A General Control Method for Half-Centralized Open Winding Permanent-Magnet Motor Drive System

In this article, a general control method based on duty ratio selection for half-centralized open winding primary permanent-magnet linear motor drive system is proposed. The proposed control method is designed from the perspective of single-phase subsystem. The novelty of this article is the voltage process and modulation, which can realize the expansion from two movers to multimovers. The design of voltage process and modulation contains voltage preprocessor, saturation limiter, and duty ratio distributor. In the voltage preprocessor, phase voltages are transferred to phase modulation index. The saturation limiter deals with excessive phase modulation indexes based on the independent overmodulation principle. The duty ratio distributor distributes the voltage demand into inverters by the common-leg-based distribution principle. Compared to existing methods, the proposed control method can realize the expansion from two movers to multimovers and has less computation burden. In addition, more mover quantities will not increase the complexity of analysis and design. Finally, the effectiveness of the proposed control method has been verified by experimental results.