Wind turbine blade and a wind turbine

Abstract

Provided is a wind turbine blade for a wind turbine, including a web extending along a longitudinal direction of the blade, an electrically conductive beam extending along the longitudinal direction of the blade and being connected to the web, a lightning conductor extending along the longitudinal direction of the blade and being attached to the web, and a ply including carbon fibers, wherein the ply is attached to both the lightning conductor and the beam to electrically connect the lightning conductor to the beam. This has the advantage that an extensive and a continuous electrical connection between the lightning conductor and the beam is provided and that a plurality of cables electrically connecting the lightning conductor with the beam may be substituted.

Claims

1. A wind turbine blade for a wind turbine, comprising a web extending along a longitudinal direction of the blade, an electrically conductive beam extending along the longitudinal direction of the blade and being connected to the web, wherein the beam has a beam surface, wherein the web intersects the beam surface where the beam is connected to the web, a lightning conductor extending along the longitudinal direction of the blade and being attached to the web, and a ply comprising carbon fibers, the ply including a first edge along the longitudinal direction of the blade and a second edge along the longitudinal direction of the blade, wherein the ply is a structural component of the web, attached to both the lightning conductor and the beam to electrically connect the lightning conductor to the beam, wherein the ply covers a first part of the beam surface facing the web on a first side of the web, wherein the beam has a second part of the beam surface facing the web on a second side of the web, and a third part of the beam surface adjacent to an inner surface of the blade, wherein the ply extends along the first part of the beam surface and third part of the beam surface, such that the first part of the beam surface and third part of the beam surface are covered by the ply, wherein the second side of the beam surface is not covered by the ply, and wherein at least one of the first edge and second edge terminate on the beam surface.

2. The wind turbine blade according to claim 1, having a blade tip and a blade root, wherein the lightning conductor extends from the blade tip to the blade root, and wherein the ply has a length that extends along at least a portion of a length of the lightning conductor.

3. The wind turbine blade according to claim 1, wherein the ply is attached to the lightning conductor and the beam along the ply's total length.

4. The wind turbine blade according to claim 1, having a further beam comprising carbon fibers, being electrically conductive, and which is connected to the web, wherein the ply is attached to the further beam for electrically connecting the lightning conductor to the further beam.

5. The wind turbine blade according to claim 4, wherein the web is located between the beam and the further beam forming an I-shaped cross section.

6. The wind turbine blade according to claim 4, having a further ply comprising carbon fibers electrically connecting the beam to the further beam, which is arranged parallel to the ply, and which is attached to the beam and the further beam.

7. The wind turbine blade according to claim 1, having an outer blade shell, wherein the beam is connected to the outer blade shell.

8. A wind turbine having a wind turbine blade according to claim 1.

9. A wind turbine blade for a wind turbine, comprising a web extending along a longitudinal direction of the blade; an electrically conductive beam extending along the longitudinal direction of the blade and being connected to the web, wherein the beam is located between the web and an inner surface of the blade, wherein the beam has a first beam surface facing the web on one side of the web, a second beam surface facing another side of the web, and a third beam surface adjacent to the inner surface of the blade; a lightning conductor extending along the longitudinal direction of the blade and being attached to the web; and a ply comprising carbon fibers, wherein the ply is attached to both the lightning conductor and the beam to electrically connect the lightning conductor to the beam, wherein the ply extends along the first beam surface and third beam surface such that the first beam surface and third beam surface are covered by the ply.

Description

BRIEF DESCRIPTION

(1) Some of the embodiments will be described in detail, with references to the following Figures, wherein like designations denote like members, wherein:

(2) FIG. 1 shows a perspective view of a wind turbine according to one embodiment;

(3) FIG. 2 shows a perspective view of a wind turbine blade of the wind turbine according to FIG. 1;

(4) FIG. 3 shows a cross-sectional view from FIG. 2;

(5) FIG. 4 shows a detail view IV from FIG. 3 in accordance with one embodiment;

(6) FIG. 5 shows a detail view IV from FIG. 3 in accordance with a further embodiment;

(7) FIG. 6 shows a detail view IV from FIG. 3 in accordance with a further embodiment;

(8) FIG. 7 shows a cross-sectional view VII-VII from FIG. 4;

(9) FIG. 8 shows a partial cross-sectional view of a further embodiment of the wind turbine blade;

(10) FIG. 9 shows a partial cross-sectional view of a further embodiment of the wind turbine blade; and

(11) FIG. 10 shows a partial cross-sectional view of a further embodiment of the wind turbine blade.

(12) In the Figures, like reference numerals designate like or functionally equivalent elements, unless otherwise indicated.

DETAILED DESCRIPTION

(13) FIG. 1 shows a wind turbine 1. The wind turbine 1 comprises a rotor 2 connected to a generator (not shown) arranged inside a nacelle 3. The nacelle 3 is arranged at the upper end of a tower 4 of the wind turbine 1.

(14) The rotor 2 comprises three wind turbine blades 5. The wind turbine blades 5 are connected to a hub 6 of the wind turbine 1. Rotors 2 of this kind may have diameters ranging from, for example, 30 to 200 meters or even more. The wind turbine blades 5 are subjected to high wind loads. At the same time, the wind turbine blades 5 need to be lightweight. For these reasons, wind turbine blades 5 in modem wind turbines 1 are manufactured from fiber-reinforced composite materials. Therein, glass fibers are generally preferred over carbon fibers for cost reasons. Oftentimes, glass fibers in the form of unidirectional fiber mats are used.

(15) FIG. 2 shows a wind turbine blade 5. The wind turbine blade 5 comprises an aerodynamically designed portion 7 which is shaped for optimum exploitation of the wind energy and a blade root 8 for connecting the wind turbine blade 5 to the hub 6. Further, the wind turbine blade 5 comprises a blade tip 9 which is arranged averted from the blade root 8. The wind turbine blade 5 extends in a longitudinal direction L.

(16) FIG. 3 shows a cross-sectional view from FIG. 2. The wind turbine blade 5 comprises an outer blade shell 10 comprising a first half-shell 11 and a second half-shell 12 which are connected together at one side 13 of the wind turbine blade 5, in particular at a trailing edge, and at the other side 14 of the wind turbine blade 5, in particular at a leading edge, to form the outer shell 10 of the wind turbine blade 5. The blade shell 10 may comprise composite fiber material. Further, the first half-shell 11 and the second half-shell 12 may be glued together. Alternatively, the blade shell 10 may be provided as a one-piece element.

(17) The first half-shell 11 comprises an inner surface 15 and the second half-shell 12 comprises an inner surface 16 being opposite to each other, wherein an inner space 17 of the wind turbine blade 5 is defined by the inner surfaces 15, 16. A web 18 is located inside the inner space 17 extending from the inner surface 15 of the first half-shell 11 to the inner surface 16 of the second half-shell 12. The wind turbine blade 5 further comprises a first beam 19 connected to the first half-shell 11 and a second beam 20 connected to the second half-shell 12. The first and the second beam 19, 20 are electrically conductive and extend along the longitudinal direction L.

(18) The web 18 is located between the first beam 19 and the second beam 20, wherein the web 18 and the beams 19, 20 are forming an I-shaped cross section. The web 18 and the beams 19, 20 are forming a support structure preventing breaking or crippling of the wind turbine blade 5. The web 18 extends along the longitudinal direction L of the blade 5. Further, a lightning conductor 21 is provided extending along the longitudinal direction L and being attached to the web 18. Furthermore, a ply 22 comprising carbon fibers is provided.

(19) The ply 22 is attached to both the lightning conductor 21 and the first beam 19 to electrically connect the lightning conductor 21 to the first beam 19. Preferably, the ply 22 is also connected to the second beam 20. Moreover, a further ply 23 is provided comprising carbon fibers electrically connecting the first beam 19 with the second beam 20. The further ply 23 is arranged parallel to the ply 22 and is attached to the first beam 19 and the second beam 20. The further ply 23 is arranged at a side 24 of the web 18 which is averted from the ply 22.

(20) Alternatively, the blade 5 may be provided without the further ply 23.

(21) FIG. 4 shows a detail view IV from FIG. 3. Contrary to FIG. 3 the further ply 23 (see FIG. 3) is not provided. A surface 25 of the first beam 19 which faces the web 18 is divided by the web 18 in a first part 26 (left part) and a second part 27 (right part). The ply 22 only covers the first part 26 of all surfaces of the beam 19 and is connected thereto. “Cover” may mean that the ply 22 is directly or indirectly connected to the beam 19 and that an overlap is provided.

(22) Furthermore, the web 18 may be connected to the first beam 19 and/or the second beam 20 by means of a connecting element serving as a receptacle for the web 18 (not shown).

(23) FIG. 5 shows a detail view IV from FIG. 3 of a further embodiment of the wind turbine blade 5. Contrary to FIG. 4, the ply 22 is wrapped around the beam 19 such that only the part 26, a surface 28 which is averted from the surface 25, and a surface 29 connecting the part 26 and the surface 28 are covered by the ply 22. Alternatively (not shown), the ply 22 may be wrapped completely around the beam 19 such that also the part 27 of the surface 25 is covered by the ply 22.

(24) FIG. 6 shows a detail view IV from FIG. 3 of a further embodiment of the wind turbine blade 5. Contrary to FIG. 4, the ply 22 is attached to the first beam 19 by means of a conductive layer 30, in particular a metallic or carbon layer. Such a metallic layer may comprise metallic cooper and/or an aluminum mesh.

(25) FIG. 7 shows a cross-sectional view VII-VII of FIG. 4. The lightning conductor 21 has a length L1 extending essentially from the blade tip 9 to the blade root 8 (see FIG. 2). Further, the ply 22 has a length L2 in longitudinal direction L. The ply 22 is attached to the lightning conductor 21 and the first beam 19 along the ply's 22 total length L2.

(26) In particular, the ply 22 has the length L2 being at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 100% of a length L1 of the lightning conductor 21.

(27) FIG. 8 shows a partial cross-sectional view of a further embodiment of the wind turbine blade 1. In contrast to FIG. 4, a second lightning conductor 31 extending along the longitudinal direction L of the blade 5 is provided, wherein the first lightning conductor 21 is arranged at one side 32 of the web 18 and the second lightning conductor 31 is arranged at the other side 35 of the web 18 being averted from the one side 32. The second lighting conductor 31 is attached to the web 18 and the further ply 23. The second lightning conductor 31 is covered by the further ply 23. The further ply 23 is arranged as described in FIG. 3.

(28) FIG. 9 shows a partial cross-sectional view of a further embodiment of the wind turbine blade 1. In contrast to FIG. 4, the ply 22 contacts the complete surface 25, wherein the ply 22 is bended at an edge 33 of the beam 19 such that the part 27 is covered two-ply by the ply 22 and extends further towards the lightning conductor 21. Further, the web 18 is connected to the beam 19 by means of the ply 22.

(29) FIG. 10 shows a partial cross-sectional view of a further embodiment of the wind turbine blade 1. In contrast to FIG. 3, the beam 19 is connected to the half-shell 11 by means of a ply 34, in particular having carbon fibers and being electrically conductive. The ply 34 covers the complete surface 28 and is connected thereto. The ply 34 attaches the ply 22 and the ply 23. In particular, the beam 20 is connected to the half-shell 12 by means of a ply 36, in particular having carbon fibers and being electrically conductive. The ply 36 may be provided equally to the ply 34.

(30) Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

(31) For the sake of clarity, it is to be understood that the use of ‘a’ or ‘an’ throughout this application does not exclude a plurality, and ‘comprising’ does not exclude other steps or elements.