Nonlinear robust control to maximize energy capture in a variable speed wind turbine using an induction generator

The emergence of wind turbine systems for electric power generation can help satisfy the growing global demand. This paper proposes a control strategy to maximize the wind energy captured in a variable speed wind turbine, with an internal induction generator, at low to medium wind speeds. The proposed strategy controls the tip speed ratio, via the rotor angular speed, to an optimum point at which the efficiency constant (or power coefficient) is maximal for a particular blade pitch angle and wind speed. This control method allows for aerodynamic rotor power maximization without exact wind turbine model knowledge.