Analytic calculation of magnetic field and electromagnetic performances of spoke type IPM topologies with auxiliary magnets

This paper presents a 2D analytical method based on subdomain model for the computation of magnetic field and electromagnetic performances in spoke-type interior permanent-magnet motor (IPM) topologies. The conventional spoke-type IPM rotor is constituted with ferrite permanent magnets magnetized in tangential direction. To maximize the torque density, auxiliary ferrite magnets magnetized in radial direction are inserted in the center of the conventional spoke-type IPM rotor in different way to get different topologies. Obtained analytical results are verified with those issued from finite element method (FEM) and a comparison is done between the topologies.