causing damage to the IGBT switching device and bus capacitor. Therefore, it is necessary to promptly consume the feedback energy generated by the drive motor's back-electromotive force. The commonly used protection strategy is active short-circuit control, which puts the three phases of the drive motor in a short-circuit state, thereby generating a large short-circuit current and forming a reverse braking torque, quickly consuming the feedback energy generated by the drive motor's back-electromotive force to protect the safety of the device and the entire vehicle.

[0004] However, the active short-circuit protection strategy will generate a large short-circuit current in a short period of time, causing the local temperature of the controller to rise sharply. Continuous active short-circuit control strategy will cause the drive motor to overheat, leading to the risk of demagnetization of the drive motor rotor magnet. Especially when the fault of the drive motor is a serious fault such as an IGBT bridge arm short circuit, the opening of the active short-circuit protection strategy switch will cause a short circuit between the upper and lower bridge arms, and even cause a huge risk of power battery fire. Summary of the Invention

[0005] The present application provides a drive motor failure protection method, device, equipment and readable storage medium, which aims to solve the technical problem that when a vehicle is driving at high speed and a serious fault such as power loss occurs in the drive motor system, the use of an active short-circuit protection strategy will generate a large short-circuit current in a short period of time, causing the local temperature of the controller to rise sharply. The continuous active short-circuit control strategy will cause the drive motor to overheat, resulting in the risk of demagnetization of the drive motor rotor magnet. In particular, when the fault of the drive motor is a serious fault such as an IGBT bridge arm short circuit, the opening of the active short-circuit protection strategy switch will cause a short circuit between the upper and lower bridge arms, and may even cause the power battery to catch fire.

[0006] In a first aspect, an embodiment of the present application provides a method for protecting a drive motor from failure, the method comprising:

[0007] When the vehicle's drive motor loses power, the drive motor is controlled to shut down;

[0008] If the speed of the drive motor is greater than or equal to the preset intervention speed, the generator is controlled to output electric torque to consume the back electromotive force feedback energy generated by the drive motor.

[0009] Optionally, after controlling the generator to output electric torque to consume back electromotive force feedback energy generated by the drive motor, the method further includes:

[0010] If the driving motor speed is less than or equal to the preset exit speed, the generator and engine are controlled to stop;

[0011] If the driving motor speed is greater than the preset exit speed, the process returns to executing the step of controlling the generator to output electric torque to consume the back electromotive force feedback energy generated by the driving motor. The preset exit speed is the difference between the preset intervention speed and the preset hysteresis speed.

[0012] Optionally, controlling the generator to output electric torque includes:

[0013] According to the current bus capacitor voltage and drive motor speed, the value of the electric torque is determined by looking up the calibration relationship table between the bus capacitor voltage, drive motor speed and electric torque;

[0014] The generator is controlled to output electric torque at a determined value.

[0015] Optionally, before determining the value of the electric torque by searching a calibration relationship table between the bus capacitor voltage, the drive motor speed, and the electric torque according to the current bus capacitor voltage and the drive motor speed, the method further includes:

[0016] Under different bus capacitor voltages and drive motor speeds, when the drive motor has a power loss fault and the back electromotive force is greater than the bus capacitor voltage, the size of the generator output electric torque is adjusted, and the value of the generator output electric torque when the back electromotive force is equal to the bus capacitor voltage is recorded to obtain a calibration relationship table between the bus capacitor voltage, drive motor speed and electric torque.

[0017] Optionally, controlling the generator to output electric torque further includes:

[0018] If the generator is in standby mode, the generator is started and enters torque mode to output electric torque;

[0019] If the generator is in torque mode, the generator maintains the torque mode and outputs electric torque.

[0020] If the generator is operating in speed mode, it switches to torque mode and outputs electric torque.

[0021] In a second aspect, an embodiment of the present application provides a drive motor failure protection device, the drive motor failure protection device comprising:

[0022] The first control module is used to control the drive motor to shut down when a power loss failure occurs in the drive motor of the vehicle;

[0023] The second control module is configured to control the generator to output electric torque if the speed of the drive motor is greater than or equal to a preset intervention speed, so as to consume the back electromotive force feedback energy generated by the drive motor.

[0024] Optionally, the drive motor failure protection device further includes an exit module, configured to:

[0025] If the driving motor speed is less than or equal to the preset exit speed, the generator and engine are controlled to stop;

[0026] If the driving motor speed is greater than the preset exit speed, the process returns to executing the step of controlling the generator to output electric torque to consume the back electromotive force feedback energy generated by the driving motor. The preset exit speed is the difference between the preset intervention speed and the preset hysteresis speed.

[0027] Optionally, the second control module is configured to:

[0028] According to the current bus capacitor voltage and drive motor speed, the value of the electric torque is determined by looking up the calibration relationship table between the bus capacitor voltage, drive motor speed and electric torque;

[0029] The generator is controlled to output electric torque at a determined value.

[0030] In a third aspect, an embodiment of the present application provides a drive motor failure protection device, which includes a processor, a memory, and a drive motor failure protection program stored in the memory and executable by the processor, wherein when the drive motor failure protection program is executed by the processor, the steps of the drive motor failure protection method described above are implemented.

[0031] In a fourth aspect, an embodiment of the present application provides a readable storage medium, on which a drive motor failure protection program is stored. When the drive motor failure protection program is executed by a processor, the steps of the drive motor failure protection method as described above are implemented.

[0032] The beneficial effects of the technical solutions provided in the embodiments of the present application include:

[0033] In an embodiment of the present application, when a power loss fault occurs in the vehicle's drive motor, the drive motor is controlled to be shut down; if the drive motor speed is greater than or equal to a preset intervention speed, the generator is controlled to output electric torque to consume the back electromotive force feedback energy generated by the drive motor. According to an embodiment of the present application, when a power loss fault occurs in the vehicle's drive motor, the drive motor is controlled to be shut down. If the drive motor speed is greater than or equal to the preset intervention speed, it means that the current vehicle speed is high, the drive motor speed is high, and there is a risk that the back electromotive force amplitude generated by the drive motor will exceed the bus capacitor voltage. Therefore, by controlling the generator to output electric torque to consume the back electromotive force feedback energy generated by the high-speed operation of the drive motor, the risk of current backflow caused by the back electromotive force amplitude exceeding the bus capacitor voltage can be avoided. This provides effective protection for the drive motor system when a power loss fault occurs in the drive motor system during high-speed driving of the vehicle, and also avoids a series of risks that may arise from the use of an active short-circuit protection strategy. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a flow chart of an embodiment of a method for protecting a drive motor from failure according to the present application;

[0035] Figure 2 This is another flowchart of an embodiment of the drive motor failure protection method of the present application;

[0036] Figure 3 For this application Figure 1 Detailed flow chart of step S20;

[0037] Figure 4 This is a functional module diagram of an embodiment of a drive motor failure protection device of the present application;

[0038] Figure 5 This is a schematic diagram of the hardware structure of the drive motor failure protection device involved in the embodiment of the present application. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0040] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0041] In a first aspect, an embodiment of the present application provides a method for protecting a drive motor from failure.

[0042] In one embodiment, referring to Figure 1 , Figure 1 This is a flow chart of an embodiment of the drive motor failure protection method of the present application. Figure 1 As shown, the drive motor failure protection method includes:

[0043] Step S10: When a power loss fault occurs in the driving motor of the vehicle, the driving motor is controlled to shut down.

[0044] In this embodiment, applied to hybrid vehicles, power loss faults include overcurrent, overvoltage, resolver faults, and IGBT module faults. Specifically, relevant detection algorithms can be used to detect these fault conditions, thereby determining whether the vehicle's drive motor has experienced a power loss fault. In the event of a power loss fault in the vehicle's drive motor, the drive motor is shut down. This shut-down means shutting down all IGBTs in the drive motor, i.e., all IGBTs are inoperative, and the drive motor enters an open-circuit protection operating state. If the drive motor's speed is low, in the open-circuit protection operating state, the back EMF generated by the drive motor is lower than the bus capacitor voltage, preventing it from being rectified and fed back to the high-voltage battery via the freewheeling diode, thus failing to form a closed circuit. In this case, the back EMF of the drive motor will not cause any impact damage to devices connected to the DC bus.

[0045] In step S20 , if the speed of the driving motor is greater than or equal to the preset intervention speed, the generator is controlled to output electric torque to consume the back electromotive force feedback energy generated by the driving motor.

[0046] In this embodiment, when the vehicle is traveling at a high speed and the drive motor has a power loss fault, the speed of the drive motor is high, and the back electromotive force amplitude generated by the high-speed operation of the drive motor may be higher than the bus capacitor voltage. In order to avoid the risk that the back electromotive force amplitude generated by the high-speed operation of the drive motor may be higher than the bus capacitor voltage, if it is further detected that the drive motor speed is greater than or equal to the preset intervention speed, it means that the current vehicle speed is high, the drive motor speed is high, and there is a risk that the back electromotive force amplitude generated by the high-speed operation of the drive motor will be higher than the bus capacitor voltage. Therefore, by controlling the generator to output electric torque to consume the back electromotive force feedback energy generated by the high-speed operation of the drive motor, the risk of current backflow caused by the back electromotive force amplitude being higher than the bus capacitor voltage can be avoided. This provides effective protection for the drive motor system when the vehicle is traveling at high speed and the drive motor system has a power loss fault, and also avoids a series of risks that may be caused by the use of an active short-circuit protection strategy. The preset intervention speed can be set with reference to the relationship between the drive motor speed and the generated back electromotive force and the bus capacitor voltage. For example, to ensure safety, a slightly smaller safety value can be set for the bus capacitor voltage based on the rated operating voltage. The back electromotive force generated by the preset intervention speed is smaller than the safety value of the bus capacitor voltage. Current backflow refers to the flow of current into the power supply, because current always flows into a place with low potential, such as a voltage source, which generally outputs current. However, if there is another power supply at the same time and the potential is higher than this power supply, current will flow into this power supply, which is called backflow. It is similar to a battery, which can be charged or discharged. Regarding the back electromotive force of the motor, according to the law of electromagnetics, when the magnetic field changes, the nearby conductor will generate an induced electromotive force, the direction of which conforms to Faraday's law and Lenz's law, and is exactly opposite to the voltage originally applied to the two ends of the coil. This voltage is the back electromotive force. The rotation of the motor rotor cuts the magnetic lines of force to generate an induced electromotive force, the direction of which is opposite to the external voltage, so it is called the motor "back electromotive force". The back electromotive force of the permanent magnet synchronous motor refers to an electric potential generated by the motor during operation, which is opposite to the direction of rotation of the motor rotor. Its magnitude is proportional to the motor speed, the magnetic flux density, and the number of pole pairs. The role of the back electromotive force is to offset the potential supplied to the motor by the power supply, thereby ensuring that the motor can maintain a stable speed under a certain load.

[0047] In this embodiment, applied to a hybrid vehicle, a specific fault loss scenario can be detected using a relevant detection algorithm. When a power loss fault is determined in the vehicle's drive motor, the drive motor is controlled to shut down, that is, all IGBTs of the drive motor are turned off, and the drive motor enters an open-circuit protection state. If the drive motor speed is low, during the open-circuit protection state, the back EMF generated by the drive motor is lower than the bus capacitor voltage and cannot be rectified and fed back to the high-voltage battery through the freewheeling diode, thus failing to form a closed circuit. In this case, the back EMF of the drive motor does not cause any impact damage to devices connected to the DC bus. Furthermore, if the drive motor speed is detected to be greater than or equal to a preset intervention speed, it indicates that the current vehicle speed is high. The back EMF amplitude generated by the high-speed drive motor is high, and there is a risk that it will exceed the bus capacitor voltage. Therefore, by controlling the generator to output electric torque to dissipate the back EMF feedback energy generated by the high-speed drive motor, the risk of current backflow caused by the back EMF amplitude exceeding the bus capacitor voltage is avoided. This provides effective protection for the drive motor system when a power loss fault occurs during high-speed driving, and avoids a series of risks that may arise from the use of active short-circuit protection strategies.

[0048] Furthermore, in one embodiment, referring to Figure 2 , Figure 2 This is another flow chart of an embodiment of the drive motor failure protection method of the present application. Figure 2 As shown, after step S20, the following steps are included:

[0049] Step S30: If the driving motor speed is less than or equal to the preset exit speed, the generator and the engine are controlled to stop;

[0050] In step S40, if the driving motor speed is greater than the preset exit speed, the process returns to executing the step of controlling the generator to output electric torque to consume the back electromotive force feedback energy generated by the driving motor. The preset exit speed is the difference between the preset intervention speed and the preset hysteresis speed.

[0051] In this embodiment, in the above-mentioned step S20, the generator is controlled to output electric torque. After consuming the back electromotive force generated by the drive motor, the speed of the drive motor will decrease. If the speed of the drive motor after the decrease is less than or equal to the preset exit speed, the generator and the engine are controlled to stop, and the vehicle is repaired for flameout faults. If the speed of the drive motor after the decrease is greater than the preset exit speed, it means that the speed of the drive motor is still high, and the back electromotive force generated by the drive motor is still high, and there is still a risk of exceeding the bus capacitor voltage. Therefore, the generator is continued to be controlled to output electric torque, and the back electromotive force feedback energy generated by the drive motor is continuously consumed. This situation is particularly suitable for the high-speed limp condition of four-wheel drive vehicles. When the front or rear drive motor of the four-wheel drive vehicle loses power, in order to provide a good car-using experience, it can be switched to use the motor that has not failed to continue driving the vehicle, and a higher vehicle speed may be maintained. For this working condition, it can provide good and continuous protection for the drive motor.

[0052] Furthermore, in one embodiment, referring to Figure 3 , Figure 3 For this application Figure 1 The detailed flow chart of step S20 is as follows: Figure 3 As shown, step S20 includes:

[0053] Step S201, determining the value of the electric torque by searching a calibration relationship table between the bus capacitor voltage, the drive motor speed, and the electric torque according to the current bus capacitor voltage and the drive motor speed;

[0054] Step S202 : controlling the generator to output electric torque according to a determined value.

[0055] In this embodiment, based on the current bus capacitor voltage and drive motor speed, the value of the electric torque corresponding to the current bus capacitor voltage and drive motor speed can be determined by looking up the calibration relationship table between the bus capacitor voltage, drive motor speed and electric torque, and then the generator is controlled to output the electric torque with the determined value. It should be noted that if there is no value of the electric torque corresponding to the current bus capacitor voltage and drive motor speed in the calibration relationship table, it can be determined by interpolation.

[0056] Furthermore, in one embodiment, before step S201, the following steps are included:

[0057] Under different bus capacitor voltages and drive motor speeds, when the drive motor has a power loss fault and the back electromotive force is greater than the bus capacitor voltage, the size of the generator output electric torque is adjusted, and the value of the generator output electric torque when the back electromotive force is equal to the bus capacitor voltage is recorded to obtain a calibration relationship table between the bus capacitor voltage, drive motor speed and electric torque.

[0058] In this embodiment, different bus capacitor voltages and drive motor speeds can be set under a bench test environment to create a power loss fault in the drive motor, and the back electromotive force is made greater than the bus capacitor voltage to control the drive motor to shut down. At this time, by adjusting the magnitude of the electric torque output by the generator, the value of the electric torque output by the generator when the back electromotive force is equal to the bus capacitor voltage is the value of the appropriate electric torque. The value of the electric torque is recorded, and the correspondence between the bus capacitor voltage, the drive motor speed and the electric torque is calibrated. For example, the correspondence between the drive motor speed and the electric torque under a certain bus capacitor voltage is shown in Table 1. In Table 1, the drive motor speed starts from the minimum speed n1 and is gradually adjusted to the maximum speed n1 in steps of 500 rpm (revolutions per minute). max Through the above calibration process, the electric torque corresponding to the speed of each driving motor under the bus capacitor voltage is obtained.

[0059] Table 1.

[0060] Drive motor speed <![CDATA[n1]]> <![CDATA[n1+500]]> <![CDATA[n1+1000]]> … <![CDATA[n max ]]> Electric torque <![CDATA[T1]]> <![CDATA[T2]]> <![CDATA[T3]]> … <![CDATA[T max ]]>

[0061] Furthermore, in one embodiment, step S20 further includes:

[0062] If the generator is in standby mode, the generator is started and enters torque mode to output electric torque;

[0063] If the generator is in torque mode, the generator maintains the torque mode and outputs electric torque.

[0064] If the generator is operating in speed mode, it switches to torque mode and outputs electric torque.

[0065] In this embodiment, if the generator is in the standby state, it is necessary to start the generator and put it into torque mode to output electric torque. Generators in the operating state generally have two modes: torque mode and speed mode. The speed mode controls the motor's speed, while the torque mode controls the motor's torque. The speed mode controls the motor's speed by changing parameters such as the motor's voltage, frequency, and current, thereby achieving control. The torque mode controls the motor's torque by changing parameters such as the motor's voltage and current, thereby achieving control. If the generator is in torque mode, the torque mode is maintained. If the generator is in speed mode, the generator is switched to torque mode, controlling the generator's output electric torque to consume the back electromotive force generated by the drive motor. The magnitude of the output electric torque can be determined using the method in step S201.

[0066] In a second aspect, an embodiment of the present application also provides a drive motor failure protection device.

[0067] In one embodiment, referring to Figure 4 , Figure 4 This is a functional module diagram of an embodiment of the drive motor failure protection device of the present application, as shown in FIG. Figure 4 As shown, the drive motor failure protection device includes:

[0068] The first control module 10 is used to control the drive motor to shut down when a power loss failure occurs in the drive motor of the vehicle;

[0069] The second control module 20 is configured to control the generator to output electric torque if the speed of the driving motor is greater than or equal to a preset intervention speed, so as to consume the back electromotive force feedback energy generated by the driving motor.

[0070] Furthermore, in one embodiment, the drive motor failure protection device further includes an exit module for:

[0071] If the driving motor speed is less than or equal to the preset exit speed, the generator and engine are controlled to stop;

[0072] If the driving motor speed is greater than the preset exit speed, the process returns to executing the step of controlling the generator to output electric torque to consume the back electromotive force feedback energy generated by the driving motor. The preset exit speed is the difference between the preset intervention speed and the preset hysteresis speed.

[0073] Furthermore, in one embodiment, the second control module 20 is configured to:

[0074] According to the current bus capacitor voltage and drive motor speed, the value of the electric torque is determined by looking up the calibration relationship table between the bus capacitor voltage, drive motor speed and electric torque;

[0075] The generator is controlled to output electric torque at a determined value.

[0076] Furthermore, in one embodiment, the drive motor failure protection device further includes a recording module, which is used to:

[0077] Under different bus capacitor voltages and drive motor speeds, when the drive motor has a power loss fault and the back electromotive force is greater than the bus capacitor voltage, the size of the generator output electric torque is adjusted, and the value of the generator output electric torque when the back electromotive force is equal to the bus capacitor voltage is recorded to obtain a calibration relationship table between the bus capacitor voltage, drive motor speed and electric torque.

[0078] Furthermore, in one embodiment, the second control module 20 is further configured to:

[0079] If the generator is in standby mode, the generator is started and enters torque mode to output electric torque;

[0080] If the generator is in torque mode, the generator maintains the torque mode and outputs electric torque.

[0081] If the generator is operating in speed mode, it switches to torque mode and outputs electric torque.

[0082] Among them, the functional implementation of each module in the above-mentioned drive motor failure protection device corresponds to the various steps in the above-mentioned drive motor failure protection method embodiment, and their functions and implementation processes will not be repeated here one by one.

[0083] In a third aspect, an embodiment of the present application provides a drive motor failure protection device.

[0084] Reference Figure 5 , Figure 5 Schematic diagram of the hardware structure of the drive motor failure protection device involved in the embodiment of the present application. In the embodiment of the present application, the drive motor failure protection device may include a processor, a memory, a communication interface and a communication bus.

[0085] The communication bus may be of any type and is used to interconnect the processor, memory, and communication interface.

[0086] Communication interfaces include input / output (I / O) interfaces, physical interfaces, and logical interfaces, which are used to interconnect components within the drive motor failure protection device, as well as interfaces used to interconnect the drive motor failure protection device with other devices (such as other computing devices or user devices). Physical interfaces can be Ethernet, fiber, or ATM interfaces; user devices can be displays, keyboards, and other devices.

[0087] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0088] The processor may be a general-purpose processor that can call a drive motor failure protection program stored in a memory and execute the drive motor failure protection method provided in the embodiments of the present application. For example, the general-purpose processor may be a central processing unit (CPU). The method executed when the drive motor failure protection program is called can refer to the various embodiments of the drive motor failure protection method of the present application and will not be repeated here.

[0089] Those skilled in the art will understand that Figure 5 The hardware structure shown in the figure does not constitute a limitation to the present application and may include more or fewer components than shown in the figure, or a combination of certain components, or a different arrangement of components.

[0090] In a fourth aspect, an embodiment of the present application also provides a readable storage medium.

[0091] The readable storage medium of the present application stores a drive motor failure protection program, wherein when the drive motor failure protection program is executed by the processor, the steps of the drive motor failure protection method as described above are implemented.

[0092] Among them, the method implemented when the drive motor failure protection program is executed can refer to the various embodiments of the drive motor failure protection method of this application, and will not be repeated here.

[0093] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0094] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit the "first", "second" and "third" to different types.

[0095] In the description of the embodiments of this application, the words "exemplary," "for example," or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary," "for example," or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "for example," or "for example" is intended to present the relevant concepts in a concrete manner.

[0096] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0097] In some processes described in the embodiments of the present application, multiple operations or steps are included that appear in a specific order. However, it should be understood that these operations or steps may not be performed in the order in which they appear in the embodiments of the present application or may be performed in parallel. The sequence numbers of the operations are only used to distinguish between different operations, and the sequence numbers themselves do not represent any order of execution. In addition, these processes may include more or fewer operations, and these operations or steps may be performed in sequence or in parallel, and these operations or steps may be combined.

[0098] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, of course, it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes a number of instructions for enabling a terminal device to execute the methods described in each embodiment of the present application.

[0099] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A drive motor failure protection method, characterized in that: The drive motor failure protection method includes: When the vehicle's drive motor loses power, the drive motor is controlled to shut down; If the speed of the drive motor is greater than or equal to the preset intervention speed, the generator is controlled to output electric torque to consume the back electromotive force feedback energy generated by the drive motor; After controlling the generator to output electric torque to consume the back electromotive force feedback energy generated by the drive motor, the method includes: If the driving motor speed is less than or equal to the preset exit speed, the generator and engine are controlled to stop; If the driving motor speed is greater than the preset exit speed, the process returns to executing the step of controlling the generator to output electric torque to consume the back electromotive force feedback energy generated by the driving motor. The preset exit speed is the difference between the preset intervention speed and the preset hysteresis speed.

2. The drive motor failure protection method according to claim 1, characterized in that: The controlling the generator to output electric torque comprises: According to the current bus capacitor voltage and drive motor speed, the value of the electric torque is determined by looking up the calibration relationship table between the bus capacitor voltage, drive motor speed and electric torque; The generator is controlled to output electric torque at a determined value.

3. The drive motor failure protection method according to claim 2, characterized in that: Before determining the value of the electric torque by searching a calibration relationship table between the bus capacitor voltage, the drive motor speed, and the electric torque according to the current bus capacitor voltage and the drive motor speed, the method includes: Under different bus capacitor voltages and drive motor speeds, when the drive motor has a power loss fault and the back electromotive force is greater than the bus capacitor voltage, the size of the generator output electric torque is adjusted, and the value of the generator output electric torque when the back electromotive force is equal to the bus capacitor voltage is recorded to obtain a calibration relationship table between the bus capacitor voltage, drive motor speed and electric torque.

4. The drive motor failure protection method according to claim 1, wherein: The controlling the generator to output electric torque further comprises: If the generator is in standby mode, the generator is started and enters torque mode to output electric torque; If the generator is in torque mode, the generator maintains the torque mode and outputs electric torque. If the generator is operating in speed mode, it switches to torque mode and outputs electric torque.

5. A drive motor failure protection device, characterized in that: The drive motor failure protection device includes: The first control module is used to control the drive motor to shut down when a power loss failure occurs in the drive motor of the vehicle; a second control module, configured to control the generator to output electric torque if the speed of the drive motor is greater than or equal to a preset intervention speed, so as to consume back electromotive force feedback energy generated by the drive motor; The drive motor failure protection device further includes an exit module for: If the driving motor speed is less than or equal to the preset exit speed, the generator and engine are controlled to stop; If the driving motor speed is greater than the preset exit speed, the process returns to executing the step of controlling the generator to output electric torque to consume the back electromotive force feedback energy generated by the driving motor. The preset exit speed is the difference between the preset intervention speed and the preset hysteresis speed.

6. The drive motor failure protection device according to claim 5, characterized in that: The second control module is configured to: According to the current bus capacitor voltage and drive motor speed, the value of the electric torque is determined by looking up the calibration relationship table between the bus capacitor voltage, drive motor speed and electric torque; The generator is controlled to output electric torque at a determined value.

7. A drive motor failure protection device, characterized in that: The drive motor failure protection device includes a processor, a memory, and a drive motor failure protection program stored in the memory and executable by the processor, wherein when the drive motor failure protection program is executed by the processor, the steps of the drive motor failure protection method as described in any one of claims 1 to 4 are implemented.

8. A readable storage medium, characterized in that: The readable storage medium stores a drive motor failure protection program, wherein when the drive motor failure protection program is executed by the processor, the steps of the drive motor failure protection method according to any one of claims 1 to 4 are implemented.

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