Analysis of Dual PM Vernier Machines With Different Consequent-Pole PM Topologies

In order to further improve the torque density of flux modulation machines, two novel dual-PM vernier machines (DPMVMs) with two PM pieces and two ferromagnetic iron poles on each stator tooth are proposed in this paper. Together with two conventional DPMVMs, four types of DPMVMs with different consequent-pole PM topologies are comprehensively investigated and compared. The working harmonics and the dominating harmonics that contribute to torque production of four machines are analyzed. Aiming at maximum torque, four machines are all optimized and their electromagnetic performances in terms of cogging torque, back-EMF, rated torque, overload capability, power factor, loss, and efficiency are evaluated and compared using finite element (FE) method. Finally, a prototype is fabricated and tested. The experimental results have validated the theoretical analysis.