VARIABLE ROTOR SPEED WIND TURBINE, WIND PARK, METHOD OF TRANSMITTING ELECTRIC POWER AND METHOD OF SERVICING OR INSPECTING A VARIABLE ROTOR SPEED WIND TURBINE

• US 20090224607A1
• Filed: 07/01/2005
• Published: 09/10/2009
• Est. Priority Date: 07/01/2005
• Status: Active Grant

• Current Assignee: Vestas Wind Systems A/S
• Original Assignee: Vestas Wind Systems A/S
• Inventors: Kjaer, Philip Richard Carne, Helle, Lars
• Granted Patent: US 9,306,473 B2
• Time in Patent Office: Days
• US Class Current: 307/82
• CPC Class Codes: F03D 13/20 Arrangements for mounting or supporting wind motors; Masts or towers for wind motors
• CPC Class Codes: F03D 9/255 connected to electrical distribution networks; Arrangements therefor
• CPC Class Codes: H02J 2300/28 The renewable source being wind energy
• CPC Class Codes: H02J 3/38 Arrangements for parallely feeding a single network by two or more generators, converters or transformers
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02M 1/325 with means for allowing continuous operation despite a fault, i.e. fault tolerant converters
• CPC Class Codes: H02M 5/458 using semiconductor devices only
• CPC Class Codes: H02M 7/493 the static converters being arranged for operation in parallel
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction
• CPC Class Codes: Y02E 10/728 Onshore wind turbines
• CPC Class Codes: Y02E 10/76 Power conversion electric or electronic aspects

Abstract

The invention relates to a variable rotor speed wind turbine transmitting AC electric power to a utility grid. The wind turbine includes at least one AC generator and at least one power electronic converter unit. Further, it includes means for transforming at least one nominal output value of the generator to at least one different nominal input value of the at least one power electronic converter unit.

The invention also relates to a wind park and a method of transmitting AC electric power to a utility grid from a variable rotor speed wind turbine as well as a method of servicing or inspecting a variable rotor speed wind turbine.

Claims

1. A variable rotor speed wind turbine transmitting electric AC power to a utility grid, said wind turbine comprising

at least one AC generator, and

at least one power electronic converter unit, and

at least one nominal output value transformer for transforming at least one nominal output value of said generator to at least one different nominal input value of said at least one power electronic converter unit.

2. A variable rotor speed wind turbine according to claim 1 wherein said AC generator is a polyphase synchronous or asynchronous AC generator.

3. A variable rotor speed wind turbine according to claim 2 wherein said AC generator is a synchronous generator magnetised electrically or by permanent magnets.

4. A variable rotor speed wind turbine according to claim 2 wherein said AC generator is a low-speed, high pole-number synchronous generator.

5. A variable rotor speed wind turbine according to claim 1, wherein said AC generator is connected to said at least one power electronic converter unit through said nominal output value transformer.

6. A variable rotor speed wind turbine according to claim 1, wherein said at least one power electronic converter unit include more than one unit.

7. A variable rotor speed wind turbine according to claim 6 wherein said more than one power electronic converter unit have the same nominal ratings or number and/or are of the same type.

8. A variable rotor speed wind turbine according to claim 1 wherein said nominal output value transformer comprises a fixed transformation ratio.

9. A variable rotor speed wind turbine according to claim 1 wherein said nominal output value transformer transforms the nominal generator voltage and/or number of phases.

10. A variable rotor speed wind turbine according to claim 9 wherein said nominal output value transformer transforms a nominal voltage output value of the AC generator to a different nominal voltage input value of said at least one power electronic converter unit.

11. A variable rotor speed wind turbine according to claim 10 wherein said nominal output value transformer transforms a high voltage to a lower voltage from a value ranging beyond 3.300 Volt.

12. A variable rotor speed wind turbine according to claim 11 wherein said high voltage is chosen between the values of:

3.300, 4.160, 6.600, 10.000, 11.000 and 13.200 Volt, and said lower voltage is chosen between values of

690, 1.000, 2.200 and 3.300 Volt per power electronic converter unit.

13. A variable rotor speed wind turbine according to claim 1, wherein said nominal output value transformer transforms a number of phases of the AC generator to a different number of phases of said at least one power electronic converter unit.

14. A variable rotor speed wind turbine according to claim 1 wherein said at least one power electronic converter unit is at least one AC-DC-AC converter.

15. A variable rotor speed wind turbine according to claim 1, wherein said at least one power electronic converter unit is connected to the utility grid through at least one utility grid transformer.

16. A variable rotor speed wind turbine according to claim 15 wherein said nominal output value transformer and said utility grid transformer transform three phases of the AC generator to three phases of the utility grid through at least two three-phase power electronic converter units such as three three-phase power electronic converter units.

17. A variable rotor speed wind turbine according to claim 15 wherein said nominal output value transformer and said utility grid transformer transform M times three phases of the AC generator to three phases of the utility grid through at least two three-phase power electronic converter units comprising a nine-phase AC generator to three three-phase power electronic converter units.

18. A variable rotor speed wind turbine according to claim 15 wherein said at least one utility grid transformer transforms the output voltage rating and/or number of phases of said at least one power electronic converter unit to the utility grid.

19. A variable rotor speed wind turbine according to claim 15 wherein said at least one utility grid transformer steps up the nominal output voltage of said at least one power electronic converter unit.

20. A variable rotor speed wind turbine according to claim 1 wherein a connection between the AC generator and said nominal output value transformer comprises a minimum cable or busbar distance enabling the connection to extend out of a nacelle.

21. A variable rotor speed wind turbine according to claim 1 wherein said at least one power electronic converter unit is located outside a nacelle.

22. A variable rotor speed wind turbine according to claim 1 wherein said at least one power electronic converter unit is located in a tower of the wind turbine at a lower part of the tower such as at or in proximity of the tower foundation.

23. A variable rotor speed wind turbine according to claim 1 wherein said at least one power electronic converter unit is located outside a nacelle and tower of the wind turbine.

24. A variable rotor speed wind turbine according to claim 1 wherein an organization and location of the power electronic converter units enables redundancy in said wind turbine by N−

1 operation.

25. A variable rotor speed wind turbine according to claim 1 wherein each of said at least one power electronic converter unit includes switchgear a first switchgear in a connection before each unit and second switchgear in a connection after each unit.

26. A variable rotor speed wind turbine according to claim 25 wherein at least one nominal output value transformer, at least one power electronic converter unit, switchgear and at least one utility grid transformer form a power module.

27. A variable rotor speed wind turbine according to claim 1 wherein the number of power electronic converter units is between 2 and 10 parallel units.

28. Wind park such as an offshore wind park, said park comprising at least two variable rotor speed wind turbines according to claim 1.

29. Wind park according to claim 28 wherein power electronic converter units of different wind turbines are located in a common housing.

30. Method of transmitting electric power to an AC utility grid from a variable rotor speed wind turbine, said method comprising:

generating AC power with at least one AC generator,

transforming at least one nominal value of said AC generator to at least one different nominal input value of at least one power electronic converter unit with at least one nominal output value transformer, and

converting the power to said AC utility grid with said at least one power electronic converter unit.

31. Method of transmitting electric power to an AC utility grid according to claim 30 with a variable rotor speed wind turbine comprising

at least one AC generator, and

at least one power electronic converter unit, and

at least one nominal output value transformer for transforming at least one nominal output value of said generator to at least one different nominal input value of said at least one power electronic converter unit.

32. Method of transmitting electric power to an AC utility grid according to claim 31, where at least one of said at least one power electronic converter unit is connected or disconnected with switchgear in connections to said unit.

33. Method of transmitting electric power to an AC utility grid according to claim 32, where the transmitted power per unit of the remaining power electronic converter units is controlled to a value close to a nominal power rating of said unit.

34. Method of servicing or inspecting a variable rotor speed wind turbine transmitting electric AC power to a utility grid, said method comprising

transforming at least one nominal value of said AC generator to at least one different nominal input value of at least two power electronic converter units with at least one nominal output value transformer,

transforming at least one nominal value of said at least two power electronic converter units with at least one utility grid transformer,

disconnecting one converter unit under servicing or inspection of said unit from the nominal output value and utility grid transformers with switchgear, and

operating the remaining units of the wind turbine in N−

1 operation.

35. Method according to claim 34 where said wind turbine is a variable rotor speed wind turbine comprising

at least one AC generator, and

at least one power electronic converter unit, and

at least one nominal output value transformer for transforming at least one nominal output value of said generator to at least one different nominal input value of said at least one power electronic converter unit.