Nonlinear Tracking Controller of Variable Speed Wind Turbines with the Parameter Adjusted by Fuzzy Logic

Based on the analysis of the wind turbine model characteristics, the essence of the maximum wind energy tracking problem of variable speed wind turbines is transformed into controlling the rotor speed to track the optimal rotor speed. The generator torque is used as a control input to force the wind turbine to stay close to the maximum energy point in the below-rated power region. In this paper, a nonlinear tracking controller of variable speed wind turbines with a fuzzy logic adjustable parameter is proposed, which does not need wind speed measurement and avoids the complex linearization. The controller makes the wind turbines output more power and the mechanical loads acceptable, which is verified in the simulation using the FAST (Fatigue, Aerodynamics, Structures, and Turbulence) code.