부산대학교 도서관

Rotating high frequency voltage injection is widely used for sensorless control of permanent magnet synchronous motor (PMSM) at zero and low speed range. However, with the increasing of rotor speed, the frequency of the negative sequence component gradually deviates from the central frequency of the bandpass filter (BPF), the accuracy of rotor position estimation is degraded. Aimed at this issue, adaptive Butterworth bandpass filter based rotating high frequency voltage injection is proposed to improve the accuracy of rotor position estimation in this paper. Compared with the conventional BPF, the central frequency of the proposed BPF can be adjusted adaptively according to the rotor speed. Meanwhile, based on the variation law between the filter coefficients and the center frequency, 3rd order polynomial is proposed to fit the coefficient of the adaptive BPF. Therefore, the frequency of the negative sequence component of the high frequency (HF) current can be tracked adaptively by the proposed BPF regardless the increasing of the rotor speed. DC bias error due to phase shift of the conventional BPF is eliminated and the accuracy of rotor position is improved. The experiment results confirm the effectiveness of the proposed method.