Adaptive optimal fuzzy control for variable speed fixed pitch wind turbines

Automatic control is crucial to the efficiency and reliability of wind power generation systems. Variable speed fixed pitch wind turbines have strong nonlinear and unstable characteristics with many uncertain factors and disturbances at large wind speed ranges. Based on the motion equation of the generator and wind turbine, adaptive optimal fuzzy system for rotational speed control is proposed by using the algorithm of the nearest-neighbour clustering learning. This algorithm synthesizes both mechanical and electrical dynamics of wind energy conversion system. System identification is a part of the controller. The rotational speed reference is determined by estimated aerodynamic torque using Kalman filter. The method avoids the inaccuracy of measuring the wind speed. Simulation results verify the effectiveness of the proposed control methods.