WIND TURBINE GENERATOR SYSTEM

• US 20110049889A1
• Filed: 11/05/2010
• Published: 03/03/2011
• Est. Priority Date: 01/08/2004
• Status: Active Grant

• Current Assignee: Hitachi Industrial Products, Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd.
• Inventors: FUTAMI, Motoo, ICHINOSE, Masaya, SAKAI, HIromitsu
• Granted Patent: US 7,964,980 B2
• Time in Patent Office: Days
• US Class Current: 290/44
• CPC Class Codes: F03D 7/026 for starting-up
• CPC Class Codes: F03D 9/255 connected to electrical distribution networks; Arrangements therefor
• CPC Class Codes: F05B 2270/337 Electrical grid status parameters, e.g. voltage, frequency or power demand
• CPC Class Codes: H02P 2101/15 for wind-driven turbines
• CPC Class Codes: H02P 9/007 Control circuits for doubly fed generators
• CPC Class Codes: H02P 9/10 Control effected upon generator excitation circuit to reduce harmful effects of overloads or transients, e.g. sudden application of load, sudden removal of load, sudden change of load
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction

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.

Claims

1. A controller for a wind turbine generator system,

wherein the wind turbine generator system includes

a doubly-fed generator that includes a stator and rotor, the rotor being coupled to a wind turbine for generating electric power,

a switch arranged on a side of the stator for linkage with a grid, and

a power converter for exciting a secondary winding of the doubly-fed generator,

wherein the controller comprises:

an adjuster that, when the switch on the side of the stator is open, decreases an amplitude difference or a phase difference between a grid voltage and a stator voltage of the doubly-fed generator.

2. A method for use in a controller in a wind turbine generator system,

wherein the wind turbine generator system includes

a doubly-fed generator that includes a stator and rotor, the rotor being coupled to a wind turbine for generating electric power,

a switch arranged on a side of the stator for linkage with a grid, and

a power converter for exciting a secondary winding of the doubly-fed generator,

wherein the method comprises:

on a condition that the switch on the side of the stator is open, decreasing an amplitude difference or a phase difference between a grid voltage and a stator voltage of the doubly-fed generator; and

controlling power generation performed by the rotor based on whether the switch on the side of the stator is open or closed.