Patent ID: 8210811
Filing Date: 2012-07-03
Classification: F03D,F05B,Y02E

Abstract:
1. A method for operating a wind turbine, the wind turbine comprising a rotor including at least one rotor blade and a pitch drive system coupled to the at least one rotor blade, the pitch drive system being configured to pitch the at least one rotor blade, said method comprising: determining an actual value of a first variable indicative of an overspeed state of the wind turbine; determining an actual value of a second variable of the wind turbine correlated to the rate of change over time of the first variable; and estimating an occurrence of an overspeed state of the wind turbine from at least the determined actual values of the first and second variables, wherein the pitch drive system pitches the at least one rotor blade for aerodynamically braking said rotor based on the result of said estimation.