IPMSM with ferrite magnets for high speed

This paper describes an interior permanent magnet synchronous motor (IPMSM) employing ferrite magnets instead of rare earth magnets that can be driven at high speeds. Neodymium and dysprosium are raw materials of rare earth magnets used in IPMSM, and the prices of these materials rose until recently. Although the prices are stable at present, the use of high performance rare earth magnets is increasing and the prices are not low at all. Therefore, it is very important to reduce the amount of the rare earth magnets in IPMSM. We propose an analysis motor model, and discuss the torque, output, mechanical strength of the rotor, and efficiency obtained by the finite element method (FEM). Simulation results show that the proposed motor model can maintain the high output at high speeds.