CN110829949A

CN110829949A - Electric drive system fault protection method and device, vehicle and storage medium

Info

Publication number: CN110829949A
Application number: CN201911060818.1A
Authority: CN
Inventors: 苏瑞涛; 李帅; 李伟亮; 王韶涵; 陈晓娇; 李芝炳
Original assignee: FAW Group Corp
Current assignee: FAW Group Corp
Priority date: 2019-11-01
Filing date: 2019-11-01
Publication date: 2020-02-21

Abstract

The embodiment of the invention discloses a fault protection method and device for an electric drive system, a vehicle and a storage medium. The method comprises the following steps: when the acquired motor information of the vehicle motor is fault information, acquiring voltage at two ends of the bus capacitor and/or a rotating speed signal of the motor; determining a switching state of the motor based on the voltage and/or the rotating speed signal in combination with a preset condition; and determining a corresponding working instruction based on the conversion state, and controlling the motor to execute the working instruction. The problem of system damage caused by the situation that the protection is not timely due to low response speed when the electric drive system breaks down suddenly is solved. And when the system detects the fault information, the system does not need to wait for a system processing instruction, and determines the switching state and the working instruction of the motor according to the preset conditions to process the fault, so that the fault processing time is saved, and the fault processing efficiency is improved.

Description

Electric drive system fault protection method and device, vehicle and storage medium

Technical Field

The embodiment of the invention relates to a motor protection technology, in particular to a method and a device for protecting a fault of an electric drive system, a vehicle and a storage medium.

Background

The electric driving system of the electric automobile is a power source of the vehicle, and the driving safety of the electric automobile is influenced. The electric automobile adopting the permanent magnet synchronous motor is provided with an inverter for specially controlling the motor, controlling the rotating speed, the torque and the like of the permanent magnet synchronous motor, converting the electric energy of a high-voltage power battery into the mechanical energy of the motor, and driving an axle to rotate through a mechanical device so as to enable the automobile to run.

At present, when an electric automobile runs and an electric drive system breaks down, the electric automobile needs to be in a safe state so as to prevent the vehicle from being out of control to influence personal safety or damage high-voltage components. Particularly, when an electric vehicle adopting the permanent magnet synchronous motor runs at a high speed, sudden faults of the electric drive system, such as IGBT faults, sensors or data communication faults, need to enable the electric drive system to enter a safe state until the vehicle stops. In this process, it is also necessary to perform short-circuit control and idling control of the motor.

However, in the conventional scheme, a single chip microcomputer and a peripheral hardware circuit are adopted, so that motor short-circuit control and idle control can be realized, but the flexibility is poor, the expansion cannot be realized, only simple control can be realized, and complicated detection, logic judgment and fault processing mechanisms cannot be realized.

Disclosure of Invention

The invention provides a fault protection method and device for an electric drive system, a vehicle and a storage medium, which are used for protecting a motor when a fault occurs.

In a first aspect, an embodiment of the present invention provides a fault protection method for an electric drive system, where the electric drive system includes at least a bus capacitor and a motor, and the fault protection method includes:

when the acquired motor information of the vehicle motor is fault information, acquiring voltage at two ends of the bus capacitor and/or a rotating speed signal of the motor;

determining a switching state of the motor based on the voltage and/or the rotating speed signal in combination with a preset condition;

and determining a corresponding working instruction based on the conversion state, and controlling the motor to execute the working instruction.

In a second aspect, an embodiment of the present invention further provides an electric drive system fault protection device, where the electric drive system includes at least a bus capacitor and a motor, and the drive system fault protection device includes:

the acquisition module is used for acquiring the voltage at two ends of the bus capacitor and/or the rotating speed signal of the motor when the acquired motor information of the vehicle motor is fault information;

the determining module is used for determining the conversion state of the motor based on the voltage and/or the rotating speed signal in combination with preset conditions;

and the execution module is used for determining a corresponding working instruction based on the conversion state and controlling the motor to execute the working instruction.

In a third aspect, an embodiment of the present invention further provides a vehicle, including:

an electric drive system is provided with an electric drive system,

one or more controllers;

a storage device for storing one or more programs,

when executed by the one or more controllers, cause the one or more controllers to implement a method of fault protection for an electric drive system as described in any of the embodiments of the present invention.

In a fourth aspect, the embodiments of the present invention further provide a computer-readable storage medium, on which a computer program is stored, which when executed by a processor implements a fault protection method for an electric drive system according to any one of the embodiments of the present invention.

According to the embodiment of the invention, when the acquired motor information of the vehicle motor is fault information, the voltage at two ends of the bus capacitor and/or the rotating speed signal of the motor are/is acquired; determining a switching state of the motor based on the voltage and/or the rotating speed signal in combination with a preset condition; and determining a corresponding working instruction based on the conversion state, and controlling the motor to execute the working instruction, so that the problem of system damage caused by the situation of untimely protection due to low response speed when the electric drive system breaks down suddenly is solved. And when the system detects the fault information, the system does not need to wait for a system processing instruction, and determines the switching state and the working instruction of the motor according to the preset conditions to process the fault, so that the fault processing time is saved, and the fault processing efficiency is improved.

Drawings

FIG. 1 is a flow chart of a method for fault protection of an electric drive system according to a first embodiment of the present invention;

FIG. 2 is a block diagram of an electric drive system of an electric vehicle according to a first embodiment of the present invention;

fig. 3 is a functional block diagram of a CPLD in the first embodiment of the present invention;

fig. 4 is a flow chart of a fault logic processing mechanism of a CPLD according to a first embodiment of the present invention;

FIG. 5 is a flow chart of a method for fault protection of an electric drive system in accordance with a second embodiment of the present invention;

FIG. 6 is a block diagram of an electric drive system fault protection device in accordance with a third embodiment of the present invention;

fig. 7 is a schematic structural diagram of a vehicle according to a fourth embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

Example one

Fig. 1 is a flowchart of a fault protection method for an electric drive system according to an embodiment of the present invention, where the present embodiment is applicable to a case where a fault occurs in the electric drive system, and the method may be executed by a fault protection device for the electric drive system, where the electric drive system is applied to a vehicle, and the electric drive system includes at least a bus capacitor and an electric motor, and fig. 2 provides a block diagram of a structure of the electric drive system for an electric vehicle.

The electric drive system comprises a high-voltage power supply 1, a bus supporting capacitor 2, a power switch device 3, a power motor 4, a switch 5, a drive unit 6 and a control unit 7. The high-voltage power supply 1 may be specifically understood as a power battery of a pure electric vehicle, a power battery of a hybrid electric vehicle, or a component for providing electric energy, such as a super capacitor. And a bus supporting capacitor 2, wherein the positive electrode of the bus capacitor 2 is connected with the positive electrode of the high-voltage power supply 1, and the negative electrode of the bus capacitor 2 is connected with the ground of the high-voltage power supply 1, so that the voltage of the high-voltage power supply 1 is stabilized. The power switch device 3 adopts a three-phase full-bridge topology structure, the

power devices

3a, 3b and 3c form an upper bridge switch of the inverter, the

power devices

3d, 3e and 3f form a lower bridge switch of the inverter, the power switch device 3 can be an insulated gate bipolar transistor IGBT or a field effect transistor MOSFET, and the like, and the description of the embodiment is given by taking the power device as the IGBT. The power motor 4 is a three-phase permanent magnet synchronous motor, and the power motor 4 plays a role in driving wheels to rotate so as to enable the vehicle to run. The control unit collects information of the high-voltage power supply 1 and the power motor 4 and is used for calculating switching time sequences of the

IGBT devices

3a, 3b, 3c, 3d, 3e and 3f, the driving unit drives the

IGBT devices

3a, 3b, 3c, 3d, 3e and 3f to be switched on and switched off, electric isolation between the driving unit and the control unit is achieved, and the power motor 4 outputs torque according to requirements and protects a power drive system to work safely. And a relay switch 6 for switching on or off the electrical connection between the high-voltage power supply 1 and the IGBT. When the vehicle runs electrically, the motor 4 obtains energy from the high-voltage power supply 1, converts electric energy into mechanical energy and drives the vehicle to run. When the motor energy is recovered by braking, the power motor 4 converts the mechanical energy into electric energy to charge the high-voltage power supply 1, so that the situation that the braking energy is completely converted into heat to reduce the energy utilization efficiency is avoided.

When the electric drive system has IGBT fault, sensor or data communication failure, the motor 4 can not work normally. If the motor 4 is still rotating at a high speed and the rotating speed is higher than the safety threshold n1, the motor needs to be actively short-circuited to prevent the counter electromotive force of the motor from being too high, and overcharging the bus supporting capacitor 2 to cause damage to related high-voltage components. The motor enters a short-circuit mode, high-

side switches

3a, 3b and 3c of a power switch device 3 can be switched on, and low-

side switches

3d, 3e and 3f are switched off at the same time; it is also possible to switch the

power switches

3d, 3e, 3f on while switching the

power switches

3a, 3b, 3c off. When the rotating speed of the motor is reduced below a safety threshold n2, the counter electromotive force of the motor is correspondingly reduced to the safety threshold, and at the moment, in order to avoid excessive negative torque generated by short circuit of the motor, the 3a, 3b, 3c, 3d, 3e and 3f are closed, so that the motor idles.

Further, fig. 3 provides a functional block diagram of a CPLD, which is a part of the control unit. The CPLD is used for fault diagnosis and treatment, and the CPLD is used for respectively connecting signals of IGBT faults, three-phase current overcurrent faults, bus voltage overvoltage faults and the like of the driving unit to each pin of the CPLD. Upon a fault trigger, the CPLD can respond quickly and handle the fault within the us class. The interrupt resources of the singlechip are limited, and each fault signal cannot be connected to an interrupt pin, so that the response speed of the singlechip is slower than that of the CPLD, and the system is damaged due to the condition of untimely protection. In addition, the CPLD is arranged between the singlechip and the driving unit, the PWM signal output by the singlechip is firstly sent to the CPLD, and the CPLD judges the dead zone time and then outputs the dead zone time to the driving unit, so that the dead zone protection function can be realized, and the reliability of the system is improved. The CPLD can verify 2 paths of PWM signals of the same bridge arm output by the single chip microcomputer, and once the dead zone time is smaller than the set time, the CPLD blocks the PWM output or prolongs the dead zone time to the set time. And when the system detects the fault, the fault processing can be carried out according to the preset logic without waiting for the instruction of the single chip microcomputer, and meanwhile, a specific fault signal is reported to the single chip microcomputer. The CPLD reports the fault signal to the singlechip through the SPI communication mode, so that I/O resources of the singlechip can be saved and the singlechip can be ensured to store the corresponding fault for further fault diagnosis and treatment compared with the method of transmitting the fault signal through an I/O pin. The active short enable signal in fig. 3 is a function of the speed of rotation, and when the motor speed is greater than the safety threshold n1, the active short enable signal is enabled and assigned a value of 1. When the rotating speed of the motor is reduced from the rotating speed n1 to the rotating speed n2, the active short-circuit signal is enabled until the rotating speed is reduced to n2, the active short-circuit signal is not enabled at the moment, and the value is assigned to 0. This is equivalent to adding a rotation speed hysteresis function for active short circuit, so that the system state is more stable, and the state is prevented from being frequently switched under special working conditions.

Fig. 4 provides a flow chart of a fault logic processing mechanism of the CPLD, which shows the logic operation timing of the CPLD. The motor active short circuit needs to select a short-circuit upper bridge arm or a short-circuit lower bridge arm according to the IGBT fault state, and when the IGBT upper bridge arm fails, the short circuit needs to be performed on the IGBT lower bridge arm; when the lower bridge arm of the IGBT breaks down, the upper bridge arm of the IGBT needs to be short-circuited. When no IGBT fault occurs but only other high-level faults, such as an overcurrent fault, an overvoltage fault, and the like, the upper arm of the IGBT can be shorted, and the lower arm of the IGBT can also be shorted, and the short circuit of the lower arm of the IGBT is defaulted in this embodiment. When the active short-circuit fault signal is switched to a non-enabled state from an enabled state, the fact that the rotating speed of the motor is reduced to a safety threshold value is indicated, at the moment, the 6 paths of PWM signals need to be closed, and the motor is enabled to idle.

By respectively connecting the fault signal to each pin of the CPLD, once the fault trigger signal is generated, the CPLD can quickly respond in the us level and process the fault, thereby improving the fault response speed, realizing timely processing of the fault when the system is in fault, further preventing the system from being damaged, and prolonging the use of the system. And the CPLD is arranged between the singlechip and the driving unit, the PWM signal output by the singlechip is firstly sent to the CPLD, and the CPLD judges the dead zone time and then outputs the dead zone time to the driving unit, so that the dead zone protection function can be realized, and the reliability of the system is improved. When the system detects a fault, the system can process the fault according to the preset logic without waiting for the instruction of the singlechip, and simultaneously report a specific fault signal to the singlechip. The CPLD identifies and logically processes the faults, the number of I/O pins of the single chip microcomputer for detecting the faults is reduced, all the faults are reported to the single chip microcomputer in a fault code mode between the single chip microcomputer and the CPLD in an SPI communication mode, the design of the single chip microcomputer is greatly optimized, and the single chip microcomputer can be ensured to store the corresponding faults so as to further diagnose and process the faults. And when the single chip microcomputer fails, the CPLD can still continue to work, so that the vehicle enters a safe state until the vehicle stops, and the running safety of the vehicle is improved.

A fault protection method for an electric drive system specifically comprises the following steps:

and 11, when the acquired motor information of the vehicle motor is fault information, acquiring voltage at two ends of the bus capacitor and/or a rotating speed signal of the motor.

The motor information may be specifically understood as some information reflecting the condition of the motor itself, and the bus capacitor may be specifically understood as a circuit element stabilizing the voltage of the high-voltage power supply.

Specifically, the motor information of the vehicle motor may be obtained by connecting a pin for transmitting the motor information to a hardware circuit; the voltage at the two ends of the bus capacitor can be obtained through instruments such as a voltmeter, an oscilloscope, an alternating current millivoltmeter and the like; the method for acquiring the rotating speed signal of the motor can be acquired by instruments such as a multimeter, a motor rotating speed measuring instrument and the like.

And step 12, determining the conversion state of the motor based on the voltage and/or the rotating speed signal and preset conditions.

The preset conditions may be specifically understood as state transition conditions preset according to the working environment and requirements of different electric drive systems, and used for determining the transition state of the motor.

Specifically, the manner of determining the state of the motor may be that when the voltage and/or the rotational speed signal are obtained, whether the voltage at this time meets the voltage conversion condition and/or whether the rotational speed signal meets the rotational speed signal conversion condition is determined by a preset condition, and accordingly, whether the motor performs state conversion and a state that the motor should perform state conversion are determined.

And step 13, determining a corresponding working instruction based on the conversion state, and controlling the motor to execute the working instruction.

The work instruction can be specifically understood as an instruction issued by the system according to the work requirement.

Specifically, the work instruction may be determined by determining a corresponding work instruction in a switching state of the motor.

According to the method, when the acquired motor information of the vehicle motor is fault information, the voltage at two ends of the bus capacitor and/or the rotating speed signal of the motor are/is acquired; determining a switching state of the motor based on the voltage and/or the rotating speed signal in combination with a preset condition; and determining a corresponding working instruction based on the conversion state, and controlling the motor to execute the working instruction, so that the problem of system damage caused by the situation of untimely protection due to low response speed when the electric drive system breaks down suddenly is solved. And when the system detects the fault information, the system does not need to wait for a system processing instruction, and determines the switching state and the working instruction of the motor according to the preset conditions to process the fault, so that the fault processing time is saved, and the fault processing efficiency is improved.

Example two

Fig. 5 is a flowchart of a fault protection method for an electric drive system according to a second embodiment of the present invention. The technical scheme of the embodiment is further refined on the basis of the technical scheme, and specifically mainly comprises the following steps:

and 21, when the acquired motor information of the vehicle motor is fault information, acquiring voltage at two ends of the bus capacitor and/or a rotating speed signal of the motor.

Wherein the fault information at least includes: a short circuit fault signal, a drive voltage under-voltage fault signal, and/or a battery relay status signal.

And step 22, determining the conversion state of the motor based on the voltage and/or the rotating speed signal and preset conditions.

Wherein the preset condition at least comprises: presetting a voltage threshold range and a rotating speed threshold range.

Specifically, the preset voltage threshold range is used for judging whether the motor fails or not and whether the state needs to be switched or not according to whether the voltage is in the voltage threshold range or not; the preset rotating speed threshold range has the function of judging whether the motor breaks down or not and whether the state needs to be converted or not according to whether the rotating speed signal of the motor is in the rotating speed threshold range or not.

And 23, when the voltage is in the voltage threshold range and the rotating speed signal is not in the rotating speed threshold range, determining the switching state of the motor by combining the rotating speed signal with a rotating speed state switching condition, wherein the rotating speed state switching condition is preset according to the working condition of the corresponding electric drive system.

The rotation speed state transition condition may be specifically understood as a transition condition in which the rotation speed of the motor is set according to the operating condition and the requirement of the electric drive system.

Specifically, the switching state of the motor may be determined by a voltage or a rotation speed signal, that is, when the voltage is within the voltage threshold range and the rotation speed signal is not within the rotation speed threshold range, determining whether a rotation speed state switching condition is met according to the rotation speed signal, thereby determining the switching state of the motor.

Further, the determining the conversion state of the motor by the rotation speed signal in combination with the rotation speed state conversion condition includes: when the rotating speed signal meets the rotating speed state conversion condition, determining that the conversion state is an active short circuit; otherwise, determining that the conversion state is idle.

Specifically, the switching state required to be performed by the motor is determined according to the rotating speed state switching condition, that is, when the rotating speed signal meets the rotating speed state switching condition, the state required to be performed by the motor is determined to be switched to an active short circuit, and when the rotating speed signal does not meet the rotating speed state switching condition, the state required to be performed by the motor is determined to be switched to idle.

And 24, when the rotating speed signal is in the rotating speed threshold range and the voltage is not in the voltage threshold range, determining the switching state of the motor by combining the voltage with a voltage state switching condition, wherein the voltage state switching condition is preset according to the working condition of the corresponding electric drive system.

The voltage state transition condition may be specifically understood as a transition condition set by the bus capacitor voltage according to the operating condition and the requirement of the electric drive system.

Specifically, the switching state of the motor may be determined by a voltage or a rotation speed signal, that is, when the rotation speed signal is within the rotation speed threshold range and the voltage is not within the voltage threshold range, determining whether a voltage state switching condition is met according to the voltage, thereby determining the switching state of the motor.

Further, the determining the switching state of the motor by the voltage in combination with the voltage state switching condition includes: when the voltage meets the voltage state conversion condition, determining that the conversion state is an active short circuit; otherwise, determining that the conversion state is idle.

Specifically, the conversion state required to be performed by the motor is determined according to a voltage state conversion condition, that is, when the voltage meets the voltage state conversion condition, the state required to be performed by the motor is determined to be converted into an active short circuit, and when the voltage does not meet the rotating speed state conversion condition, the state required to be performed by the motor is determined to be converted into an idle running state.

Step 25, when the rotating speed signal is not in the rotating speed threshold range and the voltage is not in the voltage threshold range, determining a motor switching state by combining the rotating speed signal with the rotating speed state switching condition; or, the switching state of the motor is determined by the voltage in combination with the voltage state switching condition.

Specifically, the switching state of the motor may be determined by a voltage or a rotation speed signal, that is, when the rotation speed signal is not within the rotation speed threshold range and the voltage is not within the voltage threshold range, both the voltage and the rotation speed signal are abnormal signals, and the switching state of the motor may be determined by both the voltage and the rotation speed signal, so that one of the states is selected to determine the switching state of the motor, that is, whether the rotation speed signal meets the rotation speed state switching condition or whether the voltage meets the voltage state switching condition is determined according to the voltage, so as to determine the switching state of the motor.

Step 26, when the difference value between the voltage and a preset voltage threshold value is within a first preset interval, determining that the conversion state is kept unchanged; and/or when the difference value between the rotating speed signal and a preset rotating speed threshold value is within a second preset interval, determining that the conversion state is kept unchanged.

The preset voltage threshold can be specifically understood as a voltage value preset according to the working environment and the requirement of the electric drive system; the first preset interval can be specifically understood as a protection interval which is combined with voltage and is set in advance according to the working environment and the requirement of the electric drive system; the preset rotation speed threshold value can be specifically understood as a rotation speed value preset according to the working environment and the requirement of the electric drive system; the second predetermined interval may be understood as a protection interval that is set in advance in accordance with the operating environment and the requirements of the electric drive system in combination with the rotational speed.

Specifically, the switching state may be determined by calculating a difference between the voltage and a preset voltage threshold, and keeping the switching state of the motor unchanged when the difference is within a first preset interval; and/or, by calculating the difference value between the rotating speed and a preset rotating speed threshold value, when the difference value is in a second preset interval, keeping the switching state of the motor unchanged.

The preset voltage threshold value is used as a standard value or a reference value in the state conversion process, when the voltage value exceeds the value or is smaller than the value, the motor is considered to be abnormal, and when the abnormal condition occurs, the state of the motor needs to be converted into idling or active short circuit to protect the motor, so that the motor is not damaged or the damage of the motor is reduced. However, in an actual working environment, when the motor is abnormal, the voltage usually fluctuates within a range of a preset voltage threshold, and if the motor state is switched at this time, the motor is switched between two states frequently without stop, so that the motor is damaged. Therefore, a first preset interval is set at the moment, and if the difference value between the voltage of the motor and the preset voltage threshold value is within the first preset interval, the state of the motor at the moment is kept unchanged. For example, the preset voltage threshold is 220V, the first preset interval is 20V, and when the voltage value is 200V or less than 200V, the voltage conversion state is determined to be idle or active short circuit according to the working environment and requirements of the electric drive system. And when the voltage is more than 200V, determining the voltage conversion state to be idle or active short circuit according to the working environment and the requirement of the electric drive system. Similarly, the preset rotation speed threshold is used as a standard value or a reference value in the state transition process, and when the rotation speed signal exceeds the value or is smaller than the value, the motor is considered to be abnormal, so that a second preset interval is set at the moment, and if the difference value between the rotation speed signal of the motor and the preset rotation speed threshold is within the second preset interval, the state of the motor at the moment is kept unchanged. For example, the preset rotation speed threshold is 1000r/s, the first preset interval is 200r/s, and when the rotation speed signal is 800r/s or less than 800r/s, the voltage conversion state is determined to be idle or active short circuit according to the working environment and the requirement of the electric drive system. And when the voltage is more than 800r/s, determining the voltage conversion state to be idle or active short circuit according to the working environment and the requirement of the electric drive system.

Through setting for first preset interval and second preset interval, confirm the motor the changeover state is for switching the changeover state or remain unchanged, can avoid the motor to ceaselessly frequently switch between two states, has realized the effect of motor protection, has improved motor life.

And 27, determining a corresponding working instruction based on the conversion state, and controlling the motor to execute the working instruction.

Specifically, the conversion state comprises an active short circuit and an idle running, and when the conversion state is the active short circuit, a motor active short circuit instruction is sent out, and the motor is controlled to execute the active short circuit instruction; and when the conversion state is idle, sending a motor idle instruction and controlling the motor to execute the idle instruction.

According to the method, when the acquired motor information of the vehicle motor is fault information, the voltage at two ends of the bus capacitor and/or the rotating speed signal of the motor are/is acquired; determining a switching state of the motor based on the voltage and/or the rotating speed signal in combination with a preset condition; and determining a corresponding working instruction based on the conversion state, and controlling the motor to execute the working instruction, so that the problem of system damage caused by the situation of untimely protection due to low response speed when the electric drive system breaks down suddenly is solved. And when the system detects the fault information, the system does not need to wait for a system processing instruction, determines the conversion state and the working instruction of the motor according to the preset conditions to process the fault, and reports a specific fault signal to the system, thereby saving the fault processing time, improving the fault processing efficiency, avoiding the motor from being switched frequently between two states ceaselessly, realizing the effect of motor protection and prolonging the service life of the motor.

EXAMPLE III

Fig. 6 is a structural diagram of a fault protection device of an electric drive system according to a third embodiment of the present invention, where the electric drive system includes at least a bus capacitor and an electric motor, and a driving control device of the vehicle includes: an acquisition module 31, a determination module 32 and an execution module 33.

The acquiring module 31 is configured to acquire a voltage across the bus capacitor and/or a rotation speed signal of the motor when the acquired motor information of the vehicle motor is fault information; a determination module 32, configured to determine a switching state of the motor based on the voltage and/or the rotation speed signal in combination with a preset condition; and the execution module 33 is configured to determine a corresponding work instruction based on the conversion state, and control the motor to execute the work instruction.

Optionally, the fault information at least includes: a short circuit fault signal, a drive voltage under-voltage fault signal, and/or a battery relay status signal.

Optionally, the preset condition at least includes: presetting a voltage threshold range and a rotating speed threshold range.

Further, the apparatus further comprises: the state judgment module is used for determining that the conversion state is kept unchanged when the difference value of the voltage and a preset voltage threshold value is within a first preset interval; and/or when the difference value between the rotating speed signal and a preset rotating speed threshold value is within a second preset interval, determining that the conversion state is kept unchanged.

Specifically, the determining module 32 includes:

and the first determining unit is used for determining the switching state of the motor by combining the rotating speed signal with a rotating speed state switching condition when the voltage is in the voltage threshold range and the rotating speed signal is not in the rotating speed threshold range, wherein the rotating speed state switching condition is preset according to the working condition of the corresponding electric drive system.

Further, when the rotating speed signal meets the rotating speed state conversion condition, determining that the conversion state is an active short circuit; otherwise, determining that the conversion state is idle.

And the second determining unit is used for determining the switching state of the motor by combining the voltage with a voltage state switching condition when the rotating speed signal is in the rotating speed threshold range and the voltage is not in the voltage threshold range, wherein the voltage state switching condition is preset according to the working condition of the corresponding electric drive system.

Further, when the voltage meets the voltage state transition condition, determining that the transition state is an active short circuit; otherwise, determining that the conversion state is idle.

A third determining unit, configured to determine a motor switching state by combining the rotation speed signal with the rotation speed state switching condition when the rotation speed signal is not within the rotation speed threshold range and the voltage is not within the voltage threshold range; or, the switching state of the motor is determined by the voltage in combination with the voltage state switching condition.

The fault protection device for the electric drive system, provided by the embodiment of the invention, can execute the fault protection method for the electric drive system, provided by any embodiment of the invention, and has corresponding functional modules and beneficial effects of the execution method.

Example four

Fig. 7 is a schematic structural diagram of a vehicle according to a fourth embodiment of the present invention, as shown in fig. 7, the vehicle includes an electric drive system 40, a controller 41, a memory 42, an input device 43, and an output device 44; the number of the controllers 41 in the vehicle may be one or more, and one controller 41 is illustrated in fig. 7; the electric drive system 40, the controller 41, the memory 42, the input device 43, and the output device 44 in the vehicle may be connected by a bus or other means, and the bus connection is exemplified in fig. 7.

The memory 42 serves as a computer-readable storage medium for storing software programs, computer-executable programs, and modules, such as program instructions/modules corresponding to the driving control method of the vehicle in the embodiment of the present invention (for example, the acquisition module 31 and the determination module 32 and the execution module 33 in the electric drive system fault protection device of the vehicle). The controller 41 executes various functional applications and data processing of the vehicle, that is, implements the above-described driving control method of the vehicle, by executing software programs, instructions, and modules stored in the memory 42.

The memory 42 may mainly include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required for at least one function; the storage data area may store data created according to the use of the terminal, and the like. Further, the memory 42 may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other non-volatile solid state storage device. In some examples, the memory 42 may further include memory remotely located from the controller 41, which may be connected to the vehicle over a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.

The input device 43 may be used to receive input numeric or character information and generate key signal inputs related to user settings and function control of the cloud platform. The output device 44 may include a display device such as a display screen.

EXAMPLE five

Embodiments of the present invention also provide a storage medium containing computer-executable instructions, which when executed by a computer processor, perform a method of fault protection for an electric drive system, the electric drive system including at least a bus capacitor and an electric machine, the method comprising:

Of course, the embodiment of the present invention provides a storage medium containing computer-executable instructions, and the computer-executable instructions are not limited to the operations of the method described above, and can also perform related operations in the method for protecting the fault of the electric drive system provided by any embodiment of the present invention.

From the above description of the embodiments, it is obvious for those skilled in the art that the present invention can be implemented by software and necessary general hardware, and certainly, can also be implemented by hardware, but the former is a better embodiment in many cases. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which may be stored in a computer-readable storage medium, such as a floppy disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a FLASH Memory (FLASH), a hard disk or an optical disk of a computer, and includes several instructions for enabling a computer device (which may be a personal computer, a server, or a network device) to execute the methods according to the embodiments of the present invention.

It should be noted that, in the embodiment of the fault protection device for an electric drive system, the units and modules included in the embodiment are merely divided according to functional logic, but are not limited to the above division as long as the corresponding functions can be realized; in addition, specific names of the functional units are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present invention.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for fault protection of an electric drive system, said electric drive system including at least a bus capacitor and an electric machine, comprising:

2. The method according to claim 1, characterized in that the fault information comprises at least:

a short circuit fault signal, a drive voltage under-voltage fault signal, and/or a battery relay status signal.

3. The method according to claim 1, wherein the preset conditions at least comprise:

presetting a voltage threshold range and a rotating speed threshold range.

4. The method of claim 3, wherein prior to determining a corresponding work order based on the transition state and controlling the motor to execute the work order, further comprising:

when the difference value of the voltage and a preset voltage threshold value is within a first preset interval, determining that the conversion state is kept unchanged; and/or the presence of a gas in the gas,

and when the difference value between the rotating speed signal and a preset rotating speed threshold value is within a second preset interval, determining that the conversion state is kept unchanged.

5. The method of claim 4, wherein determining the transition state of the motor based on the voltage and/or the speed signal in combination with a preset condition comprises:

when the voltage is in the voltage threshold range and the rotating speed signal is not in the rotating speed threshold range, determining the switching state of the motor by combining the rotating speed signal with a rotating speed state switching condition, wherein the rotating speed state switching condition is preset according to the working condition of the corresponding electric drive system; alternatively, the first and second electrodes may be,

when the rotating speed signal is in the rotating speed threshold range and the voltage is not in the voltage threshold range, determining the switching state of the motor by combining the voltage with a voltage state switching condition, wherein the voltage state switching condition is preset according to the working condition of the corresponding electric drive system; alternatively, the first and second electrodes may be,

when the rotating speed signal is not in the rotating speed threshold range and the voltage is not in the voltage threshold range, determining a motor switching state by combining the rotating speed signal with the rotating speed state switching condition; or, the switching state of the motor is determined by the voltage in combination with the voltage state switching condition.

6. The method of claim 5, wherein determining the transition state of the electric machine from the speed signal in combination with a speed state transition condition comprises:

when the rotating speed signal meets the rotating speed state conversion condition, determining that the conversion state is an active short circuit; otherwise, determining that the conversion state is idle.

7. The method of claim 5, wherein determining the transition state of the electric machine from the voltage in combination with the voltage state transition condition comprises:

when the voltage meets the voltage state conversion condition, determining that the conversion state is an active short circuit; otherwise, determining that the conversion state is idle.

8. An electric drive system fault protection device, said electric drive system including at least a bus capacitor and an electric machine, comprising:

9. A vehicle, characterized by comprising:

an electric drive system is provided with an electric drive system,

one or more controllers;

a storage device for storing one or more programs,

when executed by the one or more controllers, cause the one or more controllers to implement the method of any one of claims 1-7.

10. A computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the method according to any one of claims 1-7.