阅读说明：本技术 基于调制函数的五相永磁同步电机单相开路故障svpwm控制方法 (SVPWM control method for single-phase open-circuit fault of five-phase permanent magnet synchronous motor based on modulation function ) 是由 陈益广 张元玮 沈勇环 郝伟杰 于 2020-04-09 设计创作，主要内容包括：本发明公开了一种基于调制函数的五相永磁同步电机单相开路故障SVPWM控制方法,应用在五相永磁同步电机单相开路故障的容错控制,提高直流电压利用率,减小运算时间。容错控制系统生成两相静止坐标系调制电压指令和三次谐波空间调制电压指令,进行预处理得到一组系数为常数的调制函数。在实时运算时,对六个扇区进行判断之后直接调用对应扇区的调制函数,将其直接加载入各相驱动脉冲的比较值寄存器与时基计数寄存器比较得到各相SVPWM脉冲。通过简化基本空间电压矢量作用顺序选择、作用时间计算和开关动作时刻转换过程,精简SVPWM调制计算程序,降低SVPWM调制环节运算时间和整体控制时间,实现相同控制器下控制频率的提高,进而获得更优良的控制性能。(The invention discloses a modulation function-based SVPWM control method for a single-phase open-circuit fault of a five-phase permanent magnet synchronous motor, which is applied to fault-tolerant control of the single-phase open-circuit fault of the five-phase permanent magnet synchronous motor, improves the utilization rate of direct-current voltage and reduces the operation time. The fault-tolerant control system generates a two-phase static coordinate system modulation voltage instruction and a third harmonic space modulation voltage instruction, and a group of modulation functions with constant coefficients are obtained through preprocessing. During real-time operation, the modulation function of the corresponding sector is directly called after the six sectors are judged, and the modulation function is directly loaded into the comparison value register of each phase of driving pulse and the time base counting register to be compared to obtain each phase of SVPWM pulse. By simplifying the processes of basic space voltage vector action sequence selection, action time calculation and switching action time conversion, the SVPWM modulation calculation program is simplified, the operation time and the overall control time of the SVPWM modulation link are reduced, the control frequency is improved under the same controller, and further more excellent control performance is obtained.)

1. A SVPWM control method for single-phase open-circuit fault of a five-phase permanent magnet synchronous motor based on a modulation function is characterized in that: the method simplifies the calculation procedures of the SVPWM modulation method and reduces the SVPWM operation time by simplifying the processes of basic space voltage vector action sequence selection, action time calculation and switching action time conversion; the realization process is as follows:

the method comprises the steps of preprocessing a modulation voltage command and a third harmonic space modulation voltage command under a two-phase static coordinate system to obtain a group of modulation functions with coefficients as constants, judging sectors and then directly calling corresponding modulation functions to configure a comparison value register during real-time operation, directly loading the modulation functions of the sectors as comparison values into the comparison value register and a time base counting register to be compared to obtain upper bridge arm switching pulses of each phase, wherein the lower bridge arm pulses are complementary with the upper bridge arm pulses, and the upper bridge arm pulses and the lower bridge arm pulses of each phase are respectively added with dead zone signals which are control pulse signals of a power switching tube, so that duty ratio control of PWM pulses is completed, and SVPWM control during single-phase open circuit fault of the five-phase permanent magnet synchronous motor is realized.

2. The SVPWM control method for single-phase open-circuit fault of five-phase permanent magnet synchronous motor based on modulation function according to claim 1, is characterized by comprising the following steps:

when the A-phase winding of the five-phase permanent magnet synchronous motor has open circuit faultThe fault-tolerant control system controls and generates three modulation voltage commands, namely α -axis and β -axis modulation voltage commands of a two-phase static coordinate system according to an A-phase open-circuit fault-tolerant control strategy of the five-phase permanent magnet synchronous motorAndand third harmonic space zero sequence modulation voltage command

When an A-phase winding of the five-phase permanent magnet synchronous motor has an open circuit fault, an α shaft defining a stator fundamental wave two-phase static coordinate system is coincided with an A-phase winding axis, a β shaft leads a α shaft in a counterclockwise way by 90 electrical angles, and voltage commands are modulated by α shafts and β shafts of the two-phase static coordinate systemAndsynthesized reference voltage vector U^*Amplitude ofReference voltage vector U^*At the spatial position on the complex plane of the fundamental wave

With reference voltage vector U^*Dividing the complex plane of the fundamental wave into six sectors at the space position electrical angle of the complex plane of the fundamental wave in a two-phase static coordinate system, wherein the 0& lt & gt 59.5536 degree is the I-th sector, the 59.5536 & lt & gt 120.4464 degree is the II-th sector, the 120.4464 & lt & gt 180 degree is the III-th sector, the 180 & lt & gt 239.5536 degree is the IV-th sector, the 239.5536 & lt & gt 300.4464 degree is the V-th sector, and the 300.4464 & lt & gt 360 degree is the VI-th sector;

three decision conditions are introduced for the purpose of sector decisionAndand defining sector judging function N as sign x₁+2signx₂+4signx₃Wherein sign is a sign function;

calculating the numerical value of N according to the positive and negative relations of the three judgment conditions, and realizing sector judgment according to the numerical value of N:

if N is 5, reference voltage vector U^*Located in the I sector;

if N is 7, reference voltage vector U^*Located in sector II;

if N is 3, reference voltage vector U^*Located in sector III;

if N is 2, reference voltage vector U^*Located in sector IV;

if N is equal to 0, reference voltage vector U^*Located in the V-th sector;

if N is 4, reference voltage vector U^*Located in the VI sector;

for fundamental waves, the switching states of upper bridge arms of an inverter bridge connected with 16 fundamental wave space voltage vectors and corresponding residual healthy BCDE four-phase windings are respectively as follows: u shape₀(0000)、U₁(0001)、U₂(0010)、U₃(0011)、U₄(0100)、U₅(0101)、U₆(0110)、U₇(0111)、U₈(1000)、U₉(1001)、U₁₀(1010)、U₁₁(1011)、U₁₂(1100)、U₁₃(1101)、U₁₄(1110) And U₁₅(1111) (ii) a The amplitude and position angle of the space voltage vector of the 16 fundamental wave spaces are respectively: u shape₀(0∠0°)、U₁(0.4413∠-59.5536°)、U₂(0.3245∠-133.5630°)、U₃(0.6155∠-90°)、U₄(0.3245∠133.5630°)、U₅(0.1453∠-90°)、U₆(0.4472∠180°)、U₇(0.4413∠-120.4464°)、U₈(0.4413∠59.5536°)、U₉(0.4472∠0°)、U₁₀(0.1453∠90°)、U₁₁(0.3245∠-46.4370°)、U₁₂(0.6155∠90°)、U₁₃(0.3245∠46.4370°)、U₁₄(0.4413 ∠ 120.4464 deg.) and U₁₅(0 ∠ 0 degree) wherein U is₁、U₂、U₃、U₄、U₅、U₆、U₇、U₈、U₉、U₁₀、U₁₁、U₁₂、U₁₃And U₁₄Is the effective space voltage vector, U, of 14 fundamental spaces₀And U₁₅Is the zero space voltage vector of the fundamental space;

for the third harmonic, the spatial voltage vectors of 16 third harmonic spaces and the corresponding switch states of upper bridge arms of an inverter bridge connected with the residual healthy BCDE four-phase winding are respectively as follows: u shape_z0(0000)、U_z1(0001)、U_z2(0010)、U_z3(0011)、U_z4(0100)、U_z5(0101)、U_z6(0110)、U_z7(0111)、U_z8(1000)、U_z9(1001)、U_z10(1010)、U_z11(1011)、U_z12(1100)、U₁₃(1101)、U_z14(1110) And U_z15(1111) (ii) a The magnitude and position angle of the space voltage vector of the 16 third harmonic spaces are respectively: u shape_z0(0∠0°)、U_z1(0.2351∠90°)、U_z2(0.3804∠-90°)、U_z3(0.1453∠-90°)、U_z4(0.3804∠90°)、U_z5(0.6155∠90°)、U_z6(0∠0°)、U_z7(0.2351∠90°)、U_z8(0.2351∠-90°)、U_z9(0∠0°)、U_z10(0.6155∠-90°)、U_z11(0.3804∠-90°)、U_z12(0.1453∠90°)、U_z13(0.3804∠90°)、U_z14(0.2351∠-90°)、U_z15(0∠0°)；

For the fundamental wave, the specific distribution of the effective space voltage vectors of 14 fundamental wave spaces in the six sectors is as follows: the effective space voltage vector of the 3 fundamental wave spaces in the I-th sector is U₉、U₈And U₁₃The effective space voltage vector of the 4 fundamental wave spaces in the II sector is U₈、U₁₀、U₁₂And U₁₄The effective space voltage vector of the 3 fundamental wave spaces in the III-th sector is U₄、U₆And U₁₄The effective space voltage vector of the 3 fundamental wave spaces in the IV sector is U₂、U₆And U₇The effective space voltage vector of the 4 fundamental wave spaces in the V-th sector is U₁、U₃、U₅And U₇The effective space voltage vector of the 3 fundamental wave spaces in the VI-th sector is U₁、U₉And U₁₁；

When reference voltage vector U^*When the voltage vector is positioned in a certain sector on the complex plane of the fundamental wave space of the two-phase static coordinate system, only 3 effective space voltage vectors in the fundamental wave space and 2 zero voltage vectors in the fundamental wave space are selected in each sector to be a reference voltage vector U^*The effect of the voltage vector is equivalent, and the effective space voltage vector U of the fundamental wave space with the shortest mode length is not selected in the sector II₁₀In the V-th sector, the effective space voltage vector U of the fundamental wave space with the shortest modular length is not selected any more₅(ii) a The effective space voltage vector of the selected 3 fundamental wave spaces in the I-th sector is U₉、U₈And U₁₃The effective space voltage vector of the selected 3 fundamental wave spaces in the II sector is U₈、U₁₂And U₁₄The effective space voltage vector of the selected 3 fundamental wave spaces in the III sector is U₄、U₆And U₁₄The effective space voltage vector of the selected 3 fundamental wave spaces in the IV sector is U₂、U₆And U₇The effective space voltage vector of the selected 3 fundamental wave spaces in the V-th sector is U₁、U₃And U₇The effective space voltage vector of the selected 3 fundamental wave spaces in the VI-th sector is U₁、U₉And U₁₁；

When reference voltage vector U^*When located in a certain sector on the complex plane of the fundamental wave space of the two-phase static coordinate system, the effective space voltage vector sum 2 of the selected 3 fundamental wave spaces in the sector can be usedThe zero space voltage vector of the fundamental wave space is synthesized into the reference voltage vector U^*Using the selected 3 effective space voltage vectors and 2 zero voltage vectors in fundamental wave space in each sector to reference voltage vector U^*When the action effects are equivalent, the action sequence of the space voltage vector of the fundamental wave space selected by each sector is as follows:

in sector I is U₀→U₈→U₉→U₁₃→U₁₅→U₁₃→U₉→U₈→U₀；

In sector II is U₀→U₈→U₁₂→U₁₄→U₁₅→U₁₄→U₁₂→U₈→U₀；

In sector III is U₀→U₄→U₆→U₁₄→U₁₅→U₁₄→U₆→U₄→U₀；

In sector IV is U₀→U₂→U₆→U₇→U₁₅→U₇→U₆→U₂→U₀；

In the V-th sector is U₀→U₁→U₃→U₇→U₁₅→U₇→U₃→U₁→U₀；

In sector VI is U₀→U₁→U₉→U₁₁→U₁₅→U₁₁→U₉→U₁→U₀；

When reference voltage vector U^*When the motor is in a certain sector, three modulation voltage commands, namely α -axis and β -axis modulation voltage commands of a two-phase static coordinate system are given according to an A-phase open-circuit fault-tolerant control system of the five-phase permanent magnet synchronous motorAndandthird harmonic space zero sequence modulation voltage instructionCalculating the modulation function of the remaining four phases under the sector; the specific contents are as follows:

when reference voltage vector U^*When the three modulation voltage commands are positioned in the I-th sector of the fundamental wave space complex plane, three modulation voltage commands generated by the A-phase open-circuit fault-tolerant control system of the five synchronous motorsAndselecting the space voltage vector U of 5 fundamental wave spaces corresponding to the sector₀、U₈、U₉、U₁₃And U₁₅Synthesizing to realize equivalent reference voltage vector U^*The SVPWM module calculates the I sector modulation function according to the three instructionsAndthe expression is as follows:

when reference voltage vector U^*When the motor is positioned in the second sector of the fundamental wave space complex plane, the A-phase open-circuit fault-tolerant control system of the five synchronous motors generates three modulation voltage commandsAndselecting the space voltage vector of 5 fundamental wave spaces corresponding to the sectorU₀、U₈、U₁₂、U₁₄And U₁₅Synthesizing to realize equivalent reference voltage vector U^*The SVPWM module calculates the second sector modulation function according to the three instructionsAndthe expression is as follows:

when reference voltage vector U^*When the three-phase fault-tolerant control system is positioned in the third sector of the fundamental wave space complex plane, the A-phase open-circuit fault-tolerant control system of the five-phase synchronous motor generates three modulation voltage commandsSelecting the space voltage vector U of 5 fundamental wave spaces corresponding to the sector₀、U₄、U₆、U₁₄And U₁₅Synthesizing to realize equivalent reference voltage vector U^*The SVPWM module calculates the modulation function of the III sector according to the three instructionsAndthe expression is as follows:

when reference voltage vector U^*When the motor is positioned in the IV sector of the fundamental wave space complex plane, the A-phase open-circuit fault-tolerant control system of the five synchronous motors generates three modulation voltage commandsSelecting the space voltage vector U of 5 fundamental wave spaces corresponding to the sector₀、U₂、U₆、U₇And U₁₅Synthesizing to realize equivalent reference voltage vector U^*The SVPWM module calculates the IV sector modulation function according to the three instructionsAndthe expression is as follows:

when reference voltage vector U^*When the five synchronous motors are positioned in the V-th sector of the fundamental wave space complex plane, the A-phase open-circuit fault-tolerant control system of the five synchronous motors generates three modulation voltage commandsSelecting the space voltage vector U of 5 fundamental wave spaces corresponding to the sector₀、U₁、U₃、U₇And U₁₅Synthesizing to realize equivalent reference voltage vector U^*The SVPWM module calculates a V-th sector modulation function according to the three instructionsAndthe expression is as follows:

when reference voltage is appliedVector U^*When the motor is positioned in the VI sector of the fundamental wave space complex plane, the A-phase open-circuit fault-tolerant control system of the five synchronous motors generates three modulation voltage commandsSelecting the space voltage vector U of 5 fundamental wave spaces corresponding to the sector₀、U₁、U₉、U₁₁And U₁₅Synthesizing to realize equivalent reference voltage vector U^*The SVPWM module calculates a VI sector modulation function according to the three instructionsAndthe expression is as follows:

the modulation function of each sector is directly loaded into a comparison value register as a comparison value and is compared with a time base counting register to obtain the upper bridge arm switching pulse of each phase, the lower bridge arm pulse is complementary with the upper bridge arm pulse, and the upper bridge arm pulse and the lower bridge arm pulse of each phase are respectively added with a dead zone signal to be used as a control pulse signal of the power switching tube; therefore, duty ratio control of PWM pulse is completed, and SVPWM control during A-phase open circuit fault of the five-phase permanent magnet synchronous motor is realized;

similarly, according to the process of realizing the SVPWM control when the A-phase of the five-phase permanent magnet synchronous motor is in open circuit fault, the SVPWM control when one phase of winding in other four-phase windings of the five-phase permanent magnet synchronous motor is in open circuit fault is also realized.

Technical Field

The invention belongs to the field of electrical engineering, and relates to a modulation function-based SVPWM control method for a single-phase open-circuit fault of a five-phase permanent magnet synchronous motor.

Background

The five-phase permanent magnet synchronous motor has the characteristics of high power density, small torque fluctuation, wide rotating speed range, strong overload capacity and the like, can realize fault-tolerant operation through open-circuit fault-tolerant control under the condition of phase loss, and has higher reliability. The space voltage vector pulse width modulation (SVPWM) algorithm of the five-phase voltage source inverter is widely applied to a five-phase permanent magnet synchronous motor control system due to clear physical significance, high voltage utilization rate and simple realization, however, the traditional SVPWM algorithm has the defects of large calculation amount, complex operation and poor real-time performance, and puts high requirements on the performance of a controller.

Disclosure of Invention

Aiming at the problems in the traditional single-phase open-circuit fault-tolerant control of the five-phase synchronous motor, the invention provides a modulation function-based single-phase open-circuit fault-tolerant control method of the five-phase permanent magnet synchronous motor, which eliminates the adverse effects on the real-time performance of a control system caused by the complicated processes of basic space voltage vector action sequence selection, action time calculation and switching action time conversion by means of a modulation function-generated SVPWM (space vector pulse width modulation) method, reduces the time required by digital control, thereby realizing the improvement of the control frequency under the same controller and optimizing the performance under the single-phase open-circuit fault of the five-phase synchronous motor.

In order to solve the problems of large calculation amount and complex calculation in the traditional fault-tolerant control method, the SVPWM control method for the single-phase open-circuit fault of the five-phase permanent magnet synchronous motor based on the modulation function, which is provided by the invention, simplifies the processes of basic space voltage vector action sequence selection, action time calculation and switching action time conversion, realizes the simplification of a calculation program of the SVPWM method, and reduces the SVPWM operation time; the realization process is as follows: the method comprises the steps of preprocessing a modulation voltage command and a third harmonic space modulation voltage command under a two-phase static coordinate system to obtain a group of modulation functions with coefficients as constants, judging sectors and then directly calling corresponding modulation functions to configure a comparison value register during real-time operation, directly loading the modulation functions of the sectors as comparison values into the comparison value register and a time base counting register to be compared to obtain upper bridge arm switching pulses of each phase, wherein the lower bridge arm pulses are complementary with the upper bridge arm pulses, and the upper bridge arm pulses and the lower bridge arm pulses of each phase are respectively added with dead zone signals which are control pulse signals of a power switching tube, so that duty ratio control of PWM pulses is completed, and SVPWM control during single-phase open circuit fault of the five-phase permanent magnet synchronous motor is realized. The specific process is as follows:

when an A-phase winding of the five-phase permanent magnet synchronous motor has an open-circuit fault, the fault-tolerant control system controls and generates three modulation voltage instructions, namely α -axis and β -axis modulation voltage instructions of a two-phase static coordinate system according to an A-phase open-circuit fault-tolerant control strategy of the five-phase permanent magnet synchronous motorAndand third harmonic space zero sequence modulation voltage command

When an A-phase winding of the five-phase permanent magnet synchronous motor has an open circuit fault, an α shaft defining a stator fundamental wave two-phase static coordinate system is coincided with an A-phase winding axis, a β shaft leads a α shaft in a counterclockwise way by 90 electrical angles, and voltage commands are modulated by α shafts and β shafts of the two-phase static coordinate systemAndsynthesized reference voltage vector U^*Amplitude ofReference voltage vector U^*At the spatial position on the complex plane of the fundamental wave

With reference voltage vector U^*Dividing the complex plane of the fundamental wave into six sectors at the space position electrical angle of the complex plane of the fundamental wave in a two-phase static coordinate system, wherein the 0& lt & gt 59.5536 degree is the I-th sector, the 59.5536 & lt & gt 120.4464 degree is the II-th sector, the 120.4464 & lt & gt 180 degree is the III-th sector, the 180 & lt & gt 239.5536 degree is the IV-th sector, the 239.5536 & lt & gt 300.4464 degree is the V-th sector, and the 300.4464 & lt & gt 360 degree is the VI-th sector;

three decision conditions are introduced for the purpose of sector decisionAndand defining sector judging function N as sign x₁+2signx₂+4signx₃Wherein sign is a sign function;

calculating the numerical value of N according to the positive and negative relations of the three judgment conditions, and realizing sector judgment according to the numerical value of N:

if N is 5, reference voltage vector U^*Located in the I sector;

if N is 7, reference voltage vector U^*Located in sector II;

if N is 3, reference voltage vector U^*Located in sector III;

if N is 2, reference voltage vector U^*Located in sector IV;

if N is equal to 0, reference voltage vector U^*Located in the V-th sector;

if N is 4, reference voltage vector U^*Located in the VI sector;

for fundamental waves, the switching states of upper bridge arms of an inverter bridge connected with 16 fundamental wave space voltage vectors and corresponding residual healthy BCDE four-phase windings are respectively as follows: u shape₀(0000)、U₁(0001)、U₂(0010)、U₃(0011)、U₄(0100)、U₅(0101)、U₆(0110)、U₇(0111)、U₈(1000)、U₉(1001)、U₁₀(1010)、U₁₁(1011)、U₁₂(1100)、U₁₃(1101)、U₁₄(1110) And U₁₅(1111) (ii) a The amplitude and position angle of the space voltage vector of the 16 fundamental wave spaces are respectively: u shape₀(0∠0°)、U₁(0.4413∠-59.5536°)、U₂(0.3245∠-133.5630°)、U₃(0.6155∠-90°)、U₄(0.3245∠133.5630°)、U₅(0.1453∠-90°)、U₆(0.4472∠180°)、U₇(0.4413∠-120.4464°)、U₈(0.4413∠59.5536°)、U₉(0.4472∠0°)、U₁₀(0.1453∠90°)、U₁₁(0.3245∠-46.4370°)、U₁₂(0.6155∠90°)、U₁₃(0.3245∠46.4370°)、U₁₄(0.4413 ∠ 120.4464 deg.) and U₁₅(0 ∠ 0 degree) wherein U is₁、U₂、U₃、U₄、U₅、U₆、U₇、U₈、U₉、U₁₀、U₁₁、U₁₂、U₁₃And U₁₄Is the effective space voltage vector, U, of 14 fundamental spaces₀And U₁₅Is the zero space voltage vector of the fundamental space;

for the third harmonic, the spatial voltage vectors of 16 third harmonic spaces and the corresponding switch states of upper bridge arms of an inverter bridge connected with the residual healthy BCDE four-phase winding are respectively as follows: u shape_z0(0000)、U_z1(0001)、U_z2(0010)、U_z3(0011)、U_z4(0100)、U_z5(0101)、U_z6(0110)、U_z7(0111)、U_z8(1000)、U_z9(1001)、U_z10(1010)、U_z11(1011)、U_z12(1100)、U₁₃(1101)、U_z14(1110) And U_z15(1111) (ii) a The magnitude and position angle of the space voltage vector of the 16 third harmonic spaces are respectively: u shape_z0(0∠0°)、U_z1(0.2351∠90°)、U_z2(0.3804∠-90°)、U_z3(0.1453∠-90°)、U_z4(0.3804∠90°)、U_z5(0.6155∠90°)、U_z6(0∠0°)、U_z7(0.2351∠90°)、U_z8(0.2351∠-90°)、U_z9(0∠0°)、U_z10(0.6155∠-90°)、U_z11(0.3804∠-90°)、U_z12(0.1453∠90°)、U_z13(0.3804∠90°)、U_z14(0.2351∠-90°)、U_z15(0∠0°)；

For the fundamental wave, the specific distribution of the effective space voltage vectors of 14 fundamental wave spaces in the six sectors is as follows: the effective space voltage vector of the 3 fundamental wave spaces in the I-th sector is U₉、U₈And U₁₃The effective space voltage vector of the 4 fundamental wave spaces in the II sector is U₈、U₁₀、U₁₂And U₁₄The effective space voltage vector of the 3 fundamental wave spaces in the III-th sector is U₄、U₆And U₁₄The effective space voltage vector of the 3 fundamental wave spaces in the IV sector is U₂、U₆And U₇The effective space voltage vector of the 4 fundamental wave spaces in the V-th sector is U₁、U₃、U₅And U₇The effective space voltage vector of the 3 fundamental wave spaces in the VI-th sector is U₁、U₉And U₁₁；

When reference voltage vector U^*When the voltage vector is positioned in a certain sector on the complex plane of the fundamental wave space of the two-phase static coordinate system, only 3 effective space voltage vectors in the fundamental wave space and 2 zero voltage vectors in the fundamental wave space are selected in each sector to be a reference voltage vector U^*The effect of the voltage vector is equivalent, and the effective space voltage vector U of the fundamental wave space with the shortest mode length is not selected in the sector II₁₀In the V-th sector, the effective space voltage vector U of the fundamental wave space with the shortest modular length is not selected any more₅(ii) a The effective space voltage vector of the selected 3 fundamental wave spaces in the I-th sector is U₉、U₈And U₁₃The effective space voltage vector of the selected 3 fundamental wave spaces in the II sector is U₈、U₁₂And U₁₄The effective space voltage vector of the selected 3 fundamental wave spaces in the III sector is U₄、U₆And U₁₄The effective space voltage vector of the selected 3 fundamental wave spaces in the IV sector isU₂、U₆And U₇The effective space voltage vector of the selected 3 fundamental wave spaces in the V-th sector is U₁、U₃And U₇The effective space voltage vector of the selected 3 fundamental wave spaces in the VI-th sector is U₁、U₉And U₁₁；

When reference voltage vector U^*When located in a sector on the complex plane of the fundamental wave space of the two-phase static coordinate system, the reference voltage vector U can be synthesized by using the effective space voltage vectors of 3 selected fundamental wave spaces and the zero space voltage vectors of 2 fundamental wave spaces in the sector^*Using the selected 3 effective space voltage vectors and 2 zero voltage vectors in fundamental wave space in each sector to reference voltage vector U^*When the action effects are equivalent, the action sequence of the space voltage vector of the fundamental wave space selected by each sector is as follows:

in sector I is U₀→U₈→U₉→U₁₃→U₁₅→U₁₃→U₉→U₈→U₀；

In sector II is U₀→U₈→U₁₂→U₁₄→U₁₅→U₁₄→U₁₂→U₈→U₀；

In sector III is U₀→U₄→U₆→U₁₄→U₁₅→U₁₄→U₆→U₄→U₀；

In sector IV is U₀→U₂→U₆→U₇→U₁₅→U₇→U₆→U₂→U₀；

In the V-th sector is U₀→U₁→U₃→U₇→U₁₅→U₇→U₃→U₁→U₀；

In sector VI is U₀→U₁→U₉→U₁₁→U₁₅→U₁₁→U₉→U₁→U₀；

When reference voltage vector U^*When the motor is in a certain sector, three modulation voltage commands, namely α -axis and β -axis modulation voltage commands of a two-phase static coordinate system are given according to an A-phase open-circuit fault-tolerant control system of the five-phase permanent magnet synchronous motorAndand third harmonic space zero sequence modulation voltage commandCalculating the modulation function of the remaining four phases under the sector; the specific contents are as follows:

when reference voltage vector U^*When the three modulation voltage commands are positioned in the I-th sector of the fundamental wave space complex plane, three modulation voltage commands generated by the A-phase open-circuit fault-tolerant control system of the five synchronous motorsAndselecting the space voltage vector U of 5 fundamental wave spaces corresponding to the sector₀、U₈、U₉、U₁₃And U₁₅Synthesizing to realize equivalent reference voltage vector U^*The SVPWM module calculates the I sector modulation function according to the three instructionsAndthe expression is as follows:

when reference voltage vector U^*When the second sector is in the second sector of the complex plane of the fundamental wave space, the fifth sector is the same as the first sectorThree modulation voltage instructions generated by step motor A-phase open-circuit fault-tolerant control systemAndselecting the space voltage vector U of 5 fundamental wave spaces corresponding to the sector₀、U₈、U₁₂、U₁₄And U₁₅Synthesizing to realize equivalent reference voltage vector U^*The SVPWM module calculates the second sector modulation function according to the three instructionsAndthe expression is as follows:

when reference voltage vector U^*When the three-phase fault-tolerant control system is positioned in the third sector of the fundamental wave space complex plane, the A-phase open-circuit fault-tolerant control system of the five-phase synchronous motor generates three modulation voltage commandsSelecting the space voltage vector U of 5 fundamental wave spaces corresponding to the sector₀、U₄、U₆、U₁₄And U₁₅Synthesizing to realize equivalent reference voltage vector U^*The SVPWM module calculates the modulation function of the III sector according to the three instructionsAndthe expression is as follows:

when reference voltage vector U^*When the motor is positioned in the IV sector of the fundamental wave space complex plane, the A-phase open-circuit fault-tolerant control system of the five synchronous motors generates three modulation voltage commandsSelecting the space voltage vector U of 5 fundamental wave spaces corresponding to the sector₀、U₂、U₆、U₇And U₁₅Synthesizing to realize equivalent reference voltage vector U^*The SVPWM module calculates the IV sector modulation function according to the three instructionsAndthe expression is as follows:

when reference voltage vector U^*When the five synchronous motors are positioned in the V-th sector of the fundamental wave space complex plane, the A-phase open-circuit fault-tolerant control system of the five synchronous motors generates three modulation voltage commandsSelecting the space voltage vector U of 5 fundamental wave spaces corresponding to the sector₀、U₁、U₃、U₇And U₁₅Synthesizing to realize equivalent reference voltage vector U^*The SVPWM module calculates a V-th sector modulation function according to the three instructionsAndthe expression is as follows:

when reference voltage vector U^*When the motor is positioned in the VI sector of the fundamental wave space complex plane, the A-phase open-circuit fault-tolerant control system of the five synchronous motors generates three modulation voltage commandsSelecting the space voltage vector U of 5 fundamental wave spaces corresponding to the sector₀、U₁、U₉、U₁₁And U₁₅Synthesizing to realize equivalent reference voltage vector U^*The SVPWM module calculates a VI sector modulation function according to the three instructionsAndthe expression is as follows:

the modulation function of each sector is directly loaded into a comparison value register as a comparison value and is compared with a time base counting register to obtain the upper bridge arm switching pulse of each phase, the lower bridge arm pulse is complementary with the upper bridge arm pulse, and the upper bridge arm pulse and the lower bridge arm pulse of each phase are respectively added with a dead zone signal to be used as a control pulse signal of the power switching tube; therefore, duty ratio control of PWM pulse is completed, and SVPWM control during A-phase open circuit fault of the five-phase permanent magnet synchronous motor is realized. Similarly, according to the process of realizing the SVPWM control when the A-phase of the five-phase permanent magnet synchronous motor is in open circuit fault, the SVPWM control when one phase of winding in other four-phase windings of the five-phase permanent magnet synchronous motor is in open circuit fault is also realized.

The invention discloses a fault-tolerant control system of a five-phase permanent magnet synchronous motor when an open-circuit fault occurs in a single-phase winding, which is also a rotating speed current double closed-loop system, and adopts a control method that a direct axis current instruction of a fundamental wave space rotor synchronous rotating coordinate system is zero, a rotating speed loop is compared with a fed-back actual rotating speed and input into a speed regulator, the output of the speed regulator is an alternating axis current instruction of the fundamental wave space rotor synchronous rotating coordinate system, the alternating axis instruction of the fundamental wave space rotor synchronous rotating coordinate system is regenerated into a third harmonic wave space zero sequence current instruction, the three current instructions are compared with respective fed-back actual currents and respectively input into a direct axis current controller, an alternating axis current controller and a third harmonic wave space current controller of the fundamental wave space rotor synchronous rotating coordinate system to realize a direct axis current controller, an alternating axis current controller and a third harmonic wave zero sequence current controller, and the direct axis current, the alternating current and the, The alternating current controller and the third harmonic space current controller realize the control of direct current, alternating current and third harmonic current. And the outputs of the three current controllers are used as system SVPWM modulation voltage commands, and the output of the three current controllers calls modulation functions of each sector to generate PWM control signals which are used as driving control signals of a system inverter. The modulation function-based single-phase open-circuit fault-tolerant control method for the five-phase permanent magnet synchronous motor can greatly simplify SVPWM program calculation steps and reduce time required by digital control, thereby improving control frequency and control performance under the same controller.

Drawings

FIGS. 1-1 and 1-2 are, respectively, six sectors of fundamental space and 16 space voltage vector distribution plots of fundamental plane and third harmonic plane in an open-circuit fault condition of phase A;

2-1 and 2-2 are relationships between a reference voltage vector and a fundamental wave space plane space voltage vector, a third harmonic space plane space voltage vector, respectively, in the I-th sector in the A-phase open circuit fault condition, respectively;

3-1 and 3-2 are relationships between the reference voltage vector and the fundamental wave space plane space voltage vector, the third harmonic space plane space voltage vector, respectively, in the II sector under the A-phase open circuit fault condition, respectively;

4-1 and 4-2 are relationships between the reference voltage vector and the fundamental and third harmonic space plane space voltage vectors, respectively, in sector III under the A-phase open circuit fault condition;

FIGS. 5-1 and 5-2 are relationships between the reference voltage vector and the fundamental and third harmonic space-plane space-voltage vectors, respectively, in the IV sector under an A-phase open circuit fault condition;

6-1 and 6-2 are relationships between the reference voltage vector and the fundamental wave space plane space voltage vector, the third harmonic space plane space voltage vector, respectively, in the Vth sector in the A-phase open circuit fault condition, respectively;

7-1 and 7-2 are relationships between the reference voltage vector and the fundamental and third harmonic space plane space voltage vectors, respectively, in the VI sector under an A-phase open circuit fault condition;

FIG. 8 is a digital pulse width modulation schematic;

FIG. 9 is a reference voltage vector U^*When the PWM is positioned in the I sector, the duty ratio of each phase of PWM pulse is schematic diagram;

FIG. 10 is a reference voltage vector U^*When the PWM is positioned in the II sector, the duty ratio of each phase of PWM pulse is schematic diagram;

FIG. 11 is a reference voltage vector U^*A schematic diagram of duty ratio of each phase PWM pulse when located in the third sector;

FIG. 12 is a reference voltage vector U^*A schematic diagram of duty ratio of each phase PWM pulse when located in the IV sector;

FIG. 13 is a reference voltage vector U^*When the PWM is positioned in the V-th sector, the duty ratio of each phase of PWM pulse is schematic;

FIG. 14 is a reference voltage vector U^*When the PWM is positioned in the VI sector, the duty ratio of each phase of PWM pulse is schematic diagram;

fig. 15 is a block diagram of an open-circuit fault-tolerant control system for phase a of a five-phase permanent magnet synchronous motor.

Detailed Description

Embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. In this embodiment, SVPWM control in the case of an open-circuit fault of the a-phase of the five-phase permanent magnet synchronous motor is taken as an example. SVPWM space voltage vector distribution under A-phase open-circuit fault condition shown in FIGS. 1-1 and 1-2The method is divided into a fundamental wave space α - β plane and a third harmonic space z plane, wherein a α axis of a two-phase static αβ coordinate system of a stator fundamental wave space is coincided with an axis of a winding of a phase A of a stator, and a α axis and a β axis are respectively coincided with a real axis and an imaginary axis of a complex plane of the fundamental wave space, and under a normal state, according to the principle that amplitudes are equal, a coordinate transformation matrix T from a five-phase static coordinate system of the stator to a two-phase static coordinate system of the stator⁵Is composed of

Wherein, theta is the electrical angle between two adjacent axes in the five-phase coordinate system, and the value of theta is 2 pi/5.

When open-circuit fault occurs to A phase, at T₅On the basis of matrix, removing one column related to phase A, under the condition of fault, the fundamental wave space and third harmonic wave space are no longer orthogonal, under the condition of only considering fundamental wave space, removing third row, in order to ensure that two coordinate axes α and β are orthogonal, correcting the above-mentioned matrix, making every row be orthogonal so as to obtain decoupling matrix T when phase A is open-circuit fault⁴And the fourth row represents the zero sequence component.

In the case of an open-circuit fault of the A phase, a stator fundamental wave space two-phase static αβ coordinate system α axis modulation voltage commandβ Axis modulation Voltage CommandAnd third harmonic spatial z-axis modulation voltage commandAnd terminal voltage u of the remaining four-phase winding_B、u_C、u_DAnd u_EThe following relationship is satisfied:

under the A-phase open circuit fault, the effective phase voltage of the five-phase full-bridge inverter can be used as the switching state quantity S of the upper bridge arm_B、S_C、S_DAnd S_EExpressed, the expression is:

wherein S is_i1 indicates that the upper arm switching tube is on (i ═ B, C, D, E), S_iAnd the value of 0 indicates that the upper bridge arm switching tube is cut off, and the upper bridge arm switching tube and the lower bridge arm switching tube are in a complementary state.

The expression is substituted into a relation between the two-phase static coordinate system voltage and the four-phase static coordinate system voltage, compensation operation is carried out, and an α axis modulation voltage instruction is obtainedβ Axis modulation Voltage CommandAnd z-axis modulation voltage commandRelation to switching state quantity:

according to the switch state quantity S_E、S_D、S_CAnd S_BDifferent values are obtained, when the A-phase of the five-phase permanent magnet synchronous motor is open-circuited, the space voltage vectors of 16 fundamental wave spaces and the corresponding switch states of upper bridge arms of an inverter bridge connected with the residual healthy BCDE four-phase winding are respectively as follows: u shape₀(0000)、U₁(0001)、U₂(0010)、U₃(0011)、U₄(0100)、U₅(0101)、U₆(0110)、U₇(0111)、U₈(1000)、U₉(1001)、U₁₀(1010)、U₁₁(1011)、U₁₂(1100)、U₁₃(1101)、U₁₄(1110)、U₁₅(1111) (ii) a The space voltage vectors of 16 third harmonic spaces when the A phase of the five-phase permanent magnet synchronous motor is open and the switch states of the upper bridge arm of the inverter bridge connected with the residual healthy BCDE four-phase winding corresponding to the space voltage vectors are respectively as follows: u shape_z0(0000)、U_z1(0001)、U_z2(0010)、U_z3(0011)、U_z4(0100)、U_z5(0101)、U_z6(0110)、U_z7(0111)、U_z8(1000)、U_z9(1001)、U_z10(1010)、U_z11(1011)、U_z12(1100)、U₁₃(1101)、U_z14(1110) And U_z15(1111)。

The switching state quantity is brought into a relation equation of the voltage of the two-phase static coordinate system and the switching state quantity, and a corresponding relation table of the switching state of the upper bridge arm of the inverter bridge and the space voltage vector of the fundamental wave and the third harmonic as shown in table 1 can be obtained. The table shows the space voltage vector representation signs of 16 fundamental wave spaces and 16 third harmonic wave spaces corresponding to 16 switch states, and the corresponding mode length and space position angle of the space voltage vector. In Table 1, the switch states (S)_ES_DS_CS_B) Corresponding binary number is converted into corresponding decimal number n, and fundamental wave and third harmonic space voltage vector corresponding to each switch state are used as U_nAnd U_znTo indicate. Fundamental space voltage vector U_nHas a mode length and a spatial position angle relative to the axis of the fundamental wave biphase stationary coordinate system α of U_nAnd theta_n(ii) a Third harmonic space voltage vector U_znAnd a two-phase stationary coordinate system α with respect to the third harmonic₃The spatial position angle of the shaft is U_znAnd theta_zn。

For the fundamental wave, the magnitude and position angle of the space voltage vector of the 16 fundamental wave spaces are respectively: u shape₀(0∠0°)、U₁(0.4413∠-59.5536°)、U₂(0.3245∠-133.5630°)、U₃(0.6155∠-90°)、U₄(0.3245∠133.5630°)、U₅(0.1453∠-90°)、U₆(0.4472∠180°)、U₇(0.4413∠-120.4464°)、U₈(0.4413∠59.5536°)、U₉(0.4472∠0°)、U₁₀(0.1453∠90°)、U₁₁(0.3245∠-46.4370°)、U₁₂(0.6155∠90°)、U₁₃(0.3245∠46.4370°)、U₁₄(0.4413 ∠ 120.4464 deg.) and U₁₅(0 ∠ 0 degree) wherein U is₁、U₂、U₃、U₄、U₅、U₆、U₇、U₈、U₉、U₁₀、U₁₁、U₁₂、U₁₃And U₁₄Is the effective space voltage vector, U, of 14 fundamental spaces₀And U₁₅Is the zero space voltage vector of the fundamental space;

for the third harmonic, the magnitude and position angle of the space voltage vector of the 16 third harmonic spaces are: u shape_z0(0∠0°)、U_z1(0.2351∠90°)、U_z2(0.3804∠-90°)、U_z3(0.1453∠-90°)、U_z4(0.3804∠90°)、U_z5(0.6155∠90°)、U_z6(0∠0°)、U_z7(0.2351∠90°)、U_z8(0.2351∠-90°)、U_z9(0∠0°)、U_z10(0.6155∠-90°)、U_z11(0.3804∠-90°)、U_z12(0.1453∠90°)、U_z13(0.3804∠90°)、U_z14(0.2351∠-90°)、U_z15(0∠0°)；

TABLE 2 inverter bridge arm switching state and fundamental wave and third harmonic space voltage vector corresponding relation table

Three decision conditions are introduced for the decision of a sectorAndsector judgment is realized by judging the positive and negative relations of three judgment conditions:

when x is₁＞0、x₂＜0、x₃When > 0, reference voltage vector U^*Located in the I sector;

when x is₁＞0、x₂＞0、x₃When > 0, reference voltage vector U^*Located in sector II;

when x is₁＞0、x₂＞0、x₃Reference voltage vector U < 0^*Located in sector III;

when x is₁＜0、x₂＞0、x₃Reference voltage vector U < 0^*Located in sector IV;

when x is₁＜0、x₂＜0、x₃Reference voltage vector U < 0^*Located in the V-th sector;

when x is₁＜0、x₂＜0、x₃When > 0, reference voltage vector U^*Located in sector VI.

To further simplify sector determination, a sector determination function N is defined as sign x₁+2signx₂+4signx₃Wherein sign is a sign function, and sector judgment is realized by calculating the numerical value of N:

if N is 5, reference voltage vector U^*Located in the I sector;

if N is 7, reference voltage vector U^*Located in sector II;

if N is 3, reference voltage vector U^*Located in sector III;

if N is 2, reference voltage vector U^*Located in sector IV;

if N is equal to 0, reference voltage vector U^*Located in the V-th sector;

if N is 4, reference voltage vector U^*Located in sector VI.

Reference voltage vector U^*Located on a certain fan on the complex plane of the fundamental wave space of the two-phase static coordinate systemWhen the area is in the region, only the effective space voltage vectors of 3 fundamental wave spaces in the sector and the zero voltage vectors of 2 fundamental wave spaces in the sector are selected to be equivalent to the action effect of the reference voltage, and the effective space voltage vector U of the fundamental wave space with the shortest modular length is not selected in the sector II₁₀In the V-th sector, the effective space voltage vector U of the fundamental wave space with the shortest modular length is not selected any more₅。

The fundamental wave plane space voltage vector and the third harmonic plane space voltage vector in the I sector under the A-phase open circuit fault state shown in the figure 2-1 and the figure 2-2 are respectively connected with the reference voltage vector U^*The relation between the reference voltage vector U and the reference voltage vector U can be known^*When the control system is positioned in the I-th sector of the fundamental wave plane, 3 modulation voltage commands are given by the control systemAndeffective space voltage vector U of 3 fundamental wave spaces selected by the sector₈、U₉And U₁₃And zero space voltage vector U of 2 fundamental wave spaces₀And U₁₅Performing equivalence in each control period T_sZero space voltage vector U of inner 2 fundamental wave spaces₀And U₁₅The time of action is the same T₀＝T₁₅The action time allocated to the effective space voltage vector of the 3 fundamental wave spaces is T₈、T₉And T₁₃According to the volt-second balance theory, the same control effect can be realized by using a basic space voltage vector, and the relation of the vector satisfies the following relation:

substituting the correlation values yields:

as shown in FIGS. 3-1 and 3-2The fundamental wave plane space voltage vector and the third harmonic plane space voltage vector in the second sector under the A-phase open-circuit fault state are respectively connected with the reference voltage vector U^*The relation between the reference voltage vector U and the reference voltage vector U can be known^*When located in the second sector of the fundamental wave space plane, 3 modulation voltage commands given by the control systemAndeffective space voltage vector U of 3 fundamental wave spaces selected by the sector₈、U₁₂And U₁₄And zero space voltage vector U of 2 fundamental wave spaces₀And U₁₅Performing equivalence in each control period T_sZero space voltage vector U of inner 2 fundamental wave spaces₀And U₁₅The time of action is the same T₀＝T₁₅The action time allocated to the effective space voltage vector of the 3 fundamental wave spaces is T₈、T₁₂And T₁₄According to the volt-second balance theory, the same control effect can be realized by using a basic space voltage vector, and the relation of the vector satisfies the following relation:

substituting the correlation values yields:

the fundamental plane space voltage vector and the third harmonic plane space voltage vector in the sector III in the open-circuit fault state of phase A shown in FIG. 4-1 and FIG. 4-2 are respectively connected with the reference voltage vector U^*The relation between the reference voltage vector U and the reference voltage vector U can be known^*3 modulation voltage commands given by the control system when located in the third sector of the fundamental wave space planeAndeffective space voltage vector U of 3 fundamental wave spaces selected by the sector₄、U₆And U₁₄And zero space voltage vector U of 2 fundamental wave spaces₀And U₁₅Performing equivalence in each control period T_sZero space voltage vector U of inner 2 fundamental wave spaces₀And U₁₅The time of action is the same T₀＝T₁₅The action time allocated to the effective space voltage vector of the 3 fundamental wave spaces is T₄、T₆And T₁₄According to the volt-second balance theory, the same control effect can be realized by using a basic space voltage vector, and the relation of the vector satisfies the following relation:

substituting the correlation values yields:

the fundamental plane space voltage vector and the third harmonic plane space voltage vector in the IV sector in the A-phase open circuit fault state shown in FIG. 5-1 and FIG. 5-2 are respectively connected with the reference voltage vector U^*The relation between the reference voltage vector U and the reference voltage vector U can be known^*When located in the IV sector of the fundamental wave space plane, 3 modulation voltage commands given by the control systemAndeffective space voltage vector U of 3 fundamental wave spaces selected by the sector₂、U₆And U₇And zero space voltage vector U of 2 fundamental wave spaces₀And U₁₅Performing equivalence in each control cyclePeriod T_sZero space voltage vector U of inner 2 fundamental wave spaces₀And U₁₅The time of action is the same T₀＝T₁₅The action time allocated to the effective space voltage vector of the 3 fundamental wave spaces is T₂、T₆And T₇According to the volt-second balance theory, the same control effect can be realized by using a basic space voltage vector, and the relation of the vector satisfies the following relation:

substituting the correlation values yields:

the fundamental wave plane space voltage vector and the third harmonic plane space voltage vector in the V-th sector in the A-phase open circuit fault state shown in the figure 6-1 and the figure 6-2 are respectively connected with the reference voltage vector U^*The relation between the reference voltage vector U and the reference voltage vector U can be known^*3 modulation voltage commands given by the control system when located in the V-th sector of the fundamental wave space planeAndeffective space voltage vector U of 3 fundamental wave spaces selected by the sector₁、U₃And U₇And zero space voltage vector U of 2 fundamental wave spaces₀And U₁₅Performing equivalence in each control period T_sZero space voltage vector U of inner 2 fundamental wave spaces₀And U₁₅The time of action is the same T₀＝T₁₅The action time allocated to the effective space voltage vector of the 3 fundamental wave spaces is T₁、T₃And T₇According to the volt-second balance theory, the same control effect can be realized by using a basic space voltage vector, and the relation of the vector satisfies the following relation:

substituting the correlation values yields:

the fundamental plane space voltage vector and the third harmonic plane space voltage vector in the VI-th sector in the open-circuit fault state of the phase A shown in FIG. 7-1 and FIG. 7-2 are respectively connected with the reference voltage vector U^*The relation between the reference voltage vector U and the reference voltage vector U can be known^*When located in the VI sector of the fundamental wave space plane, 3 modulation voltage commands given by the control systemAndeffective space voltage vector U of 3 fundamental wave spaces selected by the sector₁、U₉And U₁₁And zero space voltage vector U of 2 fundamental wave spaces₀And U₁₅Performing equivalence in each control period T_sZero space voltage vector U of inner 2 fundamental wave spaces₀And U₁₅The time of action is the same T₀＝T₁₅The action time allocated to the effective space voltage vector of the 3 fundamental wave spaces is T₁、T₉And T₁₁According to the volt-second balance theory, the same control effect can be realized by using a basic space voltage vector, and the relation of the vector satisfies the following relation:

substituting the correlation values yields:

fig. 8 is a digital pulse width modulation schematic. And comparing the modulation wave with the triangular carrier wave to obtain the PWM duty cycle waveform. Wherein, the amplitude of the triangular carrier wave is set as 1, and the modulation wave calculates an updated modulation function for each period. In each switching period T_sIn the method, a modulation function is calculated to obtain a new modulation function value, and the modulation function is updated at the peak of the carrier wave. I, II, III, IV, V, VI represents the corresponding I to VI sectors, I is B, C, D, E represents the corresponding remaining healthy phases, and the duty ratio of the corresponding sectors corresponding to the remaining healthy phases is obtainedAnd a modulation function f_i ^j(t) is given as a relational expression. If the amplitude of the triangular carrier wave is 1, the amplitude of the modulation wave is the modulation ratio. By using bottom point sampling, according to the similar triangle principle, the following relation can be obtained:

FIG. 9 shows a reference voltage vector U^*And when the voltage transformer is positioned in the I-th sector, the duty ratio of each phase is schematically shown, and the action sequence of 3 fundamental wave space effective space voltage vectors and 2 fundamental wave space zero space voltage vectors is also shown. When reference voltage vector U^*In sector I, in each switching period T_sIn the method, 3 fundamental wave space effective space voltage vectors U are obtained through calculation₈、U₉And U₁₃Time of action T₈、T₉And T₁₃Satisfies the following relation:

from the above equation, it can be derived that the duty ratio expressions of the remaining healthy phases are:

according to the digital pulse width modulation schematic diagram shown in fig. 8, the relationship between the duty ratio of each phase of PWM waveform in the I-th sector and the calculated modulation function is:

the expression of the modulation function obtained by simultaneous two formulas is:

FIG. 10 shows a reference voltage vector U^*And when the voltage transformer is positioned in a sector II, the duty ratio diagram of each phase is shown, and the action sequence of 3 fundamental wave space effective space voltage vectors and 2 fundamental wave space zero space voltage vectors is also shown. When reference voltage vector U^*In sector II, each switching period T_sIn the method, 3 fundamental wave space effective space voltage vectors U are obtained through calculation₈、U₁₂And U₁₄Time of action T₈、T₁₂And T₁₄Satisfies the following relation:

from the above equation, it can be derived that the duty ratio expressions of the remaining healthy phases are:

according to the digital pulse width modulation schematic diagram shown in fig. 8, the relationship between the duty ratio of each phase of PWM waveform in the sector II and the calculated modulation function is:

the expression of the modulation function obtained by simultaneous two formulas is:

FIG. 11 shows a reference voltage vector U^*And when the voltage transformer is positioned in the sector III, the duty ratio of each phase is schematically shown, and the action sequence of 3 fundamental wave space effective space voltage vectors and 2 fundamental wave space zero space voltage vectors is also shown. When reference voltage vector U^*In sector III, in each switching period T_sIn the method, 3 fundamental wave space effective space voltage vectors U are obtained through calculation₄、U₆And U₁₄Time of action T₄、T₆And T₁₄Satisfies the following relation:

from the above equation, it can be derived that the duty ratio expressions of the remaining healthy phases are:

according to the digital pulse width modulation schematic diagram shown in fig. 8, the relationship between the duty ratio of each phase PWM waveform in the sector III and the calculated modulation function is:

the expression of the modulation function obtained by simultaneous two formulas is:

FIG. 12 shows a reference voltage vector U^*And when the voltage transformer is positioned in the IV sector, the duty ratio of each phase is shown schematically, and the action sequence of 3 fundamental wave space effective space voltage vectors and 2 fundamental wave space zero space voltage vectors is also shown. When reference voltage vector U^*In sector IV, in each switching period T_sIn the method, 3 fundamental wave space effective space voltage vectors U are obtained through calculation₂、U₆And U₇Time of action T₂、T₆And T₇Satisfies the following relation:

from the above equation, it can be derived that the duty ratio expressions of the remaining healthy phases are:

according to the digital pulse width modulation schematic diagram shown in fig. 8, the relationship between the duty ratio of each phase of PWM waveform in the IV sector and the calculated modulation function is:

the expression of the modulation function obtained by simultaneous two formulas is:

FIG. 13 shows a reference voltage vector U^*And when the voltage transformer is positioned in a V-th sector, the duty ratio of each phase is schematically shown, and the action sequence of 3 fundamental wave space effective space voltage vectors and 2 fundamental wave space zero space voltage vectors is also shown. When reference voltage vector U^*In the V-th sector, in each switching period T_sIn the method, 3 fundamental wave space effective space voltage vectors U are obtained through calculation₁、U₃And U₇Time of action T₁、T₃And T₇Satisfies the following relation:

from the above equation, it can be derived that the duty ratio expressions of the remaining healthy phases are:

according to the digital pulse width modulation schematic diagram shown in fig. 8, the relationship between the duty ratio of each phase of PWM waveform in the V-th sector and the calculated modulation function is:

the expression of the modulation function obtained by simultaneous two formulas is:

FIG. 14 shows a reference voltage vector U^*And when the voltage transformer is positioned in a VI sector, the duty ratio of each phase is schematically shown, and the action sequence of 3 fundamental wave space effective space voltage vectors and 2 fundamental wave space zero space voltage vectors is also shown. When reference voltage vector U^*In the VI-th sector, in each switching period T_sIn the method, 3 fundamental wave space effective space voltage vectors U are obtained through calculation₁、U₉And U₁₁Time of action T₁、T₉And T₁₁Satisfies the following relation:

from the above equation, it can be derived that the duty ratio expressions of the remaining healthy phases are:

according to the digital pulse width modulation schematic diagram shown in fig. 8, the relationship between the duty ratio of each phase of PWM waveform in the VI-th sector and the calculated modulation function is:

the expression of the modulation function obtained by simultaneous two formulas is:

a block diagram of an open-circuit fault-tolerant control system for phase a of five synchronous motors constructed according to the above principle is shown in fig. 15.

The control system detects the actually detected residual four-phase current i_B、i_C、i_DAnd i_EDirect axis current i transformed into a synchronous rotating coordinate system by a transformation matrix_dQuadrature axis current i_qAnd third harmonic current i_z。

The control system measures the rotor position angle theta through a position sensor coaxially mounted with the rotor of the five-phase permanent magnet synchronous motor, and the actual angular speed omega of the motor can be calculated.

Angular speed given signal omega of motor^*And the actual signal omega of the angular speed of the motor is compared with the actual signal omega of the angular speed of the motor and then serves as the input of a speed regulator, and the speed regulator adopts a traditional PI (proportional integral) regulator. The output signal of the speed regulator is used as the quadrature axis current given signal of the rotor fundamental wave synchronous rotating coordinate systemByAnd rotor position electrical angle theta can be calculated to obtain a third harmonic current set signal

Quadrature axis current set signalWith feedback quadrature axis current signal i_qThe compared signals are used as input signals of a quadrature axis current controller and sent to the quadrature axis current controller, the quadrature axis current controller selects a PI regulator, and the output of the PI regulator is a quadrature axis voltage instruction

The system adopts direct-axis current signalsControl method of (1), straight axis current settingAnd feedback direct axis current signal i_dThe compared signals are used as input signals of a direct-axis current controller, the direct-axis current controller selects a PI regulator, and the output of the PI regulator is a direct-axis voltage instruction

Third harmonic current given signalAnd a feedback current signal i_zAfter comparison, the signal is used as the input signal of the third harmonic current controller, the third harmonic current controller adopts a selected PR (proportional resonance) regulator, and the output of the third harmonic current controller is a third harmonic modulation voltage command

AC and DC axis voltage commandα and β axis modulation voltage commands are obtained through coordinate transformationAccording to the three modulation voltage commandsAndcalculating the modulation function of each sector, judging six sectors during real-time operation, directly calling the modulation function of the corresponding sector, and comparing the modulation function directly used as the modulation signal of each phase of drive pulse with the carrier signalTo each phase SVPWM pulse. By simplifying the processes of basic space voltage vector action sequence selection, action time calculation and switching action time conversion, the SVPWM modulation calculation program is simplified, the SVPWM modulation link operation time and the overall control time are reduced, the control frequency is improved under the same controller, and the control performance of the A-phase open-circuit fault of the five-phase permanent magnet synchronous motor is optimized.

According to the SVPWM control process for realizing the open-circuit fault of the a-phase of the five-phase permanent magnet synchronous motor, similarly, the SVPWM control can be realized when the open-circuit fault occurs in one of the other four-phase windings of the five-phase permanent magnet synchronous motor, and details are not repeated herein.