Fractional order PID control with rate-limited anti-windup for the pitch system of wind turbines

This contribution analyses the performance of a fractional order PID (FOPID) controller with an anti-windup strategy for magnitude and rate applied to the pitch control of a wind turbine. Due to the fact that the operating point of wind turbines changes with the wind speed and that the plant is nonlinear, the controller includes a gain scheduling procedure to adjust the controller parameters. In order to avoid undesired oscillations on the tower due to the pitching activity, an active tower damping control is coupled with the pitch control. A 20 MW reference wind turbine is used as virtual plant, which is implemented in the simulation software FAST. Simulation results show that the control system based on the FOPID approach contributes to an improvement in the control performance of the wind turbine.