US 7,321,221 B2 | ||
Method for operating a wind power plant and method for operating it | ||
Andreas Bücker, Hasbergen (Germany); Wilhelm Janssen, Saterland (Germany); and Henning Lütze, Bad Bentheim (Germany) | ||
Assigned to General Electric Company, Schenectady, N.Y. (US) | ||
Appl. No. 10/521,614 PCT Filed Jul. 17, 2003, PCT No. PCT/EP03/07776 § 371(c)(1), (2), (4) Date Feb. 10, 2006, PCT Pub. No. WO2004/008627, PCT Pub. Date Jan. 22, 2004. |
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Claims priority of application No. 102 32 423 (DE), filed on Jul. 17, 2002. | ||
Prior Publication US 2006/0163881 A1, Jul. 27, 2006 | ||
Int. Cl. H20P 9/00 (2006.01) |
U.S. Cl. 322—44 [322/55; 322/43; 322/54; 322/25] | 19 Claims |
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.
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