Modelling, Parametrization and Observer Design of a 20 MW Reference Wind Turbine for Control Purposes

In the present contribution, the model development of a wind turbine with focus on an advanced control system design is reported. The aim is to produce a model that captures essential dynamics over the simplest cases but maintaining an acceptable level of complexity. The problem of parameter reduction from high-resolution models, as used in the simulation of reference turbines, to models with low number of parameters, as normally used for control purposes, is also studied. The obtained parametric model is validated by developing an observer, which can be used for state-space control as well as effective wind speed estimation. As numerical example, a 20 MW reference wind turbine is used. Very large wind turbines are very flexible and nonlinear, therefore very simple rigid models do not lead to satisfactory results. The proposed observer is adjusted during operation in order to overcome this problem.