Research on High-frequency Negative Current Harmonics in Rotor Position Estimation of SMPMM

When using the method of rotating high-frequency voltage injection to estimate the rotor position of Surface-Mounted Permanent-Magnet Machine(SMPMM),the negative current harmonics,which resulted from the asymmetry of the distribution of high-frequency inductance,will give rise to some errors to the rotor position estimation.This paper discussed this issue from both hand of theory and experiment,and primitively demonstrated the reason the negative current harmonics occurred and its effects.The measures to solve it were also presented.