Position Sensorless Control System of Permanent Magnet Synchronous Linear Motor Based on Sliding Mode Observer with an Improved Phase-Locked Loop

In this paper,position sensorless control system of permanent magnet synchronous linear motor(PMSLM)based on sliding mode observer(SMO)with an improved phase-locked loop(PLL)is studied.Firstly,according to the mathematical model,a SMO is designed for sensorless control PMSLM drive.Thereafter,an improved PLL is proposed to tackle the imperfection of data overflow existed in the traditional PLL.The designed SMO incorporating with the improved PLL can be effectively suppress the pulsation of the estimated position and hence the chattering of the derived electrical angular velocity.At last,simulated and experimental results are presented to verify the effectiveness and feasibility of the position sensorless control system.