LAUSR

This article presents a position and speed estimation scheme based on the extended state observer in the linear synchronous motor (LSM) drives for high-speed maglev application. The mathematical models of LSM in the SF and DF modes are established. Based on that, a hybrid position estimation strategy in the SF and DF modes is proposed with the consideration of transition between different stator sections. This strategy includes two ESOs. One ESO is designed to estimate back EMF in the SF mode, which is considered as an external disturbance. Then, the angle position and speed are obtained from the estimated back EMF by simply using a phase-locked loop. Another ESO applied in DF mode is designed as a reduced order form to reduce the complexity of the observer. The effectiveness and feasibility of the proposed sensorless control scheme have been verified by hardware-in-the-loop experiments.