The influence of permanent magnet length on electromagnetic performance in flux switching machine

The influence of permanent magnet (PM) length on electromagnetic performance of a flux switching PM machine, including torque characteristics, loss, and efficiency is investigated in this paper by finite element (FE) analysis. FE results show that the average torque per PM volume, cogging torque and torque ripple can be improved by optimizing PM length. More importantly, for achieving a higher average torque and a higher efficiency, it is always recommended to design a machine with a small PM outer edge than the stator outer radius, reducing PM volume and cost.