Nonlinear Model Predictive Control for Suppressing Variations of Blade Bending Stress in Floating Offshore Wind Turbines Affected by Strong Winds

Abstract

We designed a nonlinear model predictive controller with collective blade pitch control for floating offshore wind turbines affected by strong winds. We derived a linear time-invariant wind turbine model from an operating point and constructed a nonlinear blade bending stress model for control design. Then, we designed a nonlinear model predictive controller by evaluating the stress model. The controller also includes disturbance previews of wind speed. Finally, we evaluated the control performances through numerical simulations on a precise numerical simulator, FAST. The results showed that the proposed controller reduced blade bending stresses more than other controllers.