High-speed Interior Permanent-magnet Rotor Made of Dual-phase Magnetic Materials

High-speed is a research hotspot to increase the power density thereby reducing the size and weight of the motor. The key problem limiting the speed is the high centrifugal force, which might lead to rotor cracking. In order to strengthen the rotor, the flux bridge area of an interior permanent-magnet rotor is usually enlarged, which leads to high flux leakage and reduced torque. In this paper, a dual-phase magnetic material consisting of non-magnetic and magnetic regions is used and a high-speed interior permanent magnet synchronous motor (IPMSM) is designed. The performance of two rotor structures made of the dual-phase magnetic material are compared. The effect of rotor design on the performance of the high-speed IPMSM is investigated.