Sensorless Control of Permanent Magnet Synchronous Motor Based on Adaptive Exponential Reaching Law Sliding Mode Observer

Aiming at the problems of low observation accuracy and serious chattering in traditional sliding mode observer (SMO), an adaptive exponential reaching law sliding mode observer (AERLSMO) is proposed in this paper. In the traditional SMO, the constant velocity reaching law is used to realize the observation of the back electromotive force (back-EMF) signal. However, the reaching speed of the constant velocity reaching law cannot change with the system state, so it will produce large chattering. Using exponential reaching law (ERL) can solve this problem. However, the performance of the traditional ERL cannot meet some occasions with high requirements for motor control performance. Therefore, this paper introduces adaptive gain to design adaptive ERL. Based on the designed adaptive ERL, a SMO is constructed to effectively achieve chattering suppression and observation performance improvement. Finally, the effectiveness and feasibility of the proposed AERLSMO are verified by experiments.