Research on Sensorless Control of Permanent Magnet Synchronous Motor Based on Adaptive Sliding Mode Observer

摘要

In this paper, an adaptive feedback gain sliding mode observer is designed to solve the chattering and low speed problems of traditional sliding mode observer. By introducing the feedback value of extended back electromotive force into the current observation equation and reasonably designing the adaptive rate, the sliding mode observer can obtain better low-speed performance. At the same time, it is convenient to design the sliding mode gain and avoid the serious problem of low-speed chattering caused by excessive gain value. On the other hand, in order to suppress chattering of sliding mode observer, saturation function is used instead of symbol function as switch control function. In order to solve the phase delay problem caused by low-pass filter, a low-pass filter with variable cut-off frequency is designed. Finally, the effectiveness of the improved method is verified by simulation.