阅读说明：本技术 三电平六相永磁同步电机双模式运行控制系统及控制方法 (Dual-mode operation control system and control method for three-level six-phase permanent magnet synchronous motor ) 是由 高晗璎 张国强 桂勇 于 2019-09-20 设计创作，主要内容包括：三电平六相永磁同步电机双模式运行控制系统及控制方法。目前的三电平逆变器功率等级受限,谐波相对较高,电机转矩脉动较大。本发明组成包括：控制电路,控制电路输出的PWM信号与驱动电路(5)电连接,驱动电路与六相逆变器(2)电连接,六相逆变器与变频器的三相不控整流电路(1)电连接,变频器的三相不控整流电路前端并联有缺相检测电路(4),变频器的三相不控整流电路后端与母线电压检测电路(3)电连接,缺相检测电路和母线电压检测电路与控制器的A/D接口电连接,六相逆变器经过六相电流采样电路12输入至控制电路的A/D接口。本发明用于三电平六相永磁同步电机的双模式运行控制。(A three-level six-phase permanent magnet synchronous motor dual-mode operation control system and a control method. The power grade of the existing three-level inverter is limited, the harmonic wave is relatively high, and the torque ripple of the motor is large. The invention comprises the following components: the control circuit, the PWM signal that control circuit output is connected with drive circuit (5) electricity, drive circuit is connected with six looks inverter (2) electricity, six looks inverter is connected with three-phase uncontrollable rectifier circuit (1) electricity of converter, three-phase uncontrollable rectifier circuit front end of converter has run flat detection circuit (4) in parallel, three-phase uncontrollable rectifier circuit rear end and bus voltage detection circuit (3) electricity of converter are connected, run flat detection circuit and bus voltage detection circuit are connected with the AD interface electricity of controller, six looks inverter inputs the AD interface to control circuit through six looks current sampling circuit 12. The invention is used for the dual-mode operation control of the three-level six-phase permanent magnet synchronous motor.)

1. A dual-mode operation control system of a three-level six-phase permanent magnet synchronous motor comprises the following components: the control circuit is characterized in that: the PWM signal output by the control circuit is electrically connected with a drive circuit, the drive circuit is electrically connected with a six-phase inverter, the six-phase inverter is electrically connected with a three-phase uncontrolled rectifying circuit of the frequency converter, the front end of the three-phase uncontrolled rectifying circuit of the frequency converter is connected with a phase-lack detection circuit in parallel, the rear end of the three-phase uncontrolled rectifying circuit of the frequency converter is electrically connected with a bus voltage detection circuit, the phase-lack detection circuit and the bus voltage detection circuit are electrically connected with an A/D interface of the controller, and the six-phase inverter is input to the A/D interface of the control circuit through a six-phase current sampling circuit.

2. A dual-mode operation control system of a three-level six-phase permanent magnet synchronous motor according to claim 1, wherein: the controller consists of a DSP and an FPGA, and the DSP is electrically connected with the FPGA.

3. A dual-mode operation control system of a three-level six-phase permanent magnet synchronous motor according to claim 1 or 2, characterized in that: and the DSP is in communication connection with the upper computer through a CAN communication circuit.

4. A dual-mode operation control system of a three-level six-phase permanent magnet synchronous motor according to claim 1, wherein: the six-phase inverter is also electrically connected with a six-phase permanent magnet synchronous motor, and the six-phase permanent magnet synchronous motor is in communication connection with the QEP interface of the DSP through a rotary transformer.

5. A control method of a dual-mode operation control system of a three-level six-phase permanent magnet synchronous motor according to claims 1 to 4, characterized in that: detecting a double-Y30-degree-shift six-phase permanent magnet synchronous motor control system in real time through a sampling circuit, and judging whether the control system is in a normal operation state or a phase-failure fault state so as to facilitate the control system to select a control strategy;

when the system normally operates, a double three-level SVPWM control strategy is adopted, the current adopts a four-dimensional current closed-loop control mode, namely the current participating in the electromechanical energy conversion is subjected to closed-loop control, the harmonic current is also subjected to closed-loop control, and the current participating in the electromechanical energy conversion is subjected to closed-loop controlThe control method of (1) adopts a proportional-integral controller to regulate the current, and harmonic current is given because the current is direct currentBecause the harmonic current is an alternating current quantity, the proportional resonance controller is adopted for regulation, and the voltage control quantity of the control circuit is obtained、、、；

During open-phase operation, when the Z phase is in open circuit, the other five-phase windings are not symmetrical, and at the moment, a fault-tolerant control scheme needs to be selected according to different optimization targets, so that the system is restored to be stable again, and the remaining phase current is optimized according to the targets of minimum stator copper consumption and maximum output torque.

6. The control method of a dual-mode operation control system of a three-level six-phase permanent magnet synchronous motor according to claim 5, characterized in that: the specific steps in normal operation are as follows: firstly, the voltage control quantity of the control circuit is calculated through a rotating speed closed loop and a current closed loop、、、And performing inverse transformation on the voltage control quantity to obtain the six-phase voltage required by the motor、、、、、Component is then

Secondly due to the doubleThe neutral point isolation characteristic of the windings of the Y-shift 30-degree six-phase permanent magnet synchronous motor is that six-phase voltages belong to two sets of ABC and XYZ windings respectively and are respectively coupled、、And、、the voltage component is converted from three-phase static state to two-phase static state to obtain、And、component is then

Wherein the content of the first and second substances,、、、、、respectively representing six-phase motor stator voltages;

、and、respectively representing the components of the first set of winding ABC and the second set of winding XYZ in a two-phase static coordinate system;

finally to、Component sum、And (3) writing the modulation wave data into the FPGA in an XINTF external RAM mode, realizing two sets of three-phase three-level SVPWM modulation strategies by using a Verilog language to obtain a PWM waveform for driving a three-level six-phase inverter, controlling a three-level six-phase driver, and realizing the control of a double-Y30-degree six-phase permanent magnet synchronous motor.

7. The control method of a dual-mode operation control system of a three-level six-phase permanent magnet synchronous motor according to claim 5, characterized in that: the specific process of optimizing the residual phase current by taking the minimum copper loss of the stator as the target is as follows:

the six-phase motor has the following phases in normal operation:

（1）

in the formula:is the amplitude of the stator phase current;

when open circuit occurs in Z phaseAnd the total synthetic magnetic potential of the stator before and after the open-circuit fault is not changed, so that the remaining five-phase current must meet the following conditions:（2）

by simplifying equation (2), we can get the following equation by subtracting the same coefficients from both sides:

（3）

according to the trigonometric function formula, the current in each phase winding is expressed as follows:

（4）

bringing equation (4) into equation (3) and separating its real and imaginary parts yields:

（5）

because the six-phase PMSM has the characteristic of neutral point isolation, the following constraint conditions are required to be met:

（6）

by solving equations (5) and (6) simultaneously, the solutions of which are not unique, the remaining individual phase currents are calculated based on the minimum stator copper loss as an optimization objective, and an objective function thereof is constructed:

constructing a lagrange function of

From the Lagrange multiplier method, it can be concluded that the remaining phase currents can be expressed as

（7）。

8. The control method of a dual-mode operation control system of a three-level six-phase permanent magnet synchronous motor according to claim 5, characterized in that: the specific process for optimizing the residual phase current based on the maximum target of the output torque is as follows: analyzing an optimization mode based on the maximum output torque, balancing the amplitudes of the remaining phase currents, minimizing the current amplitudes, representing a performance index by using the maximum value in the amplitudes of the remaining phase currents, and writing an objective function in a column:

（8）

the optimization goal of equation (8) is to find the set of maximum solutions that minimizes the value of F, use F as the objective function, the constraints are equations (5) and (6), and solve the expressions for the remaining individual phase currents:

（9）

the size and the phase of the remaining current of each phase are adjusted by two optimization modes, modulated wave data are written into the FPGA in an XINTF external expansion RAM mode, a carrier stacking comparison control mode is realized by using a Verilog language, and the double-Y30-degree-shift six-phase permanent magnet synchronous motor can be ensured to run without stopping after a phase-lack fault occurs.

The technical field is as follows:

the invention relates to the field of motor control, in particular to a dual-mode operation control system and a control method for a three-level six-phase permanent magnet synchronous motor.

Background art:

at present, a two-level inverter and a three-level inverter are dominant in an alternating current driving inverter, and the two-level inverter control technology is more mature, but the power level of the two-level inverter is limited compared with that of the three-level inverter. Because the number of the two levels is small, the harmonic wave of the inverter is relatively high, and the motor torque pulsation is large due to the high harmonic wave content; the inverter power cannot be too large either. In order to reduce the harmonic content output by the inverter and meet the requirements of power level and system reliability, a three-level inversion structure is provided, and the three-level driving system can effectively reduce the harmonic content output by the inverter.

The invention content is as follows:

the invention aims to solve the problems of limited power grade, relatively high harmonic wave and large motor torque pulsation of the conventional three-level inverter, and provides a three-level six-phase permanent magnet synchronous motor dual-mode operation control system and a control method, which can realize non-stop operation of a dual-Y-shift 30-degree six-phase permanent magnet synchronous motor after a phase-lack fault occurs by switching different control methods without reconstructing a driving topological circuit.

The above purpose is realized by the following technical scheme:

a dual-mode operation control system of a three-level six-phase permanent magnet synchronous motor comprises the following components: the control circuit is used for outputting a PWM signal which is electrically connected with the drive circuit, the drive circuit is electrically connected with the six-phase inverter, the six-phase inverter is electrically connected with the three-phase uncontrolled rectifying circuit of the frequency converter, the front end of the three-phase uncontrolled rectifying circuit of the frequency converter is connected with the open-phase detection circuit in parallel, the rear end of the three-phase uncontrolled rectifying circuit of the frequency converter is electrically connected with the bus voltage detection circuit, the open-phase detection circuit and the bus voltage detection circuit are electrically connected with the A/D interface of the controller, and the six-phase inverter is input to the A/D interface of the control circuit through the six-phase current sampling circuit.

The dual-mode operation control system of the three-level six-phase permanent magnet synchronous motor is characterized in that the controller consists of a DSP and an FPGA, and the DSP is electrically connected with the FPGA.

The three-level six-phase permanent magnet synchronous motor dual-mode operation control system is characterized in that the DSP is in communication connection with an upper computer through a CAN communication circuit.

The three-level six-phase permanent magnet synchronous motor double-mode operation control system is characterized in that the six-phase inverter is also electrically connected with the six-phase permanent magnet synchronous motor, and the six-phase permanent magnet synchronous motor is in communication connection with a QEP interface of the DSP through a rotary transformer.

A control method of a dual-mode operation control system of a three-level six-phase permanent magnet synchronous motor detects the control system of the two-Y-shift six-phase permanent magnet synchronous motor by a sampling circuit in real time, and judges whether the control system is in a normal operation state or a phase-failure fault state so as to facilitate the control system to select a control strategy;

when the system is in normal operation, a four-dimensional current closed-loop control mode is adopted, namely, the current participating in the electromechanical energy conversion is subjected to closed-loop control, the harmonic current is also subjected to closed-loop control, and the current participating in the electromechanical energy conversion is adoptedThe control method of (1) adopts a proportional-integral controller to regulate the current, and harmonic current is given because the current is direct currentBecause the harmonic current is an alternating current quantity, the proportional resonance controller is adopted for regulation, and the voltage control quantity of the control circuit is obtained、、、；

During open-phase operation, when the Z phase is in open circuit, the other five-phase windings are not symmetrical, and at the moment, a fault-tolerant control scheme needs to be selected according to different optimization targets, so that the system is restored to be stable again, and the remaining phase current is optimized according to the targets of minimum stator copper consumption and maximum output torque.

The control method of a dual-mode operation control system of a three-level six-phase permanent magnet synchronous motor according to claim 5, characterized in that: the specific steps in normal operation are as follows: firstly, the voltage control quantity of the control circuit is calculated through a rotating speed closed loop and a current closed loop、、、And performing inverse transformation on the voltage control quantity to obtain the six-phase voltage required by the motor、、、、、Component is then

Secondly, due to the neutral point isolation characteristic of the windings of the double-Y30-degree six-phase permanent magnet synchronous motor, six-phase voltages belong to ABC and XYZ sets of windings respectively and are respectively opposite to each other、、And、、the voltage component is converted from three-phase static state to two-phase static state to obtain、And、component is then

Wherein the content of the first and second substances,、、、、、respectively representing six-phase motor stator voltages;

、and、respectively representing the components of the first set of winding ABC and the second set of winding XYZ in a two-phase static coordinate system;

finally to、Component sum、And (3) writing the modulation wave data into the FPGA in an XINTF external RAM mode, realizing two sets of three-phase three-level SVPWM modulation strategies by using a Verilog language to obtain a PWM waveform for driving a three-level six-phase inverter, controlling a three-level six-phase driver, and realizing the control of a double-Y30-degree six-phase permanent magnet synchronous motor.

The control method of a dual-mode operation control system of a three-level six-phase permanent magnet synchronous motor according to claim 5, characterized in that: the specific process of optimizing the residual phase current by taking the minimum copper loss of the stator as the target is as follows:

the six-phase motor has the following phases in normal operation:

（1）

in the formula:is the amplitude of the stator phase current;

when open circuit occurs in Z phaseAnd the total synthetic magnetic potential of the stator before and after the open-circuit fault is not changed, so that the remaining five-phase current must meet the following conditions: （2）

by simplifying equation (2), we can get the following equation by subtracting the same coefficients from both sides:

（3）

according to the trigonometric function formula, the current in each phase winding is expressed as follows:

（4）

bringing equation (4) into equation (3) and separating its real and imaginary parts yields:

（5）

because the six-phase PMSM has the characteristic of neutral point isolation, the following constraint conditions are required to be met:

（6）

by solving equations (5) and (6) simultaneously, the solutions of which are not unique, the remaining individual phase currents are calculated based on the minimum stator copper loss as an optimization objective, and an objective function thereof is constructed:

constructing a lagrange function of

From the Lagrange multiplier method, it can be concluded that the remaining phase currents can be expressed as

（7）

8. The control method of a dual-mode operation control system of a three-level six-phase permanent magnet synchronous motor according to claim 5, characterized in that: the specific process for optimizing the residual phase current based on the maximum target of the output torque is as follows: analyzing an optimization mode based on the maximum output torque, balancing the amplitudes of the remaining phase currents, minimizing the current amplitudes, representing a performance index by using the maximum value in the amplitudes of the remaining phase currents, and writing an objective function in a column:

（8）

the optimization goal of equation (8) is to find the set of maximum solutions that minimizes the value of F, use F as the objective function, the constraints are equations (5) and (6), and solve the expressions for the remaining individual phase currents:

（9）

the size and the phase of the remaining current of each phase are adjusted by two optimization modes, modulated wave data are written into the FPGA in an XINTF external expansion RAM mode, a carrier stacking comparison control mode is realized by using a Verilog language, and the double-Y30-degree-shift six-phase permanent magnet synchronous motor can be ensured to run without stopping after a phase-lack fault occurs.

Has the advantages that:

1. according to the invention, when the double-Y shift 30-degree six-phase permanent magnet synchronous motor is in a normal operation state, a double three-phase three-level SVPWM modulation strategy is adopted, and the complexity of a three-level six-phase SVPWM control algorithm is reduced.

When the double-Y shift 30-degree six-phase permanent magnet synchronous motor is in a normal running state, closed-loop control is adopted for harmonic current, and the content of 5 and 7 harmonics in stator current can be effectively reduced.

When the double-Y30-degree-shift six-phase permanent magnet synchronous motor is in the phase-failure fault state, the driving topology circuit does not need to be reconstructed, and the double-Y30-degree-shift six-phase permanent magnet synchronous motor can be ensured to operate without stopping after the phase-failure fault occurs by switching into a fault-tolerant control strategy.

The invention provides a control method for driving a three-level medium-voltage high-capacity double-Y30-degree six-phase permanent magnet synchronous motor.

Description of the drawings:

FIG. 1 is a diagram of a six-phase motor control system;

in the figure: 1. a three-phase uncontrolled rectifying circuit; 2. a six-phase inverter; 3. a voltage detection circuit; 4. a phase loss detection circuit; 5. a drive circuit; 6. an FPGA; 7. a DSP; 8. other peripheral circuits; 9. a CAN communication circuit; 10. a load; 11. a six-phase permanent magnet synchronous motor; 12. a six-phase current sampling circuit; 13. a rotary transformer; 14. an overcurrent protection circuit; 15. a QEP circuit; 16. and (4) an upper computer.

FIG. 2 is a diode clamped three-level six-phase inverter topology;

FIG. 3 is a diagram of a six-phase PMSM system architecture based on dual three-level SVPWM control;

FIG. 4 is a block diagram of a fault-tolerant control strategy system based on carrier stacking comparison;

FIG. 5 is a voltage detection circuit;

FIG. 6 is a current sensing circuit;

FIG. 7 is a circuit for detecting a phase loss at the front end of a rectifier bridge;

FIG. 8 is a drive circuit;

FIG. 9 is a CAN communication circuit;

FIG. 10 is a system main program flowchart;

FIG. 11 is an interrupt subroutine flowchart;

FIG. 12 is a waveform diagram of the response of the rotation speed based on the double three-phase three-level SVPWM and the switching based on the stator copper loss minimum optimization mode;

FIG. 13 is a torque response waveform diagram based on dual three-phase three-level SVPWM and based on stator copper loss minimum optimization switching;

FIG. 14 is a waveform diagram of current response under switching based on dual three-phase three-level SVPWM and based on a stator copper loss minimum optimization mode;

FIG. 15 is a waveform diagram of the response of the rotation speed based on the dual three-phase three-level SVPWM and the switching based on the maximum optimization mode of the output torque;

FIG. 16 is a waveform diagram of torque response under switching based on dual three-phase three-level SVPWM and based on the maximum optimization mode of output torque;

FIG. 17 is a waveform diagram of current response under switching based on dual three-phase three-level SVPWM and based on the maximum optimization mode of output torque;

the specific implementation mode is as follows: