A Novel Stator Dual-PM Flux-Switching Machine with Improved Utilization of High-Order Harmonics and Reduced Flux Leakage

This paper proposes a novel stator dual-permanent magnet flux-switching (SDPM-FS) machine with enhanced torque density compared to the conventional flux-switching permanent-magnet (FSPM) machines. The SDPM-FS machine features a unique arrangement of PMs located on the stator tooth region. A set of radially magnetized PMs is added into the dummy slots, and the side teeth on the stator are removed to enhance the 4th-order harmonic of the stator PM excited magnetomotive (MMF). The utilization of 2 pole-pair working harmonic of air-gap flux density is significantly improved while the flux leakage of spoke-type PMs is simultaneously reduced. Consequently, the phase flux linkage increases, and the no-load phase back EMF is further enlarged. In this paper, the working principle of the proposed SDPM-FS machine is analytically introduced by using a simplified magnetomotive force (MMF)-permeance model. Subsequently, a non-dominated sorting genetic algorithm II (NSGA-II) is used to conduct the global optimization. Furthermore, the performance of the proposed SDPM-FS machine is comprehensively compared with a conventional multi-tooth FSPM machine using finite element analysis (FEA). The results demonstrate that the SDPM-FSM exhibits notable enhancements in torque density and efficiency.