Novel Flux Observer Based On The Butterworth Filter For Vector Control Of Induction Motor

In this paper, a novel hybrid model rotor flux observer based on the second order butterworth high-pass filter is proposed. Firstly, for the traditional current model flux observer, two improvements are made to eliminate the cross coupling items. Then, by introducing a PI feedback correction link, it can adjust the coupling of traditional voltage model and current model, so the current model plays a role in low frequency and voltage model in high frequency. The transfer function of the observer is presented to analyze the flux. Finally, by comparing and analyzing the second-order butterworth high-pass filter and the observer transfer function, the optimal PI controller parameters is calculated. The proposed scheme is robust to the machine parameter variations. The simulation and experimental results have verified the effectiveness of the proposed observer.