Wind turbine individual pitch control for load reduction based on fuzzy controller design

The individual pitch control technique for large-scale wind turbines is analyzed in this article. Based on linear blade element momentum theory, the wind turbine model about blade loads is established. To make the control design problem time invariant, blade root moments in the periodic frame of reference are transformed to tilt and yaw moments in the nonrotating reference frame, which are decoupled into two single-input single-output linear systems by the Coleman transformation, so the controller design is simplified and fuzzy controller is used. Simulation results show that compared with collective pitch control, the strategy of individual pitch control not only ensures output power approximately equal, but also reduces fatigue loads of blades and other key components.