CN107743004B - Dual-redundancy permanent-magnet synchronous motor coil turn-to-turn short circuit on-line fault diagnosis method - Google Patents

Abstract

The invention discloses an on-line detection method for inter-turn short circuit of a double-redundant permanent magnet synchronous motor coil, which is based on the principle that the remaining normal winding impedance of the faulty set decreases when the coil has an inter-turn short circuit. When working, if the coil has inter-turn short circuit, the equivalent resistance and inductance parameters in the Park equation of the faulty set of windings will have a certain amount of reduction. Since the currents of the two sets of windings are almost the same, the direct axes of the two sets of windings There will be a certain deviation in the voltage. Utilize the positive, negative and absolute value of the average value of the difference between the direct axis given voltages of the two sets of windings in each PWM sampling control period of the current several DSPs, combined with the positive and negative values of the permanent magnet rotor rotation direction and the given current of the quadrature axis Based on the judgment of the motor running status, it can be diagnosed online that there is no electromagnetic coupling between the phase windings, and the low thermal coupling double redundancy permanent magnet synchronous motor is in the double redundancy operation mode. Which set of three-phase windings has a coil inter-turn short circuit fault .

Description

On-line Diagnosis Method for Turn-to-Turn Short Circuit Fault of Double Redundant Permanent Magnet Synchronous Motor

technical field

The invention belongs to a motor fault diagnosis method. Aiming at the problem of online diagnosis of inter-turn short circuit faults of permanent magnet synchronous motor coils with no electromagnetic coupling between windings of each phase and low thermal coupling with double redundancy, a method is proposed based on the current operating state of the motor and the direct current of two sets of windings. The magnitude of the positive and negative values of the average value of the shaft given voltage difference and the absolute value, online diagnosis of no electromagnetic coupling between the phase windings, low thermal coupling, double redundancy permanent magnet synchronous motor, which set of three-phase windings occurred during double redundancy operation A method for short-circuit faults between turns of coils.

Background technique

Permanent magnet synchronous motor has the advantages of high power density, high operating efficiency, simple structure, simple control, etc., and has been widely used in various fields. Due to its superiority, the permanent magnet synchronous motor has received more and more attention and attention in the fields of aerospace, electric vehicles and military affairs. With the development of modernization, there are higher requirements for the reliability of the motor servo system. Redundancy technology is one of the most effective ways to improve reliability. In occasions with high reliability requirements, a double-redundant permanent magnet synchronous motor is required. There are two sets of three-phase symmetrical Y-connected windings on the stator of the double-redundant permanent magnet synchronous motor, which share a permanent magnet rotor. The two sets of three-phase symmetrical Y-connected windings are respectively powered by two sets of three-phase inverters. At present, there is mutual inductance between the two sets of windings of many double-redundant permanent magnet synchronous motors with parallel structure, that is, there is electromagnetic coupling. When a coil short-circuit fault occurs in one set of three-phase windings, another set of normal three-phase windings will also be affected. Certain electromagnetic influences.

In the non-electromagnetic coupling and low thermal coupling double-redundancy permanent magnet synchronous motor among the phase windings involved in the present invention, under normal circumstances, two sets of three-phase Y-connected symmetrical windings on the stator work at the same time, and are in a double-redundancy working mode; when one of them When a set of three-phase windings fails, the control system stops supplying power to this set of windings, and continues to supply power to another set of three-phase windings. It is in a single-redundancy working mode, and the reliability of the motor is effectively improved. The main fault of double redundancy permanent magnet synchronous motor with no electromagnetic coupling between each phase winding and low thermal coupling is winding open circuit or short circuit fault. When there is a winding open circuit fault single redundant operation, the faulty sleeve winding has no adverse effect on the normal sleeve winding. When the inter-turn short circuit fault occurs in the coil, it needs to be detected online in time, and the power supply for the set of three-phase windings where the inter-turn short circuit fault occurs in the coil should be stopped in time to prevent the continuous spread of the coil short circuit fault. When the inter-turn short circuit occurs in the coil, although the winding structure and permanent magnet induced electromotive force of the two sets of windings on the motor stator are different, since the two sets of winding control systems are controlled by the same speed regulator, the current regulator input of the two sets of windings are the same, and the adjustment speed of the current regulator is extremely fast, so the three-phase currents input by the two sets of windings are basically the same, and almost the same waveform distortion will be generated. Although the coil inter-turn short-circuit fault can be diagnosed according to the current waveforms of the two sets of windings, it is impossible to diagnose which set of windings has the coil inter-turn short-circuit fault. There are currently some coil-turn-to-turn short-circuit fault diagnosis methods, some of which have a large computational workload, and some are proposed for the model when two sets of windings are powered by an ideal voltage source, and they do not consider two sets of double-redundancy motors when they are running. The input voltage of the winding is the output PWM voltage after being automatically adjusted by the speed and current double closed-loop control system after being disturbed by the electromagnetic pulsating torque that contains twice the rotation frequency of the permanent magnet rotor generated by the coil short-circuit current. It is difficult to realize the online diagnosis of which set of three-phase windings has inter-turn short-circuit faults when there is no electromagnetic coupling between each phase winding and low thermal coupling double redundancy permanent magnet synchronous motor double redundancy operation.

Contents of the invention

Aiming at the prior art, the present invention provides an online diagnosis of no electromagnetic coupling and low thermal coupling between the windings of each phase based on the current operating state of the motor, the positive and negative values of the average value of the difference between the current two sets of winding direct-axis given voltages, and the absolute value. A method for determining which set of three-phase windings has inter-turn short-circuit faults in double-redundant permanent magnet synchronous motors during double-redundant operation.

In order to solve the above-mentioned technical problems, the present invention proposes an online diagnosis method for inter-turn short-circuit faults of double-redundant permanent magnet synchronous motor coils, which is characterized in that there is no electromagnetic coupling between the windings of each phase involved, low thermal coupling and double-redundant permanent magnet synchronous The hardware of the motor control system includes a digital signal processor commonly called DSP, two inverters, no electromagnetic coupling between each phase winding, a low thermal coupling double-redundancy permanent magnet synchronous motor and a permanent magnet rotor position sensor; there is no electromagnetic coupling between each phase winding There are two sets of three-phase symmetrical Y-connected windings on the electromagnetic coupling low-thermal coupling double-redundancy permanent magnet synchronous motor, and the two sets of three-phase symmetrical Y-connected windings are recorded as the first set of windings and the second set of windings; DSP controls the work of two inverters , the two inverters are respectively connected with two sets of three-phase symmetrical Y-connected windings; the permanent magnet rotor position sensor provides the position information of the permanent magnet rotor of the motor for the DSP; the DSP contains a speed regulator, two sets of winding current regulators, two sets of Winding SVPWM generator, various coordinate transformers, fault diagnosis and redundancy controller function modules and all control algorithms of double redundancy permanent magnet synchronous motor without electromagnetic coupling between windings of each phase and on-line diagnosis of coil inter-turn short circuit fault Algorithm; all control algorithms and on-line diagnosis algorithms for inter-turn short-circuit faults of the double-redundancy permanent magnet synchronous motor without electromagnetic coupling between each phase winding are completed on the DSP, the method is as follows:

After the control system is powered on and initialized, the fault diagnosis and redundancy controller issues a command to allow the operation of the two inverters that supply power to the two sets of three-phase symmetrical Y-connected windings;

There is no electromagnetic coupling between the windings of each phase and low thermal coupling. The control system of the dual-redundant permanent magnet synchronous motor is a speed-current double-closed-loop speed regulation system. It adopts the direct-axis current _id = 0 vector control technology and SVPWM technology. When the two sets of motor stators When the three-phase symmetrical Y-connected winding is normal, the inverters supplying power to two sets of three-phase symmetrical Y-connected windings work at the same time, and the motor is in the double-redundant operation mode;

Direct-axis current _id = 0 Vector control is the direct-axis given current of the current regulator of the two sets of windings in the control system is always 0;

When the two sets of three-phase symmetrical Y-connected windings on the motor stator are normal and the motor is in the double-redundancy operation mode, the speed and current double-closed-loop speed regulation system of the control system shares the same speed regulator, and the given speed is compared with the actual negative feedback speed After that, it is input to the speed regulator, and the output of the speed regulator is input to the current regulators of the two sets of windings respectively after the output of the speed regulator is limited by the maximum absolute value. , The given current of the direct axis and the actual current of the quadrature axis and the direct axis of the negative feedback are compared one by one and then input to the respective current regulators respectively. The outputs of the two sets of winding current regulators are the quadrature axes, The direct-axis given voltage, the output of the two sets of windings’ quadrature-axis and direct-axis given voltages after rotation and inverse transformation are two given voltages in the two-phase stationary coordinate system of the two sets of windings respectively; the two given voltages are respectively input to The SVPWM generators of two sets of windings, the SVPWM generators of the two sets of windings respectively output 6-way PWM pulses, and the two sets of 6-way PWM pulses respectively control the 6 three-phase inverter bridges in the two inverters corresponding to the two sets of windings Power switching tube, two inverters respectively output three-phase PWM voltage to supply power for two sets of windings on the motor stator;

While the control system completes the execution of the control strategy control command, the fault diagnosis and redundancy controller in the system perform an online diagnosis of the inter-turn short circuit fault of the motor coil; in each PWM sampling control period of the DSP, the current first set Calculate the difference between the current two sets of winding direct axis given voltages by subtracting the second set of winding direct axis given voltages from the winding direct axis given voltage, and calculate the N points of the difference between the current two sets of winding direct axis given voltages One value, the value of N/N of the difference between the current two sets of winding direct axis given voltages and the difference between the two sets of winding direct axis given voltages in each PWM sampling control cycle of (N-1) DSPs obtained before The value of one-Nth of the difference is summed to obtain the average value of the difference between the two sets of winding direct-axis given voltages in each PWM sampling control cycle of the current N DSPs;

If the absolute value of the average value of the difference between the given voltages on the direct axes of the two sets of windings in each PWM sampling control period of the current N DSPs is less than the set threshold, it is judged that the two sets of three-phase symmetrical Y-connected windings are normal, and the process ends. On-line diagnosis of coil turn-to-turn short-circuit fault in the second control cycle, and return to the main program of the control system;

If the absolute value of the average value of the difference between the two sets of winding direct-axis given voltages in each PWM sampling control period of the current N DSPs is greater than or equal to the set threshold, then according to each PWM sampling control period of the current N DSPs The positive and negative of the average value of the difference between the direct-axis given voltages of the two sets of windings and the current operating state of the motor continue to carry out online diagnosis of the inter-turn short circuit fault of the double-redundant permanent magnet synchronous motor coil, including one of the following situations:

1) If the average value of the difference between the two sets of winding direct-axis given voltages in each PWM sampling control cycle of the current N DSPs is positive, the absolute value is greater than the threshold, and the motor is in the forward or reverse motor state, the diagnosis is A coil in the first set of windings has an inter-turn short circuit fault;

2) If the average value of the difference between the two sets of winding direct-axis given voltages in each PWM sampling control cycle of the current N DSPs is negative, the absolute value is greater than the threshold, and the motor is in the forward or reverse motor state, the diagnosis is A coil in the second set of windings has an inter-turn short circuit fault;

3) If the average value of the difference between the two sets of winding direct-axis given voltages in each PWM sampling control cycle of the current N DSPs is positive, the absolute value is greater than the threshold, and the motor is in the forward or reverse feedback braking state, then It is diagnosed that a coil in the second set of windings has an inter-turn short circuit fault;

4) If the average value of the difference between the two sets of winding direct-axis given voltages in each PWM sampling control cycle of the current N DSPs is negative, the absolute value is greater than the threshold, and the motor is in the forward or reverse feedback braking state, then It is diagnosed that a coil in the first set of windings has an inter-turn short circuit fault;

When the fault diagnosis and redundancy controller detects that a turn-to-turn short-circuit fault occurs in the coils of a certain set of three-phase windings, the fault diagnosis and redundancy controller issues a command to stop supplying power to the set of three-phase windings where the turn-to-turn short-circuit fault occurs The inverter works, and the inverter that supplies power to another set of normal three-phase windings continues to work, and the control system is transferred to the single-redundancy operation mode;

When the control system is transferred to the single-redundancy operation mode, the fault diagnosis and redundancy controller can also issue other instructions to change the control algorithm or control parameters of speed and current, and further improve the operating performance of the motor during single-redundancy operation; then The above-mentioned online diagnosis program for inter-turn short circuit faults of coils of permanent magnet synchronous motors with no electromagnetic coupling and low thermal coupling between windings of each phase is no longer executed.

The present invention is proposed based on the principle that the equivalent impedance of the remaining three-phase windings of the set of three-phase windings where the inter-turn short-circuit fault of the coil occurs when the double-redundancy permanent magnet synchronous motor is operated with no electromagnetic coupling and low thermal coupling between the phase windings is reduced. of.

If the coils in the first set of windings have a turn-to-turn short circuit, the equivalent resistance and inductance parameters in the Park equation of the first set of windings will decrease by ΔR and ΔL, and the direct-axis voltage equations of the two sets of windings are respectively

In the formula, R is the resistance of the phase winding when it is normal; ΔR is the equivalent reduction of the phase winding resistance when the coil inter-turn short circuit occurs; L is the inductance of the phase winding when it is normal; ΔL is the equivalent when the coil inter-turn short circuit occurs Reduction of phase winding resistance; u _d1 , i _d1 and i _q1 are respectively the direct axis voltage, direct axis current and quadrature axis current of the first set of windings in the rotor synchronous rotating coordinate system; u _d2 , i _d2 and i _q2 are respectively is the direct-axis voltage, direct-axis current and quadrature-axis current of the second set of windings in the rotor synchronous rotation coordinate system; ω _e is the electrical angular velocity of the permanent magnet rotor of the motor, and

ω _e = p ₀ ω (3)

In the formula, ω is the mechanical angular velocity of the permanent magnet rotor of the motor; p ₀ is the number of pole pairs of the permanent magnet rotor.

Since the current regulators of the two sets of winding inverters are controlled by the same speed regulator in the control system, the input of the current regulators of the two sets of windings is the same quadrature-axis given current, and at the same time, to realize the direct-axis current _id = 0 vector Control, the direct-axis given current of the two sets of winding current regulators in the control system is always 0, and the adjustment speed of the current regulator is extremely fast, so the three-phase current input by the two sets of windings is basically the same, even if there is a short circuit between coil turns When a fault occurs, the three-phase currents of the two sets of windings will also produce almost the same distortion, and the instantaneous values of the three-phase currents of the two sets of windings are almost the same, so the instantaneous values of the quadrature axis and direct axis phase currents of the two sets of windings are also almost the same of. That is to say, when the motor is normal and the coil has an inter-turn short circuit fault, there is always

After bringing formula (4) and formula (5) into formula (1) and formula (2), subtract formula (2) from formula (1) to get the faulty set winding (the first set of winding) and the normal set of winding (the first set of windings) The difference between the direct-axis voltages of the two sets of windings)

It can be seen from _formula (6) that since the control system adopts id = 0 control, the direct axis current id _changes between positive and negative values, and basically remains at 0. Therefore, when the double-redundancy permanent magnet synchronous motor works stably, i _d ΔR≈0, and (di _d /dt)ΔL has a large change between positive and negative values, and ωi _q ΔL is a finite value.

The DSP obtains a direct-axis voltage difference Δu _d between the faulty sleeve winding and the normal sleeve winding in each sampling period. If the average value of the latest N Δu _d is continuously calculated, it is equivalent to digital average filtering for it. When When N takes a larger appropriate value, then there is

Where, τ _sample is the same current sampling period as the PWM control time.

Therefore, Δu _dav is mainly determined by the electrical angular velocity and quadrature axis current of the motor in each sampling period of the latest N DSPs, and can also be determined by the running state of the motor.

Since the actual value of the direct-axis voltage of the two sets of windings is not easy to measure, the given value of the direct-axis voltage of the two sets of windings is proportional to the actual value of the direct-axis voltage of the two sets of windings; and because the adjustment speed of the current regulator is extremely fast, the current The actual value can basically track the upper given value, so the direct-axis voltage given value and the quadrature-axis current given value of two sets of windings are used in the online diagnosis of the specific coil inter-turn short circuit fault.

Description of drawings

Figure 1 is a cross-sectional view of a double-redundancy permanent magnet synchronous motor with no electromagnetic coupling and low thermal coupling between the windings of each phase and a partial enlarged view of part I. In the figure: 10-permanent magnet, 20-winding, 30-heat shield, 40- Small teeth, 50-large teeth.

Figure 2 is a connection diagram between the phase windings without electromagnetic coupling, low thermal coupling, double redundancy permanent magnet synchronous motor and two independent inverters;

Fig. 3 is a block diagram of the control system of the dual-redundant permanent magnet synchronous motor with no electromagnetic coupling and low thermal coupling between the windings of each phase for online diagnosis of coil turn-to-turn short circuit fault;

Fig. 4 is a flow chart of an algorithm program for online diagnosis of an inter-turn short circuit fault of a coil of a permanent magnet synchronous motor with no electromagnetic coupling, low thermal coupling, and double redundancy between the windings of each phase;

Figure 5 shows the calculation of the direct-axis given voltage of the first set of windings and the given direct-axis voltage of the second set of windings in the algorithm program for the online diagnosis of no electromagnetic coupling between the windings of each phase and low thermal coupling between turns of the permanent magnet synchronous motor with double redundancy. The subroutine flow chart of the difference;

Fig. 6 is a program flow chart for initializing the control quantities and variables in the relevant registers in the on-line diagnosis algorithm program for inter-turn short-circuit faults of permanent magnet synchronous motor coils with no electromagnetic coupling between windings of each phase and low thermal coupling with double redundancy when the control system is powered on.

Detailed ways

The embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings.

It can be seen from the cross-sectional view of the double-redundancy permanent magnet synchronous motor with no electromagnetic coupling between the windings of each phase and low thermal coupling shown in Figure 1 that the motor is evolved from the traditional 12-slot, 10-pole three-phase fractional-slot concentrated winding permanent magnet synchronous motor. It sets a small tooth 40 (reference number 50 in Fig. 1 is a large tooth) at the center of the slot where the adjacent two-phase winding coils share the same slot on the stator of the traditional permanent magnet synchronous motor, so that the coil sides of the small slots on both sides of the small tooth 40 belong to the For windings of different phases, the slot leakage magnetic flux of the coil is closed through the small tooth 40, and there is almost no electromagnetic coupling between the two adjacent phase windings 20; the mutual inductance between the windings of each phase is almost zero, and there is no electromagnetic coupling. Heat shields 30 are placed on both sides of the small tooth 40 so that the thermal coupling between the windings of each phase is low. The permanent magnet rotor is a surface mount type, and the permanent magnet 10 is tile-shaped and magnetized in parallel. A total of 6 phase windings 20 such as A1, B2, C1, A2, B1 and C2 are arranged on the stator, and each phase winding is composed of 2 coils connected in forward series and 1 reverse series, or composed of 1 reverse coil. It is formed by connecting two coils in series and one forward in series. The law of series connection of the two coils in the three phase windings of A1, B1 and C1 is just opposite to the law of series connection of the two coils of the three phase windings of A2, B2 and C2. The electromotive forces of the six phase windings are equal in magnitude, and the phases differ by 120° electrical angle in turn; the resistance and inductance of each phase winding are the same; the mutual inductance between each phase winding is 0. A1 and A2, B2 and B1, C1 and C2 phase winding axes coincide. If X1, Y1 and Z1, X2, Y2 and Z2 are connected together to form two star-connected points, two sets of three-phase symmetrical star-connected windings A1B1C1 and A2B2C2 are formed, and the two sets of three-phase symmetrical windings are spaced. arranged cross each other. There is no electromagnetic coupling between the windings of each phase, and low thermal coupling. The two sets of three-phase symmetrical windings on the stator of the double-redundant permanent magnet synchronous motor are coordinated and controlled by two inverters, and the two inverters share a DC power supply. It can be seen from the connection diagram between the phase windings without electromagnetic coupling, low thermal coupling, double redundancy permanent magnet synchronous motor and two independent inverters that the three output terminals A1, B1 and C1 of the first inverter are respectively Correspondingly connected to the input terminals A1, B1 and C1 of the first set of three-phase symmetrical windings of the double-redundant permanent magnet synchronous motor with no electromagnetic coupling between the windings of each phase and the three output terminals A2, B2 and C2 is correspondingly connected with the input ends A2, B2 and C2 of the second set of three-phase symmetrical windings of the second set of three-phase symmetrical windings of the double-redundant permanent magnet synchronous motor without electromagnetic coupling between the windings of each phase. There is no electromagnetic coupling between the windings of each phase. The rotor shaft of the low-thermal coupling double redundancy permanent magnet synchronous motor (DRPMSM) is also fastened to the rotor with a permanent magnet rotor position sensor on the non-mechanical output shaft. When the motor is running, the permanent magnet rotor position sensor PG The rotor rotates together with the permanent magnet rotor, and the stator of the permanent magnet rotor position sensor PG is installed at the corresponding position on the motor end cover at the non-mechanical output end of the motor shaft; the cable on the permanent magnet rotor position sensor PG stator is connected to the system control It is connected with the controller to provide real-time information on the position angle θ of the permanent magnet rotor for the control system. The position angle θ of the permanent magnet rotor is multiplied by the number of pole pairs of the permanent magnet rotor p ₀ , and then transformed into the information of the electric angle θ _{e of the permanent magnet rotor position. The electric angle θ e of} the permanent magnet rotor position is used to convert the actual current in the two-phase stationary αβ coordinate system The forward transformation of i _α1 and i _β1 , i _α2 and i _β2 is used to obtain the actual current i _q1 and i _d1 , i _q2 and i _d2 in the synchronously rotating dq coordinate system, or the orthogonal direct axis voltage in the synchronously rotating dq coordinate system instruction and and The voltage reference in the two-phase static αβ coordinate system is obtained by inverse rotation transformation and and The position angle θ of the permanent magnet rotor is differentiated with time to obtain the actual angular velocity ω of the motor. The actual angular velocity ω of the motor is used as the speed negative feedback input for the speed closed-loop control to the speed controller ASR. The actual angular velocity ω of the motor is also used to judge the operating state of the motor And input to fault diagnosis and redundancy controller.

It can be seen from the block diagram of the control system of the dual-redundancy permanent magnet synchronous motor with no electromagnetic coupling between the windings of each phase and low thermal coupling between the windings of the online diagnosis coil turn-to-turn short circuit shown in Figure 3. All control algorithms and on-line diagnosis of coil inter-turn short circuit faults are completed on the digital signal processor (DSP). The control system is a speed and current double closed-loop speed regulation system using space voltage vector pulse width modulation (SVPWM) technology with double redundancy permanent magnet synchronous motor direct axis current to zero ( _id = 0).

The control system is equipped with a fault diagnosis and redundancy controller, and the fault diagnosis and redundancy controller has three enabling control command signals EN1, EN2 and EN3. After the system is powered on and started, the enable control command signals EN1=1 and EN2=1 are in the "enable" state, allowing the first inverter VSI1 and the second inverter VSI2 to work at the same time, and at the same time for each phase winding The two sets of three-phase symmetrical Y-connected windings of the non-electromagnetic coupling low-thermal coupling double-redundancy permanent magnet synchronous motor supply power, and there is no electromagnetic coupling between the phase windings. The low-thermal coupling double-redundancy permanent magnet synchronous motor is in the dual-redundancy operation mode; The command signal EN3=0 is the state of "prohibited". When the dual redundancy permanent magnet synchronous motor with no electromagnetic coupling between each phase winding and low thermal coupling is in the dual redundancy operation mode, the fault diagnosis and redundancy controller will perform real-time detection of no electromagnetic coupling between each phase winding and low thermal coupling dual redundancy permanent magnet synchronous motor The motor is judged according to the current running state of the motor, the positive and negative values of the average value of the difference between the current two sets of winding direct-axis given voltages, and the absolute value, and judges whether there is no electromagnetic coupling between the windings of each phase, low thermal coupling, and double-redundancy permanent magnet synchronous motor. A coil inter-turn short-circuit fault occurs, and it is judged which set of three-phase windings has a coil inter-turn short-circuit fault. If it is judged that a coil in the first set of windings has an inter-turn short-circuit fault, the enable control command signal EN1=0 will change from the "enable" state to the "prohibited" state, and the first inverter VSI1 is prohibited from being the motor's The first set of windings supplies power, and the enable control command signal EN2=1 is still in the "enable" state, the second inverter VSI2 continues to supply power to the second set of windings of the motor, and the enable control command signal EN3 = 1 is changed from "prohibited"" state changes to "enable" state, change the control algorithm or control parameters of speed and current, and further improve the operating performance of the motor during single-redundancy operation. There is no electromagnetic coupling between each phase winding and low thermal coupling double-redundancy permanent magnet synchronous motor works In the single-redundancy operation mode; similarly, if it is judged that there is a coil inter-turn short-circuit fault in the second set of windings, the enable control command signal EN2=1 changes from the "enable" state to the "prohibited" state, The second inverter VSI2 is prohibited from supplying power to the second set of windings of the motor, and the enable control command signal EN1=0 is still in the "enable" state, and the first inverter VSI2 continues to supply power to the first set of windings of the motor. The enable control command signal EN3=1 changes from the "prohibited" state to the "enabled" state, changing the control algorithm or control parameters of speed and current, further improving the operating performance of the motor during single-redundancy operation, and there is no electromagnetic between the windings of each phase Coupled low thermal coupling double redundancy permanent magnet synchronous motor works in single redundancy operation mode. Regardless of whether there is no electromagnetic coupling between the phase windings and the low-thermal coupling double-redundancy permanent magnet synchronous motor works in the double-redundancy operation mode or the single-redundancy operation mode, the given angular velocity ω ^* of the motor is compared with the actual angular velocity ω of the motor and then input to a motor with proportional-integral characteristics. In the (PI) speed regulator ASR, the output signal adjusted by the speed regulator ASR is limited by the maximum absolute value and then used as two sets of three-phase symmetrical Y-connected windings to set the quadrature axis current in the synchronous rotating dq coordinate system Two sets of three-phase symmetrical Y-connected windings in the synchronously rotating dq coordinate system set the current on the quadrature axis It is also used to judge the running state of the motor and input to the fault diagnosis and redundancy controller.

There is no electromagnetic coupling between the windings of each phase, low thermal coupling, double redundant permanent magnet synchronous motor, two sets of three-phase symmetrical Y-connected windings, and the given current of the quadrature axis is the same in the synchronously rotating dq coordinate system The purpose is to achieve the effect of current sharing control on the two sets of winding currents when the motor is running with double redundancy.

In the first set of winding current control loops, the quadrature axis given current Compared with the actual current i _q1 of the negative feedback quadrature axis in the synchronous rotation dq coordinate system obtained through coordinate transformation of the first set of windings, The deviation compared with i _q1 is input to the current regulator ACR1 with proportional integral characteristics (PI), and the output signal adjusted by the current regulator ACR1 is used as the quadrature axis given voltage At the same time, the direct axis current given as 0 Compared with the negative feedback direct axis actual current i _d1 in the synchronous rotating dq coordinate system obtained by the coordinate transformation of the first set of windings, The deviation compared with i _d1 is input to the current regulator ACR1 with proportional integral characteristics (PI), and the output adjusted by the current regulator ACR1 is used as the direct axis given voltage The quadrature axis and direct axis in the dq coordinate system will be rotated synchronously to give the voltage and The given voltages of the α-axis and β-axis in the two-phase stationary αβ coordinate system are obtained by inverse rotation transformation and α-axis and β-axis given voltage in two-phase stationary αβ coordinate system and The 6 PWM control pulse signals of the 6 power switch tubes in the internal three-phase inverter full bridge in the first inverter VSI1 are obtained through the SVPWM control technology algorithm, and the three-phase PWM voltage output by the three-phase inverter full bridge are respectively input to the The winding input terminals A1, B1 and C1 of the first set of windings of the double-redundancy permanent magnet synchronous motor without electromagnetic coupling and low thermal coupling. Use the Hall-type non-contact current sensor to detect the two-phase actual current i _A1 and i _B1 input to the first set of windings A1 and B1, and the two-phase actual currents of A1 and B1 belonging to the three-phase stationary ABC coordinate system in the first set of windings After i _A1 and i _B1 are transformed from the three-phase stationary ABC coordinate system to the two-phase stationary αβ coordinate system, the actual currents i _α1 and i _β1 of the α-axis and β-axis in the two-phase stationary αβ coordinate system are obtained. The actual currents i _α1 and i _β1 in the two-phase static αβ coordinate system are rotated and transformed to obtain the actual currents i _q1 and i _d1 of the quadrature axis and the direct axis in the synchronously rotating dq coordinate system, and the actual currents i _q1 and i q1 of the quadrature axis and the direct axis As a current negative feedback, i _d1 participates in the current closed-loop control of the first set of windings. Among them, the direct axis given voltage It is also used to judge the running state of the motor and input to the fault diagnosis and redundancy controller.

Similarly, in the second set of winding current control loops, the quadrature axis given current Compared with the actual current i _q2 of the negative feedback quadrature axis in the synchronous rotating dq coordinate system obtained through coordinate transformation of the second set of windings, The deviation compared with i _q2 is input to the current regulator ACR2 with proportional integral characteristics (PI), and the output signal adjusted by the current regulator ACR2 is used as the quadrature axis given voltage At the same time, the direct axis current given as 0 Compared with the negative feedback direct-axis actual current i _d2 in the synchronous rotating dq coordinate system obtained through coordinate transformation of the second set of windings, The deviation compared with i _d2 is input to the current regulator ACR2 with proportional integral characteristics (PI), and the output adjusted by the current regulator ACR2 is used as the direct axis given voltage The quadrature axis and direct axis in the dq coordinate system will be rotated synchronously to give the voltage and The given voltages of the α-axis and β-axis in the two-phase stationary αβ coordinate system are obtained by inverse rotation transformation and α-axis and β-axis given voltage in two-phase stationary αβ coordinate system and Through the SVPWM control technology algorithm, the 6 PWM control pulse signals of the 6 power switch tubes in the internal three-phase inverter full bridge of the second inverter VSI2 are obtained, and the 3 PWM voltages output by the three-phase inverter full bridge are respectively input to the The winding input terminals A2, B2 and C2 of the second set of windings of the double-redundancy permanent magnet synchronous motor without electromagnetic coupling and low thermal coupling. Use the Hall-type non-contact current sensor to detect the two-phase actual current i _A2 and i _B2 input to the second set of windings A2 and B2, and the two-phase actual currents of A2 and B2 belonging to the three-phase stationary ABC coordinate system in the second set of windings After i _A2 and i _B2 are transformed from the three-phase stationary ABC coordinate system to the two-phase stationary αβ coordinate system, the actual currents i _α2 and i _β2 of the α-axis and β-axis in the two-phase stationary αβ coordinate system are obtained. The actual currents i _α2 and i _β2 in the two-phase static αβ coordinate system are rotated and transformed to obtain the actual currents i _q2 and i _d2 of the quadrature axis and the direct axis in the synchronously rotating dq coordinate system, and the actual currents i _q2 and i q2 of the quadrature axis and the direct axis i _d2 is used as a current negative feedback to participate in the current closed-loop control of the second set of windings. Among them, the direct axis given voltage It is also used to judge the running state of the motor and input to the fault diagnosis and redundancy controller.

Fig. 4 is the flow chart of the program flow chart of the on-line diagnosis algorithm for inter-turn short-circuit fault of the coils of permanent magnet synchronous motors with no electromagnetic coupling, low thermal coupling and double redundancy between the windings of each phase in the present invention, and this program is executed once in each PWM sampling control period of the DSP. Fig. 5 is an algorithm program for finding the direct-axis given voltage of the first set of windings and the direct-axis of the second set of windings in the algorithm program of the online diagnosis of no electromagnetic coupling between the windings of each phase, low thermal coupling, and double-redundancy permanent magnet synchronous motor coils. The subroutine flow chart of the given voltage difference. Fig. 6 is the program flow for initializing the control quantities and variables in the relevant registers in the algorithm program for the on-line diagnosis of no electromagnetic coupling between the windings of each phase, low thermal coupling, double redundancy permanent magnet synchronous motor coil turn-to-turn short circuit fault algorithm program when the control system is powered on picture. Every time the control system is powered on, the program is initialized, and the control variables and variables in the relevant registers in the program of the inter-turn short-circuit fault algorithm program of the non-electromagnetic coupling low thermal coupling double-redundant permanent magnet synchronous motor coil between the windings of each phase are initialized: EN1 = 1 control"Enable", allowing the first inverter VSI1 to supply power to the first set of windings of the motor; EN2 = 1 controls "enable", allowing the second inverter VSI1 to supply power to the second set of windings of the motor; EN3 = 0 Control "prohibition", the system works in the double redundancy mode; it will correspond to the relevant variables involved when calculating the average value of the difference between the direct axis given voltage of the first set of windings and the given voltage of the second set of windings on the direct axis The initial value of the variables in the relevant registers is set to 0, and the variables whose initial value is set to 0 are the average value of the difference between the direct axis given voltage of the first set of windings and the given voltage of the second set of windings on the direct axis One-Nth value of the difference between the direct axis given voltage of the first set of windings and the given voltage of the second set of windings on the direct axis One-Nth value of the difference between the direct-axis given voltage of the first set of windings and the given voltage of the second set of windings on the direct axis in the previous two times One-Nth value of the difference between the direct axis given voltage of the first set of windings and the given voltage of the second set of windings on the direct axis of the current (N-1) times One-Nth value of the difference between the given voltage on the direct axis of the first set of windings and the given voltage on the direct axis of the second set of windings N times before the current

In each PWM sampling control period of the DSP, the algorithm program for inter-turn short-circuit fault between the coils of the permanent magnet synchronous motor with no electromagnetic coupling and low thermal coupling between the on-line diagnosis of the present invention is executed once. When the program is executed, at first, Read in the fault diagnosis set in the control system and the four inputs of the redundancy controller: the angular velocity ω of the permanent magnet rotor of the motor, and the quadrature-axis given current of the two sets of windings in the rotor synchronously rotating dq coordinate system The direct-axis given voltage of the first set of windings in the rotor synchronously rotating dq coordinate system and the direct axis given voltage of the first set of windings in the rotor synchronously rotating dq coordinate system Then, enter the online diagnosis of no electromagnetic coupling between the windings of each phase, low thermal coupling, double-redundancy permanent magnet synchronous motor coil turn-to-turn short circuit fault algorithm program to obtain the direct-axis given voltage of the first set of windings and the given direct-axis voltage of the second set of windings The difference subroutine is used to obtain the direct-axis given voltage of the first set of windings in the rotor synchronous rotation coordinate system and the direct axis given voltage of the first set of windings in the rotor synchronous rotating coordinate system One-Nth of the difference Then calculate the average value of the difference between the two sets of winding direct-axis given voltages in each PWM sampling control cycle of the current N DSPs proceed immediately operation; and then sequentially replace the N/N value of the difference between the two sets of winding direct-axis given voltages in each PWM sampling control period of the current N DSPs, and the completion and Wait for the operation to calculate the average value of the difference between the direct axis given voltage of the first set of windings and the given voltage of the second set of windings on the direct axis for the next time Get ready; thus, end the subroutine for calculating the difference between the given voltage on the direct axis of the first set of windings and the given voltage on the direct axis of the second set of windings, and switch to online diagnosis of no electromagnetic coupling between windings of each phase and low thermal coupling double redundancy Algorithm program for permanent magnet synchronous motor coil turn-to-turn short circuit fault. Then, judge the difference between the given voltage on the direct axis of the first set of windings and the given voltage on the direct axis of the second set of windings absolute value of Whether it is greater than or equal to the set threshold U _T , that is, " "judgment; if the absolute value of the average value of the difference between the direct-axis given voltages of the two sets of windings in each PWM sampling control cycle of the first N DSPs is less than the set threshold U _T , that is It is judged that the two sets of three-phase symmetrical Y-connected windings are normal, and the online diagnosis of coil inter-turn short circuit fault in this control cycle is ended, and the main program of the control system is returned; if each PWM sampling control cycle of the first N DSPs is two The absolute value of the average value of the difference between the given voltages on the direct axis of the set of windings is greater than or equal to the set threshold, that is then there is a right To make a judgment on the positive or negative, that is, to carry out " "judgment; in which is" is positive" or which is" Negative" one of the two judgment results, and then judge the rotation direction of the current permanent magnet rotor of the motor, that is, "ω≥0? "; after obtaining one of the two judgment results of ω≥0, that is, "ω is positive" or ω<0, that is, "ω is negative", and then judge the positive or negative of the current given current of the quadrature axis, that is, carry out " "Judgment; finally get which is" is positive" or which is" One of the two judgment results. In this way, when the difference between the given voltage on the direct axis of the first set of windings and the given voltage on the direct axis of the second set of windings absolute value of When it is greater than or equal to the set threshold U _T , one of the eight diagnostic results will be obtained. According to the final and only one judgment result, it is diagnosed online that there is no electromagnetic coupling between each phase winding, low thermal coupling, double redundancy, and double redundancy of permanent magnet synchronous motor. During high-speed operation, which set of three-phase windings has a coil-to-turn short-circuit fault, and corresponding control operations are performed. After the control operation is completed, the double-redundancy permanent magnet synchronous motor with no electromagnetic coupling and low thermal coupling between the windings of each phase is controlled to switch to the single redundancy operation mode. On-line diagnosis of coil inter-turn short-circuit faults, and finally, transfer to the main control program, and in the future there will be no electromagnetic coupling between each phase winding, low thermal coupling, double-redundancy permanent magnet synchronous motor single-redundancy operation mode, the above-mentioned coil turn-to-turn fault will no longer be performed Short circuit fault online diagnosis.

When the difference between the given voltage on the direct axis of the first set of windings and the given voltage on the direct axis of the second set of windings absolute value of When is greater than or equal to the set threshold U _T , the 8 diagnostic results that can be obtained and the subsequent operations are as follows:

(1) If ω≥0 and If the motor is in the forward motor state, it is diagnosed that a coil in the first set of windings has an inter-turn short circuit fault. Then execute EN1=0 to control "prohibition" to stop the first inverter VSI1 from supplying power to the first set of windings of the motor; EN2=1 to control "enable" to allow the second inverter VSI1 to supply the second set of motor windings Winding power supply, single redundancy mode of operation. EN3=1 controls "enabling", changes the control algorithm or control parameters of speed and current, and further improves the operating performance of the motor during single-redundancy operation; since then, the online diagnosis program for coil inter-turn short circuit faults will no longer be run.

(2) If ω≥0 and If the motor is in the positive feedback braking state, it is diagnosed that a coil in the second set of windings has an inter-turn short circuit fault. Then execute EN1=1 to control "enable", allowing the first inverter VSI1 to supply power to the first set of windings of the motor; EN2 = 0 to control "disable", to stop the second inverter VSI1 from supplying the second set of motor Winding power supply, single redundancy mode of operation. EN3=1 controls "enabling", changes the control algorithm or control parameters of speed and current, and further improves the operating performance of the motor during single-redundancy operation; since then, the online diagnosis program for coil inter-turn short circuit faults will no longer be run.

(3) If ω<0 and If the motor is in the state of reverse feedback braking, it is diagnosed that a coil in the second set of windings has an inter-turn short circuit fault. Then execute EN1=1 to control "enable", allowing the first inverter VSI1 to supply power to the first set of windings of the motor; EN2 = 0 to control "disable", to stop the second inverter VSI1 from supplying the second set of motor Winding power supply, single redundancy mode of operation. EN3=1 controls "enabling", changes the control algorithm or control parameters of speed and current, and further improves the operating performance of the motor during single-redundancy operation; since then, the online diagnosis program for coil inter-turn short circuit faults will no longer be run.

(4) ω<0 and If the motor is in the state of reverse motor, it is diagnosed that there is an inter-turn short circuit fault in the coil in the first set of windings. Then execute EN1=0 to control "prohibition" to stop the first inverter VSI1 from supplying power to the first set of windings of the motor; EN2=1 to control "enable" to allow the second inverter VSI1 to supply the second set of motor windings Winding power supply, single redundancy mode of operation. EN3=1 controls "enabling", changes the control algorithm or control parameters of speed and current, and further improves the operating performance of the motor during single-redundancy operation; since then, the online diagnosis program for coil inter-turn short circuit faults will no longer be run.

(5) If ω≥0 and If the motor is in the forward motor state, it is diagnosed that a coil in the second set of windings has an inter-turn short circuit fault. Then execute EN1=1 to control "enable", allowing the first inverter VSI1 to supply power to the first set of windings of the motor; EN2 = 0 to control "disable", to stop the second inverter VSI1 from supplying the second set of motor Winding power supply, single redundancy mode of operation. EN3=1 controls "enabling", changes the control algorithm or control parameters of speed and current, and further improves the operating performance of the motor during single-redundancy operation; since then, the online diagnosis program for coil inter-turn short circuit faults will no longer be run.

(6) If ω≥0 and If the motor is in the positive feedback braking state, it is diagnosed that a coil in the first set of windings has an inter-turn short circuit fault. Then execute EN1=0 to control "prohibition" to stop the first inverter VSI1 from supplying power to the first set of windings of the motor; EN2=1 to control "enable" to allow the second inverter VSI1 to supply the second set of motor windings Winding power supply, single redundancy mode of operation. EN3=1 controls "enabling", changes the control algorithm or control parameters of speed and current, and further improves the operating performance of the motor during single-redundancy operation; since then, the online diagnosis program for coil inter-turn short circuit faults will no longer be run.

(7) If ω<0 and If the motor is in the state of reverse feedback braking, it is diagnosed that a coil in the first set of windings has an inter-turn short circuit fault. Then execute EN1=0 to control "prohibition" to stop the first inverter VSI1 from supplying power to the first set of windings of the motor; EN2=1 to control "enable" to allow the second inverter VSI1 to supply the second set of motor windings Winding power supply, single redundancy mode of operation. EN3=1 controls "enabling", changes the control algorithm or control parameters of speed and current, and further improves the operating performance of the motor during single-redundancy operation; since then, the online diagnosis program for coil inter-turn short circuit faults will no longer be run.

(8) If ω<0 and If the motor is in the reverse motor state, it is diagnosed that a coil in the second set of windings has an inter-turn short circuit fault. Then execute EN1=1 to control "enable", allowing the first inverter VSI1 to supply power to the first set of windings of the motor; EN2 = 0 to control "disable", to stop the second inverter VSI1 from supplying the second set of motor Winding power supply, single redundancy mode of operation. EN3=1 controls "enabling", changes the control algorithm or control parameters of speed and current, and further improves the operating performance of the motor during single-redundancy operation; since then, the online diagnosis program for coil inter-turn short circuit faults will no longer be run.

The above eight diagnostic results can be further summarized as follows:

(1) If the average value of the difference between the two sets of winding direct-axis given voltages in each PWM sampling control cycle of the current N DSPs is positive, the absolute value is greater than the threshold, and the motor is in the forward or reverse motor state, then diagnosis Turn-to-turn short-circuit fault occurred in a coil in the first set of winding;

(2) If the average value of the difference between the two sets of winding direct-axis given voltages in each PWM sampling control cycle of the current N DSPs is negative, the absolute value is greater than the threshold, and the motor is in the forward or reverse motor state, then diagnose Turn-to-turn short-circuit fault occurred in a coil in the second set of winding;

(3) If the average value of the difference between the direct axis given voltages of the two sets of windings in each PWM sampling control cycle of the current N DSPs is positive, the absolute value is greater than the threshold, and the motor is in the forward or reverse feedback braking state, Then it is diagnosed that a coil in the second set of windings has an inter-turn short circuit fault;

(4) If the average value of the difference between the direct-axis given voltages of the two sets of windings in each PWM sampling control cycle of the current N DSPs is negative, the absolute value is greater than the threshold, and the motor is in the forward or reverse feedback braking state, Then it is diagnosed that a coil in the first set of windings has an inter-turn short circuit fault.

Among them, the value of N is generally 10 to 20, which is more appropriate. When the obtained value of N is small, less DSP resources are occupied, and the digital filtering effect is worse, but the fault diagnosis is faster; when the obtained value of N is larger, more DSP resources are occupied, the digital filtering effect is better, and the fault diagnosis is relatively slow Some. Whether the value of N is large or small is also related to the length of each PWM sampling control cycle of the DSP. If the control cycle is long, the value of N should be smaller.

According to the above-mentioned process, according to the current running state of the motor, the positive and negative values of the average value of the difference between the current two sets of winding direct-axis given voltages, and the absolute value, online diagnosis of no electromagnetic coupling between the windings of each phase and low thermal coupling double redundancy Which set of three-phase windings has a coil-to-turn short-circuit fault during double-redundancy operation of a permanent magnet synchronous motor.

Although the present invention has been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments, and the above-mentioned specific embodiments are only illustrative, rather than restrictive. Under the enlightenment of the present invention, many modifications can be made without departing from the gist of the present invention, and these all belong to the protection of the present invention.

Claims (1)

1. A method for on-line diagnosis of double-redundant permanent-magnet synchronous motor coil turn-to-turn short-circuit faults, characterized in that: no electromagnetic coupling and low thermal coupling between the involved phase windings. Inverter, no electromagnetic coupling between each phase winding, low thermal coupling double redundancy permanent magnet synchronous motor and permanent magnet rotor position sensor; no electromagnetic coupling between each phase winding, low thermal coupling double redundancy permanent magnet synchronous motor has two sets of three-phase Symmetrical Y-connected windings, two sets of three-phase symmetrical Y-connected windings are recorded as the first set of windings and the second set of windings; DSP controls the work of two inverters, and the two inverters are respectively connected to two sets of three-phase symmetrical Y-connected windings The permanent magnet rotor position sensor provides DSP with the position information of the permanent magnet rotor of the motor; the DSP includes a speed regulator, two sets of winding current regulators, two sets of winding SVPWM generators, various coordinate converters, fault diagnosis and redundancy All control algorithms of the controller function module and non-electromagnetic coupling low thermal coupling double redundancy permanent magnet synchronous motor between each phase winding and online diagnosis algorithm for coil inter-turn short circuit fault; no electromagnetic coupling low thermal coupling dual redundancy permanent magnet synchronous between each phase winding All the control algorithms of the motor and the on-line diagnosis algorithm of coil inter-turn short circuit fault are completed on the DSP, the method is as follows: After the control system is powered on and initialized, the fault diagnosis and redundancy controller issues a command to allow the operation of the two inverters that supply power to the two sets of three-phase symmetrical Y-connected windings; There is no electromagnetic coupling between the windings of each phase and low thermal coupling. The control system of the dual-redundant permanent magnet synchronous motor is a speed-current double-closed-loop speed regulation system. It adopts the direct-axis current _id = 0 vector control technology and SVPWM technology. When the two sets of motor stators When the three-phase symmetrical Y-connected winding is normal, the inverters supplying power to two sets of three-phase symmetrical Y-connected windings work at the same time, and the motor is in the double-redundant operation mode; Direct-axis current _id = 0 Vector control is the direct-axis given current of the current regulator of the two sets of windings in the control system is always 0; When the two sets of three-phase symmetrical Y-connected windings on the motor stator are normal and the motor is in the double-redundancy operation mode, the speed and current double-closed-loop speed regulation system of the control system shares the same speed regulator, and the given speed is compared with the actual negative feedback speed After that, it is input to the speed regulator, and the output of the speed regulator is input to the current regulators of the two sets of windings respectively after the output of the speed regulator is limited by the maximum absolute value. , The given current of the direct axis and the actual current of the quadrature axis and the direct axis of the negative feedback are compared one by one and then input to the respective current regulators respectively. The outputs of the two sets of winding current regulators are the quadrature axes, The direct-axis given voltage, the output of the two sets of windings’ quadrature-axis and direct-axis given voltages after rotation and inverse transformation are two given voltages in the two-phase stationary coordinate system of the two sets of windings respectively; the two given voltages are respectively input to The SVPWM generators of two sets of windings, the SVPWM generators of the two sets of windings respectively output 6-way PWM pulses, and the two sets of 6-way PWM pulses respectively control the 6 three-phase inverter bridges in the two inverters corresponding to the two sets of windings Power switching tube, two inverters respectively output three-phase PWM voltage to supply power for two sets of windings on the motor stator; While the control system completes the execution of the control strategy control command, the fault diagnosis and redundancy controller in the system perform an online diagnosis of the inter-turn short circuit fault of the motor coil; in each PWM sampling control period of the DSP, the current first set Calculate the difference between the current two sets of winding direct axis given voltages by subtracting the second set of winding direct axis given voltages from the winding direct axis given voltage, and calculate the N points of the difference between the current two sets of winding direct axis given voltages One value, the difference between the N/N value of the difference between the current two sets of winding direct-axis given voltages and the difference between the two sets of winding direct-axis given voltages in each PWM sampling control cycle of N-1 DSPs previously obtained The value of N/N is summed to obtain the average value of the difference between the two sets of winding direct axis given voltages in each PWM sampling control cycle of the current N DSPs; If the absolute value of the average value of the difference between the given voltages on the direct axes of the two sets of windings in each PWM sampling control period of the current N DSPs is less than the set threshold, it is judged that the two sets of three-phase symmetrical Y-connected windings are normal, and the process ends. On-line diagnosis of coil turn-to-turn short-circuit fault in the second control cycle, and return to the main program of the control system; If the absolute value of the average value of the difference between the two sets of winding direct-axis given voltages in each PWM sampling control period of the current N DSPs is greater than or equal to the set threshold, then according to each PWM sampling control period of the current N DSPs The positive and negative of the average value of the difference between the direct-axis given voltages of the two sets of windings and the current operating state of the motor continue to carry out online diagnosis of the inter-turn short circuit fault of the double-redundant permanent magnet synchronous motor coil, including one of the following situations: 1) If the average value of the difference between the two sets of winding direct-axis given voltages in each PWM sampling control cycle of the current N DSPs is positive, the absolute value is greater than the threshold, and the motor is in the forward or reverse motor state, the diagnosis is A coil in the first set of windings has an inter-turn short circuit fault; 2) If the average value of the difference between the two sets of winding direct-axis given voltages in each PWM sampling control cycle of the current N DSPs is negative, the absolute value is greater than the threshold, and the motor is in the forward or reverse motor state, the diagnosis is A coil in the second set of windings has an inter-turn short circuit fault; 3) If the average value of the difference between the two sets of winding direct-axis given voltages in each PWM sampling control cycle of the current N DSPs is positive, the absolute value is greater than the threshold, and the motor is in the forward or reverse feedback braking state, then It is diagnosed that a coil in the second set of windings has an inter-turn short circuit fault; 4) If the average value of the difference between the two sets of winding direct-axis given voltages in each PWM sampling control cycle of the current N DSPs is negative, the absolute value is greater than the threshold, and the motor is in the forward or reverse feedback braking state, then It is diagnosed that a coil in the first set of windings has an inter-turn short circuit fault; When the fault diagnosis and redundancy controller detects that a turn-to-turn short-circuit fault occurs in the coils of a certain set of three-phase windings, the fault diagnosis and redundancy controller issues a command to stop supplying power to the set of three-phase windings where the turn-to-turn short-circuit fault occurs The inverter works, and the inverter that supplies power to another set of normal three-phase windings continues to work, and the control system is transferred to the single-redundancy operation mode; When the control system is transferred to the single-redundancy operation mode, the fault diagnosis and redundancy controller can also issue other instructions to change the control algorithm or control parameters of speed and current, and further improve the operating performance of the motor during single-redundancy operation; then The above-mentioned online diagnosis program for inter-turn short circuit faults of coils of permanent magnet synchronous motors with no electromagnetic coupling and low thermal coupling between windings of each phase is no longer executed.