US Patent 9784241 System and method for controlling a wind turbine

A wind turbine includes a rotor, a plurality of rotor blades coupled to the rotor, and a blade pitch control system coupled to each rotor blade. A computer-implemented method for controlling the wind turbine includes determining at least one pitch position for a first blade. The method also includes determining whether there is a malfunction of the blade pitch control system associated with the first blade. The method further includes predicting a rotor imbalance using a model of at least a portion of the wind turbine. The method also includes comparing the predicted rotor imbalance with a predetermined threshold value. The method further includes one of regulating the pitch position for the second blade such that the predicted rotor imbalance is restored to a value below the predetermined threshold and regulating a pitch position for a second blade such that the predicted rotor imbalance does not exceed the predetermined threshold.