Advanced control based on extended Kalman filter for variable speed wind turbine

Aerodynamic forces acting on wind turbines are turbulent in nature as the wind speed varies stochastically and aero elastic coupling generates disturbances. Since it is impractical to predict system inputs from wind speed measurement, one should estimate them to achieve robust control design. Considerable research activity dealing with observer based controllers has been reported in the literature. In this work, an advanced technique based on the extended Kalman filter is proposed. This exponential filter is considered within the framework of Indirect Speed Control and Aerodynamic Torque Feed forward control. Simulations have shown that the proposed wind speed observer tracks accurately the mean tendency of real wind speed while discarding high frequency components. Excellent performance was obtained in terms of the extracted electric energy without demanding excessive generator torque values. The obtained results have shown also that fatigue loads are well decreased in comparison with Kalman filter based methods.