HEV용 매입형 영구자석 동기전동기의 출력밀도 향상설계

Due to concern about exhaustion of natural resources and pollution caused by the use of fossil fuel, research for the electric vehicle is on the increase. Especially, the HEV becomes an object of attention because it has engine to compensate defect of insufficient battery capacity and advantage of relatively low production costs. Traction motor of HEV is IPMSM type which has the merits of high torque, high power and high efficiency because of using reluctance torque. This paper dealt with analysis of the IPMSM used in the specific HEV and shows problem of initial motor. Based on the defect suggested, improving design is conducted by alteration of permanent magnet shape and change of design factors which are related to electromagnetic characteristics. The initial motor has high torque ripple which causes noise and vibration and has grooves between the pole and pole to protect demagnetization generated by eddy current. The modified design guarantees Q-axis flux path to increase the reluctance torque and minimizes volume by growth of turns from introduction of closed slot design. So, the modified motor improves power performance and reduces cogging torque. The manufacturing costs are also decreased by reduction in amount of magnet and core weight.