A Novel Variable-Flux Permanent Magnet Machine with Multiple Winding Switching Modules

In order to maintain high torque at low speeds, and achieve high efficiency across an entire speed range, a novel multi-winding-switching variable-flux machine(MWS-VFM) incorporating three flexible switching modules is proposed. A special winding switching circuit which enables dynamic switching among three distinct operational modes through reconfigurable interconnection topology of its three constituent modules, is designed to provide the proposed MWS-VFM with enhanced operating flexibility, thereby covering a broader range of speeds and loads. This paper first introduces the structure of the proposed MWS-VFM. Subsequently, the multi-module switching method is elaborated, which is capable of stepwise flux adjustment to achieve high torque, high efficiency, and an extended wide speed range performance. Finally, the electromagnetic performance of the proposed MWS-VFM is evaluated and compared with that of the conventional winding switching variable-flux permanent magnet machine (WS-VFM). The simulation results demonstrate that significantly wider operational speed range, higher torque output, and improved efficiency compared to conventional designs.