A Sliding Mode Pitch Control for Multi-Megawatt Offshore Wind Turbines

A sliding mode controller with conditional integrator is proposed for pitch angle regulation in multi-megawatt wind turbines working under high speed wind conditions. The control objective is to improve the transient and steady-state performance of conventional continuous sliding mode pitch controllers by adding a conditional integrator, that is only active within the boundary layer. The control design is validated using the 5-MW offshore wind turbine model from NREL's FAST comprehensive aeroelastic simulator and considering pitch actuator dynamics. Furthermore, the mechanical response of different elements of the wind turbine is evaluated using MLife.