Novel 4/4 stator/rotor single-phase asymmetric-stator-pole doubly salient permanent magnet machine

A novel 4/4 stator/rotor single-phase doubly salient permanent magnet machine (DSPMM) with asymmetric stator poles is proposed in this paper. The stator poles of proposed machine are distributed non-uniformly along the circumference of the stator yoke. Firstly, it investigates the new topology and operation principle based on diagram description and mathematical derivation. Then, the dimension equation, equivalent magnetic circuit model and current expression are derived and verified based on two-dimension finite element analysis (2-D FEA) in details. Finally, full comparison on electromagnetic performance indexes of the new machine with those of a traditional one is also presented. It indicates that the proposed novel structure has much higher torque density, lower losses and higher efficiency than those of the traditional one under the same volume, electrical load, etc.