Nonlinear PI Control of a 20 MW Reference Wind Turbine

This contribution presents the control of the collective pitch system of a 20 MW wind turbine by using a nonlinear PI control (NPI) approach. Due to the fact that the operating point changes with the wind speed and that the plant is nonlinear, the controller has to adjust its parameters. This is done by using a gain scheduling procedure with bumpless transfer combined with an active tower damping mechanisms in order to reduce the effects produced by the pitching activity. As simulation platform, the software FAST is used for the representation of the wind turbine. Simulation results show that the control system based on the NPI approach contributes to an improvement in the control performance of very large wind turbines.