Wind turbine for producing electrical power and a method of operating the same

• US 20040201221A1
• Filed: 05/21/2003
• Published: 10/14/2004
• Est. Priority Date: 04/08/2003
• Status: Active Grant

• Current Assignee: Converteam GMBH (GE Power Conversion Technology Ltd)
• Original Assignee: Alstom Limited (Alstom SA)
• Inventors: Moehlenkamp, Georg
• Granted Patent: US 7,190,085 B2
• Time in Patent Office: Days
• US Class Current: 290/44
• CPC Class Codes: F03D 15/10 using gearing not limited to rotary motion, e.g. with oscillating or reciprocating members
• CPC Class Codes: F03D 7/0224 Adjusting blade pitch
• CPC Class Codes: F03D 9/11 storing electrical energy
• CPC Class Codes: F03D 9/255 connected to electrical distribution networks; Arrangements therefor
• CPC Class Codes: F05B 2220/70642 of the synchronous type
• CPC Class Codes: F05B 2240/96 as part of a wind turbine farm
• CPC Class Codes: H02J 2300/28 The renewable source being wind energy
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction
• CPC Class Codes: Y02E 10/76 Power conversion electric or electronic aspects
• CPC Class Codes: Y02E 70/30 Systems combining energy storage with energy generation of non-fossil origin

Abstract

A wind turbine includes a turbine rotor with at least one blade and a generator with a rotor and a stator. The turbine rotor is mechanically coupled with the rotor of the generator. A diode rectifier is electrically coupled to the stator of the generator. A direct current link is electrically coupled with the diode rectifier. A line converter is electrically coupled with the direct current link.

Claims

1. A wind turbine for producing electrical power comprising:

a turbine rotor with at least one blade;

a generator with a rotor and a stator, the turbine rotor being mechanically coupled with the rotor of the generator;

a diode rectifier being electrically coupled to the stator of the generator;

a direct current link being electrically coupled with the diode rectifier; and

a line converter being electrically coupled with the direct current link.

2. The wind turbine of claim 1, wherein the generator is a synchronous generator.

3. The wind turbine of claim 1, wherein the generator is excited with permanent magnets.

4. The wind turbine of claim 1, wherein the generator is excited electrically.

5. The wind turbine of claim 1, further comprising a gear box being mechanically coupled between the turbine rotor and the rotor of the generator.

6. The wind turbine of claim 5, wherein the gear box is provided with a step-up speed transmission having a fixed ratio.

7. The wind turbine of claim 1, further comprising a capacitor being electrically coupled to the stator of the generator.

8. The wind turbine of claim 1, wherein the direct current link includes a step up/step down converter and a direct current link with a fixed voltage, the direct current link with the fixed voltage being electrically coupled with the step up/step down converter and with the line converter.

9. The wind turbine of claim 8, wherein the direct current link includes a direct current link with a variable voltage, the direct current link with the variable voltage being electrically coupled with the diode rectifier and with the step up/step down converter.

10. The wind turbine of claim 8, wherein the diode rectifier and the direct current link with the fixed voltage are connected at an operating point of the wind turbine.

11. The wind turbine of claim 9, wherein the direct current links with the variable frequency and the direct current link with the fixed frequency are connected at an operating point of the wind turbine.

12. The wind turbine of claim 10 wherein the connection is upheld as long as the fixed voltage of the direct current link is higher than the rectified line side voltage of the line converter.

13. The wind turbine of claim 1, further comprising a control unit for controlling the electrical power flowing through the line converter.

14. The wind turbine of claim 1, further comprising a controller for controlling the actual speed (Nact) of the rotor by adjusting the pitch of the rotor blade (5).

15. The wind turbine of claim 1, further comprising a filter being electrically coupled to the line converter and further electrically connected with a capacitor.

16. The wind turbine of claim 1, further comprising a first switch being a low voltage switch (23), a transformer (24) and a second switch being a medium voltage switch for coupling the wind turbine to a utility grid.

20. The wind turbine of claim 1, wherein the generator is excited electronically, via slip rings or brushless.

17. A method of operating a wind turbine, the wind turbine comprising a turbine rotor with at least one blade, a generator with a rotor and a stator, the turbine rotor being mechanically coupled with the rotor of the generator, a diode rectifier being electrically coupled to the stator of the generator, a direct current link being electrically coupled

with the diode rectifier, and a line converter being electrically coupled with the direct current link, and the method comprising:

measuring an actual power flowing through the line converter; and

adjusting the actual power to a given desired power of the wind turbine.

18. The method of claim 17, further comprising evaluating the desired power based on a speed of the rotor, a pitch of the rotor blade, a speed and direction of wind and/or on further operating values of the wind turbine.

19. The method of claim 17, further comprising controlling an actual speed (Nact) of the rotor by adjusting a pitch of the rotor blade.