Analysis of a Fault-Tolerant Dual-Permanent-Magnet Vernier Machine With Hybrid Stator

A fault-tolerant dual-permanent-magnet vernier machine characterized by dual-sided permanent magnet and hybrid stator is proposed and analyzed in this paper, which not only possesses good fault tolerance but also offers improved torque density and power factor. First, operation principle of the machine is investigated by analyzing the permanent-magnet flux linkage and electromagnetic torque production due to the dual-sided permanent-magnet structure. Then, modulated single-phase armature-winding field and three leakage flux components are modeled. By considering magnetic field modulation process and dimensional parameters of the hybrid stator structure, the air gap inductance and three leakage inductance components as well as power factor of the machine can be accurately analyzed. In addition, the key design parameter analysis of proposed machine and the performance comparison with existing machines are conducted. Finally, a prototyped machine is built and tested. Both simulated and experimental results verify the effectiveness of theoretical analyses.