Comparative Analysis and Experimental Verification of an Effective Permanent-Magnet Vernier Machine

This paper presents an effective permanent-magnet vernier (PMV) machine for direct-drive applications, in which the low-speed outer rotor employs a spoke-magnet arrangement with flux focusing to improve air-gap flux density, and the stator adopts an open-slot structure to enable the stator teeth to achieve field modulation. Using the finite element analysis, the performance characteristics of the proposed machine are investigated and compared with the split-slot surface PMV machine. A prototype is also built for experimentation to verify the validity. Both simulation and experimental results show that the proposed machine can offer the advantages of improved torque capability and low voltage regulation.