Research on the Influence of End Turn Length on Consequent-Pole Vernier Permanent-Magnet Machines

This article investigates the influences of end turn length on consequent-pole Vernier permanent-magnet (CPVPM) machines. Four structures are compared to discuss the tradeoff between the end turn length and the gear ratio, and nine structures are compared to discuss the tradeoff between the end turn length and the winding factor. It is found that, when the end turn length is taken into account, the CPVPM machines with concentrated winding have the potential to produce larger torque than those with the distributed winding. Motivated by the above observations, an integral slot concentrated winding CPVPM machine is proposed to be a promising candidate in VPM machine family, which has high torque capability, small end turn length, good fault tolerance, and desired power factor. The influences of key design parameters are investigated. The machine prototype is manufactured, and the electromagnetic performances are experimentally validated.