Sensorless Control Strategy of a Permanent Magnet Synchronous Motor Based on an Improved Sliding Mode Observer

This paper analyzes the problems and reasons of high frequency chattering, phase delay, unmanageable with low-speed rotation in traditional SMO control strategy sensor-less a permanent magnet synchronous motor based on sliding mode observer. Aiming at shortcomings above-mentioned strategy, an improved is presented by replacing signum function synovial observer sigmoid to reduce chattering system. Meanwhile, proposed introduces adaptive filter eliminate harmonics adaptively compensates estimated back-EMF value estimation error caused delay. The was tested through Matlab/Simulink simulation real experiments respectively. results verified that can significantly delay achieve good performance low speeds, as well maintain full speed.