Position sensorless control of PMLSM based on adaptive complex coefficient sliding mode observer

Abstract

In order to suppress the problems of chattering, harmonic and three phase electromotive force unbalance of sliding mode observer in the sensorless control of permanent magnet linear synchronous motor, an improved sliding mode observer is studied in this paper. These negative disadvantages can be addressed by adaptive complex coefficient filters with band pass and positive and negative sequence frequency selection characteristics. Therefore, the low pass filter of traditional sliding mode observer is replaced by adaptive complex coefficient filter in this paper.Meanwhile, the nonlinear saturation function is used instead of the symbolic function to reduce the chattering of the sliding mode observer. The experimental results show that the presented algorithm can improve the speed and position observation accuracy of the sliding mode observer.

Keywords

• Sliding mode observer
• Permanent magnet linear synchronous motor
• Adaptive complex coefficient filter