A Novel SVPWM Strategy With Model Prediction Torque Control of Six-Phase Open-Winding PMSM Considering the Nonsinusoidal Back-EMF

Compared with ordinary three-phase motor, multiphase open-winding motor has higher DC voltage utilization and output power, so it is well-suited for high-power drive applications. However, there are few researches on multiphase open-winding motors at present, in which model predictive current control(MPCC) is the main focus. However, in the applications requiring high dynamic response speed such as marine propulsion, The model predictive torque control(MPTC) is more suitable for application scenario, and the influence of non-sinusoidal back-electromotive force(EMF) on multiphase open-winding motor control system is rarely considered. Therefore, this article takes the six-phase open-winding permanent magnet synchronous motor(SOW-PMSM) as the research object and establishes a complete control system of the multiphase open winding motor. Firstly, the paper analyzes the harmonic generation mechanism of the motor and derives the effects of non-sinusoidal back-EMF and inverter dead time on the motor. It then establishes a mathematical model of the SOW-PMSM that takes into account harmonic in permanent magnet(PM) flux linkage and based on this mathematical model, the reference voltage required by Space Vector Pulse Width Modulation (SVPWM) is obtained by using the deadbeat torque control. In addition, a new SVPWM strategy is proposed by using the abundant voltage vectors of the six H-bridge inverters. By using multiple effective vectors, the motor can achieve a high DC voltage utilization while the harmonic plane vector synthesis is zero. Finally, the rationality of the proposed algorithm is verified by simulation.