Fault-tolerant Control of PMSM Based on Double Quasi-Z-Source Four-Leg Indirect Matrix Converter

Aiming at the problem that the voltage transfer ratio of the three-leg matrix converter is low, the equipment cannot operate normally under the condition of unbalanced load and the lack of phase of the motor, this paper proposes a double quasi-Z source four-leg indirect matrix converter (DQZS Four-Leg IMC) topology. The quasi-Z-source (QZS) network is incorporated into the rectifier stage and the inverter stage of the four-leg indirect matrix converter. Using the dual space vector modulation (SVM) method and reasonably inserting the shoot-through zero vector, the influence of the excessive shoot-through duty cycle of a single QZS network can be effectively reduced, and the voltage transmission ratio can be improved. With the introduction of the fourth bridge arm, the mathematical model of the single-phase fault of the permanent magnet synchronous motor (PMSM) is established, and the zero-axis current compensation closed-loop control mode is adopted to ensure the regular operation of the motor. The MATLAB / Simulink simulation results show that the proposed scheme not only improves the voltage transmission ratio, but also improves the fault tolerance performance of the motor control system.