Power control method and device, vehicle and equipment

Abstract

The invention relates to a power control method and device, a vehicle and equipment, and relates to the technical field of vehicles. The method is applied to a dual-motor system, the dual-motor system comprises a first motor and a second motor, and the method comprises the following steps: determining a fault type of the first motor based on fault information of the first motor under the condition that the first motor has a fault; determining the working mode of the first motor based on at least one of the fault type and the counter electromotive force generated by the first motor; and performing power control on the first motor and / or the second motor based on a power control strategy corresponding to the working mode. Therefore, safety risks possibly caused by counter electromotive force generated by rotation of the motor when the motor has a serious fault can be avoided.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, in particular to the field of vehicle power control technology, and specifically to a power control method, device, vehicle and equipment. Background Art

[0002] In order to enable the vehicle to have a diverse driving mode experience, enhanced torque output capability and excellent longitudinal stability, the new energy vehicle design adopts the configuration of front and rear dual permanent magnet synchronous motors. In the event of a serious failure of one motor, the system can intelligently call another normally functioning motor to continue to provide the necessary torque, ensuring that the vehicle can continue to drive to the repair shop for emergency treatment. However, when a serious failure occurs in the permanent magnet synchronous motor, the back electromotive force generated by the motor rotation may cause the motor and electronic control to have the risk of over-temperature ablation, and the battery to have the risk of over-charge and over-discharge.

[0003] In a related technology, it is proposed to set speed thresholds for entering active short control (ASC) mode and free wheeling (FW) mode, and by monitoring the motor speed of the motor system under operating conditions, it is determined that the motor system fails and then enters the ASC and FW states according to the thresholds.

[0004] Another related technology proposes to classify faults. For motor system faults in ASC mode, speed thresholds for entering ASC and FW are set through speed and electrical system parameters. When the speed is low, FW is entered, and when the speed is high, ASC is entered. Summary of the invention

[0005] The present application provides a power control method, device, vehicle and equipment to at least solve the technical problem in the related art that when a serious fault occurs in the motor, the back electromotive force generated by the motor rotation may cause safety risks. The technical solution of the present application is as follows:

[0006] According to the first aspect provided by the present application, a power control method is provided, including: applied to a dual-motor system, the dual-motor system includes a first motor and a second motor, including: in the event of a failure of the first motor, determining the fault type of the first motor based on the fault information of the first motor; determining an operating mode of the first motor based on at least one of the fault type and the back electromotive force generated by the first motor; and performing power control on the first motor and / or the second motor based on a power control strategy corresponding to the operating mode.

[0007] According to the above-mentioned technical means, when one of the motors in a dual-motor system fails, the present application can perform power control on the faulty motor and the normal motor based on the fault type of the faulty motor and at least one of the back electromotive force generated by the first motor. Furthermore, by taking the back electromotive force of the faulty motor into consideration, the risk of over-temperature ablation of the motor, ablation of the electronic control, and over-charging and over-discharging of the battery caused by the back electromotive force generated by the faulty motor can be avoided.

[0008] In a possible implementation, the working mode includes: ASC mode or FW mode.

[0009] According to the above technical means, the present application can be applied to different fault scenarios through ASC mode and FW mode, thereby reasonably allocating the power output of the first motor and the second motor.

[0010] In one possible implementation, the fault types include: a first type and a second type; wherein, when the first motor is in the first type, the IGBT switch tube of the first motor is in a normal state; when the first motor is in the second type, the IGBT switch tube is in an abnormal state.

[0011] According to the above technical means, the present application can distinguish the fault types and take different countermeasures according to the severity of the fault, thereby ensuring that the operation can be maintained in the case of minor faults and quickly protecting the equipment in the case of serious faults.

[0012] In one possible implementation, the operating mode of the first motor is determined based on at least one of the fault type and the back electromotive force generated by the first motor, including: when the fault type is the first type and the back electromotive force is greater than a first threshold, or when the fault type is the second type, determining the operating mode to be the ASC mode.

[0013] According to the above technical means, the present application can enable the ASC mode only when there is a first type of fault and the back electromotive force is high, or when there is a second type of fault, to avoid overreaction to minor faults, thereby avoiding the risk of over-temperature burns of the motor, burns of the electronic control, and over-charging and over-discharging of the battery due to the back electromotive force generated by the faulty motor.

[0014] In one possible implementation, when the operating mode is the ASC mode, power control is performed on the first motor and / or the second motor based on the power control strategy corresponding to the operating mode, including: obtaining the speed and heat rise rate of the first motor; and power control is performed on the first motor and / or the second motor based on the speed and heat rise rate of the first motor.

[0015] According to the above-mentioned technical means, the present application can monitor the speed and heat rise rate of the first motor in real time, and perform power control on the first motor and / or the second motor based on the speed and heat rise rate of the first motor to prevent risks such as thermal runaway of the faulty motor (first motor) in the ASC mode.

[0016] In one possible implementation, power control is performed on the first motor and / or the second motor based on the speed and heat rise rate of the first motor, including: if the speed of the first motor is greater than a speed threshold, or the heat rise rate is greater than a rate threshold, the speed of the first motor is reduced by limiting the power output of the second motor; the speed threshold and the rate threshold are determined based on the oil cooler flow and the oil cooler water outlet temperature of the first motor; if the speed of the first motor is less than or equal to the speed threshold, and the heat rise rate is less than or equal to the rate threshold, the first motor is controlled to maintain the current power output.

[0017] According to the above-mentioned technical means, the present application can reduce the speed of the first motor by adjusting the power of the second motor when the speed and heat rise rate of the faulty motor (first motor) are fast, thereby effectively reducing the problem of excessive speed or rapid heat rise rate of the faulty motor in the ASC mode, which may lead to motor overheating and excessive reverse electric force.

[0018] In a possible implementation, when the fault type is the first type and the back electromotive force is less than a first threshold, the working mode is determined to be the FW mode.

[0019] According to the above-mentioned technical means, the present application can switch the operating mode of the first motor to FW mode when the fault type is the first type (a relatively minor fault) and the back electromotive force is less than the first threshold. In FW mode, the three-phase rectifier circuit is completely disconnected, the current path between the motor and the power supply is cut off, and the current will not flow back to the power supply through the freewheeling diode, thereby avoiding the impact and damage of the current on the motor.

[0020] In one possible implementation, when the working mode is the FW mode, power control is performed on the first motor and / or the second motor based on the corresponding power control strategy of the working mode, including: controlling the first motor and the second motor to maintain the current power output.

[0021] According to the above technical means, the present application can maintain the power output of the motor unchanged in FW mode and ensure the stability of the entire power system.

[0022] According to the second aspect provided by the present application, a power control device is provided, including: an acquisition unit, a determination unit and a control unit; the acquisition unit is used to determine the fault type of the first motor based on the fault information of the first motor when a fault occurs to the first motor; the determination unit is used to determine the working mode of the first motor based on at least one of the fault type and the back electromotive force generated by the first motor; the control unit is used to perform power control on the first motor and / or the second motor based on the power control strategy corresponding to the working mode.

[0023] In a possible implementation, the determination unit is specifically configured to: when the fault type is the first type and the back electromotive force is greater than the first threshold, or when the fault type is the second type, determine that the operating mode is the ASC mode.

[0024] In a possible implementation, the control unit is specifically used to: obtain the rotation speed and heat rise rate of the first motor;

[0025] Power control is performed on the first motor and / or the second motor based on the rotation speed and the heat rise rate of the first motor.

[0026] In one possible implementation, the control unit is specifically used to: if the speed of the first motor is greater than a speed threshold, or the heat rise rate is greater than a rate threshold, reduce the speed of the first motor by limiting the power output of the second motor; the speed threshold and the rate threshold are determined based on the oil cooler flow and the oil cooler water outlet temperature of the first motor; if the speed of the first motor is less than or equal to the speed threshold, and the heat rise rate is less than or equal to the rate threshold, control the first motor to maintain the current power output.

[0027] In a possible implementation, the determination unit is specifically configured to: when the fault type is the first type and the back electromotive force is less than a first threshold, determine that the working mode is the FW mode.

[0028] In one possible implementation, the control unit is specifically used to control the first motor and the second motor to maintain the current power output.

[0029] According to the third aspect provided by the present application, a vehicle is provided, comprising: a power control device and a dual-motor system; the dual-motor system comprises a first motor and a second motor; the power control device is used to obtain the back electromotive force generated by the first motor when a fault occurs to the first motor, and determine the fault type of the first motor based on the fault information of the first motor; the power control device is also used to perform power control on the first motor and the second motor based on the fault type and / or the back electromotive force.

[0030] According to the fourth aspect provided by the present application, an electronic device is provided, comprising: a processor; a memory for storing processor executable instructions; wherein the processor is configured to execute instructions to implement the method of the above-mentioned first aspect and any possible implementation manner thereof.

[0031] According to the fifth aspect provided by the present application, a computer-readable storage medium is provided. When the instructions in the computer-readable storage medium are executed by a processor of an electronic device, the electronic device is enabled to execute the method in the above-mentioned first aspect and any possible implementation method thereof.

[0032] According to the sixth aspect provided by the present application, a computer program product is provided, the computer program product comprising computer instructions, and when the computer instructions are executed on an electronic device, the electronic device executes the method of the above-mentioned first aspect and any possible implementation manner thereof.

[0033] It should be noted that the technical effects brought about by any implementation method in the second to sixth aspects can refer to the technical effects brought about by the corresponding implementation method in the first aspect, and will not be repeated here.

[0034] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application, and do not constitute an improper limitation on the present application.

[0036] Figure 1 is a schematic structural diagram of a vehicle according to an exemplary embodiment;

[0037] Figure 2 is a schematic diagram of a hardware structure of a power control system according to an exemplary embodiment;

[0038] Figure 3 is a flow chart of a power control method according to an exemplary embodiment;

[0039] Figure 4 is a schematic diagram showing a fault handling process according to an exemplary embodiment;

[0040] Figure 5 is a schematic diagram showing a fault classification process according to an exemplary embodiment;

[0041] Figure 6 is a schematic diagram showing a threshold setting process according to an exemplary embodiment;

[0042] Figure 7 is a schematic diagram of another fault handling process according to an exemplary embodiment;

[0043] Figure 8 is a schematic diagram showing a mode determination process according to an exemplary embodiment;

[0044] Fig. 9 is a block diagram of a power control device according to an exemplary embodiment;

[0045] Fig.10 It is a block diagram of an electronic device according to an exemplary embodiment. DETAILED DESCRIPTION

[0046] In order to enable ordinary persons in the art to better understand the technical solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0047] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application 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 data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims.

[0048] First, some of the terms and related technologies involved in this application are explained to facilitate understanding by those skilled in the art.

[0049] ASC mode: ASC mode is an important motor system protection mechanism. Its working principle is to open the upper three bridges or the lower three bridges at the same time to form a closed loop for the motor stator winding. This mechanism is mainly used for motor safety protection to prevent the controller system from being damaged.

[0050] For example, when the motor is at high speed, the back EMF generated by the motor may exceed the bus voltage of the high-voltage battery. At this time, if the insulated-gate bipolar transistor (IGBT) is allowed to rectify naturally, unpredictable braking torque may be generated. By implementing ASC, this situation can be avoided and the motor and controller can be protected from damage.

[0051] FW mode: FW mode refers to a special mode that the motor enters when all three-phase rectifier circuits are disconnected in the motor control system. In this state, the relationship between the motor's back EMF and the bus voltage determines the behavior of the current. If the motor's back EMF is less than the bus voltage, the current will not flow into the power supply through the freewheeling diode, and the system remains in a safe state. However, when the motor's back EMF is greater than the bus voltage, the current will flow in the opposite direction, from the motor through the freewheeling diode into the power supply, and current backflow will occur. This is equivalent to charging the bus capacitor. If charged for a long time, the bus capacitor voltage may be too high, and there is a risk of capacitor breakdown.

[0052] The above is a brief introduction to the terms involved in the embodiments of the present application, which will not be repeated below.

[0053] In order to facilitate understanding of the technical content of this solution, the relevant technologies are introduced below.

[0054] With the rapid progress of my country's new energy vehicle technology, in order to achieve the diversification of vehicle driving modes, improve torque output and enhance longitudinal stability, new energy vehicles generally adopt the configuration of front and rear dual permanent magnet synchronous motors. In order to give full play to the performance advantages of dual motors, when one of the motors encounters a serious failure, the vehicle can rely on the other normally functioning motor to continue to provide torque, thereby avoiding power interruption and ensuring that the driving experience is not seriously affected.

[0055] Four-wheel drive models equipped with permanent magnet synchronous motors at the front and rear can use another normally functioning motor to provide power in the event of a motor failure, allowing the vehicle to continue driving to a maintenance station for emergency treatment. However, it is worth noting that when a permanent magnet synchronous motor fails seriously, the vehicle can trigger two safety modes: one is the ASC mode, in which the back electromotive force generated by the motor rotation may cause the risk of over-temperature ablation of the motor, and the other is the free safety FW mode, in which the back electromotive force generated by the motor rotation may damage the electronic control system and cause the risk of overcharging or over-discharging the battery.

[0056] Therefore, in order to effectively avoid the serious consequences that may be caused by the above risks, there is an urgent need for an electric drive system and vehicle handling method for new energy vehicles equipped with dual motors after a serious motor failure occurs.

[0057] As mentioned in the background technology, in order to solve the safety problem that may be caused by the back electromotive force generated by the rotation of the motor when a serious fault occurs in the motor in the related technology, the present application provides a power control method, which can obtain the back electromotive force generated by the first motor when the first motor fails, and determine the fault type of the first motor based on the fault information of the first motor, so as to further perform power control on the first motor and the second motor based on the fault type and / or the back electromotive force.

[0058] Based on this, when one of the motors in a dual-motor system fails, the present application can perform power control on the faulty motor and the normal motor based on the fault type and / or back electromotive force of the faulty motor. By taking the back electromotive force of the faulty motor into consideration, the risk of over-temperature ablation of the motor, ablation of the electronic control, and over-charging and over-discharging of the battery caused by the back electromotive force generated by the faulty motor can be avoided.

[0059] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0060] The power control method provided in the embodiment of the present application can be applied in a vehicle. A vehicle can also be called a vehicle, a mobile carrier, an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), a fuel cell vehicle (FCV), an autonomous vehicle, an intelligent and connected vehicle (ICV), a driverless vehicle, etc.

[0061] For example, Figure 1 As shown, Figure 1 is a schematic structural diagram of a vehicle 100 according to an exemplary embodiment.

[0062] In the embodiments of the present application, the vehicle may be a sedan, a sport utility vehicle (SUV), a truck, an electric vehicle, a motorcycle, a tricycle, a special vehicle (such as an ambulance, a fire truck, a police car, etc.), an unmanned taxi, an intelligent networked bus, an automatic driving logistics vehicle, an electric truck, etc. In addition, the method is also applicable to various special vehicles, such as agricultural vehicles, mining vehicles, forestry vehicles, airport vehicles, port vehicles, etc. This application does not make specific restrictions on this.

[0063] In some embodiments, Figure 2 As shown, Figure 2 It is a schematic diagram of the hardware structure of a power control system according to an exemplary embodiment.

[0064] In a possible implementation, the power control system 20 may be deployed in a vehicle. The power control system 20 may include a power control device 201 , a data acquisition device 202 , and a dual motor system 203 . The dual motor system 203 may include a first motor 2031 and a second motor 2032 .

[0065] Optionally, Figure 2 A communication connection can be established between the power control device 201 and the data acquisition device 202. A connection can be established between the data acquisition device 202 and the dual motor system 203. A connection can be established between the power control device 201 and the dual motor system 203.

[0066] In practical applications, the power control device 201 may be communicatively connected to one or more data acquisition devices 202 .

[0067] For ease of understanding, the present application takes the communication connection between a power control device 201 and a data acquisition device 202 as an example for explanation.

[0068] Optional, Figure 2 The power control device 201 and the data acquisition device 202 may be functional modules integrated into the same device, or may be devices independently arranged from each other. This application does not impose any limitation on this.

[0069] It is easy to understand that when the power control device 201 and the data acquisition device 202 are functional modules integrated in the same device, the communication method between the power control device 201 and the data acquisition device 202 is the communication between the internal modules of the device. In this case, the communication process between the two is the same as the "communication process when the power control device 201 and the data acquisition device 202 are independently set up".

[0070] For ease of understanding, the present application is mainly explained by taking the example of the power control device 201 and the data acquisition device 202 being independently configured.

[0071] Optionally, the first motor 2031 and the second motor 2032 may be motors of the same type or motors of different types, which is not limited in the present application.

[0072] It is easy to understand that when the first motor 2031 and the second motor 2032 are motors of the same type, the functions that can be achieved can be the same as "the first motor 2031 and the second motor 2032 are motors of different types".

[0073] For ease of understanding, the present application is mainly described by taking the first motor 2031 and the second motor 2032 as motors of the same type.

[0074] Figure 2 The data acquisition device 202 can acquire the back electromotive force generated by the first motor 2031. The power control device 201 can obtain the back electromotive force generated by the first motor 2031 from the data acquisition device 202, and determine the fault type of the first motor based on the fault information of the first motor, so as to further perform power control on the first motor 2031 and the second motor 2032 based on the fault type and / or the back electromotive force.

[0075] Optionally, Figure 2 The power control device 201 in the embodiment may be a terminal, a server, or other types of electronic devices. Figure 2 What is shown in the figure is only an example of the equipment form of the power control device 201 and does not constitute a limitation thereto.

[0076] In the case where the power control device 201 is a terminal, the terminal can be a device for providing voice and / or data connectivity to a user, a handheld device with a wireless connection function, or other processing devices connected to a wireless modem. The terminal can communicate with one or more core networks via a radio access network (RAN). The terminal can be a mobile terminal, such as a computer with a mobile terminal, or a mobile device built into the power control system 20, which exchanges language and / or data with a radio access network, such as a mobile phone, a tablet computer, a laptop computer, a netbook, a personal digital assistant (PDA). This application does not impose any restrictions on this.

[0077] When the power control device 201 is a server, the server may be a single server, or a server cluster composed of multiple servers. In some implementations, the server cluster may also be a distributed cluster. This application does not impose any restrictions on this.

[0078] It should be noted that the structure illustrated in the embodiment of the present application does not constitute a limitation on the power control system 20. It may include more or fewer components than shown in the figure, or combine some components, or split some components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0079] For ease of understanding, the power control method provided in the present application is specifically introduced below with reference to the accompanying drawings.

[0080] Figure 3 is a flow chart of a power control method according to an exemplary embodiment. Figure 3 As shown, the power control method includes the following steps: S301-S303.

[0081] S301 : When a first motor fails, determine a fault type of the first motor based on fault information of the first motor.

[0082] The fault type may include: a first type and a second type. When the first motor is in the first type, the IGBT switch tube of the first motor is in a normal state. When the first motor is in the second type, the IGBT switch tube of the first motor is in an abnormal state.

[0083] It should be noted that the abnormal state of the IGBT switch tube of the first motor can be used to indicate that the motor control system corresponding to the first motor cannot normally control the IGBT switch tube, resulting in the motor control system being unable to work normally and unable to exit the ASC mode normally.

[0084] In a possible implementation, when the first motor fails, the power control device may receive fault information sent by the motor control system corresponding to the first motor, wherein the fault information may include the cause of the motor failure and whether the IGBT switch tube is in an abnormal state. The power control device may parse the fault information to determine the fault type of the first motor.

[0085] Exemplarily, if it is determined that the IGBT switch tube of the first motor is not in an abnormal state, that is, a normal state, then it is determined that the fault type of the first motor is the first type.

[0086] Alternatively, if it is determined that the IGBT switch tube of the first motor is in a normal state, then the fault type of the first motor is determined to be the first type.

[0087] S302: Determine an operating mode of the first motor based on at least one of the fault type and the back electromotive force generated by the first motor.

[0088] The working mode includes: ASC mode or FW mode. The ASC mode and FW mode can refer to the above-mentioned glossary. No further details will be given here.

[0089] It should be noted that the permanent magnet synchronous motor has the advantages of simple structure, high efficiency and good reliability. The motor rotor of the permanent magnet synchronous motor is composed of magnetic steel and silicon steel sheets, and the stator is composed of coils embedded in silicon steel sheets. Therefore, it can be determined that the back electromotive force of the motor is proportional to the speed, and the expression of the back electromotive force is opposite to the supply voltage. The back electromotive force and the speed satisfy the following first formula:

[0090] E=k*wFirst formula

[0091] Among them, E can be used to characterize the back electromotive force, w can be used to characterize the motor speed, and k can be used to characterize the back electromotive force coefficient, where k is a preset parameter.

[0092] Exemplarily, k may be the ratio of the back electromotive force to the rotation speed when the rotation speed of the motor is 1000 revolutions per minute (rpm).

[0093] In addition, the heat generated by the motor stator is proportional to the back electromotive force. The higher the speed of the motor rotor, the higher the heat generated by the motor stator. The heat generated by the motor stator and the back electromotive force satisfy the following second formula:

[0094] Q=U2t / RThe second formula

[0095] Among them, Q can be used to characterize the heat generated by the motor stator, R can be used to characterize the coil resistance, and t can be used to characterize the time.

[0096] In a possible implementation, the power control device may be configured with a first formula and a second formula. The power control device may obtain the rotation speed of the first motor, and determine the back electromotive force of the first motor based on the rotation speed of the first motor and the first formula.

[0097] Exemplarily, the power control device can obtain the speed of the first motor from the CAN signal as V. k is the ratio of the back electromotive force to the speed when the motor speed is 1000 rpm. The power control device can calculate the back electromotive force of the first motor as E=k*v based on the first formula.

[0098] Alternatively, the power control device may obtain the heat generation of the motor stator, the coil resistance and the time, and determine the back electromotive force of the first motor based on the heat generation of the motor stator, the coil resistance, the time and the second formula. This application does not make specific restrictions on this.

[0099] In one possible implementation, the power control device may determine that the operating mode of the first motor is the ASC mode when the fault type is the first type and the back electromotive force is greater than the first threshold, or when the fault type is the second type.

[0100] Optionally, the first threshold value may be set according to actual needs. For example, the first threshold value may be greater than or equal to the voltage of the power battery, or may be less than the voltage of the power battery. This application does not impose any specific restrictions on this.

[0101] It should be noted that when the fault type of the first motor is the first type, the LGBT switch tube of the first motor is not faulty. At this time, the first motor can freely switch the working mode, that is, the first motor can freely switch between FW mode and ASC mode. In addition, since the back electromotive force of the first motor is proportional to the rotation speed of the first motor, when the back electromotive force of the first motor is greater than the first threshold, it means that the rotation speed of the first motor is high. At this time, the rotation speed needs to be reduced to reduce the harm to the first motor and achieve safe driving.

[0102] In addition, when the fault type of the first motor is the second type, the LGBT switch tube of the first motor fails, causing the first motor to be in ASC mode and unable to switch normally.

[0103] In yet another possible implementation, the power control device may determine that the operating mode of the first motor is the FW mode when the fault type is the first type and the back electromotive force is less than a first threshold.

[0104] It should be noted that, when the fault type of the first motor is the first type and the back electromotive force is less than the first threshold, it can be determined that the speed of the first motor is low, no pressure difference can be generated between the motor system and the power battery, and no current loop is generated. At this time, the vehicle can drive normally in FW mode, and the vehicle computer reminds the driver that the first motor of the vehicle has a fault.

[0105] S303: Perform power control on the first motor and / or the second motor based on a power control strategy corresponding to the working mode.

[0106] In a possible implementation, when the first motor is in the ASC mode, the power control device can perform power control on the first motor and / or the second motor based on the power control strategy corresponding to the ASC mode. The specific implementation of the power control device performing power control on the first motor and / or the second motor based on the power control strategy corresponding to the ASC mode can be referred to in the following S401-S402. No further details will be given here.

[0107] In another possible implementation, the power control device may perform power control on the first motor and / or the second motor based on the corresponding power control strategy of the FW mode, wherein the corresponding power control strategy of the FW mode includes: controlling the first motor and the second motor to maintain the current power output.

[0108] Based on the above technical solution, when one of the motors in a dual-motor system fails, the present application can perform power control on the faulty motor and the normal motor based on the fault type and / or back electromotive force of the faulty motor. By taking the back electromotive force of the faulty motor into consideration, the risk of over-temperature ablation of the motor, ablation of the electronic control, and over-charging and over-discharging of the battery caused by the back electromotive force generated by the faulty motor can be avoided.

[0109] In some embodiments, when the working mode is the ASC mode, power control is performed on the first motor and / or the second motor based on a power control strategy corresponding to the working mode, including the following steps: S401 - S402 .

[0110] S401, obtaining a rotation speed and a heat rise rate of a first motor.

[0111] Optionally, the power control device may obtain the rotation speed of the first motor from the CAN signal, or the motor system corresponding to the first motor may send the rotation speed of the first motor to the power control device. This application does not impose any specific restrictions on this.

[0112] In one possible implementation, the heat rise rate of the first motor can be characterized as the rise rate of the motor stator temperature. The power control device can obtain the motor stator temperature corresponding to each moment in the first time series. The motor stator temperature can be calculated based on the motor stator temperature corresponding to each moment in the first time series to calculate the heat rise rate of the first motor.

[0113] The first time series includes the current time and the time before the current time.

[0114] S402: Based on the rotation speed and heat rise rate of the first motor, perform power control on the first motor and / or the second motor.

[0115] In one possible implementation, if the rotation speed of the first motor is greater than a rotation speed threshold, or the heat rise rate is greater than a rate threshold, the rotation speed of the first motor is reduced by limiting the power output of the second motor.

[0116] The speed threshold and the rate threshold are determined based on the oil cooler flow rate and the oil cooler water inlet temperature of the first motor. The oil cooler water inlet temperature may include the oil cooler water inlet temperature and the oil cooler water outlet temperature.

[0117] In one possible implementation, the power control device can obtain the oil cooler flow, oil cooler inlet temperature and oil cooler outlet temperature of the first motor, and based on the first mapping relationship, determine a speed threshold that matches the oil cooler flow and the oil cooler inlet temperature.

[0118] The first mapping relationship is a mapping (MAP) table of speed threshold-oil cooler flow-oil cooler water inlet temperature. The power control device can determine the speed threshold based on the oil cooler flow-oil cooler water inlet temperature.

[0119] It should be noted that when the motor is in the ASC mode, the oil pump requests the maximum oil pump speed, and the power control device can record the oil cooler at different water inlet temperatures and flows through the motor system. When the oil cooler outlet temperature reaches a stable value and no longer changes, the oil cooler is at a thermal equilibrium point, and the motor speed Vmax is recorded at this time. The power control device can record the motor speed Vmax, oil cooler flow, and oil cooler water inlet temperature at this time to obtain a first mapping relationship.

[0120] In yet another possible implementation, the power control device may determine the rate threshold based on the oil cooler flow rate, the oil cooler water inlet temperature, and the oil cooler water outlet temperature.

[0121] It should be noted that in ASC mode, the main heat source of the first motor is the coil stator. If the temperature of the first motor is too high, it will cause the rotor magnet to demagnetize. Therefore, in ASC mode, the stator temperature cannot exceed the motor system temperature threshold Tmax. The power control device can obtain the motor stator temperature Tmax through a single test, and calculate the corresponding motor speed threshold after a cooling cycle Δt in the oil circuit.

[0122] Among them, the rate threshold, the oil cooler flow rate, the oil cooler water inlet temperature and the oil cooler water outlet temperature satisfy the following third formula:

[0123] σ max =(T 2 -T 1 ) / (Δt*L)The third formula

[0124] Among them, σ max Can be used to characterize rate threshold. 2 It can be used to characterize the oil cooler outlet temperature. 1 It can be used to characterize the water inlet temperature of the oil cooler. Δt can be used to characterize the time required for one cycle of the oil circuit. L can be used to characterize the flow rate of the oil cooler.

[0125] In one possible implementation, if the speed of the first motor is greater than a speed threshold, or the heat rise rate is greater than a rate threshold, the power control device may determine a first difference between the speed of the first motor and the speed threshold, and determine a second difference between the heat rise rate and the rate threshold. The power control device may determine a first ratio between the first difference and the speed threshold, and determine a second difference between the second difference and the rate threshold. The power control device may limit the power output of the second motor based on the first ratio and the second ratio.

[0126] For example, Figure 4 As shown, Figure 4 FIG. 5 is a schematic diagram showing a fault handling process according to an exemplary embodiment. The fault handling process includes the following steps S501-S504.

[0127] S501: If the rotation speed of the first motor is greater than the rotation speed threshold, or the heat rise rate is greater than the rate threshold.

[0128] In one possible implementation, if the rotation speed of the first motor is greater than a rotation speed threshold, or the heat rise rate is greater than a rate threshold, the following S502 or S503 is executed.

[0129] S502 : When the first ratio is less than a first ratio threshold or the second ratio is less than a second ratio threshold, gradually limit the torque of the second motor from 100% to 0%.

[0130] After it is determined that S502 is completed, S504 is executed.

[0131] S503: When the first ratio is greater than or equal to the first ratio threshold or the second ratio is greater than or equal to the second ratio threshold, the torque of the second motor is limited to 0, and the second motor is requested to output reverse torque.

[0132] After it is determined that S503 is completed, S504 is executed.

[0133] S504, performing energy recovery braking to reduce the speed of the entire vehicle, so that the rotation speed of the first motor is reduced until the rotation speed of the first motor is less than a speed threshold and the heat rise rate is less than a rate threshold.

[0134] Optionally, the first ratio threshold value may be set according to actual needs. For example, the first ratio threshold value may be 20% or 30%. This application does not impose any specific restrictions on this.

[0135] Optionally, the first ratio threshold value may be set according to actual needs. For example, the first ratio threshold value may be 10% or 20%. This application does not impose any specific restrictions on this.

[0136] In yet another possible implementation, if the rotation speed of the first motor is less than or equal to a rotation speed threshold, and the heat rise rate is less than or equal to a rate threshold, the first motor is controlled to maintain the current power output.

[0137] Based on this, the present application can monitor the speed and heat rise rate of the first motor in real time, and perform power control on the first motor and / or the second motor based on the speed and heat rise rate of the first motor to prevent risks such as thermal runaway of the faulty motor (first motor) in the ASC mode.

[0138] In some embodiments, Figure 5 As shown, Figure 5 FIG. 1 is a schematic diagram showing a fault classification process according to an exemplary embodiment. The fault classification process includes S601 - S604 .

[0139] S601, classify motor fault types.

[0140] S602, determine whether the electronic control such as the chip and the single-chip microcomputer in the motor is failed.

[0141] If not, execute S603;

[0142] If yes, execute S604.

[0143] S603: Determine the first category and return the ASC category.

[0144] In one possible implementation, in the first category, the motor can perform ASC mode and FW mode.

[0145] S604. Determine the second category, i.e., the non-refundable ASC category.

[0146] In one possible implementation, in the second category, the motor can only be in ASC mode.

[0147] In some embodiments, Figure 6 As shown, Figure 6 FIG. 1 is a schematic diagram showing a threshold setting process according to an exemplary embodiment. The threshold setting process includes the following S701 - S705 .

[0148] S701: Set a threshold.

[0149] In a possible implementation, the rotation speed threshold setting may refer to the following S702-S703, and the speed threshold setting may refer to the following S704-S705.

[0150] S702, determining the maximum motor speed allowed by the oil cooler at different flow rates and water inlet temperatures.

[0151] S703: Determine a MAP table based on the maximum motor speed allowed by the oil cooler at different flow rates and water inlet temperatures.

[0152] The MAP table is a mapping relationship table of speed threshold-oil cooler flow-oil cooler inlet temperature.

[0153] S704, conducting a single-body experiment, that is, when the motor stator temperature is T, the oil circuit of the electric drive system goes through a cycle Δt.

[0154] S705: Determine the electric drive heat exchange rate, that is, the rate threshold, based on the experimental results.

[0155] In some embodiments, Figure 7 As shown, Figure 7 FIG. 8 is a schematic diagram of another fault handling process according to an exemplary embodiment. The fault handling process includes the following steps S801-S803.

[0156] S801, determining whether the rotation speed of the first motor is less than a rotation speed threshold, and whether the heat rise rate is less than a rate threshold.

[0157] If the rotation speed of the first motor is less than the rotation speed threshold, and the heat rise rate is less than the rate threshold, execute S802; otherwise, execute S803.

[0158] S802: Control the vehicle computer to indicate a motor failure, and control the first motor to maintain a current rotation speed.

[0159] S803: Perform power control on the second motor to reduce the power of the first motor.

[0160] In some embodiments, Figure 8 As shown, Figure 8 FIG. 1 is a schematic diagram showing a mode determination process according to an exemplary embodiment. The mode determination process includes the following S901 - S904 .

[0161] S901, determine the battery voltage, and determine the back electromotive force according to the rotation speed of the first motor.

[0162] S902: Determine whether the back electromotive force is greater than the battery voltage.

[0163] If yes, execute S903;

[0164] If not, execute S904.

[0165] S903. Enter ASC mode.

[0166] S904: Enter FW mode.

[0167] Fig. 9 is a block diagram of a power control device according to an exemplary embodiment. Fig. 9 The power control device includes: an acquisition unit 1001, a determination unit 1002 and a control unit 1003.

[0168] In a possible implementation, the acquisition unit 1001 is used for determining the fault type of the first motor based on fault information of the first motor when the first motor fails.

[0169] In a possible implementation, the determination unit 1002 is configured to determine the operating mode of the first motor based on at least one of the fault type and the back electromotive force generated by the first motor.

[0170] In a possible implementation, the control unit 1003 is used to perform power control on the first motor and / or the second motor based on a power control strategy corresponding to the working mode.

[0171] In a possible implementation, the determination unit 1002 is specifically configured to: when the fault type is the first type and the back electromotive force is greater than the first threshold, or when the fault type is the second type, determine that the operating mode is the ASC mode.

[0172] In a possible implementation, the control unit 1003 is specifically configured to: obtain the rotation speed and heat rise rate of the first motor, and perform power control on the first motor and / or the second motor based on the rotation speed and heat rise rate of the first motor.

[0173] In one possible implementation, the control unit 1003 is specifically used to: if the speed of the first motor is greater than the speed threshold, or the heat rise rate is greater than the rate threshold, then the speed of the first motor is reduced by limiting the power output of the second motor; the speed threshold and the rate threshold are determined based on the oil cooler flow and the oil cooler water outlet temperature of the first motor; if the speed of the first motor is less than or equal to the speed threshold, and the heat rise rate is less than or equal to the rate threshold, then the first motor is controlled to maintain the current power output.

[0174] In a possible implementation, the determination unit 1002 is configured to determine that the working mode is the FW mode when the fault type is the first type and the back electromotive force is less than a first threshold.

[0175] In a possible implementation, the control unit 1003 is specifically used to control the first motor and the second motor to maintain the current power output.

[0176] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0177] Fig.10 FIG. 1 is a block diagram of an electronic device according to an exemplary embodiment. Fig.10 As shown, the electronic device includes but is not limited to: a processor 1101 and a memory 1102 .

[0178] The memory 1102 is used to store executable instructions of the processor 1101. It can be understood that the processor 1101 is configured to execute instructions to implement the power control method in the above embodiment.

[0179] It should be noted that those skilled in the art can understand that Fig.10 The electronic device structure shown in the figure does not constitute a limitation on the electronic device, and the electronic device may include Fig.10 More or fewer components may be shown, or certain components may be combined, or the components may be arranged differently.

[0180] The processor 1101 is the control center of the electronic device. It uses various interfaces and lines to connect various parts of the entire electronic device. By running or executing software programs and / or modules stored in the memory 1102, and calling data stored in the memory 1102, it performs various functions of the electronic device and processes data, thereby monitoring the electronic device as a whole. The processor 1101 may include one or more processing units. Optionally, the processor 1101 may integrate an application processor and a modem processor, wherein the application processor mainly processes the operating system, user interface, and application programs, and the modem processor mainly processes wireless communications. It is understandable that the above-mentioned modem processor may not be integrated into the processor 1101.

[0181] The memory 1102 may be used to store software programs and various data. The memory 1102 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application program required by at least one functional module (such as a determination unit, a processing unit, etc.), etc. In addition, the memory 1102 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0182] In an exemplary embodiment, a computer-readable storage medium including instructions is also provided, such as a memory 1102 including instructions. The above instructions can be executed by a processor 1101 of an electronic device to implement the method in the above embodiment.

[0183] In actual implementation, Fig. 9 The functions of the acquisition unit 1001, the determination unit 1002 and the control unit 1003 in the embodiment can be obtained by Fig.10 The processor 1101 in the embodiment calls the computer program stored in the memory 1102 to implement. The specific execution process can refer to the description of the method part in the above embodiment, which will not be repeated here.

[0184] Optionally, the computer-readable storage medium may be a non-temporary computer-readable storage medium, for example, the non-temporary computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc.

[0185] In an exemplary embodiment, the present application also provides a computer program product including one or more instructions, and the one or more instructions can be executed by the processor 1101 of the electronic device to complete the method in the above embodiment.

[0186] It should be noted that when the instructions in the above-mentioned computer-readable storage medium or one or more instructions in the computer program product are executed by the processor of the electronic device, the various processes of the above-mentioned method embodiment are implemented, and the same technical effect as the above-mentioned method can be achieved. To avoid repetition, they will not be repeated here.

[0187] Through the description of the above implementation methods, technical personnel in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0188] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0189] The units described as separate components may or may not be physically separated, and the components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place or distributed in multiple different places. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0190] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0191] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the prior art or the full classification part or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium, including a number of instructions to enable a device (which can be a single-chip microcomputer, chip, etc.) or a processor (processor) to execute the full classification part or part of the steps of each embodiment method of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, ROM, RAM, disk or CD and other media that can store program code.

[0192] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A power control method, characterized in that: Applicable to a dual motor system, the dual motor system includes a first motor and a second motor, including: In the case where the first motor fails, determining the fault type of the first motor based on the fault information of the first motor; determining an operating mode of the first motor based on at least one of the fault type and a back electromotive force generated by the first motor; Based on the power control strategy corresponding to the working mode, power control is performed on the first motor and / or the second motor.

2. The method according to claim 1, characterized in that The working modes include: active short circuit ASC mode or free safety state FW mode.

3. The method according to claim 2, characterized in that The fault types include: a first type and a second type; wherein, when the first motor is in the first type, the IGBT switch tube of the first motor is in a normal state; when the first motor is in the second type, the IGBT switch tube is in an abnormal state.

4. The method according to claim 3, characterized in that: The determining the working mode of the first motor based on at least one of the fault type and the back electromotive force generated by the first motor includes: When the fault type is the first type and the back electromotive force is greater than a first threshold, or when the fault type is the second type, the operating mode is determined to be the ASC mode.

5. The method according to claim 4, characterized in that When the working mode is the ASC mode, the power control strategy corresponding to the working mode is used to control the power of the first motor and / or the second motor, including: Obtaining the rotation speed and heat rise rate of the first motor; Based on the rotation speed of the first motor and the heat rise rate, power control is performed on the first motor and / or the second motor.

6. The method according to claim 5, characterized in that The performing power control on the first motor and / or the second motor based on the rotation speed of the first motor and the heat rise rate includes: If the speed of the first motor is greater than a speed threshold, or the heat rise rate is greater than a rate threshold, the speed of the first motor is reduced by limiting the power output of the second motor; the speed threshold and the rate threshold are determined based on the oil cooler flow rate and the oil cooler water outlet temperature of the first motor; If the rotation speed of the first motor is less than or equal to the rotation speed threshold, and the heat rise rate is less than or equal to the rate threshold, the first motor is controlled to maintain the current power output.

7. The method according to claim 3, characterized in that When the fault type is the first type and the back electromotive force is less than a first threshold, the working mode is determined to be the FW mode.

8. The method according to claim 7, characterized in that When the working mode is the FW mode, the power control strategy corresponding to the working mode is used to control the power of the first motor and / or the second motor, including: The first motor and the second motor are controlled to maintain current power output.

9. A power control device, characterized in that: The device comprises: an acquisition unit, a determination unit and a control unit; The acquisition unit is configured to determine a fault type of the first motor based on the fault information of the first motor when the first motor fails; The determining unit is configured to determine an operating mode of the first motor based on at least one of the fault type and a back electromotive force generated by the first motor; The control unit is used to perform power control on the first motor and / or the second motor based on the power control strategy corresponding to the working mode.

10. The power control device according to claim 9, characterized in that: The determining unit is specifically configured to: When the fault type is the first type and the back electromotive force is greater than a first threshold, or when the fault type is the second type, it is determined that the operating mode is the ASC mode.

11. A vehicle, characterized in that: include: A power control device and a dual motor system; the dual motor system comprises a first motor and a second motor; The power control device is used to obtain the back electromotive force generated by the first motor when the first motor fails, and determine the fault type of the first motor based on the fault information of the first motor; The power control device is further used to perform power control on the first motor and the second motor based on the fault type and / or the back electromotive force.

12. An electronic device, characterized in that: include: processor; a memory for storing instructions executable by the processor; The processor is configured to execute the instructions to implement the method according to any one of claims 1 to 8.

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