Efficient Nonlinear Wind-Turbine Modeling For Control Applications

A simple nonlinear model for variable pitch wind turbines is described. The model is aimed specifically at nonlinear control design and analysis. We propose a parametric model and subsequently describe a method to determine the parameters for any turbine that falls into the scope of the model. The result is a model that describes a turbine rotor, which is free to move in all six degrees of freedom. This freedom is required to model the new breed of floating offshore turbines. The resulting model is compared to experimental data with good results. Cyclic forces at large yaw offsets are not modeled well, however. Limitations of the model are discussed.