Comparative Study of High Performance Double-Stator Switched Flux Permanent Magnet Machines

In this paper, the double-stator switched flux permanent magnet (DS-SFPM) machines having 6-slots double stator are investigated. They have doubly-salient stator poles equipped with concentrated armature windings on both stators with an integrated cup-rotor made of modulating iron pieces. Also, a detailed comparative study is made between the developed DS-SFPMs, the existing conventional switched flux permanent magnet (SFPM), and the partitioned stator switched flux permanent magnet (PS-SFPM) machines by 2-dimensional finite element analysis (2D-FEA) in terms of their electromagnetic performances. The analyses show that the developed 6-stator slot machine could deliver higher torque density of about 40% than its equivalent double-stator SFPM having 12-stator slots of the same size, under the same condition. Furthermore, a comprehensive study of the iron and PM eddy current losses in these machines are also presented, together with their efficiency characteristics. Finally, a prototype is built and the FEA predicted results are validated by experiments.