Improved Speed Sensorless Control Strategy Combined With Compound Controller and Adaptive Speed Observer for Electromagnetic Launch Motor

In this paper, one speed sensorless control method with a compound controller and an adaptive speed observer of the toroidal permanent magnet linear synchronous motor (TPMLSM) for electromagnetic launch is proposed. Considering the aperiodic transient trait of launch motor, one compound controller based on feedforward strategy is designed to obtain fast dynamic response under different acceleration conditions. Moreover, one improved adaptive speed observer is constructed based on model reference adaptive system (MRAS). By introducing a disturbance observation term and a current error feedback gain matrix, the proposed observer can strengthen the system stability with superior anti-disturbance ability under transient conditions. Furthermore, the design method of the feedback gain matrix is proposed by minimizing the expectation of observation error to obtain more accurate speed signals. Comprehensive experiments have demonstrated the superiority of the proposed strategy.