Analysis of torque capability and quality in vernier permanent magnet machines

This paper presents theoretical analysis and comprehensive simulations about average torque and pulsation torque of vernier permanent magnet (VPM) machine. A general torque equation is proposed which is used to analyze torque features and the parameters effect on torque performance of VPM machines in this paper. Based on the general torque equation and finite element algorithm, it is found that smooth torque is the inherent performance of VPM machines. Furthermore, It is demonstrated that the torque density of the VPM machine is larger than that of a regular commercial PM machine by almost 60%. All these advantages demonstrate that the VPM machines can obtain much better steady and dynamic drive performance. In order to validate theoretical analysis, a prototype is built, and more experiments will be available.