Performance of partitioned primary linear switched flux PM machines

A novel partitioned primary linear switched flux PM machine (LSFPMM) is investigated, which take armature and permanent magnet poles as each side of primary respectively. The new structure makes both armature and magnetic poles have more space, so that the over-saturated problem of conventional LSFPMM is solved. However, the end effect also becomes different due to both armature and magnetic poles have two longitudinal ends. In order to investigate the influence of this end effect, two models are erected based on 2D finite element analysis (FEA). One is the periodical model and the other is practical model. With these two models, the performances of partitioned primary LSFPMM are predicted including the open-circuit flux linkage, back-EMF, thrust force and inductances. By comparison, the end effect is obtained. In addition, the effect of machining error on performance is emphatically investigated. Finally, the prototype is made to verify the predicted results. It shows that partitioned primary LSFPMM has good performance, but much easily influenced by the end effect and machining error.