Design optimization of a pole-changing biased flux machine based on sensitivity analysis

Abstract

In this paper, a novel pole-changing biased flux machine is proposed. With special rotor pole and permanent magnetic pole design, this machine has pole-changing effect. By controlling the excitation current's polarity the pole number of this machine can switch back and forth between three pole pair and six pole pair. The armature winding is designed in concentrated structure to realize higher utilization ratio of flux linkage under both pole modes. To further improve the performance of the proposed machine, topology optimization is conducted. In order to verify the feasibility of this design, electromagnetic characteristics, including coil flux linkage distribution, air gap flux density and harmonics analysis are studied under finite element method.