Influence of saturation-induced saliencies and asymmetry of stator winding to rotor position estimation based on high-frequency signal injection

Besides the physical saliencies,there are additional saturation-induced saliencies in permanent magnet motor,which mainly affect the stator leakage inductance.In addition,the rotating magnetic field would become el-lipse in shape due to the asymmetry of stator windings.The interaction of these two factors would enhance the nega-tive-sequence current harmonics and bring some error to rotor position estimation.This paper discussed this issue from both hand of theory and experiment,and primitively demonstrated the reason the negative-sequence current harmonics occurred and its effects,and the measures to solve it are also presented.