Zero-Sequence Current Suppression Strategy for Open-End Winding Permanent Magnet Synchronous Motor Based on Model Predictive Control

Compared with the traditional three-phase star connection winding, the open-end winding permanent magnet synchronous motor(OW-PMSM) system with a common direct current(DC) bus has a zero-sequence circuit, which makes the common-mode voltage and the back electromotive force(EMF) harmonic generated by the inverters produce the zero-sequence current in the zero-sequence circuit, and the zero-sequence current has great influence on the operation efficiency and stability of the motor control system. A zero-sequence current suppression strategy is presented based on model predictive current control for OW-PMSM. Through the mathematical model of OW-PMSM to establish the predictive model and the zero-sequence circuit model, the common-mode voltage under different voltage vector combinations is fully considered during vector selection and action time calculation. Then zero-sequence loop constraints are established, so as to suppress the zero-sequence current. In the end, the control strategy proposed in this paper is verified by simulation experiments.