Development of a Control-Oriented Model of Floating Wind Turbines

This paper deals with the development of a simplified, control-oriented mathematical model of an offshore variable speed wind turbine with tension leg platform. First, the model is derived with the goal of describing the most relevant physical phenomena of the turbine/platform dynamics, while limiting its complexity. The unknown model parameters are identified and a model validation phase is carried out using Fatigue, Aerodynamics, Structures, and Turbulence (FAST), an accurate reference model available in the literature. Then, an H∞ controller is designed for above-rated power operating conditions. The ability of the controller to attenuate the effect of wind variations and waves is tested in simulation both on the small-scale simulation model and on the FAST simulator.