CONTROL OF A WIND TURBINE ROTOR DURING A STOP PROCESS USING PITCH AND A SURFACE ALTERING DEVICE

摘要

A method for controlling a wind turbine during a stop process thereof from an operating state to a stand-still state, wherein the wind turbine comprises a tower and a rotor with a plurality of pitchable rotor blades, each blade comprising a main blade body and at least one trailing edge flap, which is movable with respect to the main blade body in order to alter the aerodynamic surface of the blade. In the operating state, the tower is deflected in a downwind direction due to the aerodynamic thrust force on the rotor, and the method for controlling the stop process comprises the steps of moving the at least one trailing edge flap towards the suction side of the blade in order to alleviate the aerodynamic load on the rotor, whereby the tower starts to move forward in the upwind direction, and subsequently pitching the blades to further alleviate the aerodynamic load on the rotor.