Patent ID: 8491262

Claim:
A method for shutdown of a wind turbine having one or more wind turbine blades, the method comprising: detecting an operational condition of the wind turbine that calls for an expedited or emergency shutdown of the wind turbine by means other than normal pitch control shutdown; upon detection of the operational condition, deploying one or more air brake flaps configured on each of the turbine blades by removing electrical power to a fail-safe actuator operatively coupled to each of the air brake flaps, the fail-safe actuator configured to hold the respective air brake flap at a retracted position relative to a suction side of the turbine blade in a powered state of the fail-safe actuator and to release the air brake flap for automatic deployment to an open position upon loss of electrical power to the fail-safe actuator; and including providing an initial motive force to the air brake flaps upon removing power to the fail-safe actuators to move the air brake flaps to an initial position relative to the suction side of the turbine blade so that airflow over the suction side subsequently acts on the air brake flaps and moves the air brake flaps to a fully deployed position.