Adaptive sliding mode speed identification for vector control system of doubly fed wind turbine

A adaptive sliding mode observer was proposed for the speed identification of a sensor-less vector control system of doubly fed wind turbine. This strategy combines adaptive control with variable structure control, and selects the rotor currents as model outputs, and formulates a slide mode surface according current error to get speed observer expression. By using small signal model, the convergence condition of observer was obtained, and the estimation algorithm for rotor speed was solved to guarantee the stability of the system. Theoretical analysis and simulation results show that the proposed strategy possesses the veracity of current observers and improves the dynamic and static performance of the speed estimation.