Wind turbine generator system

• US 7,095,132 B2
• Filed: 07/20/2004
• Issued: 08/22/2006
• Est. Priority Date: 07/22/2003
• Status: Active Grant

• Current Assignee: Hitachi Industrial Products, Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd.
• Inventors: Imazu, Yasuhiro, Eguchi, Yoshio, Futami, Motoo, Kikuchi, Akira
• Primary Examiner(s): Schuberg, Darren
• Assistant Examiner(s): Cuevas, Pedro J.
• Application Number:
  US10/894,050
• Publication Number:
  US 20050017512A1
• Time in Patent Office: 763 Days
• Field of Search: 290/44, 290/52, 322/29
• US Class Current: 290/52
• CPC Class Codes: F03D 7/0272 by measures acting on the electrical generator
• CPC Class Codes: F03D 7/0296 to prevent, counteract or reduce noise emissions
• CPC Class Codes: F05B 2270/327 Rotor or generator speeds
• CPC Class Codes: H02P 21/05 specially adapted for damping motor oscillations, e.g. for reducing hunting
• CPC Class Codes: H02P 2101/15 for wind-driven turbines
• CPC Class Codes: H02P 9/105 for increasing the stability
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction

Abstract

An object of the present invention is to minimize the torsional vibration caused on the shafting of the wind turbine genarator system so as to operate the windmill stably.

A wind turbine genarator system according to the present invention, equipped with a synchronous generator connected to the shaft of a windmill, converter connected to the stator of the synchronous generator, and inverter connected to the converter and also to an electric power system, extracts the torsional vibration component of the shafting between the windmill and synchronous generator from the detected rotation speed of the synchronous generator, regulates the active component of the current command to the converter according to the vibration component, and controls so as to minimize the rotation speed variation of the synchronous generator.

Claims

1. A wind turbine generator system equipped with a synchronous generator connected to the shaft of a windmill, a converter connected to the stator winding of the synchronous generator, and an inverter connected to the converter and also to an electric power system, in which the variable-frequency power generated by the synchronous generator is converted into direct current power by the converter and then the direct-current power is converted into fixed-frequency alternating current power by the inverter comprising:

a rotation speed detector that detects the rotation speed of the synchronous generator;

a current detector that detects the current through the stator of the synchronous generator;

a current controller that controls the amperage detected by the current detector and outputs a voltage command;

a filter that receives the rotation speed detected by the rotation speed detector and then extracts and outputs a specified frequency component;

a phase gain regulator that receives the output signal of the filter and then regulates and outputs phase and gain; and

an adder that adds the signal outputted from the phase gain regulator to the current command sent to the current controller.

2. A wind turbine generator system according to claim 1, wherein the filter extracts the torsional vibration component caused on the shafting between the windmill and synchronous generator.

3. A wind turbine generator system equipped with a synchronous generator connected to the shaft of a windmill, a converter connected to the stator winding of the synchronous generator, and an inverter connected to the converter and also to an electric power system, in which the variable-frequency power generated by the synchronous generator is converted into direct current power by the converter and then the direct-current power is converted into fixed-frequency alternating current power by the inverter comprising:

a rotation speed detector that detects the rotation speed of the synchronous generator;

a current detector that detects the current through the stator of the synchronous generator;

a computing unit that converts the three-phase amperage detected by the current detector into active component and reactive component;

a current controller that controls the active component and reactive component and outputs a voltage command;

a filter that receives the rotation speed detected by the rotation speed detector and then extracts and outputs a specified frequency component;

a phase gain regulator that receives the output signal of the filter and then regulates and outputs phase and gain; and

an adder that adds the signal outputted from the phase gain regulator to the active component of the current command sent to the current controller.

4. A wind turbine generator system according to claim 3, wherein the filter extracts the torsional vibration component caused on the shafting between the windmill and synchronous generator.

5. A wind turbine generator system equipped with a synchronous generator connected to the shaft of a windmill, a converter connected to the stator winding of the synchronous generator, an inverter connected to the direct current side of the converter and also to an electric power system, and control unit of the converter;

wherein

the control unit of the converter extracts the torsional vibration component of the shafting between the windmill and synchronous generator from the detected rotation speed of the synchronous generator, regulates the active component of the current command to the converter according to the vibration component, and controls so as to minimize the rotation speed variation of the synchronous generator.