Improved Sensorless Control Strategy for Long Stator Linear Synchronous Motor with Full Speed Range

The Long-stator linear synchronous motor (LSLSM) requires precise detection of speed and position information during operation. The traditional way is setting up sensors to detect speed and position information, which will increase costs. Sensorless control algorithms can effectively reduce costs. An improved sensorless control strategy of full speed range is introduced in this paper. The high-frequency (HF) signal injection method and extended electromotive force sliding mode observer (EEMF-SMO) method are effective for zero-speed startup condition and high-speed condition, respectively. However, nonideal factors will cause position error under high-speed condition. To improve the position estimation performance of the observer, a correction strategy for the position error is proposed. The proposed method can achieve sensorless control with full speed range and improve the sensorless control’s performance. Finally, a simulink model is established and the simulation results verify the feasibility of the proposed method.