Full-Speed Region Predictive Current Control Method of Symmetrical Series-Winding PMSM With Higher DC-Link Utilization
Senyi Liu, Yuxin Liu, Bowen Zhang, Chunhua Liu
Abstract
The series-end winding permanent magnet synchronous motor (SW-PMSM) drive system is ideal for applications with limited dc-link voltage. However, the controller design in the full-speed region for SW-PMSM is challenging because of the additional harmonic current subspaces. The harmonic currents and voltages affect the accurate solution for the optimal current set point in the full-speed region. This article provides an online full-speed region predictive current controller that considers harmonic current subspaces. First, three voltage limits are proposed to identify the specific operation regions. Then, the carrier-based pulsewidth modulation scheme in the full-speed region is discussed. Third, Newton's method solves the optimized current set points for different operation regions. Finally, the predictive current controller is utilized to realize the current trajectory in all subspaces. The performance of this method is verified with a five-phase SW-PMSM. DC-link utilization can increase by 17.6%, and the proposed method's copper losses are compared.