Study on a Second-Order Adaptive Sliding-Mode Observer Control Algorithm for the Sensorless Permanent Magnet Synchronous Motor

The control of a permanent magnet synchronous motor (PMSM) without position sensor based on sliding-mode observer (SMO) algorithm has serious jitter problem in the process phase tracking. A second-order adaptive was proposed, and ideas principles super-twisting were elaborated. In particular, estimation with introduction back-electromotive force (EMF) investigated, Lyapunov stability criterion used to determine convergence properties algorithm. results showed that had better suppression tracking performance than traditional experimental when velocity 800 r/min, error 0.57 r/min 0.018 rad, accuracy improvements 93.63% 58.34%, respectively. When 1000 0.94 0.022 90.55% 55.10%, system suppressed well, curve back-EMF smoother, robustness high. Therefore, is more suitable for position-sensorless PMSM.