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

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