Patent ID: 7321221
Filing Date: 2008-01-22
Classification: H02P

Abstract:
1. A method of operating a wind turbine, comprising: driving a rotor of the wind turbine by feeding rotor currents by a feed-in unit to rotor windings of an induction generator, which comprises stator coils coupled to a voltage grid; controlling the frequencies of the fed-in rotor currents depending on the rotor rotation frequency; electrically decoupling the feed-in unit from the rotor windings in the case of predetermined variations of the grid voltage amplitude by an emergency unit; releasing the fed-in rotor currents after electrically decoupling the feed-in unit using a release arrangement of the emergency unit; and when the rotor currents in the rotor windings by the variation have declined to a predetermined value, resuming the driving of the rotor of the wind turbine by feeding rotor currents by the feed-in unit to rotor windings of the induction generator after the decoupling caused by the variation of the grid voltage amplitude.