Pitch controlled wind turbine with blade connecting members

Patent metadata

Field	Value
Publication number	US-12066003-B2
Application number	US-202118257576-A
Country	US
Kind code	B2
Filing date	Dec 17, 2021
Priority date	Dec 17, 2020
Publication date	Aug 20, 2024
Grant date	Aug 20, 2024

Abstract

A pitch controlled wind turbine comprising a tower, a nacelle mounted on the tower, a hub mounted rotatably on the nacelle, and at least three wind turbine blades is disclosed. Each wind turbine blade extends between a root end connected to the hub via a pitch mechanism, and a tip end. The wind turbine further comprises at least three blade connecting members, each blade connecting member extending between a connection point on one wind turbine blade and a connection point on a neighboring wind turbine blade, the connection points being arranged at a distance from the root end and at a distance from the tip end of the wind turbine blade. The wind turbine further comprises at least three pre-tension members, each pre-tension member being connected to one of the blade connecting members and to a hub part, the pre-tension members thereby providing pre-tension in the blade connecting members.

First claim

The invention claimed is:

1. A pitch controlled wind turbine comprising a tower, a nacelle mounted on the tower, a hub mounted rotatably on the nacelle, and at least three wind turbine blades, wherein each wind turbine blade extends between a root end connected to the hub via a pitch mechanism, and a tip end, the wind turbine further comprising at least three blade connecting members, each blade connecting member extending between a connection point on one wind turbine blade and a connection point on a neighbouring wind turbine blade, where the connection point on a given wind turbine blade is arranged at a distance from the root end and at a distance from the tip end of the wind turbine blade,
wherein the wind turbine further comprises at least three pre-tension members, each pre-tension member being connected to one of the blade connecting members and to a hub part, each pre-tension member thereby providing pre-tension in the blade connecting member to which it is connected, and wherein the pre-tension members are tensioned and arranged to provide an adjustable pre-tension in the blade connecting members.

2. The pitch controlled wind turbine according to claim 1 , wherein the connection points are arranged outside an outer surface of the wind turbine blades.

3. The pitch controlled wind turbine according to claim 1 , wherein the blade connecting members are connected to the respective wind turbine blades via bearing structures mounted on or forming part of the wind turbine blades.

4. The pitch controlled wind turbine according to claim 1 , wherein the connection points on the wind turbine blades are arranged at a distance from the root end which is between 10% and 60% of the length of the wind turbine blades from the root end to the tip end.

5. The pitch controlled wind turbine according to claim 1 , wherein the connection points on the wind turbine blades are arranged at a position where a thickness-to-chord ratio of the wind turbine blades is between 20% and 50%.

6. The pitch controlled wind turbine according to claim 1 , wherein the wind turbine blades each comprise an inboard blade part comprising the root end and an outboard blade part comprising the tip end, the inboard blade part and the outboard blade part being connected to each other at a split position, and wherein the connection points on the wind turbine blades are arranged at the split positions.

7. The pitch controlled wind turbine according to claim 1 , wherein the hub comprises a hub member extending from the hub substantially along a direction defined by a rotational axis of the hub, and wherein the pre-tension members are connected to the hub member.

8. The pitch controlled wind turbine according to claim 7 , wherein the hub member is arranged to provide at least one of an adjustable pre-tension and adjustable stiffness in the pre-tension members or blade connecting members via the pre-tension members.

9. The pitch controlled wind turbine according to claim 1 , wherein the pre-tension members are connected to a common point arranged inside the hub.

10. The pitch controlled wind turbine according to claim 1 , wherein the wind turbine blades define a coning angle within the interval 2° to 20°.

11. The pitch controlled wind turbine according to claim 1 , wherein the connection points on the wind turbine blades are arranged at or near a pitch axis of the wind turbine blades.

12. The pitch controlled wind turbine according to claim 1 , wherein the wind turbine blades are each provided with at least one groove formed in an outer shell of the wind turbine blade, the at least one groove being arranged to receive part of a blade connecting member.

13. The pitch controlled wind turbine according to claim 1 , wherein each of the wind turbine blades is curved in at least one direction between the root end and the tip end, thereby causing a pitch axis of the wind turbine blades to be located exterior with respect to the wind turbine blades, at least at the connection points.

14. The pitch controlled wind turbine according to claim 1 , wherein each of the wind turbine blades extends along a longitudinal direction, and wherein the longitudinal direction forms a non-zero angle relative to a pitch axis of the pitch mechanism of the wind turbine blade.

15. The pitch controlled wind turbine according to claim 1 , wherein at least one of the pre-tension members or the blade connecting members include a vibration damping mechanism.

16. The pitch controlled wind turbine according to claim 1 , wherein at least one of the pre-tension members or the blade connecting members are provided with aerodynamic devices.

17. The pitch controlled wind turbine according to claim 1 , wherein the wind turbine is an upwind wind turbine.

18. The pitch controlled wind turbine according to claim 1 , wherein at least one of the connection points of one the wind turbine blade are arranged adjacent each other or two blade connecting members are connected to the same connection point.

19. The pitch controlled wind turbine according to claim 1 , wherein a tension in the pre-tension members is individually adjustable.

20. The pitch controlled wind turbine according to claim 8 , where the hub member comprises an adjusting mechanism having a linear actuator arranged in a direction between the rotational axis of the hub and the connection point between the blade connecting member and the pre-tension member.

Assignees

• Vestas Wind Sys As

Inventors

• Nielsen Thomas S Bjertrup
• Larsen Torben Juul
• Østerlund Mikkel Kiilerich
• Fajar Mohammed
• Bøttcher Peter
• Rudolf Robert

Classifications

• F03D1/0677

  Longitudinally segmented blades; Connectors therefor · CPC title

• F05B2240/302

  Segmented or sectional blades · CPC title

• F03D1/0664

  Pitch arrangements (controlling blade pitch F03D7/0224) · CPC title

• F05B2240/50

  Bearings · CPC title

• Y02E10/72

  Wind turbines with rotation axis in wind direction · CPC title