Coordinated Power and Structural Load Optimization for Offshore Wind Turbines with Nonlinear Model Predictive Generator Torque Control

Modern large-scale offshore wind turbines (OWTs) with pronounced flexible structure, operating in the coupled aero-hydrodynamic loads, presents a challenge for generator torque control. This study proposes OWT generator torque nonlinear model predictive control (NMPC) strategy to coordinate optimization the power production and structural load. Firstly, the prediction model is established based on aero-elastic-servo models of OWT, which predict the dynamic generator torque control behaviors to provide a preview of power production and structural loads. Subsequently, the cost function is jointly formulated by enhancing power production, regulating tower damping, and restricting actuator motion. To effectively compute the cost function, the Fast Particle Swarm Optimization (F-PSO) is proposed. Finally, the aero-elastic-hydro-servo experiment using the developed generator torque NMPC is conducted for 10 MW monopile OWT. The result under turbulence wind, irregular wave, and wind-wave misalignment proves the coordinated optimization on power production and structural loads.