A wind turbine includes a rotor having a hub, at least one rotor blade coupled to the hub, and a rotor shaft coupled to said hub for rotation therewith. The wind turbine also includes an electrical generator coupled to the rotor shaft, and a generator-side frequency converter electrically coupled to the electrical generator for converting variable frequency AC received from the electrical generator into DC. The generator-side frequency converter is electrically coupled to an electrical load and is configured to at least one of supply reactive power to the electrical load and absorb reactive power from the electrical load. The wind turbine also includes a grid-side frequency converter electrically coupled to the generator-side frequency converter for converting DC received from the generator-side frequency converter into fixed frequency AC. The grid-side frequency converter is electrically coupled to the electrical load and is configured to at least one of supply reactive power to the electrical load or absorb reactive power from the electrical load.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation application of U.S. patent application Ser. No. 11/424,989, filed Jun. 19, 2006 now U.S. Pat. No. 7,312,537, which is hereby incorporated by reference and is assigned to the assignee of the present invention.
A wind turbine includes an asynchronous generator having a rotor and a stator, means for determining an actual torque-speed curve of the generator, means for determining an actual grid frequency, and means for determining a shifted torque-speed curve in response to the determined actual grid frequency if the determined actual grid frequency is higher than a predetermined upper frequency limit or lower than a predetermined lower frequency limit. The means for determining a shifted torque-speed curve is further adapted to determine the shifted torque-speed curve such that an increase in the rotor voltage of said generator rotor is counteracted when shifting the actual torque-speed curve to the shifted torque-speed curve. The wind turbine further includes means for shifting the actual torque-speed curve of the generator to the shifted torque-speed curve.
A wind turbine includes an asynchronous generator having a rotor and a stator, means for determining an actual torque-speed curve of the generator, means for determining an actual grid frequency, and means for determining a shifted torque-speed curve in response to the determined actual grid frequency if the determined actual grid frequency is higher than a predetermined upper frequency limit or lower than a predetermined lower frequency limit. The means for determining a shifted torque-speed curve is further adapted to determine the shifted torque-speed curve such that an increase in the rotor voltage of said generator rotor is counteracted when shifting the actual torque-speed curve to the shifted torque-speed curve. The wind turbine further includes means for shifting the actual torque-speed curve of the generator to the shifted torque-speed curve.
A system and method for operating a wind turbine with a generator, drivable by a rotor, for supplying electrical power to an electric load, in particular an electric grid, are disclosed. Briefly described, one embodiment generates electrical power from an electrical generator coupled to the wind turbine, outputs the generated electrical power to an electric grid, senses a disruption in the electric grid, maintains connection of the electrical generator during the disruption, and limits the generated electrical power during at least a portion of the disruption.
The present invention relates to a method for operating a wind turbine with a generator, drivable by a rotor, for supplying electrical power to an electrical load, in particular an electric grid. In order to compensate for fluctuations in the grid as far as possible, the system of the kind initially specified is developed in such a way that the power delivered to the load by the generator is regulated in response to a current outputted to the load.
