Ferrite 영구자석을 적용한 EV 구동용 IPMSM의 전기적, 기계적 특성 연구

Abstract

Recently, because of the instability of rare-earth resource supply and demand, research on rare-earth free in various fields is urgent. Accordingly, studies are being actively conducted to apply ferrite permanent magnet to IPMSM (Interior Permanent Magnet Synchronous Motor) used as electrical vehicle (EV) traction motors. Ferrite permanent magnet is cheap and easy to obtain. However, it has lower coercive force values than rare earth permanent magnets, and there is a large armature reaction occurs during EV motor operation, it is necessary to check for irreversible demagnetization. In addition, the limited space of the vehicle requires a high power density of the motor. In order to satisfy the high power density, the motor must be speeded up. Therefore, the problem of mechanical stiffness due to the generation of very large centrifugal force must also be considered. In this paper, the irreversible demagnetization characteristics and mechanical stiffness of IPMSM with ferrite permanent magnet. When determining the rotor shape, the sensitivity of each performance is analyzed through of variance of design factors. Sensitivity analysis is based on the maximum stress of the rotor and irreversible demagnetization characteristics. P-value less than 0.05 can be used as major design factors in motor design by determining sensitivity factors for each performance.