State Observer for Variable Speed Wind Turbine

An article describes the application of a state observer technique for the estimation of wind turbine efficiency in a variable speed wind turbine, which is provided by the estimation of the aerodynamic torque acting on the rotor of the vertical axis wind turbine at a variable wind speed. The considered state observer uses the angular acceleration of a wind turbine and the generator reaction torque as input parameters taking into account rotor inertia in order to implement the aerodynamic torque estimator. This technique is illustrated by a simulated example and compared with a case when the aerodynamic torque is known. The proposed state observer can be useful to find the power coefficient of the wind turbine at alternating wind speed conditions and useful in the development of power control algorithms based on maximum power point tracking strategies for variable speed wind turbines by having no wind speed measurement.