A Winding-Switching Concept for Flux Weakening in Consequent Magnet Pole Switched Flux Memory Machine

In this paper, a consequent magnet pole switched flux memory machine (CMP-SFMM) is developed to improve the torque density and simplify the mechanical manufacturing with less magnet usage compared with its hybrid magnet counterparts. Nevertheless, owing to the significant magnetic saturation, the flux-adjustable range appears to be relatively limited, which will deteriorate the flux-weakening performance. Therefore, a novel winding-switching concept is introduced to deal with its limited flux-weakening capability, i.e., the magnetizing coils will alternatively serve as the secondary armature winding after the reversal of magnetization directions of low-coercive force magnets, thus resulting in the flux-linkage cancellation within the same phase. The machine topology, flux-weakening principle, and integrated circuit design are addressed. Then, the electromagnetic characteristics of CMP-SFMM with or without winding-switching are investigated and compared, which confirms the feasibility of the flux-weakening method.