A Complex Coefficient Low Pass Filter Based Sliding Mode Observer for SPMSM Sensorless Control

In this paper, a sliding mode position observer for surface-mounted permanent magnet synchronous motor is proposed. To achieve position and speed sensorless control, a complex coefficient low pass filter (CCLPF) is designed and employed to extracting electromotive force (EMF). The implementation of CCLPF can suppress the chattering brought by the switching function and avoid the phase shift and amplitude distortion of EMF. Experiment results verify the effectiveness of proposed method in extracting rotor position and speed.