Comparison between a spoke-type PMSM and a PMASynRM using ferrite magnets

Abstract

Increasing concerns over costs and supply of rare earth magnets have introduced more attention to Permanent Magnet Synchronous Machine (PMSM) designs that can work with ferrite magnets. Ferrite magnets are weaker in comparison to rare earth magnets which makes it a challenge to achieve high torque density. In light of this, literature has introduced several PMSM designs that show an improved performance despite the challenges of ferrite magnets. This paper presents a comparison between the spoke-type PMSM design and the Permanent Magnet Assisted Synchronous Reluctance Machine (PMASynRM), both using ferrite magnets. The spoke type PMSM is based on an existing design, whereas the PMASynRM is designed by changing the configuration of the magnets in the rotor and using a lower number of poles. The PMASynRM design also incorporates some of the best practices from literature that are used to improve its performance. The objective is to determine which rotor configuration gives the best performance. In addition, a design used for quick implementation is presented. Finite Element Analysis (FEA) is used to analyze both designs, and some experimental results are shown.