Sensorless Control of Doubly-fed Induction Generator Based on Adaptive Sliding-mode Observer

In this paper, a rotor flux based variable-structure model reference adaptive system (MRAS) observers is proposed for speed observer in a sensorless controlled doubly fed induction generator (DFIG) aligned with the stator flux. In the strategy, two rotor flux models with different structure are used. The rotor flux voltage model without including rotor position item is used as reference model, and the rotor flux current model including rotor position item as adjustable model. A slide-mode surface is formulated from the errors between the two models, and the rotor speed estimation can be obtained by a sliding mode algorithm. Meanwhile the one order inertial link is used to avoid suffering from integrator drift effects in voltage model. Simulation results confirm the validity of the approach.