Indretning og fremgangsmåde til drift af en vindmølle

摘要

A method for operating a wind turbine (10) is provided. The wind turbine (10) inciudes a rotor (18) ineluding at least one rotor blade (22) and a piteh drive system (68) eoupled to the at least one rotor blade (22). The pitch drive system (68) is adapted for pitehing the rotor blade (22). The method ineludes: determining an actual value of a first variable indieative of an overspeed state of the wind turbine (10); determining an actual value of a seeond variable of the wind turbine (10) correlated to the rate of change over time of the first variable; and, estimating an oeeurrence of an overspeed state of the wind turbine (10) from at least the determined actual values of the first and second variables. The piteh drive system (68) pitehes the at least one rotor blade (22) for aerodynamically braking the rotor (18) based on the result of the estimation.