The performance of a hybrid excitation flux switching motor with ferrite magnets for EVs

Permanent magnet (PM) motors that use rare earth magnets exhibit high performance in terms of power density and efficiency. However,rare earth magnets are of great concern because of their high cost and unstable sulpply. Unlike exsiting flux switching permanent magnet (FSPM) motors, the hybrid excitation FSPM motor proposed in this paper applys ferrite magnets rather than rare earth as its field excitation material. Additional dc field excitation coils are added into the motor to cooperate with ferrite magnets, which asure the high performance of the motor. The performance of hybrid excitation FSPM motor is evaluated based on finite element analysis (FEA) method. The analysis results show that the proposed motor is able to achieve high power density and wide speed range, which are suitable for electric vehicles.