Impact of Local Degradation in Soft Magnetic Materials on Performance of Permanent Magnet Synchronous Machines

This paper focuses on the finite element model design including a continuous model describing local degradation profiles in soft magnetic materials in permanent magnet synchronous machines. The influence of mesh design and parameter tolerances of the degradation profile is analyzed. Cutting and punching processes for producing electrical machines impact the properties of magnetic materials. A simplified but effective model for considering the local degradation of magnetic properties is presented. The material characteristics as a function of the distance from the cutting edge are directly assigned at the mesh level. In this work, different machine models are investigated. Differences between the model for local degradation of magnetic properties and multilayer approaches are analyzed by comparing model complexity, mesh size and typically derived performance parameters, e.g., flux density distribution and iron losses. A comparison of simulation results is presented and discussed.