IPM 타입 EPS용 전동기의 코깅 토크 원인 분석

This paper presents a study of an unexpected cogging torque due to the manufacturing errors. During the manufacturing, to reduce the cogging torque, various design techniques are applied. For example, adoption of skewing, rotor eccentricity and pole/slot combination can be regarded. However, some techniques, which are effective cogging torque reduction methods, become ineffective and sometimes, cause the unexpected cogging torque when the manufacturing defects exist. In this paper, the unexpected cogging torque is analyzed by using a couple of methods such as the rotor surface flux density measurement, the harmonic analysis and so on.