Wind turbine generator system
First Claim
1. A wind turbine generator system including switching means arranged at a stator side of a doubly fed generator for linkage with a grid and a converter for exciting a secondary winding of the doubly fed generator, a rotor of the doubly fed generator coupled to a wind turbine for generating electric power, comprising:
- first detection means for detecting a stator voltage at the switching means on the stator side of the doubly fed generator;
second detection means for detecting a grid voltage at the switching means on the side of the grid;
third detection means for detecting a rotation phase of the doubly fed generator;
means for obtaining a slip frequency from the voltage of the grid and the rotation phase for the converter to effect excitation from a secondary side of the generator;
first controlling means for decreasing a difference in amplitude between the grid voltage and the stator voltage when the switch is open to equalize the stator voltage generated by excitation on the secondary side with the grid voltage; and
second controlling means for decreasing a difference in phase between the grid voltage and the stator side voltage by further controlling the slip frequency to control the converter when the switch is open to synchronize the stator voltage generated by excitation on the secondary side with the grid voltage.
1 Assignment
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Accused Products
Abstract
To shorten a startup interval to reach a synchronizing condition, a phase difference and an amplitude difference between the grid voltage and the stator voltage of one phase of a winding are obtained. The difference in amplitude is decreased prior to or in parallel to synchronizing the stator voltage with the grid voltage. The calculated compensation phase compensation value is used as an initial value for synchronizing at the next synchronizing operation.
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Citations
18 Claims
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1. A wind turbine generator system including switching means arranged at a stator side of a doubly fed generator for linkage with a grid and a converter for exciting a secondary winding of the doubly fed generator, a rotor of the doubly fed generator coupled to a wind turbine for generating electric power, comprising:
- first detection means for detecting a stator voltage at the switching means on the stator side of the doubly fed generator;
second detection means for detecting a grid voltage at the switching means on the side of the grid;
third detection means for detecting a rotation phase of the doubly fed generator;
means for obtaining a slip frequency from the voltage of the grid and the rotation phase for the converter to effect excitation from a secondary side of the generator;
first controlling means for decreasing a difference in amplitude between the grid voltage and the stator voltage when the switch is open to equalize the stator voltage generated by excitation on the secondary side with the grid voltage; and
second controlling means for decreasing a difference in phase between the grid voltage and the stator side voltage by further controlling the slip frequency to control the converter when the switch is open to synchronize the stator voltage generated by excitation on the secondary side with the grid voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
- first detection means for detecting a stator voltage at the switching means on the stator side of the doubly fed generator;
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11. A wind turbine generator system comprising:
- a doubly fed generator comprising a stator, a secondary winding, and a rotor coupled to a wind turbine, for generating electric power;
a switch for coupling the stator to a grid;
a converter for exciting the secondary winding;
a first voltage detector for detecting an output of the stator when the switch is open;
a second voltage detector for detecting a voltage of the grid when the switch is open;
a detector for detecting a phase of the rotor;
a calculator for calculating a slip frequency from the detected phase of the rotor and a phase of the voltage of the grid, supplied to the converter to excite the secondary winding;
a first controller for equalizing in amplitude the output of the stator to the voltage of the grid in accordance with a difference in amplitude between the voltage of the grid and the output of the stator by controlling the converter when the switch is open; and
a second controller for synchronizing the output of the stator with the voltage of the grid in accordance with a difference in phase between the voltage of the grid and the output of the stator by controlling the slip frequency to control the converter when the switch is open. - View Dependent Claims (12, 13, 14, 15)
- a doubly fed generator comprising a stator, a secondary winding, and a rotor coupled to a wind turbine, for generating electric power;
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16. A wind turbine generator system including a switch arranged at a stator side of a doubly fed generator for linkage with a grid and a converter for exciting a secondary winding of the doubly fed generator, a rotor of the doubly fed generator coupled to a wind turbine for generating electric power, comprising:
- a first detector for detecting a stator voltage at the switch on the stator side of the doubly fed generator;
a second detector for detecting a grid voltage at the switch on the side of the grid;
a third detector for detecting a rotation phase of the doubly fed generator;
means for obtaining a slip frequency from the voltage of the grid and the rotation phase for the converter to effect excitation from a secondary side of the generator;
a first controller for decreasing a difference in amplitude between the grid voltage and the stator voltage when the switch is open to equalize the stator voltage generated by excitation on the secondary side with the grid voltage; and
a second controller for decreasing a difference in phase between the grid voltage and the stator side voltage by further controlling the slip frequency to control the converter when the switch is open to synchronize the stator voltage generated by excitation on the secondary side with the grid voltage. - View Dependent Claims (17)
- a first detector for detecting a stator voltage at the switch on the stator side of the doubly fed generator;
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18. A wind turbine generator system comprising:
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a doubly fed generator including a stator, a secondary winding, and a rotor; a wind turbine coupled to the rotor for generating electric power; a switch on a side of the stator for linkage with a grid; a first magnet contactor connected to the stator; a primary side of the first magnet contactor connected to a primary side of a second magnet contactor; a first converter connected to a secondary side of the second magnet contactor; a second converter having a D.C. terminal connected to a D.C. terminal of the first converter; and a control unit controlling the first and second magnet contactors and the first and second converters by out-putting signals thereto.
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Specification