A METHOD FOR EVALUATING PERFORMANCE OF A SYSTEM FOR CONTROLLING PITCH OF A SET OF BLADES OF A WIND TURBINE

摘要

A method for evaluating performance of a system for controlling pitch of a set of rotor blades for a wind turbine is disclosed. The wind turbine comprises a hub adapted to carry a set of rotor blades. Obtained parameter values are compared with selected theoretical values, and the performance of the system is evaluated on the basis of the comparison. The obtained parameter values are indicative for at least one load moment of the hub of the wind turbine, e.g. a yaw moment and/or a tilt moment. The theoretical values correspond the expected values of the parameter values under the given wind conditions, and suitable theoretical values are selected on the basis of obtained information regarding wind condition, such as wind speed, wind direction, etc., at the site of the wind turbine. The method preferably uses measured values of flapwise load moments on the rotor blades.