Proposal of the sensorless control method of long primary segmented PMLSM applied in electromagnetic catapult

The paper proposes a sensorless control strategy for long primary segmented permanent magnet linear synchronous motor(LPSPMLSM) used in electromagnetic catapult .Aiming at characteristics of parameter changes of LPSPMLSM, researchers mean to establish mathematical models of the motor. In accordance with the analysis of mathematical models of the motor, this paper presents an ameliorated sliding mode observer to acquire smooth observed back electromotive force (EMF). Besides, the method of two segments´ observation of back EMF and Synchronization solves the both speed and position observation problem when movers move in single stator or transgress two stators. In that way, speed closed-loop control which has high dynamic response ability can be achievable by the sensorless algorithm. Ultimately, through the verification of Simulation testing, segmented motor can satisfy the demand of EML field by using control algorithm mentioned above.