Performance Improvement of Spoke-Type Interior Permanent Magnet Motors with Asymmetric Rotor Structures

The novel spoke-type interior permanent magnet (SIPM) motors with asymmetric rotor structures and ferrite magnets for performance improvement are proposed in this paper. Three types of the proposed SIPM motors are investigated, one is designed with asymmetric rotor flux barriers, another one features asymmetric V -type PM configurations, and the last one is to slot the rotor based on the second model to improve the utilization of permanent magnets. A conventional SIPM motor is adopted for performance comparison to highlight the advantages of the three proposed models. The torque components of the motor are separated by taking use of the frozen permeability method (FPM) through the finite element analysis (FEA). The simulation results show that the proposed models can improve the torque and torque density when compared with the conventional SIPM model.