Improved electrical conductivity of wind turbine blade components

Abstract

The present disclosure relates to a wind turbine blade component for a wind turbine blade, the wind turbine blade component comprising: a metal mesh layer comprising a plurality of holes; at least a first fiber reinforcement layer comprising a plurality of first electrically conductive fibers; and a plurality of second conductive fibers. At least some of the plurality of second conductive fibers extend laterally through the plurality of apertures of the metal mesh layer to electrically connect at least the first fiber reinforcement layer with the metal mesh layer.

Description

Technical Field

[0001] The present disclosure relates to electrical conductivity in wind turbine blades and wind turbine blade components. More specifically, the present disclosure relates to lightning protection and equipotentialization of wind turbine blade components such as reinforcement components of blade shells, such as blade shell components, shear webs, spar beams, spar caps, etc. Background Art

[0002] Wind turbine blades made of fiber-reinforced polymers, and in particular the aerodynamic shells of wind turbine blades, are typically manufactured in a mold, where the pressure side and the suction side of the blade are manufactured separately by placing glass fiber mats and / or other fiber-reinforcing materials, such as carbon fibers, in each of two molds. Then, one of the two halves is flipped over and positioned on top of the other of the two halves, and the two halves are adhered together. By rotating and repositioning the entire half mold, the blade components can be positioned on top of each other.

[0003] Wind turbine blades and / or assemblies of wind turbine blades, such as webs and / or shells, can be manufactured by infusing fibers, such as glass fiber mats and / or carbon fiber mats, with a resin, such as polyester or epoxy resin. Infusion of the fibers can be provided by vacuum-assisted resin transfer molding (VARTM).

[0004] As the size of wind turbines and wind turbine blades increases, the risk of wind turbines being struck by lightning increases. Therefore, providing lightning protection measures for wind turbines and in particular for wind turbine blades has received increasing attention.

[0005] As the demand for blades for wind turbines tends to increase towards blades of increasing length, there is a need to manufacture blades with increased stiffness and relatively low weight. One way to achieve these properties is to combine various types of fibres in the laminate structure of the blade, for example, glass fibres and carbon fibres are selected for combination, and carbon fibres or glass fibres can also be advantageously combined with steel fibres. It is thus also possible to combine with other types of fibres, and it is also possible to choose to use only carbon fibres or other suitable fibre types. For example, in a so-called hybrid laminate structure, a combination of glass fibres and carbon fibres may present a problem in that some fibre types are conductive, for example, carbon fibres and steel fibres. A direct lightning strike into the laminate structure may damage the blade including the conductive fibres as they conduct the current and are thereby significantly heated. This is particularly problematic in the case of fibres with relatively poor conductivity, such as carbon fibres, and in the case of a hybrid laminate structure with, for example, mat-like fibres, where an individual mat may have, for example, a small portion of conductive fibres and a larger portion of, for example, non-conductive glass fibres.

[0006] In addition, a wind turbine may accumulate an electrostatic potential during operation. If unbalanced, this electrostatic potential may cause flashover inside the blade, thereby damaging the wind turbine blade or interfering with electronic devices. Summary of the Invention

[0007] It is an object of the present invention to provide a wind turbine blade component for a wind turbine blade that overcomes at least some of the disadvantages of the prior art.

[0008] Accordingly, the present invention relates to a wind turbine blade component for a wind turbine blade. The wind turbine blade component comprises: - a metal mesh layer including a plurality of holes, - at least a first fibre reinforcement layer including a plurality of first conductive fibres, and - a plurality of second conductive fibres, wherein at least some of the plurality of second conductive fibres extend transversely through the plurality of holes of the metal mesh layer so as to electrically connect the at least first fibre reinforcement layer to the metal mesh layer.

[0009] The wind turbine blade component may form at least a part of the main laminate structure or the spar cap of the wind turbine blade.

[0010] By providing a lateral connection between at least a first fiber-reinforced layer and a metal mesh layer, the mechanical stability of a wind turbine blade component is increased, and thereby delamination of the wind turbine component is reduced. Additionally, the electrical connection between the first fiber-reinforced layer and the metal mesh layer is increased, and thereby the potential equalization (or equipotentialization) between at least the first fiber-reinforced layer and the metal mesh layer is better promoted. The potential equalization is achieved via the metal mesh layer, protecting the main laminate structure from damage that may be caused by high currents, such as lightning strikes.

[0011] A method of manufacturing a wind turbine blade component for a wind turbine blade is also disclosed. The method includes: - providing at least a first fiber-reinforced layer including a plurality of first conductive fibers, - providing a metal mesh layer including a plurality of holes, - providing a plurality of second conductive fibers such that at least some of the second conductive fibers extend laterally through the plurality of holes of the metal mesh layer to electrically connect at least the first fiber-reinforced layer and the metal mesh layer, - providing a resin to infuse at least the first fiber-reinforced layer, the metal mesh layer, and the plurality of second conductive fibers, and - curing the resin to form a wind turbine blade component.

[0012] A wind turbine blade is also disclosed, including: - a lightning protection system including a down-conductor or a lightning receptor, - a metal mesh layer including a plurality of holes, the metal mesh layer being electrically connected to the lightning protection system, - at least a first fiber-reinforced layer including a plurality of first conductive fibers, and - a plurality of second conductive fibers, wherein at least some of the plurality of second conductive fibers extend laterally through the plurality of holes of the metal mesh layer to electrically connect at least the first fiber-reinforced layer and the metal mesh layer.

[0013] By providing an electrical connection between the metal mesh layer and the lightning protection system, current can be equalized between the load-carrying structure, i.e., the conductive fibers of the spar cap, and the lightning protection system.

[0014] The metal mesh layer can be electrically connected to the down-conductor. Alternatively, the metal mesh layer can be electrically connected to the lightning receptor. Alternatively, the metal mesh layer can be electrically connected to both the down-conductor and the lightning receptor. The metal mesh layer can be electrically connected to more than one down-conductor or lightning receptor.

[0015] The down-conductor is configured to direct current from a lightning strike to a ground connection. Thus, the down-conductor can extend between a connection point of one or more receptors and the ground connection.

[0016] At least a first fiber reinforcement layer, a metal mesh layer, and a plurality of second conductive fibers can be arranged in a mold cavity formed, for example, by a rigid mold part and a vacuum bag, and a resin is supplied into the mold cavity.

[0017] The plurality of second conductive fibers can be provided as a stitch, provided via a chopped strand mat, provided as a punched fiber, or provided in other forms that provide a mechanical connection and an electrical connection between at least the first fiber reinforcement layer and the metal mesh layer. Alternatively, the at least first fiber reinforcement layer can include a plurality of second out-of-plane conductive fibers.

[0018] For example, the plurality of second conductive fibers can be provided as a stitch connecting at least the first fiber reinforcement layer and the metal mesh layer. Providing the plurality of second conductive fibers can include providing the plurality of second conductive fibers as a stitch that combines the metal mesh layer and the at least first fiber reinforcement layer. The type of stitch can be a running stitch, a cross stitch, a diamond stitch, or other stitches suitable for connecting two layers. The plurality of second conductive fibers can be provided as conductive wires. A plurality of stitches can be provided by one wire.

[0019] The metal mesh layer can be defined by first, second, third, and fourth edges. Preferably, the stitches are provided substantially along at least some of the edges of the metal mesh layer. The edges of the metal mesh layer are most prone to delamination. Thus, by providing stitches along at least some of the edges of the metal mesh layer, the mechanical stability is increased.

[0020] Using stitches to electrically connect the mesh to at least the first fiber reinforcement layer provides a simple solution for electrically connecting the components.

[0021] The plurality of second conductive fibers can be provided as punched fibers, such as needle-punched fibers. Providing the plurality of second conductive fibers can include providing the plurality of second conductive fibers as punched fibers, such as needle-punched fibers, that combine the metal mesh layer and the at least first fiber reinforcement layer. The punched fibers can punch through the metal mesh layer and connect to the at least first fiber reinforcement layer to electrically connect the two layers. The punched fibers can be provided into the at least first fiber reinforcement layer or provided such that they contact the at least first fiber reinforcement layer.

[0022] Multiple second conductive fibers may be provided via a first chopped strand mat. The first chopped strand mat may be provided between at least a first fiber reinforcement layer and a wire mesh layer. Providing multiple second conductive fibers may include providing multiple second conductive fibers via the chopped strand mat. The method may include arranging the chopped strand mat between at least a first fiber reinforcement layer and a wire mesh layer. Some of the second conductive fibers extending transversely through the plurality of holes may be provided by applying a vacuum to the mold cavity.

[0023] Multiple second conductive fibers may extend out of the plane of the chopped strand mat. Thus, when the first chopped strand mat is provided between at least a first fiber reinforcement layer and a wire mesh layer, the multiple second conductive fibers of the first chopped strand mat provide a connection therebetween. The chopped strand mat may be a hybrid chopped strand mat including glass fibers and carbon.

[0024] Using a chopped strand mat provides a simple way to lay up the materials forming at least a first fiber reinforcement layer, the chopped strand mat, and the wire mesh layer, and wherein at least some of the chopped fibers of the chopped strand mat will provide transverse fibers that can both serve as potential-equalising connections and increase transverse mechanical strength.

[0025] When provided via the chopped strand mat, the multiple second conductive fibers may be provided as chopped fibers. When provided via the chopped strand mat, the average length of the multiple second conductive fibers may be between 1 - 100 mm, such as 1 - 70 mm, such as 5 - 50 mm.

[0026] The first chopped strand mat may have a length between 1 - 120 m, such as between 10 - 110 m, such as between 30 - 100 m. The first chopped strand mat may have a width between 1 - 30 m, such as between 1 - 25 m, such as between 5 - 15 m. The first chopped strand mat may have a thickness between 0.01 - 20.0 mm, such as 0.05 - 10.0 mm, such as 0.1 - 5.0 mm. The first chopped strand mat may extend along the entire width and / or the entire length of the wind turbine blade.

[0027] Multiple second conductive fibers may be provided via a plurality of adjacent chopped strand mats including the first chopped strand mat. The plurality of adjacent chopped strand mats are provided between a first fiber reinforcement layer and a wire mesh layer.

[0028] The thickness of each of the multiple second conductive fibers may be between 1 - 20 μm, such as 3 - 12 μm, such as 5 - 10 μm. The thickness of each of the second conductive fibers may correspond to the diameter of each fiber.

[0029] Each of the plurality of second conductive fibers may comprise a metal such as copper or carbon. Each of the plurality of second conductive fibers may comprise carbon fibers, preferably carbon fiber tows.

[0030] The metal mesh layer may comprise a conductive material such as a metal or an alloy such as copper, aluminum, silver or gold, or a combination thereof. In a preferred embodiment, the metal mesh comprises copper or aluminum. The metal mesh layer may be electrically connected to the lower conductor or lightning receiver of the wind turbine blade.

[0031] Each hole of the metal mesh layer is between 0.01 - 20.0 mm, such as 0.1 - 10.0 mm, such as 0.2 - 2.0 mm. The holes of the metal mesh layer may be configured to receive at least one second conductive fiber, but preferably receive a plurality of second conductive fibers.

[0032] The metal mesh layer may have a length between 1 - 120 m, such as between 10 - 110 m, such as between 30 - 100 m. The metal mesh layer may have a thickness between 0.1 - 5.0 mm, such as between 0.2 - 3.0 mm, such as between 0.5 - 1.0 mm. The metal mesh layer may have a width between 1 - 30 m, such as between 1 - 25 m, such as between 5 - 15 m. The metal mesh layer may extend along the entire width and / or the entire length of the wind turbine blade, in which case the metal mesh layer may be used as part of a downward conduction system. The length of the metal mesh layer may correspond to the length of the wind turbine blade and the chordal width of the wind turbine blade. However, the metal mesh layer may also have a width corresponding to the width of the spar cap.

[0033] However, in another preferred embodiment, the metal mesh layer is only formed along a part of the wind turbine blade and is used as a potential equalization part electrically connected to a downward conduction system such as a lower conductor cable. In such a system, the metal mesh (or metal mesh layer) may locally extend, for example, 5 - 200 cm, preferably 10 - 150 cm and more preferably 15 - 100 cm along the length of the wind turbine blade. The metal mesh (or metal mesh layer) may, for example, extend through the entire spar cap in the chordal direction of the blade, or at least extend along most of the width of the spar cap.

[0034] At least the first fiber - reinforced layer may comprise unidirectional fibers. The unidirectional fibers provide mechanical stability and stiffness to the blade. At least the first fiber - reinforced layer may comprise biaxial fibers and / or triaxial fibers. Compared with a layer having unidirectional fibers, a biaxial or triaxial fiber layer has a surface that is easier to connect and further provides mechanical strength in multiple directions. At least the first fiber - reinforced layer may comprise pultruded elements. The first fiber - reinforced layer and / or the second fiber - reinforced layer may comprise carbon fibers, preferably carbon fiber tows.

[0035] A wind turbine blade component may include a plurality of fiber-reinforced layers, the plurality of fiber-reinforced layers including at least a first fiber-reinforced layer and a second fiber-reinforced layer. The at least first fiber-reinforced layer may include biaxial fibers, and the second fiber-reinforced layer may include unidirectional fibers. The at least first fiber-reinforced layer may be disposed between a metal mesh layer and the second fiber-reinforced layer. Alternatively, and preferably, the at least first fiber-reinforced layer may be disposed between a first chopped strand mat and the second fiber-reinforced layer. The first chopped strand mat and the at least first fiber-reinforced layer including biaxial fibers may be sewn together, such as stitched together.

[0036] A wind turbine blade component may include a fiber-reinforced polymer layer including polymer fibers. The fiber-reinforced polymer layer may be disposed adjacent to the metal mesh layer relative to the plurality of fiber-reinforced layers, such as the first fiber-reinforced layer and / or the second fiber-reinforced layer.

[0037] A plurality of third conductive fibers may be provided via a second chopped strand mat. The second chopped strand mat may be arranged such that the metal mesh layer is disposed between the first chopped strand mat and the second chopped strand mat. The second chopped strand mat may provide a further increased mechanical connection and electrical connection between the metal mesh layer and the at least first fiber-reinforced layer, and may further provide a better potential equalization connection to the mesh layer.

[0038] A wind turbine blade component may include a plurality of metal mesh layers, such as a first metal mesh layer and a second metal mesh layer. The plurality of fiber-reinforced layers may be disposed between the first metal mesh layer and the second metal mesh layer.

[0039] The number of second conductive fibers extending laterally per square centimeter may be greater than 1, such as between 1 and 1000, such as between 5 and 500. The number of second conductive fibers extending laterally and passing through the holes of the metal mesh layer may be greater than 1, such as between 1 and 100, such as between 5 and 50. The diameter of each of the plurality of second conductive fibers may be smaller than the holes of the metal mesh layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Embodiments of the present invention will be described in more detail below with reference to the drawings. These illustrate one way of implementing the present invention and should not be construed as being limited to other possible embodiments falling within the scope of the appended claims.

[0041] Figure 1 is a schematic diagram illustrating an exemplary wind turbine,

[0042] Figure 2 is a schematic diagram illustrating an exemplary wind turbine blade,

[0043] Figure 3 is a perspective view of a part of a wind turbine blade,

[0044] Figure 4 is a cross-sectional view of an exemplary wind turbine blade,

[0045] Figures 5a - 5c is a schematic view of a cross-section of an exemplary wind turbine blade component,

[0046] Figure 5d is a perspective view of a part of a wind turbine blade,

[0047] Figure 6 is a schematic view of an exemplary wind turbine blade component, and

[0048] Figure 7 is a schematic view of an exemplary method of manufacturing a wind turbine blade component. DETAILED DESCRIPTION

[0049] Figure 1 Illustrated is a conventional modern upwind wind turbine according to the so-called "Danish concept", which has a tower 4, a nacelle 6, and a rotor with a generally horizontal rotor shaft. The rotor includes a hub 8 and three blades 10 radially extending from the hub 8, each blade having a blade root 16 closest to the hub and a blade tip 14 furthest from the hub 8.

[0050] Figure 2 A schematic view of a wind turbine blade 10 is shown. The wind turbine blade 10 has the shape of a conventional wind turbine blade and includes: a root region 30 closest to the hub, a shaped or airfoil region 34 furthest from the hub, and a transition region 32 located between the root region 30 and the airfoil region 34. The blade 10 includes a leading edge 18 and a trailing edge 20. When the blade is mounted on the hub, the leading edge 18 faces the rotational direction of the blade 10, and the trailing edge 20 faces the opposite direction of the leading edge 18.

[0051] The airfoil region 34 (also referred to as the shaped region) has an ideal or near-ideal blade shape with respect to lift generation, while the root region 30 has a generally circular or elliptical cross-section for structural considerations, for example, to make it easier and safer to mount the blade 10 onto the hub. The diameter (or chord) of the root region 30 can be constant along the entire root region 30. The transition region 32 has a transition profile that gradually changes from the circular or elliptical shape of the root region 30 to the airfoil profile of the airfoil region 34. The chord length of the transition region 32 typically increases with the increasing distance from the hub. The airfoil region 34 has an airfoil profile that has a chord extending between the leading edge 18 and the trailing edge 20 of the blade 10. The width of the chord decreases with the increasing distance from the hub.

[0052] The shoulder 40 of the blade 10 is defined as the location where the blade 10 has its maximum chord length. The shoulder 40 is typically provided at the boundary between the transition region 32 and the airfoil region 34.

[0053] It should be noted that the chords of different sections of the blade generally do not lie in a common plane, as the blade twists and / or bends (i.e., pre-bends), thus providing chord planes with correspondingly twisted and / or bent lines, which is the most common case to compensate for the local velocity of the blade depending on the radius from the hub.

[0054] The wind turbine blade 10 includes a blade shell, which includes two blade shell components or half-shells, typically made of fiber-reinforced polymer, a first blade shell component 24 and a second blade shell component 26. The wind turbine blade 10 may include additional shell components, such as a third shell component and / or a fourth shell component. The first blade shell component 24 is typically the pressure side or windward blade shell component. The second blade shell component 26 is typically the suction side or leeward blade shell component. The first blade shell component 24 and the second blade shell component 26 are fastened together along a bond line or glue joint 28 with an adhesive, such as glue, which extends along the trailing edge 20 and the leading edge 18 of the blade 10. Typically, the root ends of the blade shell components 24, 26 have a semi-circular or semi-elliptical outer cross-sectional shape.

[0055] Figure 3 A perspective view of the blade shell components 24, 26 is shown, which includes a load-bearing or reinforcing structure 50, which forms the spar cap or main laminate of the blade shell component. The blade shell component includes a metal mesh layer 80, which is arranged on the load-bearing structure 50 and distributed along the length of the blade shell. The metal mesh layers 80 may be spaced apart, for example, substantially equidistantly. The metal mesh layer 80 will be electrically connected to the lightning protection system of the blade, such as a lower conductor (not shown). The spar cap may be integrated into the blade shell component, or it may be a separate spar cap, for example, attached to the blade shell components 24, 26 by adhesion. The spar cap may be part of a separate spar structure. However, a blade may also be provided with spar caps provided at both the pressure side shell component 26 and the suction side shell component 24, with one or more shear webs 42 attached between the spar caps. Alternatively, the shear web 42 may be a spar box having spar sides, such as trailing edge spar sides and leading edge spar sides. The spar cap may include carbon fiber, while the remainder of the shell components 24, 26 may include glass fiber.

[0056] Figure 4 A cross-sectional view of an exemplary wind turbine blade 10 according to the present disclosure is shown. Note that, Figure 4The design shown includes a plurality of lightning receivers. However, it should be recognized that the present invention is also applicable to and advantageous for embodiments having only a single lightning receiver. For example, the single lightning receiver is arranged near the tip of the blade and is connected to the lower conductor in the form of a cable, which can be an insulated or non-insulated cable.

[0057] The wind turbine blade includes a blade housing, which includes blade housing components 24, 26. In the illustrated embodiment, the blade housing components 24, 26 include an integrated load-bearing structure 50 and a lightning protection system. The internal components of the blade 10 include two substantially longitudinally extending shear webs 42. The lightning protection system includes a number of lightning receivers 90 provided at the outer surface of the blade housing 24, 26. The lightning protection system includes lightning down conductors 92, each of which is electrically connected to the lightning receiver 90 via a connection member 94. In another embodiment (not shown) including a lightning protection system having only a single lightning receiver, the lightning down conductor can be directly connected to the lightning receiver.

[0058] The lightning down conductor 92 is further configured to be electrically connected to a ground connection. The lightning receiver 90 and the connection member 94 are, for example, metal elements, which are configured to conduct a lightning current that may be extremely high or strong. The lightning current must be reliably conducted from the lightning down conductor 92 to the ground connection (not shown), optionally through a spark gap. The lightning receiver 90 can be connected to the connection member 94 through a terminal, which is configured to reliably transfer the lightning current from the receiver 90 to the connection member 94. In the blade 10, the load-bearing structure 50 includes conductive fibers, such as carbon fibers. The blade 10 includes a potential equalization system, which includes a conductive metal mesh layer 80, and the conductive metal mesh layer is configured to provide a potential equalization connection between the conductive fibers of the load-bearing structure 50 and the lightning protection system. The metal mesh layers 80 are each connected to the corresponding portions of the conductive fibers in the load-bearing structure 80 and are connected to the down conductor 92 via the lightning receiver 90, or alternatively or additionally directly connected to the down conductor 92 via a separate conductor. The metal mesh is shown as a layer in Figure 4 as a layer.

[0059] As mentioned, Figure 4 the illustrated embodiment includes a plurality of lightning receivers. In another embodiment having only a single or a few lightning receivers, the lightning down conductor can be arranged inside the blade, for example, arranged on one of the shear webs. Then, the metal mesh layer can be arranged on the load-bearing structure, and the load-bearing structure is in potential equalization with the lightning down conductor via a conductor.

[0060] Figures 5a - 5cis a schematic cross-sectional view illustrating different embodiments of a wind turbine blade component, such as at least a portion of a main laminate structure or spar cap of a wind turbine blade, as visible in a cross-sectional view or chord plan view of a wind turbine blade. Figure 5d is a perspective view of a portion of a wind turbine blade of an embodiment. The wind turbine blade component 52 includes a metal mesh layer 80 and a plurality of fiber reinforced layers 60, the plurality of fiber reinforced layers including a first fiber reinforced layer 60' forming a load-bearing structure 50. The fiber reinforced layer 60 includes a plurality of first conductive fibers 62, such as carbon fibers or carbon fiber tows. The metal mesh layer 80 includes a plurality of holes 82 and includes a conductive material, such as copper. Figure 5b A plurality of transverse connectors of the conductive fibers 70 are arranged to extend transversely through the thickness of the stacked fiber layers 60 of the load-bearing structure 50. The conductive fibers 70 are configured to dissipate energy into the plurality of stacked fiber reinforced layers 60. The metal mesh layer 80 may also be connected to the lower conductor 92 in some other way. When the metal mesh layer 50 and thus the conductive fibers 62 of the fiber reinforced layer 60 are connected to the lower conductor 92, the fibers 62 of the fiber reinforced layer 60, the metal mesh layer 80, and the lower conductor 92 have the same potential, thereby at least reducing the flashover risk of the lightning current in the lower conductor 92 transferring to the fibers 62 of the load-bearing structure 50. The lightning receiver 90 is preferably arranged beside the load-bearing structure 50 so as not to impair its strength. The number and position of the lightning receivers 90 are selected according to the size of the blade 10. The metal mesh layer 50 may extend through the entire main laminate structure, and only a single lower conductor 92 is sufficient to conduct the current to the ground.

[0061] A plurality of second conductive fibers 70 provide better electrical connection between the first fiber reinforced layer 60' and the metal mesh layer 80 by providing a plurality of connections transversely. The wind turbine blade component 52 may include additional layers other than those illustrated in

[0062] as illustrated in Figures 5a - 5c such as those illustrated in Figure 6 as illustrated. Figures 5a - 5c illustrates different ways of electrically connecting at least the first fiber reinforced layer 60' to the metal mesh layer 80.

[0063] In Figure 5a a plurality of second conductive fibers 70 are provided via a chopped strand mat 72. The chopped strand mat 72 includes a plurality of chopped conductive fibers 70 extending from the plane of the chopped strand mat 72. The chopped fibers 70 extend into the metal mesh layer 80 and through the holes 82, thereby electrically connecting the metal mesh layer 80 to the first fiber reinforced layer 60' in contact with the chopped strand mat 72. The chopped strand mat 72 and the first fiber reinforced layer 60' preferably contact each other, preferably along the entire surface of at least one of the chopped strand mat 72 or the first fiber reinforced layer 60'.

[0064] exist Figure 5b In the figure, a plurality of second conductive fibers 70 are provided as stitching 74. The stitching 74 is provided so that the metal mesh layer and the first fiber reinforced layer 60' are stitched together. In the figure, a single line of the second conductive fiber 70 is illustrated. However, there may be more conductive fibers 70 extending in the same direction as the illustrated direction or extending in another direction. The stitching 74 is arranged to pass through the metal mesh layer 80 by being arranged to pass through the hole 82 before being arranged to pass through the first fiber reinforced layer 60'. The stitching 74 is illustrated as passing through the first fiber reinforced layer 60'. However, the stitching 74 may preferably pass through a plurality of fiber reinforced layers 60. The stitching 74 in the figure is illustrated as a wavy stitching, but other suitable stitching may be used in addition to or instead of this. As shown in Figure 5d As illustrated in FIG. 8 , stitching is preferably provided substantially along at least some edges 84 of the metal mesh layer 80 .

[0065] exist Figure 5b and 5c In the embodiment shown in FIG. 1 , the two layers 80 , 60 ′ are shown as being spaced apart for illustration purposes only. However, the two layers 80 , 60 ′ are in contact with each other, preferably along the entire surface of at least one of the layers 80 , 60 ′.

[0066] exist Figure 5c In the embodiment shown in , the plurality of second conductive fibers 70 are provided as piercing fibers 76, such as needle-punched fibers. The piercing fibers 76 are provided to pass through the holes 82 of the metal mesh layer 80 and contact the first fibers and the first fiber-reinforced layer 60'. The piercing fibers 76 can be pierced so that they contact the first conductive fibers 62 of the first fiber-reinforced layer 60'. Therefore, the piercing fibers 76 can be pierced into the first fiber-reinforced layer 60' (as shown), or pierced so that they contact the first fiber-reinforced layer 60'.

[0067] Figure 6 is a diagram of a wind turbine blade component, such as a wind turbine blade component including a main laminate structure or a spar cap, such as Figures 5a - 5c 5. The figure illustrates different layers that a wind turbine blade may include. Although the figure illustrates a specific combination of layers, the wind turbine blade component may include fewer layers than shown or more layers than shown.

[0068] The wind turbine blade component 52 includes a metal mesh layer 80 and a load-bearing structure 50, and the load-bearing structure includes a plurality of fiber-reinforced layers 60. The plurality of fiber-reinforced layers 60 may include a first fiber-reinforced layer 60', a second fiber-reinforced layer 60", and a third fiber-reinforced layer 60'", wherein each of the plurality of fiber-reinforced layers 60 includes a plurality of first conductive fibers 62. The metal mesh layer 80 and at least the first fiber-reinforced layer 60' are mechanically and / or electrically connected to a plurality of second conductive fibers 70. The plurality of second conductive fibers 70 are illustrated as being provided as a chopped strand mat 72. However, the plurality of second conductive fibers 70 may be provided in a manner other than as Figures 5a - 5c illustrated. First and second chopped strand mats 72 may be provided on each side of the metal mesh layer 80 as Figure 6 illustrated, or as Figure 5a illustrated, one chopped strand mat 72 may be provided.

[0069] The first fiber-reinforced layer 60' may be a biax layer or a triax layer that includes biaxial or triaxial fibers, such as carbon fiber tows. The second fiber-reinforced layer 60" may include unidirectional fibers, such as unidirectional carbon fibers or carbon fiber tows. The wind turbine blade component 52 may include a plurality of unidirectional fiber layers, i.e., a plurality of second fiber-reinforced layers 60". The wind turbine blade component 52 may include a third fiber-reinforced layer 60'", which includes biaxial or triaxial fibers. The wind turbine blade component 52 includes blade shell components 24, 26 made of a fiber-reinforced polymer material. The third fiber-reinforced layer 60'" may be disposed between the second fiber-reinforced layer 60'" or the plurality of second fiber-reinforced layers 60'" and the blade shell components 24, 26.

[0070] Figure 7 is a diagram illustrating an exemplary method 200 for manufacturing a wind turbine blade component, such as Figure 4 -5 wind turbine blade components.

[0071] The method 200 includes providing 202 a first fiber-reinforced layer, such as including carbon fibers, and providing 204 a metal mesh layer, such as including copper. The method 200 includes providing 206 a plurality of second conductive fibers, wherein the plurality of second conductive fibers may be provided 206a via a chopped strand mat, provided 206b as a stitch, or provided 206c as a puncture fiber. The method 200 further includes applying 208 a vacuum to the first fiber-reinforced layer, the metal mesh layer, and the chopped strand mat, at least in the case where the plurality of second conductive fibers are provided via a chopped strand mat. The vacuum will help the chopped fibers of the chopped strand mat to be at least partially oriented in the transverse direction and provide an electrical connection.

[0072] Then, method 200 includes providing 210 resin to infuse at least a first fiber reinforced layer, a metal mesh layer, and a plurality of second conductive fibers, and curing 212 the resin to form a wind turbine blade component. The first fiber reinforced layer, the metal mesh layer, and the plurality of second conductive fibers may be disposed in a mold cavity formed, for example, by a rigid mold component and a vacuum bag, and wherein the resin is supplied to the mold cavity.

[0073] Item

[0074] Exemplary embodiments of the present disclosure are set forth in the following items:

[0075] 1. A wind turbine blade component for a wind turbine blade, the wind turbine blade component comprising: - A metal mesh layer including a plurality of holes, - At least a first fiber reinforced layer including a plurality of first conductive fibers, and - A plurality of second conductive fibers, wherein at least some of the plurality of second conductive fibers extend laterally through the plurality of holes of the metal mesh layer to electrically connect the at least first fiber reinforced layer to the metal mesh layer.

[0076] 2. The wind turbine blade component according to item 1, wherein the plurality of second conductive fibers are provided as a stitching portion connecting the at least first fiber reinforced layer and the metal mesh layer.

[0077] 3. The wind turbine blade component according to item 2, wherein the type of the stitching portion is a wavy stitching portion, a cross stitching portion, or a diamond stitching portion.

[0078] 4. The wind turbine blade component according to item 3, wherein the metal mesh layer is defined by first, second, third, and fourth edges, and wherein the stitching portion is provided substantially along at least some of the edges of the metal mesh layer.

[0079] 5. The wind turbine blade component according to any one of the foregoing items, wherein each of the plurality of second conductive fibers includes a metal such as copper or carbon.

[0080] 6. The wind turbine blade component according to item 1, wherein the plurality of second conductive fibers are provided as piercing fibers, such as needle punching fibers.

[0081] 7. The wind turbine blade component according to item 1, wherein the plurality of second conductive fibers are provided via a first chopped strand mat, and wherein the first chopped strand mat is provided between the at least first fiber reinforced layer and the metal mesh layer.

[0082] 8. The wind turbine blade component according to item 7, wherein the average length of the plurality of second conductive fibers is between 1 and 100 mm, such as between 1 and 70 mm, such as between 5 and 50 mm.

[0083] 9. The wind turbine blade component according to any one of items 7 - 8, wherein the first chopped strand mat has a length between 1 and 120 m, such as between 10 and 110 m, such as between 30 and 100 m, and / or a thickness between 0.01 and 20.0 mm, such as between 0.05 and 10 mm, such as between 0.01 and 5.0 mm, and / or a width between 1 and 30 m, such as between 1 and 25 m, such as between 5 and 15 m.

[0084] 10. The wind turbine blade component according to any one of the foregoing items, wherein each of the plurality of second conductive fibers comprises carbon fiber, preferably a carbon fiber tow.

[0085] 11. The wind turbine blade component according to item 1, wherein the plurality of second conductive fibers are provided via a plurality of adjacent chopped strand mats including the first chopped strand mat, and wherein the plurality of adjacent chopped strand mats are provided between the first fiber - reinforced layer and the metal mesh layer.

[0086] 12. The wind turbine blade component according to any one of the foregoing items, wherein the thickness of each of the plurality of second conductive fibers is between 1 and 20 μm, such as between 3 and 12 μm, such as between 5 and 10 μm.

[0087] 13. The wind turbine blade component according to any one of the foregoing items, wherein the metal mesh layer comprises a conductive material, such as a metal or an alloy, such as copper, aluminum, silver or gold, or a combination thereof.

[0088] 14. The wind turbine blade component according to any one of the foregoing items, wherein each hole of the metal mesh layer is between 0.01 and 20.0 mm, such as between 0.1 and 10.0 mm, such as between 0.2 and 2.0 mm.

[0089] 15. The wind turbine blade component according to any one of the foregoing items, wherein the metal mesh layer is electrically connected to the lower conductor or lightning receiver of the wind turbine blade.

[0090] 16. A wind turbine blade component according to any one of the preceding items, wherein the metal mesh layer has a length between 1 and 120 m, such as between 10 and 110 m, such as between 30 and 100 m, and / or a thickness between 0.1 and 5.0 mm, such as between 0.2 and 3.0 mm, such as between 0.5 and 1.0 mm, and / or a width between 1 and 30 m, such as between 1 and 25 m, such as between 5 and 15 m.

[0091] 17. A wind turbine blade component according to any one of the preceding items, wherein at least the first fiber-reinforced layer comprises unidirectional fibers.

[0092] 18. A wind turbine blade component according to any one of the preceding items, wherein at least the first fiber-reinforced layer comprises biaxial and / or triaxial fibers.

[0093] 19. A wind turbine blade component according to any one of the preceding items, comprising a plurality of fiber-reinforced layers, the plurality of fiber-reinforced layers comprising at least a first fiber-reinforced layer and a second fiber-reinforced layer, wherein at least the first fiber-reinforced layer comprises biaxial fibers and the second fiber-reinforced layer comprises unidirectional fibers.

[0094] 20. A wind turbine blade component according to any one of the preceding items, wherein at least the first fiber-reinforced layer comprises pultruded elements.

[0095] 21. A wind turbine blade component according to any one of the preceding items, wherein at least the first fiber-reinforced layer comprises carbon fibers, preferably carbon fiber tows.

[0096] 22. A wind turbine blade component according to any one of the preceding items, wherein the wind turbine blade component forms at least part of the main laminate structure or spar cap of a wind turbine blade.

[0097] 23. A wind turbine blade component according to item 7, comprising a plurality of third conductive fibers provided via a second chopped strand mat, wherein the second chopped strand mat is arranged such that the metal mesh layer is disposed between the first chopped strand mat and the second chopped strand mat.

[0098] 24. A wind turbine blade component according to any one of the preceding items, wherein the number of second conductive fibers extending transversely per square centimeter is greater than 1, such as between 1 and 1000, such as between 5 and 500.

[0099] 25. A method of manufacturing a wind turbine blade component for a wind turbine blade, wherein the method comprises: - providing at least a first fiber-reinforced layer, which comprises a plurality of first conductive fibers, - Provide a metal mesh layer, which includes a plurality of holes, - Provide a plurality of second conductive fibers such that at least some of the second conductive fibers extend transversely through the plurality of holes of the metal mesh layer so as to electrically connect at least the first fiber reinforced layer and the metal mesh layer, - Provide a resin to infuse at least the first fiber reinforced layer, the metal mesh layer, and the plurality of second conductive fibers, and - Cure the resin to form a wind turbine blade component.

[0100] 26. The method according to item 25, wherein at least the first fiber reinforced layer, the metal mesh layer, and the plurality of second conductive fibers are arranged in a mold cavity formed, for example, by a rigid mold part and a vacuum bag, and wherein the resin is supplied into the mold cavity.

[0101] 27. The method according to any one of items 25 - 26, wherein providing a plurality of second conductive fibers includes providing a plurality of second conductive fibers via a chopped strand mat, and wherein the method includes arranging the chopped strand mat between at least the first fiber reinforced layer and the metal mesh layer.

[0102] 28. The method according to any one of items 26 - 27, wherein some of the second conductive fibers extending transversely through the plurality of holes are provided by applying a vacuum to the mold cavity.

[0103] 29. The method according to any one of items 25 - 26, wherein providing a plurality of second conductive fibers includes providing the plurality of second conductive fibers as a stitching portion that combines the metal mesh layer and at least the first fiber reinforced layer.

[0104] 30. The method according to any one of items 25 - 26, wherein providing a plurality of second conductive fibers includes providing the plurality of second conductive fibers as piercing fibers, such as needled fibers, that combine the metal mesh layer and at least the first fiber reinforced layer.

[0105] List of reference symbols 2 Wind turbine 4 Tower 6 Nacelle 8 Hub 10 Blade 14 Blade tip 15 Tip end 16 Blade root 17 Root end 18 Leading edge 20 Trailing edge 24 First blade housing component (pressure side) 26 Second blade housing component (suction side) 28 Bonding line / glued joint 30 Root region 32 Transition region 34 Airfoil region 38 Chord line 40 Shoulder 42 Shear web or spar side 44 Inner surface 50 Load-bearing structure 52 Wind turbine blade component 60′ First fiber-reinforced layer 60″ Second fiber-reinforced layer 60 Fiber-reinforced layer 62 First conductive fiber 64 Fiber-reinforced polymer layer 70 Second conductive fiber 72 Chopped strand mat 74 Stitching 76 Piercing fiber 80 Metal mesh layer 82 Hole 84 Edge 90 Receiver 92 Lower conductor 94 Connector 200 Manufacturing method 202 Provide the first fiber-reinforced layer 204 Provide the metal mesh layer 206 Provide a plurality of second conductive fibers 206a A plurality of second conductive fibers are provided via a chopped strand mat 206b A plurality of second conductive fibers are provided as stitching 206c A plurality of second conductive fibers are provided as piercing fibers 208 Apply a vacuum 210 Provide resin 212 Cure the resin

Claims

1. A wind turbine blade component for a wind turbine blade, the wind turbine blade component comprising: - A metal mesh layer including a plurality of holes, - At least a first fiber reinforced layer including a plurality of first conductive fibers, and - A plurality of second conductive fibers, wherein at least some of the plurality of second conductive fibers extend transversely through the plurality of holes of the metal mesh layer so as to electrically connect the at least first fiber reinforced layer to the metal mesh layer.

2. The wind turbine blade component according to claim 1, wherein, The plurality of second conductive fibers are provided as stitching and / or piercing fibers, such as needling fibers, connecting the at least first fiber reinforced layer and the metal mesh layer.

3. The wind turbine blade component according to claim 1, wherein, The plurality of second conductive fibers are provided via a first chopped strand mat, wherein the first chopped strand mat is provided between the at least first fiber reinforced layer and the metal mesh layer.

4. A wind turbine blade component according to any one of the preceding claims, wherein, Each of the plurality of second conductive fibers comprises a carbon fiber, preferably a carbon fiber tow.

5. A wind turbine blade component according to any one of the preceding claims, wherein, The metal mesh layer is electrically connected to a lower conductor or a lightning receiver of the wind turbine blade.

6. A wind turbine blade component according to any one of the preceding claims, wherein, The at least first fiber reinforced layer comprises a carbon fiber, preferably a carbon fiber tow.

7. A wind turbine blade component according to any one of the preceding claims, wherein, The wind turbine blade component forms at least a part of a main laminate structure or a spar cap of the wind turbine blade.

8. A method of manufacturing a wind turbine blade component for a wind turbine blade, wherein, The method comprises: - Providing at least a first fiber reinforced layer including a plurality of first conductive fibers, - Providing a metal mesh layer including a plurality of holes, - Providing a plurality of second conductive fibers such that at least some of the second conductive fibers extend transversely through the plurality of holes of the metal mesh layer so as to electrically connect the at least first fiber reinforced layer to the metal mesh layer, - Providing a resin to infuse the at least first fiber reinforced layer, the metal mesh layer and the plurality of second conductive fibers, and - Curing the resin to form the wind turbine blade component.

9. The method according to claim 8, wherein The at least first fiber reinforced layer, the metal mesh layer and the plurality of second conductive fibers are arranged in a mold cavity formed, for example, by a rigid mold part and a vacuum bag, and wherein the resin is supplied into the mold cavity.

10. The method according to any one of claims 8-9, wherein, Providing the plurality of second conductive fibers comprises providing the plurality of second conductive fibers via a chopped strand mat, and wherein the method comprises arranging the chopped strand mat between the at least first fiber reinforced layer and the metal mesh layer.

11. According to the method according to any one of claims 8-10, wherein, Some of the second conductive fibers extending transversely through the plurality of holes are provided by applying a vacuum to the mold cavity.

12. The method according to any one of claims 8-11, wherein, Providing the plurality of second conductive fibers comprises providing the plurality of second conductive fibers as stitching and / or piercing fibers, such as needling fibers, combining the metal mesh layer and the at least first fiber reinforced layer.

13. A wind turbine blade, comprising: - An aerodynamic blade shell, - A lightning protection system including a lightning receiver and a lower conductor connected to the lightning receiver, - A spar cap integrated in or connected to the aerodynamic blade shell, wherein the spar cap comprises: ο A metal mesh layer including a plurality of holes, the metal mesh layer being electrically connected to the lightning protection system, ο At least a first fiber reinforced layer including a plurality of first conductive fibers, and ο A plurality of second conductive fibers, Among them, at least some of the plurality of second conductive fibers extend transversely through the plurality of holes of the metal mesh layer so as to electrically connect the at least first fiber reinforcement layer to the metal mesh layer.

14. The wind turbine blade according to claim 13, wherein, The metal mesh layer is electrically connected to the lower conductor and / or the lightning receiver.

15. A wind turbine blade according to any one of claims 13 - 14, comprising any feature of claim 7.

Images