Super-twisting sliding mode observer based speed sensorless torque control for PMSG used in wind turbines

A speed sensorless torque control method for permanent magnet synchronous generator (PMSG) based on super-twisting sliding mode observer (STSMO) is proposed in this paper. Active back electromotive force (BEMF) can be obtained based on the STSMO. With the observed active BEMF, the rotor position angle and the speed are estimated by a phase-locked loop. Besides, a stator flux and electromagnetic torque (EMT) observation method is proposed based on the observed active BEMF. Compared to the traditional method, the robustness of the proposed one to the parameters of PMSG is improved. Then a speed sensorless EMT closed-loop control system is established. The simulation and experimental results verify the effectiveness of the proposed algorithm.