Comparative analysis of different permanent magnet arrangements in a novel flux modulated electric machine

Abstract

A novel dual permanent magnet (PM) machine with Halbach segmentation flux modulation is proposed in this paper, which is evolved from a flux switching PM machine (FSPM). In order to improve the performance of the FSPM, several PM arrangement methods have been adopted and three new different structures have been investigated. To achieve a fair comparison, all the structures are under the same size and rotate at the same speed. The performances of output torque and back EMF are compared. The analysis results show that the dual PM with Halbach segmentation has the highest torque density and power efficiency. The torque is improved by 100.3% from the FSPM while the PM volume does not increase too much. The unique of this best structure is that it not only combines the vernier machine and FSPM machine together, but also reduces the torque ripple. The performance of the motor is verified by the simulation using finite-element analysis (FEA).