Patent ID: 7939955

Claim:
Method for operating a wind energy installation ( 10 ), the wind energy installation ( 10 ) comprising a rotor ( 12 , 13 , 22 ), at least one rotor blade ( 14 ) with an adjustable angle, a mechanical brake device ( 19 ) for braking the rotor ( 14 ), an operational control device ( 15 , 15 ′) and a safety system ( 16 , 20 ), comprising the following method steps: braking of the rotor ( 12 , 13 , 22 ) by means of an angular adjustment ( 28 ) at an average angular adjustment rate of less than 8.5°/s of the at least one rotor blade ( 14 ) after a fault signal ( 30 ) occurs, braking of the rotor ( 12 , 13 , 22 ) by means of the mechanical brake device ( 19 ) as soon as the rotational speed of the rotor ( 12 , 13 , 22 ) exceeds a predefinable first rotational speed limit, and triggering of the safety system ( 16 , 20 ) as soon as the rotational speed of the rotor ( 12 , 13 , 22 ) exceeds a predefinable second rotational speed limit, the rotor ( 12 , 13 , 22 ) being braked and the second rotational speed limit being higher than the first rotational speed limit, the second rotational speed limit not being exceeded when the wind energy installation ( 10 ) is operationally capable, even in the event of load shedding by the generator ( 23 ) combined with an extreme gust of wind ( 31 ), the probability of occurrence thereof being less than once in three months.