Fretting corrosion and methods of operating a wind turbine

摘要

Methods of operating a wind turbine including one or more geared pitch systems. The method comprises a sub-nominal zone of operation for wind speeds below nominal and a supra-nominal zone of operation for wind speeds equal to or above the nominal. The sub-nominal zone of operation comprises a first operational range extending from a cut-in wind speed to a first wind speed and a second operational range extending from the first wind speed to a second wind speed, and the first operational range comprises two or more sub-ranges, wherein a different constant pitch position is defined for each of the sub-ranges. The method further comprises in the first operational range, using the geared pitch systems for setting the blades in the pitch position defined for each sub-range as a function of the current wind speed.