Redundant control system for permanent magnet synchronous motor position sensor failure scenarios

Abstract

A kind of redundancy control system for permanent magnet synchronous motor position sensor failure scene of vehicle, including: current conversion module, coordinate conversion module, voltage conversion module and position conversion module.The current conversion module, coordinate conversion module, voltage conversion module and position conversion module are provided in the present application, can be realized when key components such as rotary transformer fails the start of motor and full speed range control, provides redundancy function backup for powertrain control system, so that when rotary transformer and other position sensor components fail, power can be continued to be output by the way of position sensorless control, and static start and full speed range position sensorless control can be realized.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of automobile motors, in particular to a redundancy control system for a permanent magnet synchronous motor position sensor failure scenario for vehicles. BACKGROUND

[0002] Permanent magnet synchronous motors are widely used in new energy vehicle powertrain components due to their small size, high power density, flexible control and other characteristics. The permanent magnet synchronous motor drive control system generally needs to rely on sensors such as rotary transformers to obtain motor rotor position signal feedback, to realize current and torque control of the motor. The use of rotary transformers and other elements will increase the connection harness and system volume, and they usually need additional position decoding chips to demodulate the position signal, which also increases the manufacturing cost. In addition, the increased elements and connection harnesses also reduce the reliability of the system. When the rotary transformer or connection harness fails, the drive control system will not be able to control the motor output torque, resulting in the vehicle losing power and anchoring, and negatively affecting the driving experience of passengers. SUMMARY

[0003] The application proposes a redundancy control system for a permanent magnet synchronous motor position sensor failure scenario for vehicles to solve the above problems in the prior art. The system is provided with a current conversion module, a coordinate conversion module, a voltage conversion module and a position conversion module, which can realize motor starting and full speed range control when key components such as rotary transformers fail, provide redundancy function backup for the powertrain control system, and thus continue to output power through position sensorless control when the rotary transformer and other position sensor components fail.

[0004] The application is implemented through the following technical solutions:

[0005] The application relates to a control system for a permanent magnet synchronous motor position sensor failure for vehicles, which comprises a current conversion module, a coordinate conversion module, a voltage conversion module and a position conversion module. The current conversion module is connected to the coordinate conversion module, receives current instructions and performs conversion, and transmits the converted instructions to the coordinate conversion module. The coordinate conversion module is connected to the voltage conversion module, receives voltage instructions, current instructions and motor rotor positions, and performs conversion, and transmits the converted instructions to the current conversion module and the voltage conversion module, respectively. The voltage conversion module receives voltage instructions and performs conversion, and outputs driving voltage to drive the motor to run. The position conversion module receives rotor position related signals and performs conversion and output, and outputs rotor position signals in different working states of the modules.

[0006] The current transformation module comprises: a current instruction distribution unit and a current loop control unit connected in series, wherein: the current instruction distribution unit receives a torque instruction, obtains a current instruction and transmits the current instruction to the current loop control unit; the current loop control unit receives the current instruction, calculates a voltage instruction and transmits the voltage instruction to the coordinate transformation module after being summed with an output result of the position transformation module.

[0007] The coordinate transformation module comprises: a first coordinate transformation unit and a second coordinate transformation unit connected in series, wherein: the first coordinate transformation unit receives a voltage instruction and a motor rotor position, calculates a voltage instruction and transmits the voltage instruction to the voltage transformation module; the second coordinate transformation unit receives a three-phase current feedback value and a motor rotor position, calculates a current feedback and transmits the current feedback to the current transformation module.

[0008] The voltage transformation module comprises: a pulse width modulation unit, an inverter unit and a motor unit connected in series, wherein: the pulse width modulation unit receives a voltage instruction, calculates six driving signals, outputs a driving voltage and transmits the driving voltage to the inverter unit; the inverter unit receives the six driving signals, modulates a direct current voltage to generate a three-phase driving voltage and transmits the three-phase driving voltage to the motor unit; the motor unit receives a three-phase output voltage and outputs a torque.

[0009] The inverter unit is a three-phase six-bridge-arm power type topology structure.

[0010] The position transformation module comprises: a position sensor unit, a position decoding unit, a position signal selection unit and a position observer unit, wherein: the position sensor unit generates a feedback motor rotor position signal and transmits the feedback motor rotor position signal to the position decoding unit; the position decoding unit receives the motor rotor position signal, calculates a rotor position sampling signal and transmits the rotor position sampling signal to the position signal selection unit; the position signal selection unit receives the rotor position sampling signal and a rotor position estimation signal, and selects a rotor position signal output according to working states of the position sensor unit and the position decoding unit; the position observer unit receives a feedback value of a three-phase current of the motor, a voltage instruction and a torque instruction, and outputs an injection voltage, a rotor position estimation signal, a motor electric angular velocity estimation signal and a motor rotation speed estimation signal.

[0011] The position observer unit comprises: a third coordinate transformation unit, a fourth coordinate transformation unit, a polarity identification unit for identifying an initial rotor position when the motor is started in a static state, a high-frequency injection observer unit, a flux linkage observer unit, an injection voltage selection unit for selecting an injection voltage in a starting stage, an angle compensation unit and a phase-locked loop unit.

[0012] The third coordinate transformation unit receives a feedback value of a three-phase current of the motor, calculates a coordinate system current and transmits the coordinate system current to the fourth coordinate transformation unit and the flux linkage observer unit.

[0013] The fourth coordinate transformation unit receives the current and the rotor position estimation signal, calculates the coordinate system current, and transmits the coordinate system current to the polarity identification unit and the high-frequency injection observer unit respectively.

[0014] The high-frequency injection observer unit comprises a high-frequency voltage generation unit and an angle error calculation unit connected in sequence, wherein the high-frequency voltage generation unit receives the motor speed estimation signal, generates the high-frequency voltage and the voltage polarity signal, and transmits the high-frequency voltage and the voltage polarity signal to the angle error calculation unit; the angle error calculation unit receives the current and the voltage polarity signal, and calculates the high-frequency injection angle error signal.

[0015] The flux observer unit comprises a low-pass filter unit, a phase compensation unit, and an error calculation unit, wherein the low-pass filter unit receives the electrical angular velocity, calculates the signal adaptive selected cutoff frequency, and outputs the low-pass filtered voltage signal; the phase compensation unit receives the low-pass filtered voltage signal, compensates the low-pass filtering delay, subtracts the flux generated by the phase current, and outputs the effective flux to the error calculation unit; the error calculation unit receives the effective flux and the rotor position estimation signal, and calculates the flux observation angle error signal.

[0016] The angle compensation unit receives the speed estimation signal and the torque instruction, acquires the high-frequency injection angle error signal, and adds the polarity compensation angle to obtain the estimation angle compensation value.

[0017] The phase-locked loop unit comprises an error selection unit, a proportional-integral control unit, an integral unit, and a low-pass filter unit, wherein the error selection unit receives the speed estimation signal, selects the high-frequency injection angle error signal, and transmits the high-frequency injection angle error signal to the proportional-integral control unit; the proportional-integral control unit receives the high-frequency injection angle error signal, calculates the pre-filtered electrical angular velocity estimation signal, and transmits the pre-filtered electrical angular velocity estimation signal to the integral unit and the low-pass filter unit; the integral unit receives the angle signal, adds the estimation angle compensation value, and obtains the rotor position estimation signal; the low-pass filter unit receives the pre-filtered electrical angular velocity estimation signal, performs low-pass filtering, and obtains the motor electrical angular velocity estimation signal; the motor electrical angular velocity estimation signal is multiplied by a coefficient to obtain the motor speed estimation signal.

[0018] The position sensor unit comprises a software initialization unit, an EEPROM position sensor fault signal flag reading unit, a position sensor fault judgment unit, a position sensor signal selection unit, a software internal estimation position signal selection unit, a main program running unit, a power-down permission judgment unit, and a position sensor fault storage to EEPROM execution unit, wherein:

[0019] The software initialization unit performs the initialization work of the controller external device and the software variable after the system is powered on, and after the initialization work is completed, the program execution unit reads the EEPROM position sensor fault signal flag reading unit;

[0020] The unit for reading the EEPROM position sensor fault signal flag reads the position sensor fault signal flag pre-stored in the EEPROM into the software memory A through the interface function of the NVM module in the basic software, and executes the position sensor fault judgment unit after completion;

[0021] The position sensor fault judgment unit reads the flag bit in the A memory and judges whether the position sensor is faulty. When the position sensor is not faulty, the position sensor signal selection unit is executed. When the position sensor is faulty, the software internal estimation position signal selection unit is executed.

[0022] The position sensor signal selection unit updates the position sensor selection flag to a position sensor state and writes it into the memory B;

[0023] The software internal estimated position signal selection unit updates the position sensor selection flag to a no position sensor state and writes it into memory B;

[0024] The main program running unit reads the sensor selection flag in memory B, and the position signal used for motor control is switched to the corresponding signal source according to this status bit. The software position estimation and resolver signal diagnosis are periodically executed functions;

[0025] The power-off determination unit periodically monitors the power-off flag of the system, and executes when the system allows the store flag to be set, and stores the position sensor fault to the EEPROM execution unit, otherwise the main program operation unit continues to execute;

[0026] The position sensor fault is stored in the EEPROM execution unit, which stores the position sensor fault signal flag bit in the designated EEPROM space through the interface function of the NVM module in the basic software. After completion, the system is powered off.

[0027] The present invention relates to a control method for the above system, which comprises the following specific steps:

[0028] Step 1: The current command distribution unit receives the torque command, obtains the current command and transmits it to the current loop control unit. The current loop control unit receives the current command, calculates the voltage command, and sums it with the output result of the position transformation module and transmits it to the coordinate transformation module;

[0029] Step 2: The first coordinate transformation unit receives the voltage command and the motor rotor position, calculates the voltage command and transmits it to the voltage transformation module. The second coordinate transformation unit receives the three-phase current feedback value and the motor rotor position, calculates the current feedback and transmits it to the current transformation module.

[0030] Step 3: The pulse width modulation unit receives the voltage instruction, calculates six driving signals, outputs the driving voltage and transmits to the inverter unit, the inverter unit receives the six driving signals, modulates the direct current voltage to generate a three-phase driving voltage and transmits to the motor unit, the motor unit receives the output three-phase output voltage and outputs the torque;

[0031] Step 4: The position observer unit receives the feedback value of the motor three-phase current, the voltage instruction and the torque instruction, outputs the injection voltage, the rotor position estimation signal, the motor electric angular velocity estimation signal and the motor speed estimation signal, the position sensor unit generates the feedback motor rotor position signal and transmits to the position decoding unit, the position decoding unit receives the motor rotor position signal, calculates the rotor position sampling signal, and transmits to the position signal selection unit, the position signal selection unit receives the rotor position sampling signal and the rotor position estimation signal, and selects the rotor position signal output according to the working state of the position sensor unit and the position decoding unit, and ensures the normal operation of the motor driving system.

[0032] The position signal selection unit has the following working modes: when the position sensor unit and the position decoding unit are normally working, the rotor position sampling signal is selected as the rotor position signal output; when the position sensor unit and the position decoding unit are partially or simultaneously invalid, the rotor position estimation signal is selected as the rotor position signal output.

[0033] Technical effects

[0034] The present application solves the problem that the existing vehicle permanent magnet synchronous motor cannot continue to run when the position sensor fails; compared with the prior art, the present application can switch to the position sensorless control mode by the key after detecting the failure of the position sensor, thereby solving the problem of inconvenience to the driver after the failure of the position sensor. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 It is a schematic diagram of the overall structure of the present application;

[0036] Figure 2 It is a schematic diagram of the position observer structure of the present application;

[0037] Figure 3 It is a schematic diagram of the high-frequency injection observer structure of the present application;

[0038] Figure 4 It is a schematic diagram of the flux linkage observer unit of the present application;

[0039] Figure 5 It is a schematic diagram of the angle compensation structure of the present application

[0040] Figure 6 It is a schematic diagram of the phase-locked loop structure of the present application;

[0041] Figure 7 Polarity recognition structure schematic diagram of the present application;

[0042] Figure 8 Position sensor signal switching logic structure schematic diagram of the present application;

[0043] Figure 9 Effect schematic diagram of the embodiment;

[0044] In the figure: current command distribution unit 1, current loop control unit 2, first coordinate conversion unit 3, second coordinate conversion unit 4, pulse width modulation unit 5, inverter unit 6, motor unit 7, position sensor unit 8, position observer unit 9, position decoding unit 10, position signal selection unit 11, third coordinate conversion unit 12, fourth coordinate conversion unit 13, polarity recognition unit 14, high-frequency injection observer unit 15, flux linkage observer unit 16, injection voltage selection unit 17, angle compensation unit 18, phase-locked loop unit 19, high-frequency voltage generation unit 20, angle error calculation unit 21, low-pass filter unit 22, phase compensation unit 23, error calculation unit 24, error selection unit 25, proportional-integral control unit 26, integral unit 27, low-pass filter unit 28, software initialization unit 29, read EEPROM position sensor fault signal flag unit 30, position sensor fault judgment unit 31, position sensor signal selection unit 32, software internal estimated position signal selection unit 33, main program running unit 34, whether to allow power-down judgment unit 35, position sensor fault storage to EEPROM execution unit 36, current conversion module 37, coordinate conversion module 38, voltage conversion module 39, and position conversion module 40. DETAILED DESCRIPTION

[0045] As shown in Figure 1 , a control system for a vehicle permanent magnet synchronous motor position sensor failure according to the present embodiment, comprising: a current conversion module 37, a coordinate conversion module 38, a voltage conversion module 39, and a position conversion module 40, wherein: the current conversion module 37 is connected to the coordinate conversion module 38, receives the current command and performs conversion, and transmits to the coordinate conversion module 38; the coordinate conversion module 38 is connected to the voltage conversion module 39, receives the voltage command, the current command, and the motor rotor position and performs conversion, and transmits to the current conversion module 37 and the voltage conversion module 39, respectively; the voltage conversion module 39 receives the voltage command and performs conversion, and outputs a driving voltage to drive the motor to run; the position conversion module 40 receives the rotor position related signal and performs conversion, and outputs the rotor position signal under different working states of the module.

[0046] The current conversion module 37 includes: a current command distribution unit 1 and a current loop control unit 2 connected to each other, wherein: the current command distribution unit 1 receives the torque command , get the d and q axis current instructions 、 And transmit it to the current loop control unit 2; the current loop control unit 2 receives the d and q axis current instructions 、 and d, q axis current feedback 、 , calculate the d and q axis voltage instructions 、 , d-axis voltage command The d-axis injection voltage generated by the position observer unit 9 The summed result and the q-axis voltage command Transmitted to the coordinate transformation unit 103.

[0047] The coordinate transformation module 38 includes a first coordinate transformation unit 3 and a second coordinate transformation unit 4 which are connected to each other.

[0048] The first coordinate transformation unit 3 receives the voltage command and the motor rotor position , calculated Voltage command in coordinate system 、 And transmit it to the pulse width modulation unit 5, specifically: .

[0049] The second coordinate transformation unit 4 receives the three-phase current feedback value 、 、 and the motor rotor position , calculate the current feedback of d and q axis 、 And transmit it to the current loop control unit 2, specifically: .

[0050] The voltage conversion module 39 includes: a pulse width modulation unit 5, an inverter unit 6 and a motor unit 7 connected in sequence, wherein: the pulse width modulation unit 5 receives a voltage instruction 、 The six driving signals are calculated and generated by using a space vector pulse width modulation (SVPWM) strategy, and the driving voltage is output and transmitted to the inverter unit 6; the inverter unit 6 receives the six driving signals, modulates the direct-current voltage to generate a three-phase driving voltage and transmits the three-phase driving voltage to the motor unit 7; the motor unit 7 is a permanent magnet synchronous motor, receives the output three-phase output voltage and outputs torque, and provides power output for automobile parts.

[0051] The inverter unit 6 is a three-phase six-bridge arm power supply type topology, and the power device used is an insulated gate bipolar transistor (IGBT).

[0052] The position conversion module 40 includes a position sensor unit 8, a position decoding unit 10, a position signal selection unit 11 and a position observer unit 9, wherein: the position sensor unit 8 generates a feedback motor rotor position signal and transmits the feedback motor rotor position signal to the position decoding unit 10; the position decoding unit 10 receives the motor rotor position signal, calculates a rotor position sampling signal and transmits the rotor position sampling signal to the position signal selection unit 11; the position signal selection unit 11 receives the rotor position sampling signal transmitted by the position decoding unit 10 and the rotor position estimation signal transmitted by the position observer unit 9, and selects a rotor position signal output according to the working states of the position sensor unit 8 and the position decoding unit 10; the position observer unit 9 receives feedback values of motor three-phase currents , , , voltage instructions , and torque instructions , outputs a d-axis injection voltage , a rotor position estimation signal , a motor electrical angular velocity estimation signal and a motor speed estimation signal .

[0053] The position sensor unit 8 is a physical sampling device that rotates coaxially with the motor unit 7, and can also be an optical encoder or the like.

[0054] The working mode of the position signal selection unit 11 is: when the position sensor unit 8 and the position decoding unit 10 work normally, the rotor position sampling signal is selected as the rotor position signal and output, when the position sensor unit 8 and the position decoding unit 10 are partially or simultaneously invalid, the rotor position sampling signal selecting the rotor position estimation signal when unavailable as a rotor position signal output, ensuring that the motor drive system can continue to operate.

[0055] The position observer unit 9 comprises a third coordinate transformation unit 12, a fourth coordinate transformation unit 13, a polarity identification unit 14 for identifying the polarity of the initial rotor position when the motor is started in a stationary state, a high-frequency injection observer unit 15, a flux observer unit 16, an injection voltage selection unit 17 for selecting the injection voltage during the starting phase, an angle compensation unit 18, and a phase-locked loop unit 19.

[0056] The third coordinate transformation unit 12 receives the feedback values of the three-phase currents of the motor , , calculates the currents in the coordinate system , and transmits them to the fourth coordinate transformation unit 13 and the flux observer unit 16.

[0057] The fourth coordinate transformation unit 13 receives the currents in the coordinate system , and the rotor position estimation signal calculates the d-axis and q-axis currents , and transmits them to the polarity identification unit 14 and the high-frequency injection observer unit 15, respectively.

[0058] The polarity identification unit 14 is used to identify the polarity of the initial rotor position when the motor is started in a stationary state. It injects d-axis pulse voltages of equal magnitude but opposite polarity into the motor unit 7 in succession, compares the absolute values of the peak values of the d-axis currents generated under different polarity injection voltages, determines the polarity corresponding to the current initial rotor position, and generates a polarity compensation angle when the polarity is N-pole when the polarity is S-pole .

[0059] As shown in Figure 7 , a schematic diagram of the signals in a polarity identification process in this embodiment is provided. The polarity identification process includes forward pulse voltage injection, forward current recovery, reverse voltage pulse injection, reverse current recovery, etc. The absolute value of the d-axis current peak value during forward pulse voltage injection is greater than that during negative pulse voltage injection, indicating that the polarity corresponding to the initial rotor position is S-pole. Therefore, the final polarity compensation angle Conversely, if the absolute value of the d-axis current peak value when the positive pulse voltage is injected is less than the absolute value of the d-axis current peak value when the negative pulse voltage is injected, it indicates that the initial rotor position corresponds to the polarity of N-pole, and the final polarity compensation angle .

[0060] The high-frequency injection observer unit 15 comprises a high-frequency voltage generation unit 20 and an angle error calculation unit 21 connected to each other, wherein the high-frequency voltage generation unit 15 receives the motor speed estimation signal , generates the d-axis high-frequency voltage and the voltage polarity signal , generates the d-axis high-frequency voltage and the voltage polarity signal according to the set amplitude and frequency when the motor speed estimation signal , > , and makes and the voltage polarity signal zero, is a preset speed threshold value and is transmitted to the angle error calculation unit 21. In the embodiment, the d-axis high-frequency voltage is composed of voltage signals with equal amplitude, opposite polarity and 50% duty cycle, and the period thereof is .

[0061] The angle error calculation unit 21 receives the q-axis current and the voltage polarity signal , and calculates the high-frequency injection angle error signal ; the high-frequency injection angle error signal , wherein t represents the sampling time, is the high-frequency injection angle error correction coefficient.

[0062] The flux observer unit 16 comprises a low-pass filter unit 22, a phase compensation unit 23 and an error calculation unit 24, is the motor stator resistance, is the motor q-axis inductance, wherein the low-pass filter unit 22 receives the electrical angular velocity , calculates the adaptive selected cutoff frequency, and outputs the low-pass filtered voltage signal; the phase compensation unit 23 receives the low-pass filtered voltage signal, compensates for the delay of the low-pass filtering and subtracts the flux generated by the phase current, and outputs the effective flux in the d-q coordinate system , to the error calculation unit; the error calculation unit receives the effective flux , and the rotor position estimation signal , the flux linkage observation angle error signal In this embodiment, the flux linkage observation angle error signal , wherein: is a flux linkage observation angle error correction coefficient.

[0063] The injection voltage selection unit 17 is configured to select a d-axis injection voltage , and the working mode is as follows: when the motor unit 7 is started in a static state, the d-axis high-frequency voltage is first injected by the high-frequency injection observer unit 15 , that is, the injection voltage selection unit 17 selects the d-axis high-frequency voltage is the d-axis injection voltage , and the high-frequency injection angle error signal calculated by the high-frequency injection observer unit 15 is processed by the phase-locked loop unit 19 to obtain a rotor position estimation signal as the initial rotor position; then the high-frequency injection observer unit 15 and the phase-locked loop unit 19 stop running, the polarity recognition unit 14 starts running, and the injection voltage selection unit 17 selects the d-axis pulse voltage is the d-axis injection voltage , and the polarity recognition unit 14 completes polarity recognition according to the d-axis current and updates the polarity compensation angle ; finally, the polarity recognition unit 14 stops running, the high-frequency injection observer unit 15 and the phase-locked loop unit 19 resume running, and the injection voltage selection unit 17 selects the d-axis high-frequency voltage is the d-axis injection voltage , and at this time the motor drive system enters a position closed-loop running mode, and can drive the motor to run according to the torque command in the manner of Figure 1 .

[0064] As shown in Figure 5 , the angle compensation unit 18 receives the speed estimation signal and the torque command , obtains the high-frequency injection angle error signal under the current working condition, and adds the polarity compensation angle to obtain an estimated angle compensation value .

[0065] The phase-locked loop unit 19 includes an error selection unit 25, a proportional-integral control unit 26, an integral unit 27, and a low-pass filter unit 28, wherein: the error selection unit 25 receives the speed estimation signal , and when , selects the high-frequency injection angle error signal as the angle error signal , and when , selects the flux linkage observation angle error signal As the angle error signal ,when When the angle error signal is received, it remains unchanged and is transmitted to the proportional integral control unit 26; the proportional integral control unit 26 receives the angle error signal , calculate the electrical angular velocity estimation signal before filtering , transmitted to the integration unit 27 and the low-pass filter unit 28; the integration unit 27 receives the angle signal , the angle signal obtained by integration operation and the estimated angle compensation value Add and get the rotor position estimation signal ; Low-pass filter unit 28 receives the electric angular velocity estimation signal before filtering , perform low-pass filtering to obtain the motor electrical angular velocity estimation signal , motor electrical angular velocity estimation signal With coefficient Multiply to get the motor speed estimation signal .

[0066] The position sensor unit 8 includes: a software initialization unit 29, a unit 30 for reading an EEPROM position sensor fault signal flag, a position sensor fault judgment unit 31, a position sensor signal selection unit 32, a software internal estimated position signal selection unit 33, a main program running unit 34, a power-off determination unit 35, and a position sensor fault storage to EEPROM execution unit 36, wherein:

[0067] The software initialization unit 29 performs the initialization of the controller external devices and software variables after the system is powered on. After completion, the program execution unit reads the EEPROM position sensor fault signal flag unit 30;

[0068] The EEPROM position sensor fault signal flag unit 30 reads the position sensor fault signal flag pre-stored in the EEPROM into the software memory A through the interface function of the NVM module in the basic software, and executes the position sensor fault judgment unit 31 after completion;

[0069] The position sensor fault judgment unit 31 reads the flag bit in the A memory and judges whether the position sensor is faulty. If the position sensor is not faulty, the position sensor signal selection unit 32 is executed. If the position sensor is faulty, the software internal estimated position signal selection unit 33 is executed.

[0070] The position sensor signal selection unit 32 updates the position sensor selection flag to a position sensor state and writes it into the memory B;

[0071] The software internal estimated position signal selection unit 33 updates the position sensor selection flag bit to the no position sensor state and writes into the memory B.

[0072] The main program running unit 34 reads the sensor selection flag bit in the memory B, and the position signal for motor control is switched to the corresponding signal source according to the state bit, and the software position estimation and resolver signal diagnosis are periodical execution functions.

[0073] The whether to allow power-off judging unit 35 periodically monitors the system power-off permission flag bit, and when the system power-off permission flag bit is set, the position sensor fault is stored into the EEPROM execution unit 31, otherwise, the main program running unit 34 is continuously executed.

[0074] The position sensor fault storage EEPROM execution unit 36 stores the position sensor fault signal flag bit into the specified EEPROM space through the interface function of the NVM module in the basic software, and the system is powered off after completion.

[0075] Through specific actual experiments, in the environment setting of the electric drive assembly bench test, the motor position sensor failure condition is simulated, and the integrated above-mentioned method is run, such as Figure 9 For the measured bus voltage 350V, the motor 500rpm, the torque 40NM steady-state three-phase current waveform; from the data, when the three-phase current effective value is about 125Arms, the torque can be stably output.

[0076] Compared with the prior art, when the permanent magnet synchronous motor is used as a driving motor, how to switch the no position sensor control after the position sensor fails, the vehicle synchronous motor control system of the application can realize the vehicle limping function according to the switching logic after recognizing the position sensor fault, so as to eliminate the inconvenience brought to the driver after the position sensor fails.

[0077] The above specific implementation can be adjusted in different ways by those skilled in the art without departing from the principles and purposes of the application, the protection scope of the application is subject to the claims and is not limited by the above specific implementation, and each implementation scheme within the scope is subject to the constraints of the application.

Claims

1. A redundant control system for a vehicle permanent magnet synchronous motor position sensor failure scenario, characterized in that: include: Current conversion module, coordinate conversion module, voltage conversion module and position conversion module, wherein: the current conversion module is connected to the coordinate conversion module, receives the current instruction and converts it, and transmits it to the coordinate conversion module; the coordinate conversion module is connected to the voltage conversion module, receives the voltage instruction, current instruction and motor rotor position and converts them, and transmits them to the current conversion module and voltage conversion module respectively; the voltage conversion module receives the voltage instruction and converts it, and outputs the driving voltage to drive the motor to run; the position conversion module receives the rotor position related signal and converts it to output the rotor position signal under different working states of the module; The position conversion module includes: a position sensor unit, a position decoding unit, a position signal selection unit and a position observer unit, wherein: the position sensor unit generates a feedback motor rotor position signal and transmits it to the position decoding unit; the position decoding unit receives the motor rotor position signal, calculates a rotor position sampling signal, and transmits it to the position signal selection unit; the position signal selection unit receives the rotor position sampling signal and the rotor position estimation signal, and selects the rotor position signal for output according to the working status of the position sensor unit and the position decoding unit; the position observer unit receives the feedback value of the motor three-phase current, the voltage command and the torque command, and outputs the injection voltage, the rotor position estimation signal, the motor electrical angular velocity estimation signal and the motor speed estimation signal; The position observer unit includes: a third coordinate transformation unit, a fourth coordinate transformation unit, a polarity identification unit for identifying the initial rotor position when the motor starts in a stationary state, a high-frequency injection observer unit, a flux linkage observer unit, an injection voltage selection unit for selecting the injection voltage during the startup phase, an angle compensation unit, and a phase-locked loop unit, wherein: the third coordinate transformation unit receives the feedback value of the three-phase current of the motor and calculates The current in the coordinate system is transmitted to the fourth coordinate transformation unit and the flux observer unit; the fourth coordinate transformation unit receives The current and rotor position estimation signals in the coordinate system are used to calculate the d-axis and q-axis currents, which are transmitted to the polarity identification unit and the high-frequency injection observer unit respectively. The angle compensation unit receives the speed estimation signal and torque command, obtains the high-frequency injection angle error signal, and adds it to the polarity compensation angle to obtain the estimated angle compensation value. The high-frequency injection observer unit includes: a high-frequency voltage generation unit and an angle error calculation unit connected to each other, wherein: the high-frequency voltage generation unit receives the motor speed estimation signal, generates a high-frequency voltage and a voltage polarity signal, and transmits the high-frequency voltage and the voltage polarity signal to the angle error calculation unit; the angle error calculation unit receives the current and voltage polarity signals, and calculates the high-frequency injection angle error signal; The flux observer unit includes: a low-pass filter unit, a phase compensation unit and an error calculation unit, wherein: the low-pass filter unit receives the electrical angular velocity, calculates the signal to adaptively select the cutoff frequency, and outputs a voltage signal after low-pass filtering; the phase compensation unit receives the low-pass filtered voltage signal, compensates for the delay of the low-pass filter, subtracts the flux generated by the phase current, and outputs the effective flux to the error calculation unit; the error calculation unit receives the effective flux and the rotor position estimation signal, and calculates the flux observation angle error signal; The phase-locked loop unit includes: an error selection unit, a proportional-integral control unit, an integration unit and a low-pass filtering unit, wherein: the error selection unit receives a speed estimation signal, selects a high-frequency injection angle error signal or a flux observation angle error signal, and transmits it to the proportional-integral control unit; the proportional-integral control unit calculates an electric angular velocity estimation signal before filtering based on the received error signal, and transmits it to the integration unit and the low-pass filtering unit; the integration unit receives the electric angular velocity estimation signal, adds an angle signal obtained by integration operation to an estimated angle compensation value, and obtains a rotor position estimation signal; the low-pass filtering unit receives the electric angular velocity estimation signal before filtering, performs low-pass filtering processing, obtains a motor electric angular velocity estimation signal, and multiplies the motor electric angular velocity estimation signal by a coefficient to obtain a motor speed estimation signal.

2. The control system according to claim 1, characterized in that: The current conversion module includes: a connected current instruction distribution unit and a current loop control unit, wherein: the current instruction distribution unit receives the torque instruction, obtains the current instruction and transmits it to the current loop control unit; the current loop control unit receives the current instruction, calculates the voltage instruction, and sums it with the output result of the position conversion module and transmits it to the coordinate conversion module.

3. The control system according to claim 1, wherein: The coordinate transformation module includes: a first coordinate transformation unit and a second coordinate transformation unit connected to each other, wherein: the first coordinate transformation unit receives the voltage instruction and the motor rotor position, calculates the voltage instruction and transmits it to the voltage transformation module; the second coordinate transformation unit receives the three-phase current feedback value and the motor rotor position, calculates the current feedback and transmits it to the current transformation module.

4. The control system according to claim 1, wherein: The voltage conversion module includes: a pulse width modulation unit, an inverter unit and a motor unit connected in sequence, wherein: the pulse width modulation unit receives a voltage instruction, calculates six drive signals, outputs a drive voltage and transmits it to the inverter unit; the inverter unit receives the six drive signals, modulates the DC voltage to generate a three-phase drive voltage and transmits it to the motor unit; the motor unit receives and outputs the three-phase output voltage and outputs torque.

5. The control system according to claim 4, characterized in that: The inverter unit is a three-phase six-bridge-arm power supply topology.

6. A control method based on the control system according to any one of claims 1 to 5, characterized in that: The specific steps are: Step 1: The current command distribution unit receives the torque command, obtains the current command and transmits it to the current loop control unit. The current loop control unit receives the current command, calculates the voltage command, and sums it with the output result of the position transformation module and transmits it to the coordinate transformation module; Step 2: The first coordinate transformation unit receives the voltage command and the motor rotor position, calculates the voltage command and transmits it to the voltage transformation module. The second coordinate transformation unit receives the three-phase current feedback value and the motor rotor position, calculates the current feedback and transmits it to the current transformation module. Step 3: The pulse width modulation unit receives the voltage command, calculates six drive signals, outputs the drive voltage and transmits it to the inverter unit. The inverter unit receives the six drive signals, modulates the DC voltage to generate a three-phase drive voltage and transmits it to the motor unit. The motor unit receives the output three-phase output voltage and outputs torque. Step 4: The position observer unit receives the feedback value of the motor's three-phase current, voltage command, and torque command, and outputs an injection voltage, a rotor position estimation signal, a motor electrical angular velocity estimation signal, and a motor speed estimation signal. The position sensor unit generates a feedback motor rotor position signal and transmits it to the position decoding unit. The position decoding unit receives the motor rotor position signal, calculates a rotor position sampling signal, and transmits it to the position signal selection unit. The position signal selection unit receives the rotor position sampling signal and the rotor position estimation signal, and selects the rotor position signal output according to the working status of the position sensor unit and the position decoding unit to ensure the normal operation of the motor drive system. The specific working mode of the position signal selection unit is: when the position sensor unit and the position decoding unit are working normally, the rotor position sampling signal is selected as the rotor position signal output; when the position sensor unit and the position decoding unit partially or simultaneously fail and the rotor position sampling signal is unavailable, the rotor position estimation signal is selected as the rotor position signal output.

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