Sspar cap structure comprising stack of glass fibers with conductive elements

Abstract

In a first aspect, a spar cap structure for a wind turbine blade is provided. The spar cap structure includes a carbon fiber stack and a glass fiber stack. The carbon fiber stack comprises a plurality of layers of one or more carbon fiber members arranged one layer on top of another so as to form a row of layers of the one or more carbon fiber members; and one or more conductive yarns disposed between two consecutive rows of layers of one or more carbon fiber members. The glass fiber stack includes one or more layers of one or more glass fiber members, and a conductive element electrically connected to the conductive yarn of the carbon fiber stack. The glass fiber stack is configured to receive a lightning receiver to be electrically connected to the conductive element. Further, the one or more conductive yarns and the conductive element at least partially overlap. In another aspect, a wind turbine blade is provided that includes one or more spar cap structures according to any of the examples herein. In still another aspect, a method for manufacturing a spar cap structure and a wind turbine blade according to any of the examples herein is provided.

Description

Technical Field

[0001] This disclosure relates to a spar cap structure comprising a glass fiber stack having conductive elements, a wind turbine blade comprising a spar cap structure, and methods for manufacturing such spar cap structures and such wind turbine blades. Background Technology

[0002] Modern wind turbines are typically used to supply electricity to the grid. This type of wind turbine generally consists of a rotor with a hub and multiple turbine blades. The rotor begins to rotate under the influence of wind on the blades. The rotation of the rotor shaft is either directly (“direct drive”) or driven by a generator rotor using a gearbox. The gearbox (if present), generator, and other systems are typically housed in a nacelle atop the wind turbine tower.

[0003] Wind turbine blades are generally made of fiber-reinforced polymer or plastic (FRP), a composite material consisting of a polymer matrix reinforced with fibers. The fibers are typically glass or carbon and provide longitudinal stiffness and strength.

[0004] Wind turbine blades are typically manufactured by joining blade shell sections made of fiber-reinforced polymers, such as glass fiber or carbon fiber reinforced polymers. These blade shell sections can be molded using resin infusion or prepreg techniques. In resin infusion, fibers are placed in a mold, and resin is then injected into the mold cavity under pressure. The resin fills the volume between the cavities, and then the resin cures or hardens. Examples of resin infusion techniques include resin transfer molding (RTM) or vacuum-assisted resin transfer molding (VARTM). In VARTM, the resin is injected under vacuum or pressure below atmospheric pressure.

[0005] A load-bearing structure may be arranged between the pressure-side blade shell portion and the suction-side blade shell portion. The load-bearing structure may include reinforcing structures with opposing spars attached to the respective blade shell portions. The spars may be embedded within the composite laminate of the blade shell portion or laminated to the inner surface of the blade shell. The spars serve to receive reinforcing structures, such as a pair of opposing flanges, and to structurally reinforce the wind turbine blade. Providing spars in the blade shell portion typically improves the stiffness, buckling resistance, and strength of the wind turbine blade. The spars extend along the longitudinal length of the wind turbine blade.

[0006] The spar cap can be made of various materials, including glass fiber laminates and carbon fiber laminates. For example, glass fiber fabrics or carbon fiber fabrics can be used to manufacture the spar cap. Pultrusion composites can be used alternatively to improve mechanical properties. A pultrusion composite or pultruded part is a fiber-reinforced material impregnated with resin and stretched through a heated static die, causing the resin to cure and undergo polymerization. Pultrusion composites may include carbon fiber pultruded parts and / or glass fiber pultruded parts. Thus, the pultrusion process is typically characterized by a continuous process of producing composite sections with a constant cross-section. Therefore, multiple pultruded parts can be vacuum-cast together in a die to form the spar cap. The pultruded parts are prefabricated, which allows for high quality levels and high fiber structure and uniformity.

[0007] Recently, there has been a trend towards increasing the size of wind turbine blades to capture more wind. Larger blades typically involve higher mechanical requirements. Furthermore, manufacturing complexity increases with blade size. Carbon fibers (e.g., carbon fiber pultrusions) offer a better stiffness-to-weight ratio and fatigue resistance than glass fibers (e.g., glass fiber pultrusions). Therefore, carbon fibers (e.g., carbon fiber pultrusions) can be used to meet these high mechanical requirements.

[0008] Furthermore, as the size of wind turbine blades increases, the risk of lightning strikes on them also increases. Wind turbine blades can be equipped with lightning receivers to capture lightning strikes. These lightning receivers are electrically connected to downconductors arranged inside the wind turbine blades to conduct the lightning current to the ground.

[0009] Carbon fiber has a higher conductivity than glass fiber. A lightning strike on carbon fiber can cause it to conduct lightning current. However, the resin binding the carbon fiber layers (e.g., several carbon fiber pultrusions) has lower conductivity. Therefore, any gaps between the resin and the carbon fiber layers can impede the flow of lightning current between the carbon fiber layers (e.g., carbon fiber pultrusions). This can create a risk of internal flashover between the carbon fiber layers, which can potentially damage the material. To address this, thin conductive yarns can be provided between the carbon fiber layers, such as between carbon fiber pultrusions. These thin conductive yarns have a higher conductivity than the resin. These conductive yarns can be electrically connected to a down conductor.

[0010] The high stiffness-to-weight ratio of carbon fiber (e.g., carbon fiber pultrusions) does not allow for subsequent machining, such as the abrupt cessation of unidirectional fiber machining, because cracks would rapidly propagate from holes or orifices formed in the carbon fiber (e.g., in the unidirectional carbon fiber of a carbon fiber pultrusion). Furthermore, cutting tools used for machining carbon fiber experience significant wear and high power consumption. For these reasons, carbon fiber is not machined for subsequent installation of lightning receivers. As a result, the lightning receiver is inserted into glass fiber, for example, into the core structure near the spar cap structure.

[0011] Installing these lightning receivers within the core structure and connecting them to the conductive yarn arranged between the carbon fiber layers (e.g., carbon fiber pultrusions) of the spar cap is complex and requires several components. Copper components are generally, at least partially, arranged on the inner side of the core structure, extending from the spar cap. Some of these copper components are used to connect the conductive yarn to the down conductor. These copper components are generally arranged on the inner side of the blade shell and are separate from the spar cap.

[0012] For example, a structure called a lightning protection ear can be made of copper mesh. These lightning protection ears can extend from the spar cap and can be arranged on the inside of the core structure. Using these lightning protection ears may involve using interconnecting cables that are connected to the lightning protection ears via copper discs attached to them. These interconnecting cables can connect the lightning protection ears to the down conductor.

[0013] Conductive yarns can be bonded to the copper mesh after the spar cap is manufactured. These copper meshes can be damaged or detached from the spar cap when it is transferred from the spar cap mold to the blade shell mold. Furthermore, aligning these copper meshes with the shell (e.g., the core structure) is difficult. Additionally, because the copper mesh or lightning protection lugs are located on the inside of the core structure, it is difficult to detect damage and misalignment of the copper mesh or lightning protection system by inspection from the outside of the wind turbine blade (e.g., by ultrasonic inspection). Moreover, the adhesion between the lightning protection lugs or copper mesh and the blade shell is generally poor. The adhesion between the copper disc and the copper mesh is also generally poor.

[0014] In other examples, the copper components are arranged inside the core structure. Installing these components onto the core structure requires precision machining. Therefore, these operations are both complex and time-consuming. Furthermore, machining the core structure to house the copper components and the lightning receivers of the lightning protection system can weaken the core structure. Consequently, the structural integrity of the wind turbine blades can be adversely affected. In these examples, the connection between the conductive yarn and the copper components is also complex. The adhesion between the copper components and the core structure may also be poor.

[0015] This disclosure provides examples of systems and methods that at least partially address some of the disadvantages mentioned above. Summary of the Invention

[0016] In a first aspect, a spar cap structure for a wind turbine blade is provided. The spar cap structure comprises a carbon fiber stack and a glass fiber stack.

[0017] A carbon fiber stack comprises one or more layers of carbon fiber members arranged in a manner such that one layer is on top of another to form rows of carbon fiber members. The carbon fiber stack further comprises one or more conductive yarns disposed between two consecutive rows of carbon fiber member layers.

[0018] A fiberglass stack comprises one or more fiberglass components, one or more layers, and conductive elements electrically connected to conductive yarns in the fiberglass stack. The fiberglass stack is configured to house a lightning receiver to be electrically connected to the conductive elements.

[0019] According to this aspect, a lightning receiver for capturing potential lightning strikes can be installed in a fiberglass stack within a spar cap structure. Because the stiffness of fiberglass is lower than that of carbon fiber, the wear of cutting tools used for machining fiberglass is significantly less than that used for machining carbon fiber. This simplifies the equipment required for performing machining operations in fiberglass and reduces power consumption. Furthermore, the safety risks associated with machining fiberglass are reduced. Therefore, machining one or more layers of fiberglass components is simpler than machining one or more layers of carbon fiber components.

[0020] Fiber machining may include forming perforations or holes in the fibers. Layers of one or more glass fiber members, with reduced stiffness and lower stress compared to layers of one or more carbon fiber members, are more resistant to damage when perforated. This higher damage resistance of the glass fiber members reduces crack propagation from holes in the glass fiber members. Perforations or holes can be drilled in the glass fiber stack of the spar cap; therefore, orifices can be easily created through the entire first glass fiber stack. Thus, lightning receivers can be inserted through such orifices drilled in the glass fiber stack.

[0021] The combination of carbon fiber and glass fiber stacks in the spar cap structure allows for acceptable mechanical properties and improves the flexibility of installing lightning receivers at different locations along the longitudinal direction of the wind turbine blade. This prevents perforation of the wind turbine blade's core structure to accommodate lightning receivers. Consequently, the risk of crack propagation along the core structure is significantly reduced. As a result, the structural integrity of the wind turbine blade is improved.

[0022] Furthermore, the lightning component can be integrally integrated within the spar cap. This improves the accuracy and precision of the manufacturing process. Additionally, the handling process for placing the spar cap in the blade shell mold is simplified. This further prevents the lightning component from detaching from the blade shell (e.g., from the spar cap or from the core structure).

[0023] Furthermore, since the conductive yarn arranged between the carbon fiber pultruded component and the conductive element of the glass fiber stack forms part of the spar cap structure, the electrical connection between the conductive yarn of the carbon fiber stack and the conductive element of the glass fiber stack can be easily performed. Therefore, the conductive yarn of the carbon fiber stack can be electrically connected to the downconductor of the wind turbine blade in a simple manner via the conductive element of the glass fiber stack and / or via a lightning receiver. Thus, the electrical connection between the conductive yarn of the carbon fiber stack and the conductive element of the glass fiber stack can be performed before the entire wind turbine blade is formed. This allows for a reduction in the number of components and avoids performing some post-operational tasks, such as machining the blade shell to install a typical copper disc and brazing the conductive yarn arranged between the carbon fiber pultruded components to the copper disc.

[0024] Furthermore, by perforating the fiberglass stack, maintenance and repair operations of the lightning protection system can be easily performed from the outside of the wind turbine blade, such as repairing the connection between the lightning receiver and the conductive yarn of the carbon fiber stack. Therefore, providing a fiberglass stack in the spar cap structure allows for simplified repair of the wind turbine blade.

[0025] In this disclosure, a glass fiber stack refers to a stack comprising one or more layers of glass fiber members, each layer being disposed on top of the other. The glass fiber stack is primarily formed by layers of one or more glass fiber members. The glass fiber stack may also include a minimum amount of fibers made of other types of fibers or other components, but in an amount that does not impede perforation throughout the entire thickness of the glass fiber stack. The layers of the glass fiber members may be made of glass fiber fabric or glass fiber pultrusion. For example, each layer of one or more glass fiber members may be made of glass fiber pultrusion. Thus, the glass fiber members can be either glass fiber pultrusion or glass fiber fabric.

[0026] In this disclosure, the conductive yarn disposed in the carbon fiber stack should be understood as a thin conductive yarn made of a conductive material having a conductivity greater than that of the resin disposed between the layers, to potentially balance the two consecutive layers of the carbon fiber component. The conductive yarn of the carbon fiber stack has the shape of a sheet, foil, or mesh. The conductive yarn may include carbon fibers, metal wires, and combinations thereof arranged biaxially.

[0027] Therefore, this disclosure aims to provide a spar cap structure having a combination of high mechanical properties of one or more layers of carbon fiber members (which provide stiffness) and low mechanical properties of one or more layers of glass fiber members (which allow for drilling holes for installing lightning receivers and simplify the installation of lightning protection systems in wind turbine blades).

[0028] In another aspect, a wind turbine blade extending in a longitudinal direction is provided. The wind turbine blade includes an upper blade shell portion and a lower blade shell portion connected to the upper blade shell portion. The wind turbine blade further includes a reinforcing structure between the upper blade shell portion and the lower blade shell. Additionally, the upper blade shell portion and / or the lower blade shell portion include a sparsus cap structure according to any example disclosed in the examples herein.

[0029] In another aspect, a method for manufacturing a spar cap structure is provided. The method for manufacturing the spar cap structure includes forming a carbon fiber stack and a glass fiber stack.

[0030] Forming a carbon fiber stack includes stacking one or more carbon fiber components in multiple layers to form rows of carbon fiber components, and arranging conductive yarns between two consecutive rows of carbon fiber component layers.

[0031] The method further includes arranging one or more layers of glass fiber members and conductive elements near a carbon fiber stack. The glass fiber stack is configured to house a lightning receiver to be electrically connected to the conductive element.

[0032] The method further includes electrically connecting the conductive elements of the glass fiber stack to the conductive yarns of the carbon fiber stack, and combining the glass fiber stack and the carbon fiber stack.

[0033] In another aspect, a method for manufacturing a wind turbine blade according to any of the examples disclosed herein is provided. The method for manufacturing a wind turbine blade includes forming an upper blade shell portion and a lower blade shell.

[0034] Forming the upper blade shell portion and / or the lower blade shell portion includes arranging a spar cap structure on the outer layer laid in the mold of the blade shell portion, and incorporating the spar cap structure into the outer layer.

[0035] The method for manufacturing a wind turbine blade further includes: connecting a reinforcing structure to an upper blade shell portion and to a lower blade shell portion, such that the reinforcing structure is arranged between the upper blade shell portion and the lower blade shell portion, and connecting the upper blade shell portion to the lower blade shell portion.

[0036] The advantages gained from these aspects are similar to those mentioned regarding the first aspect. Attached Figure Description

[0037] Non-limiting examples of this disclosure will be described below with reference to the accompanying drawings, in which: Figure 1 A perspective view of a wind turbine based on an example is shown; Figure 2 A perspective view of a wind turbine blade based on an example is shown; Figure 3 A cross-sectional view of a wind turbine blade according to an example of this disclosure is shown; Figure 4A A cross-sectional view of a sparsus cap structure arranged in a wind turbine blade according to an example of the present disclosure is schematically presented; Figure 4B The illustration depicts a device housing a lightning receiver. Figure 4A A cross-sectional view of the wing-spar cap structure; Figure 5 A cross-sectional view of a portion of a spar cap structure accommodating a lightning receiver, according to an example of this disclosure, is schematically presented; Figures 6A to 6C Cross-sectional views of glass fiber pultruded parts according to examples of this disclosure are presented respectively; Figures 7A to 7C Cross-sectional views of a portion of a wind turbine blade according to an example of this disclosure are presented; Figure 7D The plug components are illustrated schematically. Figure 7A An enlarged view of the connection of the upper and lower conductor branches 410; Figure 8 A block diagram of a method for manufacturing a spar cap structure according to an example of this disclosure; and Figure 9 This is a block diagram of a method for manufacturing a wind turbine blade according to an example of this disclosure. Detailed Implementation

[0038] In these figures, the same reference symbols have been used to represent matching elements.

[0039] Figure 1 A perspective view of an example wind turbine 1 is shown. As shown, the wind turbine 1 includes a tower 2 extending from a support surface 3, a nacelle 4 mounted on the tower 2, and a rotor 5 coupled to the nacelle 4. The rotor 5 includes a rotatable hub 6 and at least one wind turbine blade 7 coupled to and extending outward from the rotor hub 6. For example, in the example shown, the rotor 5 includes three wind turbine blades 7. However, in alternative examples, the rotor 5 may include more or fewer than three blades 7. Each wind turbine blade 7 may be spaced apart from the rotor hub 6 to allow the rotor 5 to rotate, enabling the conversion of kinetic energy from the wind into usable mechanical energy, and subsequently into electrical energy. For example, the rotor hub 6 may be rotatably coupled to a generator located within or forming part of the nacelle 4 to allow the generation of electrical energy.

[0040] Figure 2An example of a wind turbine blade 7 is shown. The wind turbine blade 7 extends from the blade root end 71 to the blade tip end 72 along a longitudinal direction or longitudinal direction 37. The blade 7 includes a blade root region or portion 50 closest to the rotor hub, a profiled or airfoil portion 52 furthest from the rotor hub, and a transition portion 51 between the blade root portion 50 and the airfoil portion 52. The blade 7 includes a leading edge 53 facing the direction of rotation of the blade 7 when mounted on the rotor hub, and a trailing edge 54 facing the opposite direction to the leading edge 53.

[0041] The airfoil portion 52 has a shape designed to generate lift, while the blade root portion 50 has a circular or elliptical cross-section for structural reasons and to facilitate blade mounting to the rotor hub. The diameter or chord of the blade root portion 50 may be constant along its entire length. At the transition portion 51, the profile gradually changes from the circular or elliptical cross-section of the blade root portion 50 to the airfoil profile of the airfoil portion 52. The wind turbine blade 7 can be connected to the rotor hub via the blade root attachment portion 55.

[0042] The wind turbine blade 7 includes a blade shell 73. The blade shell 73 includes an outer or outer surface that defines the external shape of the blade (e.g., the external shape at the blade root portion and the external shape at the airfoil portion). The blade shell 73 also includes an inner or inner surface (not shown) that defines the internal volume of the blade and faces the load-bearing structure. The blade shell 73 may be made of fiber-reinforced polymers or plastics, such as glass fiber and / or carbon fiber.

[0043] The blade shell can be formed from multiple blade shell portions. Multiple blade shell portions can be joined together to form the blade shell. The blade shell portions can be formed and subsequently joined according to any of the examples disclosed herein. Resin infusion techniques (such as RTM or VARTM) or prepreg techniques can be used to manufacture the blade shell portions.

[0044] In some examples, the blade shell includes a lower blade shell portion and an upper blade shell portion. The lower blade shell may be a pressure-side blade shell portion. The upper blade shell portion may be a suction-side blade shell portion. The lower blade shell portion may be connected to the upper blade shell portion along connecting lines, along leading edge 53 and trailing edge 54. Each of these blade shell portions may be manufactured in a mold and then joined together to define the entire blade shell of the wind turbine blade 7. Reinforcing structures are arranged between the lower blade shell portion and the upper blade shell portion.

[0045] Figure 3A cross-sectional view of a wind turbine blade 7 according to an example of this disclosure is shown. A suction-side blade shell portion or upper blade shell portion 100 and a pressure-side blade shell portion or lower blade shell portion 200 extend from a leading edge 53 to a trailing edge 54. The wind turbine blade 7 further includes a chord 38 between the leading edge 53 and the trailing edge 54. The chord 38 extends in a lateral or chordal direction. A flapping direction 39 is substantially perpendicular to the chord 38. The upper blade shell portion 100 and the lower blade shell portion 200 are connected (e.g., joined) together along the leading edge 53 and the trailing edge 54.

[0046] The upper blade shell portion 100 includes an outer upper layer 101 and an inner upper layer 102. The outer upper layer 101 defines the external shape of the upper blade shell portion 100, and the inner upper layer 102 defines the internal shape of the upper blade shell portion 100. The outer upper layer 101 and the inner upper layer 102 may comprise glass fiber laminates. For example, one or more glass fiber laminates may be arranged to form the outer upper layer 101 and / or the inner upper layer 102. The fibers (e.g., glass fibers) may be bidirectionally oriented to enhance the torsional stiffness of the blade 7. In other examples, the fibers may be unidirectionally arranged. In other examples, the upper layers 101 and / or 102 comprise laminates having unidirectional fibers and laminates having bidirectional fibers.

[0047] The upper blade shell portion 100 of this example includes an upper wing sparsor structure 110 embedded between the upper outer layer 101 and the upper inner layer 102. Therefore, the upper wing sparsor structure 110 is arranged between the upper outer layer 101 and the upper inner layer 102. The upper wing sparsor structure 110 structurally reinforces the upper blade shell portion 100.

[0048] In some portions of the upper blade shell portion 100, a core structure may be arranged between the upper outer layer 101 and the upper inner layer 102. For example, a portion of the core structure may extend between the upper spar cap structure 110 and the leading edge. Alternatively, a portion of the core structure may extend between the upper spar cap structure 110 and the trailing edge 54. The core structure typically increases the thickness of the blade shell portion to improve stiffness without adding excessive weight. The core structure may be made of lightweight materials, such as balsa wood or polymer foam.

[0049] The lower blade shell portion 200 may be manufactured similarly to the upper blade shell portion 100. As described with reference to the upper blade shell portion 100, the lower blade shell portion 200 includes a lower outer layer 201 and a lower inner layer 202. The lower outer layer 201 and / or the lower inner layer 202 may comprise biaxially oriented glass fibers. A lower spar cap structure 210 is embedded between the lower outer layer 201 and the lower inner layer 202.

[0050] In this example, the upper spar cap structure 110 and the lower spar cap structure 210 span the flapping direction 39. The spar cap structures 110 and 210 face each other. The spar cap structures 110 and 210 may extend in length along the spanwise direction 37 of the wind turbine blade. The length of the spar cap structure may be greater than 90% of the total length of the wind turbine blade.

[0051] The spar cap structures 110 and 210 may be based on any of the examples herein. In this example, the spar cap structure includes a carbon fiber stack and a glass fiber stack. In some examples, the carbon fiber stack may include multiple carbon fiber pultrusions. Alternatively, the carbon fiber stack may include carbon fiber fabric. The carbon fiber fabric and the carbon fiber pultrusions may be arranged to form layers of carbon fiber members. The carbon fiber stack further includes conductive yarns or foils arranged between the layers of carbon fiber members. The glass fiber stack includes one or more layers of glass fiber members. The glass fiber stack further includes conductive elements. The conductive elements may be metallic conductive elements. The layers of one or more glass fiber members may be formed by glass fiber pultrusions or by glass fiber fabrics. The conductive yarns or foils are electrically connected to the conductive elements to create a conductive path from the carbon fiber stack to the glass fiber stack. The conductive yarns of the carbon fiber stack and the conductive elements of the glass fiber stack may at least partially overlap. Therefore, the conductive yarns and conductive elements may contact each other to create a conductive path.

[0052] The spar cap structures 110 and 210 are prefabricated. The glass fiber stack and the carbon fiber stack can be combined, for example, by injection molding, before being placed on the blade shell mold used to manufacture the corresponding blade shell sections. Prefabricated spar cap structures 110 and 210 simplify the electrical connection between the conductive yarns of the carbon fiber stack and the conductive elements of the glass fiber stack. For example, the conductive yarns can be easily positioned to partially overlap with the conductive elements of the glass fiber stack.

[0053] Although not shown in the figure, the lightning receiver can be inserted into the fiberglass stack to be electrically connected to the conductive elements arranged in the fiberglass stack.

[0054] The wind turbine blade 7 includes a reinforcing structure 300 disposed between the upper blade shell portion 100 and the lower blade shell portion 200. The reinforcing structure 300 provides stiffness to the wind turbine blade. The reinforcing structure 300 includes a first reinforcing beam 310 disposed between the upper spar cap structure 110 and the lower spar cap structure 210. In other examples, the reinforcing structure includes a first reinforcing beam and a second reinforcing beam.

[0055] In this example, the first reinforcing beam 310 extends along the spanwise direction 37. The first reinforcing beam 310 may extend substantially between the root portion and the tip portion. The length of the first reinforcing beam 310 may correspond to the lengths of the wing cap structures 110 and 210.

[0056] The first reinforcing beam 310 includes a web 340 extending between an upper flange 320 and a lower flange 330. The upper flange 320 of the first reinforcing beam 310 is connected to the upper blade shell portion 100. The upper flange 320 is connected (e.g., bonded) to the upper inner layer 102 in the area of ​​the upper spar cap structure 110. Similarly, the lower flange 330 is connected to the lower inner layer 202 in the area of ​​the lower spar cap structure 210. In this example, the first reinforcing beam 310 and the spar cap structures 110 and 210 form a load-bearing structure for the wind turbine blade, which is used to withstand the loads applied to the wind turbine blade.

[0057] In this example, the first reinforcing beam 310 comprises a single web. However, in other examples, the first reinforcing beam 310 may comprise two webs extending between flanges 320 and 330. This configuration may be broadly referred to as a wing-girder box configuration.

[0058] An adhesive layer may be disposed between flanges 320 and 330 and the corresponding inner layers 102 and 202. The adhesive layer connects flanges 320 and 330 to blade shell portions 100 and 200. Therefore, the first reinforcing beam 310 may be attached to the upper blade shell portion 100 and to the lower blade shell portion 200. Spallation cap structures 110 and 210 are disposed between the corresponding flanges 320 and 330 and the outer layers 101 and 201.

[0059] Figure 4A A cross-sectional view of a sparsor cap structure 210 arranged in a wind turbine blade according to an example of the present disclosure is schematically presented. The figure shows a sparsor cap structure (lower sparsor cap) arranged in the lower blade shell portion; however, a sparsor cap (upper and lower sparsor caps) arranged in the upper blade shell portion may also be based on any example of the lower sparsor cap disclosed herein.

[0060] In this example, the spar cap structure 210 is arranged between the lower outer layer 201 and the lower inner layer 202. The spar cap structure 210 comprises multiple layers. In this example, the layers are formed by pultruded parts 231 and 221 arranged in a stacked manner. In other examples, the layers can be formed by directly placing fibers (e.g., in the form of fabric). The pultruded part in this example is a sheet. The width of the pultruded sheet is a multiple of its thickness, for example, more than ten times. In some examples, the pultruded sheet includes a width between 20 mm and 300 mm, and a thickness between 1 mm and 6 mm, for example, 5 mm. In other examples, the pultruded part has other suitable cross-sectional shapes, such as a rectangular cross-section.

[0061] The spar cap structure 210 of this figure includes multiple carbon fiber stacks 230a, 230b, and 230c. The carbon fiber stacks 230a, 230b, and 230c are arranged side-by-side, i.e., next to each other. The carbon fiber stacks 230a, 230b, and 230c include multiple pultruded members 231 arranged one on top of another. In this example, the carbon fiber stacks 230a, 230b, and 230c are formed by four carbon fiber pultruded members 231. In some examples, the number of carbon fiber pultruded members 231 may vary along the spanwise direction 37 of the blade. The carbon fiber stack 230 may include any suitable number of carbon fiber pultruded members.

[0062] In other examples, the carbon fiber stack may comprise multiple carbon fiber fabrics arranged on each other to form rows of carbon fiber fabric. In these examples, the spar cap may comprise a single carbon fiber stack made of multiple layers, each of which comprises carbon fiber fabric.

[0063] In some examples, multiple carbon fiber stacks 230 extend along the length of the corresponding spar cap structure 210 in a direction parallel to the spanwise or longitudinal direction 37 of the wind turbine blade. In some examples, the length of the pultruded members forming a stack varies along the spanwise direction to form a stepped structure. In other examples, some pultruded members of a stack may extend the entire length of the spar cap structure.

[0064] The carbon fiber stacks 230a, 230b, and 230c in this example are made from carbon fiber pultrusions 231. The carbon fibers in these pultrusions are arranged in a unidirectional configuration. In other examples, stacks 230a, 230b, and 230c may include carbon fiber pultrusions and other types of fiber pultrusions, such as glass fiber pultrusions and / or aramid fiber pultrusions.

[0065] The carbon fiber stacks 230a, 230b, and 230c further include a conductive yarn 232 disposed between two consecutive rows of the pultruded member. The conductive yarn 232 may extend at least the width of the plurality of carbon fiber stacks 230a, 230b, and 230c. In this example, the conductive yarn 232 extends from the carbon fiber stack to the glass fiber stack 220. In some examples, the conductive yarn 232 includes a thickness of less than 0.5 mm, such as 0.05 mm and 0.45 mm. The conductive yarn 232 may include carbon fibers and / or metals, such as copper and / or steel. In some examples, the conductive yarn 232 includes carbon fibers arranged in a biaxial configuration. Alternatively or additionally, the conductive yarn 232 may include copper wire.

[0066] In this example, each conductive yarn 232 is sandwiched between two consecutive carbon fiber pultrusions. In some examples, the conductive yarn 232 may also be arranged on the top and / or bottom of the carbon fiber stack.

[0067] The spar cap structure 210 further includes a glass fiber stack 220. In other examples, the spar cap structure may include multiple glass fiber stacks. Each glass fiber stack comprises one or more layers, each layer comprising one or more glass fiber members. Layers may include pultruded members or fabrics. The glass fiber stack 220 in this example includes multiple glass fiber pultruded members 221 arranged one on top of another. In this example, the glass fiber stack 220 includes four glass fiber pultruded members 221; however, in other examples, any suitable number of glass fiber pultruded members may be provided.

[0068] In this example, all pultruded components of the glass fiber stack 220 are glass fiber pultruded components 221. Therefore, the glass fiber stack in this example does not contain any non-glass fiber pultruded components. However, in other examples, the glass fiber stack may also include a small number of pultruded components made of different fiber materials, such as aramid fiber pultruded components. Therefore, in this example, the volume of these different fiber pultruded components is less than 10%, optionally less than 5%, compared to the total volume of the glass fiber stack. Thus, the volume of pultruded components made of other types of fibers is relatively low compared to the volume of the glass fiber pultruded components. In some examples, this very low volume of non-glass pultruded components within the glass pultruded component stack does not prevent perforation of the entire thickness of the glass fiber stack. Because the damage resistance of glass fiber pultruded components is greater than that of carbon fiber pultruded components, these glass fiber stacks, formed primarily of glass fiber pultruded components, are less likely to break upon perforation than stacks formed entirely of carbon fiber pultruded components. Therefore, this higher damage resistance and lower probability of breakage allow the glass fiber stack to be perforated for use in deploying lightning receivers.

[0069] In some examples, the glass fiber stack 220 may include an electrical insulating member disposed between the glass fiber pultrusion 221 and the outer layer 201. This electrical insulating member may include foam. The electrical insulating member may improve the insulation of the glass fiber stack 220 relative to the outer side of the wind turbine blade.

[0070] The volume of carbon fiber in the spar cap 210 can be greater than the volume of glass fiber. In this example, the volume of the carbon fiber pultruded part 231 in the spar cap structure 210 is greater than the volume of the glass fiber pultruded part 221. Therefore, higher mechanical properties can be achieved. In this example, the ratio of the volume of the carbon fiber pultruded part to the volume of the glass fiber pultruded part is greater than 2. Or in other words, the volume of the carbon fiber pultruded part is twice the volume of the glass fiber pultruded part. Therefore, the amount of carbon fiber is greater than the amount of glass fiber.

[0071] The glass fiber stack 220 includes a conductive element 222. The conductive element 222 may be a metallic conductive element. In other examples, the conductive element may include another suitable conductive material. In this example, the conductive element 222 includes a metallic conductive layer 223. The glass fiber stack 220 of this example includes a metallic conductive layer 223 disposed between two consecutive glass fiber pultrusions 221. The metallic conductive element may include, for example, copper and / or steel. In this example, each metallic conductive layer 223 is connected to one of the conductive yarns 232. Each metallic conductive layer 223 and its corresponding conductive yarn 232 partially overlap.

[0072] In some examples, the conductive element 222 may extend in a direction parallel to the longitudinal direction 37. The conductive element 222 may extend the entire length of the glass fiber stack 220, for example, the entire length of the spar cap structure 210. In other examples, the conductive element 222 is discontinuous in the longitudinal direction 37.

[0073] In some examples, the metal conductive layer 223 may be integrally bonded to the glass fiber pultruded part 221. In these examples, the glass fiber pultruded part 221 includes a pultruded glass fiber portion and the metal conductive layer 223.

[0074] A glass fiber stack 220 is disposed near a carbon fiber stack 230a. One side of the carbon fiber stack 230a contacts one side of the glass fiber stack 220. In this example, the conductive yarn 232 and the conductive element 222 at least partially overlap. In this example, the conductive yarn 232 extends toward the glass fiber stack 220. In this example, the conductive yarn 232 includes a connecting portion extending toward the glass fiber stack 220. In this example, the connecting portion of each conductive yarn 232 overlaps with the conductive element 222. In this example, the conductive yarn 232 covers the entire width of the conductive element 222, such as the width of the metal conductive layer 223. In this example, the conductive yarn 232 is disposed on the outer carbon fiber pultrusion and outer metal conductive layer 223 of the carbon fiber stacks 230a, 230b, and 230c. Similarly, the conductive yarn 232 is disposed between the carbon fiber pultrusions and extends toward the glass fiber stack. Thus, the connecting portions of these conductive yarns 232 are disposed between the two layers of the glass fiber member. Therefore, the conductive yarn 232 and the corresponding metal conductive layer 223 are in contact. Thus, an electrical path can be established between the corresponding conductive yarn 232 and the metal conductive layer 223 in the carbon fiber stacks 230a, 230b and 230c.

[0075] In this example, the conductive yarn 232 includes the width of the spar cap. In other examples, a portion of the connecting portion of the conductive yarn 232 may extend between the two continuous layers. In these examples, the conductive yarn does not completely overlap with the metal conductive layer 223. Resin can be used to fill the gap between the metal conductive layer 223 and the continuous glass fiber pultrusion.

[0076] In some examples, the connecting portion may include multiple threads or fibers extending from the conductive yarn, copper wires, and / or biaxial carbon fibers. These threads or fibers may be arranged above the metallic conductive layer 223 of the glass fiber stack.

[0077] In other examples, the conductive element 222 may extend toward the carbon fiber stack. For example, a metal wire may extend from the glass fiber stack to the carbon fiber stack. Thus, the conductive element 222 and the conductive yarn may overlap and contact each other.

[0078] In this example, the width of the carbon fiber stack 230 is greater than the width of the glass fiber stack 220. This improves the mechanical properties of the spar cap structure 210. For example, the width of the carbon fiber stack can be between 30 mm and 300 mm, such as between 100 mm and 200 mm, and the width of the glass fiber stack can be between 20 mm and 130 mm, such as between 25 mm and 100 mm.

[0079] exist Figure 4A In this embodiment, the glass fiber stack 220 is disposed at the trailing edge of the spar cap structure 210. In other examples, the glass fiber stack 220 may be disposed at the leading edge of the spar cap structure 210. In other examples, the glass fiber stack 220 may be disposed between two carbon fiber stacks.

[0080] In this example, the volume of the conductive element 222 in the glass fiber stack 220 is between 5% and 50% of the total volume of the glass fiber stack 220. For example, the volume of the metal conductive element may be between 5% and 20% of the total volume of the glass fiber stack 220. In this example, the thickness of the metal conductive layer 223 is between 0.5 mm and 3 mm. In this example, the thickness of the carbon fiber component layer corresponds to the thickness of a combination of one or more glass fiber component layers and a metal conductive layer 223.

[0081] Figure 4B The illustration depicts a device housing a lightning receiver. Figure 4AA cross-sectional view of the spar cap structure 210. A lightning receiver 400 is inserted through a fiberglass stack 220. In this example, the lightning receiver 400 extends through an outer layer 201, a fiberglass stack 220, and an inner layer 202. The lightning receiver 400 has an elongated shape and extends between an outer end 401 and an inner end 402. The outer end 401 is positioned on the outside of the wind turbine blade to capture lightning strikes. In this example, the inner end 402 is located within the cavity of the wind turbine blade. In this example, the outer end 401 has a larger diameter than the inner end 402.

[0082] In this example, the lightning receiver 400 is electrically connected to the down conductor 410. The down conductor 410 extends in a direction substantially parallel to the longitudinal direction 37. The down conductor 410 may extend substantially the entire length of the wind turbine blade 7. The down conductor 410 is configured to be electrically connected to the ground in order to conduct the lightning current to the ground.

[0083] In this example, the down conductor 410 is supported by the web 340 of the first reinforcing beam 310. In other examples, the down conductor 410 may be connected to the lower flange 330 or the upper flange of the first reinforcing beam 310.

[0084] In this example, connector 420 electrically connects lightning receiver 400 to down conductor 410. One end of connector 420 is attached to the inner end 402 of lightning receiver 400, for example, wound around the inner end 402 of lightning receiver 400. The opposite end of connector 420 is attached to down conductor 410.

[0085] like Figure 4B As can be seen, the lightning receiver 400 contacts the metallic conductive layer 223 of the glass fiber stack 220. In this example, the connecting portion of the conductive yarn 232 also contacts the lightning receiver 400. Therefore, a current path can be created toward the down conductor 410. Thus, the current flowing from the conductive yarn 232 of the carbon fiber stack can be conducted through the lightning receiver 400 toward the down conductor 410.

[0086] In some examples, the wind turbine blade 7 includes a plurality of lightning receivers 400 housed in a fiberglass stack 220 within a sparsity cap structure 210. These lightning receivers 400 are electrically connected to a conductive element 222. In some examples, the lightning receivers may further contact a conductive yarn 232. In some examples, each of these lightning receivers 400 is electrically connected to a down conductor 410 via a specific connector 420.

[0087] Figure 5A cross-sectional view of a portion of a spar cap structure 210 accommodating a lightning receiver 400 according to an example of this disclosure is schematically presented. In this example, in addition to the conductive yarn 232 arranged between two layers of carbon fiber members (e.g., pultruded members 231), the conductive yarn 232 is also arranged between an outer layer 201 and the outer layer (i.e., the outermost layer) of one or more carbon fiber members. In this example, the layers of carbon fiber members include carbon fiber pultruded members 231. Therefore, the carbon fiber member can be a carbon fiber pultruded member. In this figure, each row of carbon fiber pultruded members 231 of a plurality of carbon fiber stacks 230a, 230b is associated with conductive yarn 232.

[0088] Similarly, the glass fiber stack 220 includes a glass fiber pultrusion 221 associated with the conductive element 222. In this example, each metal conductive layer 223 is associated with the glass fiber pultrusion 221.

[0089] In this example, the metal conductive layer 223 forms part of the glass fiber pultruded part 221. The glass fiber pultruded part 221 of this example includes the metal conductive layer 223 and a pultruded glass fiber portion 224. Each metal conductive layer 223 is associated with a corresponding pultruded glass fiber portion 224 to form a glass fiber pultruded part 221 having an integrally bonded metal conductive layer 223. For example, the glass fiber pultruded part 221 can be manufactured by pultruding a metal conductive element 222 (e.g., the metal conductive layer 223) and glass fibers together. In other examples, the glass fiber pultruded part 221 can be manufactured by infusion bonding the metal conductive layer 223 to the pultruded glass fiber portion 224. The thickness of the metal conductive layer 223 can be between 0.5 mm and 3 mm.

[0090] In this figure, each conductive yarn 232 extends along the width of the corresponding row of the carbon fiber pultrusion 231 and a portion of the width of the glass fiber stack 220. The conductive yarn 232 in this example includes a connecting portion extending a portion of the width of the glass fiber stack 220. Therefore, the connecting portions of these conductive yarns 232 partially overlap with the metal conductive layer 223. Thus, a portion of the conductive yarn 232 (i.e., the connecting portion) contacts a portion of the metal conductive layer 223. Therefore, each conductive yarn 232 is electrically connected to the corresponding metal conductive layer 223. In this example, the connecting portions of the conductive yarns 232 do not extend to the lightning receiver 400. However, an electrical path can be formed through the metal conductive layer 223.

[0091] In this example, the thickness of the carbon fiber pultruded part 231 is similar to the thickness of the glass fiber pultruded part 221 (including the metal conductive layer 223 and the pultruded glass fiber portion 224). For example, the thicknesses of the glass fiber pultruded part and the carbon fiber pultruded part are between 3 mm and 6 mm, such as about 5 mm. The thickness of the conductive yarn 232 is significantly smaller than the thickness of the pultruded part. For example, the thickness of the conductive yarn 232 can be less than 0.5 mm, such as 0.05 mm and 0.45 mm. The small gaps between the glass fiber pultruded parts 221 can be filled with resin or fabric.

[0092] Figures 6A to 6C These are examples of glass fiber pultruded parts according to the present disclosure. The glass fiber pultruded part 221 in these figures includes a thickness between 3 mm and 6 mm, for example about 5 mm, and a width between 20 mm and 130 mm, for example about 50 mm.

[0093] In these figures, the conductive element 222 (e.g., a metal conductive element) is integrally integrated within the glass fiber pultrusion 221. Therefore, the glass fiber pultrusion 221 in these figures includes the conductive element 222 and the pultruded glass fiber portion 224. The volume of the conductive element 222 in the glass fiber pultrusion 221 accounts for between 5% and 50% of the glass fiber pultrusion 221.

[0094] exist Figure 6A In this embodiment, the conductive element 222 includes metal conductive fibers 225 within the glass fiber pultrusion 221. The metal conductive fibers 225 may be unidirectional metal wires, such as unidirectional copper wires. The metal conductive fibers 225 and glass fibers (e.g., unidirectional glass fibers) may be pultruded together to form a glass fiber pultrusion having metal conductive fibers. In this example, the volume of the metal conductive fibers 225 accounts for between 5% and 25% of the volume of the glass fiber pultrusion 221.

[0095] When positioned near a carbon fiber stack, the metal conductive fibers 225 of the pultruded part can contact the conductive yarns 232 of the carbon fiber stack 230 to create an electrical path between the conductive yarns 232 and the conductive element 222. Similarly, the metal conductive fibers 225 can contact the lightning receiver 400 when inserted into a glass fiber pultruded part 221.

[0096] Figure 6B The metal conductive element 222 includes a metal conductive layer 223. The thickness of the metal conductive layer 223 in this figure is between 10% and 50% of the thickness of the pultruded glass fiber portion 224, for example, approximately 20%. The thickness of the metal conductive layer 223 is between 0.5 mm and 3 mm, for example, approximately 1 mm. For example, the glass fiber pultrusion 221 includes a total thickness of approximately 5 mm, corresponding to approximately 1 mm of the thickness of the metal conductive layer 223 and approximately 4 mm of the thickness of the pultruded glass fiber portion 224.

[0097] exist Figure 6C In this figure, the metal conductive element 222 includes an upper metal conductive layer 223 and a lower metal conductive layer 223. A pultruded glass fiber portion 224 is disposed between the upper and lower metal conductive layers 223. The dimensions of the conductive layers in this figure can be related to... Figure 6B The dimensions described are similar. For example, each of the metal conductive layers 223 may include a thickness of about 1 mm, and the thickness of the pultruded glass fiber portion 224 may include a thickness of about 3 mm.

[0098] Figure 6B and Figure 6C The improved arrangement of the metal conductive layer enhances the electrical connections between the conductive element 222 and the conductive yarn 232, and to the lightning receiver 400. It also simplifies the contact between the conductive element 222 and the conductive yarn 232.

[0099] In some examples, Figure 6B and Figure 6C The glass fiber pultruded part 221 is manufactured by infusing a metal conductive layer 223 together with a pultruded glass fiber portion 224. Therefore, the pultruded glass fiber portion 224 can be formed first by a pultrusion process and then attached to the metal conductive layer 223 to form the glass fiber pultruded part 221. In some examples, Figure 6B and Figure 6C The glass fiber pultruded part 221 is made by pultruding a metal conductive layer 223 and glass fiber together.

[0100] Figures 7A to 7C Cross-sectional views of a portion of a wind turbine blade according to an example of this disclosure are presented.

[0101] In these figures, an upper spar cap structure 110 is arranged in the upper blade shell portion 100, and a lower spar cap structure 210 is arranged in the lower blade shell portion 200. The spar cap structures 110 and 210 are embedded between outer layers 101 and 201 and inner layers 102 and 202. A reinforcing structure extends between the upper blade shell portion 100 and the lower blade shell portion 200. The reinforcing structure in this example includes a first reinforcing beam 310 having a web 340 extending between an upper flange 320 and a lower flange 330. The upper flange 320 is connected (e.g., coupled) to the upper blade shell portion 100, and the lower flange 330 is connected (e.g., coupled) to the lower blade shell portion 200.

[0102] The spar cap structures 110, 210 in these figures include multiple carbon fiber stacks 130a, 130b, 230a, 230b and glass fiber stacks 120, 220. The carbon fiber stacks and glass fiber stacks may be as described in any of the examples herein. In other examples, the spar cap structures 110, 210 may include fabrics forming layers of carbon fiber components and layers of glass fiber components. Thus, the fabric may be an example of a fiber component.

[0103] In these examples, glass fiber stacks 120, 220 are arranged between two carbon fiber stacks 130a, 130b, 230a, 230b. According to any of the examples herein, the conductive yarn of the carbon fiber stack is electrically connected to a conductive element. The conductive yarn includes a connecting portion extending to the glass fiber stacks 120, 220. The connecting portion of the conductive yarn is arranged on the conductive element. Therefore, the connecting portion of the conductive yarn is in contact with the conductive element.

[0104] In some examples, the connecting portion of the conductive yarn extends a portion of the width of the glass fiber stacks 120 and 220. The connecting portion of the conductive yarn of the carbon fiber stacks 130a and 230a may extend to the connecting portion of the conductive yarn of the carbon fiber stacks 130b and 230b.

[0105] In some examples, the conductive yarn may extend from carbon fiber stacks 130a, 230a to carbon fiber stacks 130b, 230b. Thus, the conductive yarn may extend along the width of the spar cap structures 110, 210.

[0106] In these examples, the fiberglass stacks 120, 220 are aligned with the first reinforcing beam 310 such that the fiberglass stacks 120, 220 and the first reinforcing beam 310 at least partially overlap. In these examples, the lightning receiver 400 is aligned with the web 340 of the first reinforcing beam 310. In other examples, the lightning receiver 400 may be aligned with flanges 320, 330.

[0107] In these figures, a lightning receiver 400 extends from an outer end 401 on the outer side of the wind turbine blade to an inner end 402 on the inner side of the wind turbine blade. The outer end 401 has a disc shape. In this figure, one lightning receiver 400 is housed in a fiberglass stack 120 of the upper blade shell portion 100, and another lightning receiver 400 is housed in a fiberglass stack 220 of the lower blade shell portion 200. Although not depicted in these figures, several lightning receivers may be arranged along the longitudinal direction of the wind turbine blade.

[0108] refer to Figure 7AThe down conductor includes an upper down conductor branch 410a and a lower down conductor branch 410b. These down conductor branches 410a and 410b can be connected at the root and / or tip portions of the wind turbine blade. In this figure, the upper down conductor branch 410a and the lower down conductor branch 410b extend length inside the web 340 of the first reinforcing beam 310. The down conductor branches 410a and 410b can extend substantially along the entire length of the first reinforcing beam 310. In other examples, at least a portion of the down conductor can extend along the flange of the first reinforcing beam. Thus, the down conductor can extend length inside the reinforcing structure. Therefore, the down conductor can be integrally integrated within the reinforcing structure. For example, the down conductor (e.g., the upper down conductor branch 410a and the lower down conductor branch 410b) can be infused with the fibers forming the first reinforcing beam. Thus, the down conductor can be arranged inside the first reinforcing beam before being placed between the upper blade shell portion 100 and the lower blade shell portion 200. Therefore, the manufacturing and assembly process can be simplified.

[0109] Additionally, wind turbine blades may include potential equalization connectors arranged at different locations along the longitudinal direction of the wind turbine blades. Figure 7A (Not shown in the image), this connector electrically connects the upper lead-down conductor 410a to the lower lead-down conductor branch 410b. These potential equalization connectors, distributed along the blade, equalize the voltage difference between the carbon fiber pultruded sheets in the upper blade shell portion 100 and the carbon fiber pultruded sheets in the lower blade shell portion 200. The potential equalization connector can extend along the first reinforcing beam 310, for example, along the web 340, between the upper lead-down conductor branch 410a and the lower lead-down conductor branch 410b. The potential equalization connector can also be arranged within the first reinforcing beam during its manufacturing process.

[0110] In this example, the inner end 402 of the lightning receiver 400 includes a plug element 403 connected to a down conductor. The plug element 403, located at the lower blade housing portion 200, is connected to a lower down conductor branch 410b, and the plug element 403, located at the upper blade housing portion 100, is connected to an upper down conductor branch 410a. The plug element 403 can engage down conductor branches 410a and 410b.

[0111] Figure 7D The plug element 403 is schematically shown. Figure 7A An enlarged view of the connection of the upper and lower conductor branches 410a. The connection between the plug element 403 and the lower conductor branch 410b may be similar to... Figure 7D The connection described in the text.

[0112] In this example, plug element 403 mates with a hole in the down conductor branch 410a. The hole may include an internal thread, and plug element 203 may include an external thread to be threaded into the hole.

[0113] In some examples, conductor branches 410a, 410b may include multiple holes arranged along the longitudinal direction of the wind turbine blade.

[0114] In some examples, plug element 403 may press against holes in conductor branches 410a, 410b. Conductor branches 410a, 410b may include slots for receiving plug element 403.

[0115] The connection from the lightning receiver 400 to the downconductor 410 can be easily performed from the outside of the wind turbine blade during post-molding operation. This simplifies the installation of the lightning protection system.

[0116] exist Figure 7B In this configuration, the upper down conductor branch 410a is arranged within the upper spar cap structure 110, and the lower down conductor branch 410b is arranged within the lower spar cap structure 210. Therefore, the down conductor extends within the spar cap structure. Thus, the down conductor branches can be encapsulated within the spar cap structure. This simplifies the assembly of the down conductors.

[0117] In this example, down conductor branches 410a and 410b are arranged within glass fiber stacks 120 and 220. In this figure, glass fiber stacks 120 and 220 include pultruded glass fiber members having a metallic conductive layer and a pultruded glass fiber portion. Additionally, glass fiber stacks 120 and 220 include corresponding down conductor branches 410a and 410b arranged at their innermost portions. The inner end 402 of the lightning receiver 400 is inserted into the down conductor branches 410a and 410b.

[0118] In this figure, the potential equalization connector 411 connects the upper lower conductor branch 410a to the lower lower conductor branch 410b. The wind turbine blade of this example further includes a plurality of potential equalization connectors 411 arranged along the spanwise direction. The potential equalization connector 411 extends inside the first reinforcing beam, for example, from one flange through the web to the opposite flange.

[0119] exist Figure 7C In this example, the glass fiber stack 120 of the upper wing cap structure 110 is integrally formed from a glass fiber pultruded member including a pultruded glass fiber portion and a metal conductive layer. However, the glass fiber stack 120 of the lower wing cap structure 210 includes a down conductor 410. Therefore, in this example, the down conductor 410 is integrally integrated into the lower wing cap structure 210. In other examples, the down conductor 410 is integrally integrated into the upper wing cap structure 110.

[0120] The lightning receiver 400 of the upper blade housing 100 is electrically connected to the down conductor 410 via a connector 420. The connector 420 extends within the first reinforcing beam 310, for example, through the web 340. The inner end 402 of the lightning receiver 400 of the upper blade housing portion 100 contacts one end of the connector 420, and the opposite end contacts the down conductor disposed on the opposite blade housing portion.

[0121] Figure 8 This is a block diagram of a method for manufacturing a spar cap structure according to one example of this disclosure. Method 500 can be used to manufacture spar cap structures 110, 210 according to any of the examples herein.

[0122] As shown in frames 510, 520 and 530 respectively, method 500 includes stacking one or more carbon fiber components in multiple layers, arranging one or more glass fiber components and conductive elements in the vicinity of the layers of carbon fiber components, and arranging conductive yarns between two consecutive rows of the layers of carbon fiber components.

[0123] As shown in box 510, multiple layers of one or more carbon fiber components, such as multiple carbon fiber pultrusions 231, can be stacked to form rows of carbon fiber components to form carbon fiber stacks 130, 230. In some examples, multiple carbon fiber stacks 130, 230 can be arranged side by side. In these examples, several carbon fiber pultrusions 231 can be arranged to form rows of carbon fiber pultrusions 231.

[0124] As shown in box 520, method 500 includes arranging one or more layers of glass fiber members and conductive elements 222 near layers of carbon fiber members to form glass fiber stacks 120, 220. The glass fiber members and conductive elements are electrically connected. As explained above, the glass fiber stacks 120, 220 are configured to accommodate a lightning receiver to be electrically connected to the conductive element 222. In some examples, each layer of the glass fiber member includes a glass fiber pultrusion 221.

[0125] In some examples, forming the carbon fiber stacks 130, 230 may include: first laying the conductive yarn 232, and then arranging rows of carbon fiber pultruded parts 231. Afterwards, the conductive yarn 232 and the carbon fiber pultruded parts 231 may be arranged as described above.

[0126] As shown in frame 530, the conductive yarn 232 is arranged between two consecutive rows of layers of carbon fiber components. The conductive yarn 232 may be placed on top of one or more layers of carbon fiber components, for example, on top of carbon fiber pultruded part 231.

[0127] In some examples, electrically connecting the conductive yarn 232 and the conductive element 222 includes arranging the conductive yarn 232 such that the conductive yarn 232 and the conductive element 222 at least partially overlap, so as to electrically connect the conductive element of the glass fiber stack 120, 220 to the conductive yarn 232 of the carbon fiber stack. Thus, a current path can be created between the conductive yarn 232 and the conductive element 222 through the contact between the conductive yarn 232 and the conductive element 222.

[0128] In some examples, layers of one or more carbon fiber components (e.g., fabrics or pultruded parts) may be laid on the spar cap mold. For example, one or more carbon fiber pultruded parts may be arranged in rows to form carbon fiber layers. Layers of one or more glass fiber components may be laid near layers of one or more carbon fiber components. For example, the glass fiber component layer may include a glass fiber pultruded part comprising a metal conductive layer 223. Conductive yarn 232 may then be laid on the layers of one or more carbon fiber components, and at least on a portion of the layers of one or more glass fiber components. Thus, conductive yarn 232 and conductive element 222 may overlap.

[0129] In some examples, the conductive yarn 232 may be laid on layers of one or more carbon fiber components and layers of one or more glass fiber components. Thus, the conductive yarn 232 may extend along the entire width of the spar cap. After the conductive yarn 232 is laid, layers of one or more carbon fiber components and layers of one or more glass fiber components may be placed on top of the conductive yarn 232.

[0130] The method may further include pultruding a glass fiber pultruded part 221. In some examples, manufacturing the glass fiber pultruded part 221 by the pultrusion process includes pulling glass fibers and metal conductive fibers 225 through a heated stationary die, applying resin to these heated fibers for curing, and obtaining a glass fiber pultruded part having metal conductive fibers 225. The metal conductive fibers 225 may be randomly arranged along the cross-section of the glass fiber pultruded part 221. In other examples, the metal conductive fibers may be pulled through a heated die below and / or above the glass fibers to form a glass fiber pultruded part 221 having pultruded glass fiber portions 224 and one or more metal conductive layers 223. In other examples, one or more pre-formed metal conductive layers 223 may be fed together with the glass fibers into a heated die to form a glass fiber pultruded part 221 having pultruded glass fiber portions 224 and one or more metal conductive layers 223.

[0131] In other examples, the metal conductive layer 223 may be attached to the pultruded glass fiber portion 224 to form a glass fiber pultruded part 221. These pultruded glass fiber portions 224 may be made substantially of glass fiber. The pultruded glass fiber portions 224 and the metal conductive layer 223 may be infused together.

[0132] In some examples, forming glass fiber stacks 120, 220 includes stacked electrical insulating elements and glass fiber pultrusions 221.

[0133] In some examples, down conductors 410, 410a, and 410b may be laid on top of the glass fiber pultruded part.

[0134] As shown in frame 540, method 500 further includes bonding glass fiber stacks 120, 220 and carbon fiber stacks 130, 230. Resin infusion or adhesive may be used to bond the stacks.

[0135] In some examples, the spar cap structures 110, 210 are prefabricated before being placed onto the blade shell portion mold. In some of these examples, glass fiber stacks 120, 220 and carbon fiber stacks 130, 230 can be infused together to obtain the prefabricated spar cap structure. Pultruded parts can be laid in the spar cap mold. Resin infusion can be used to bond these stacks of pultruded parts. Thus, resin can be injected into the spar cap mold to fill the gaps between the pultruded parts. The resin is then cured to form the prefabricated spar cap structures 110, 210. This can help automate the manufacturing process and simplify the arrangement of the stacks on the outer layers. Thus, the spar cap structures 110, 210 can be prefabricated before being arranged on top of the outer layers 101, 201 placed on the blade mold. Furthermore, this simplifies the assembly of the stacks and the connection of the carbon fiber stacks to the glass fiber stacks.

[0136] In other examples, the stack can be placed directly on the blade shell portion, for example, on the outer layer of the blade shell portion laid on a mold for the blade shell portion. In these examples, the layers of the spar cap structure can be bonded to the laminate of the blade shell portion.

[0137] Figure 9 This is a block diagram of a method for manufacturing a wind turbine blade according to one example of this disclosure. Method 600 can be used to manufacture wind turbine blades according to any example in the examples herein. These wind turbine blades include spar cap structures 110, 210 according to any example in the examples herein.

[0138] As shown in frame 610, method 600 includes forming an upper blade shell portion 100 and a lower blade shell portion 200. Forming the upper blade shell portion 100 and the lower blade shell portion 200 includes arranging spar cap structures 110, 210 on an outer layer laid in a blade shell portion mold, and attaching the spar cap structures 110, 210 to the outer layer 201.

[0139] Method 600 may include laying outer layers 101, 201 in a blade shell mold, for example, laying one or more glass fiber laminates. These glass fiber laminates may include biaxially oriented glass fibers. Spallation cap structures 110, 210 may then be laid on the outer layers 101, 201.

[0140] As explained above, the spar cap structures 110, 210 may be pre-assembled or prefabricated before being disposed on top of the outer layers 101, 201. Alternatively, the glass fiber stacks 120, 220 and the carbon fiber stacks 130, 230 may be disposed directly on top of the outer layers 101, 201. The spar cap structures may be manufactured according to any of the examples in this document.

[0141] The inner layers 102 and 202 can then be laid on top of the spar cap structures 110 and 210. The inner layers 102 and 202 may include one or more glass fiber laminates, such as glass fiber laminates with bidirectional glass fibers.

[0142] In some examples, one or more core structures may be placed near the spar cap structures 110, 210. The inner layer may be placed on top of these core structures.

[0143] The spar cap structures 110, 210 (prefabricated or directly disposed on top of the outer layer) can be bonded to the outer layers 101, 201 and to the inner layers 102, 202 to form the blade shell portions 100, 200. In some examples, bonding the spar cap structures 110, 210 to the outer layers 101, 201 and to the inner layers 102, 202 involves molding the inner layers, spar cap structures, and outer layers together using a resin infusion technique. Once the inner layer covers the spar cap structures and the outer layers, resin is injected into the mold cavity under pressure. This resin fills the space between the stack and the layers. The resin is then cured or hardened. Thus, the spar cap structure can be bonded to the inner layers and to the outer layers using a resin infusion process. After curing, the blade shell portion is obtained.

[0144] As shown in frame 620, method 600 further includes connecting the reinforcing structure 300 to the upper blade shell portion 100 and to the lower blade shell portion 200, such that the reinforcing structure 300 is arranged between the upper blade shell portion 100 and the lower blade shell portion 200. Therefore, the first reinforcing beam 310 can be connected to both the upper and lower blade shell portions. The lower flange 330 of the first reinforcing beam 310 can be connected to the lower blade shell portion 200, and the upper flange 320 of the first reinforcing beam 310 can be connected to the upper blade shell portion 100.

[0145] Connecting the flanges 320, 330 to the corresponding blade shell portions 100, 200 may include bonding or attaching the flanges 320, 330 to the corresponding inner layers 102, 202 of the blade shell portions 100, 200. Thus, an adhesive layer may be formed between the flanges 320, 330 and the inner layers 102, 202.

[0146] In some examples, the fiberglass stacks 120 and 220 of the spar cap structures 110 and 210 may be arranged in a position aligned with the first reinforcing beam 310. For example, the fiberglass stacks may be aligned with the web 340.

[0147] At frame 630, the upper blade shell portion 100 is connected to the lower blade shell portion 200. The blade shell portions are joined together by a bonding line formed at the leading edge 53 and the trailing edge 54.

[0148] In some examples, method 600 further includes inserting a plurality of lightning receivers into the fiberglass stacks 120, 220. The lightning receivers 400 may be positioned at different locations along the spanwise direction 37 of the wind turbine blade. In some examples, the lightning receivers 400 may be arranged at both the upper blade shell portion 100 and the lower blade shell portion 200. Holes may be drilled in the fiberglass stack 120 before the lightning receivers 400 are inserted.

[0149] In some examples, the inner terminal 402 of the lightning receiver 400 may be connected to the down conductors 410, 410a, 410b. The inner terminal 402 may include a plug element 403 that can be fitted into a receiver formed on the down conductors 410, 410a, 410b.

[0150] In other examples, connector 420 may be coupled to the inner end 402 of lightning receiver 400 and connected to down conductor 410.

[0151] In some examples, the method may further include connecting a potential equalization connector 411 between two down conductors (e.g., down conductor branch 410a integrally integrated within the upper wing cap structure 110 and down conductor branch 410b integrally integrated within the lower wing cap structure 210).

[0152] For the sake of completeness, various aspects of this disclosure are set forth in the following numbered clauses: Clause 1: A spar cap structure for a wind turbine blade, the spar cap structure comprising: Carbon fiber stacks, comprising: A multilayered arrangement of one or more carbon fiber components, wherein one layer is placed on top of another to form a layer of one or more carbon fiber components; and One or more conductive yarns are arranged between two consecutive rows of layers of one or more carbon fiber components; and Glass fiber stack, comprising: One or more fiberglass components, one or more layers; A conductive element electrically connected to the conductive yarn of the carbon fiber stack; and The glass fiber stack is configured to house a lightning receiver that is to be electrically connected to a conductive element.

[0153] Clause 2: The spar cap structure according to Clause 1, wherein one or more multi-layered carbon fiber components comprise multiple carbon fiber pultrusions.

[0154] Clause 3: A spar cap structure according to any one of Clauses 1 to 2, wherein the multi-layered glass fiber component comprises a plurality of glass fiber pultruded components.

[0155] Clause 4: A spar cap structure for a wind turbine blade according to any one of Clauses 1 to 3, wherein one or more conductive yarns and conductive elements at least partially overlap.

[0156] Clause 5: A spar cap structure for a wind turbine blade according to Clause 4, wherein the conductive yarn includes a connecting portion extending toward the glass fiber stack to at least partially overlap with the conductive element.

[0157] Clause 6: A spar cap structure according to any one of Clauses 1 to 5, wherein the volume of the conductive element in the fiberglass stack is between 5% and 50% of the volume of the fiberglass stack.

[0158] Clause 7: A spar cap structure according to any one of Clauses 1 to 6, wherein the conductive element comprises metallic conductive fibers within layers of one or more glass fiber members.

[0159] Clause 8: A spar cap structure according to any one of Clauses 1 to 7, wherein the conductive element comprises a metal conductive layer.

[0160] Clause 9: The spar cap structure according to Clause 7, wherein each of the layers of one or more glass fiber members comprises a glass fiber pultrusion, and wherein each of the glass fiber pultrusions comprises one or more metal conductive layers and a pultruded glass fiber portion.

[0161] Clause 10: The spar cap structure according to Clause 9, wherein the thickness of the metal conductive layer is between 10% and 50% of the thickness of the glass fiber pultruded part.

[0162] Clause 11: A spar cap structure according to any one of Clauses 9 to 10, wherein the glass fiber pultruded part has a thickness between 3 mm and 6 mm, and wherein the thickness of the metal conductive layer of each glass fiber pultruded part has a thickness between 0.5 mm and 3 mm.

[0163] Clause 12: The spar cap structure according to Clause 11, wherein the thickness of the conductive yarn of the carbon fiber stack is less than 0.5 mm.

[0164] Clause 13: A spar cap structure according to any one of Clauses 8 to 12, wherein each layer of the metal conductive layer of the glass fiber stack is at least partially overlapped by a connecting portion of a conductive yarn of the conductive yarn of the carbon fiber stack.

[0165] Clause 14: A spar cap structure according to any one of Clauses 8 to 13, wherein the glass fiber pultruded part is made by infusing a metal conductive layer together with a pultruded glass fiber portion.

[0166] Clause 15: A spar cap structure according to any one of Clauses 8 to 13, wherein the glass fiber pultruded component is made by pultruding a conductive element and glass fiber together.

[0167] Clause 16: A wind turbine blade extending in a longitudinal direction, the wind turbine blade comprising: Upper blade shell portion; The lower blade shell portion is connected to the upper blade shell portion; The reinforcing structure between the upper blade shell and the lower blade shell; and The upper blade shell portion and / or lower blade shell portion include a spar cap structure according to any one of Clauses 1 to 15.

[0168] Clause 17: The wind turbine blade pursuant to Clause 16 includes a lightning receiver housed in a fiberglass stack and electrically connected to a conductive element of the fiberglass stack.

[0169] Clause 18: A wind turbine blade pursuant to Clause 17 includes a down conductor extending in a direction substantially parallel to the longitudinal direction, wherein the down conductor is configured to be electrically connected to the ground, and wherein a plurality of lightning receivers are electrically connected to the down conductor.

[0170] Clause 19: Wind turbine blades pursuant to Clause 18, wherein the down conductor extends length inside the reinforcing structure and / or inside the glass fiber stack.

[0171] Clause 20: A wind turbine blade pursuant to Clause 19, wherein the reinforcing structure includes a first reinforcing beam, and wherein a glass fiber stack is aligned with the first reinforcing beam such that the glass fiber stack at least partially overlaps the first reinforcing beam.

[0172] Clause 21: Wind turbine blades pursuant to Clause 20, wherein multiple lightning receivers include an inner end having a plug element connected to a down conductor.

[0173] Clause 22: A method for manufacturing a spar cap structure, comprising: Stacking one or more carbon fiber components in multiple layers to form one or more rows of carbon fiber components to form a carbon fiber stack; One or more layers of glass fiber components and conductive elements are arranged near layers of one or more carbon fiber components to form a glass fiber stack, wherein the glass fiber stack is configured to house a lightning receiver to be electrically connected to the conductive elements. Conductive yarns are arranged between two consecutive rows of layers of one or more carbon fiber components, and the conductive elements of the glass fiber stack are electrically connected to the conductive yarns of the carbon fiber stack. Combining glass fiber stacks and carbon fiber stacks.

[0174] Clause 23: The method for manufacturing a spar cap structure according to Clause 22, wherein electrically connecting the conductive element of the glass fiber stack to the conductive yarn of the carbon fiber stack comprises arranging the conductive yarn such that the conductive yarn at least partially overlaps with the conductive element.

[0175] Clause 24: A method for manufacturing a wind turbine blade according to any one of Clauses 16 to 21, comprising: Forming an upper blade shell portion and a lower blade shell portion, wherein forming the upper blade shell portion and / or the lower blade shell portion includes: The sparsity cap structure is arranged on the outer layer laid in the mold of the blade shell section; and Integrate the wing spar cap structure into the outer layer; The reinforcing structure is connected to both the upper and lower blade shell portions, such that the reinforcing structure is positioned between the upper and lower blade shell portions. Connect the upper blade shell to the lower blade shell.

[0176] Clause 25: The method for manufacturing wind turbine blades according to Clause 24 includes inserting a plurality of lightning receivers into a fiberglass stack.

[0177] This written description uses examples to disclose the invention, including preferred embodiments, and also enables any person skilled in the art to practice the invention, including making and using any device or system and performing any combined methods. The scope of the invention is defined by the claims and may include other examples that would occur to a person skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that are not different from the written language of the claims, or if they include equivalent structural elements that are not substantially different from the written language of the claims. Aspects from the various embodiments described, and other known equivalents of each such aspect, may be mixed and matched by a person skilled in the art to constitute additional embodiments and techniques according to the principles of this application. If reference marks related to figures are placed in brackets in the claims, they are only for attempting to increase the comprehensibility of the claims and should not be construed as limiting the scope of the claims.

Claims

1. A spar cap structure (110, 210) for a wind turbine blade (7), the spar cap structure (110, 210) comprising: Carbon fiber stacks (230, 230a, 230b, 230c) comprising: A multilayered arrangement of one or more carbon fiber components, wherein one layer is placed on top of another to form a layer of one or more carbon fiber components; and One or more conductive yarns (232) are arranged between two consecutive rows of the layers of one or more carbon fiber members; and Glass fiber stack (220), comprising: One or more fiberglass components, one or more layers; Conductive elements (222) electrically connected to the conductive yarns (232) of the carbon fiber stacks (230, 230a, 230b, 230c); and The glass fiber stack (220) is configured to house a lightning receiver (400) to be electrically connected to the conductive element (222).

2. The wing spar cap structure (110, 210) according to claim 1, wherein, The multilayered carbon fiber component comprises one or more carbon fiber pultrusions (231).

3. The wing spar cap structure (110, 210) according to any one of claims 1 to 2, wherein, The one or more glass fiber members comprising one or more glass fiber pultrusions (221) include one or more glass fiber pultrusions.

4. The spar cap structure (110, 210) according to any one of claims 1 to 3, wherein, The one or more conductive yarns (232) and the conductive element (222) overlap at least partially.

5. The spar cap structure (110, 210) for wind turbine blades (7) according to claim 4, wherein, The conductive yarn (232) includes a connecting portion extending toward the glass fiber stack (220) to at least partially overlap with the conductive element.

6. The wing spar cap structure (110, 220) according to any one of claims 1 to 5, wherein, The conductive element (222) comprises metallic conductive fibers within the layers of the glass fiber member.

7. The wing spar cap structure (110, 220) according to any one of claims 1 to 6, wherein, The conductive element (222) includes a metal conductive layer (223).

8. The wing spar cap structure (110, 220) according to claim 7, wherein, Each of the layers of one or more glass fiber members includes a glass fiber pultrusion (221), and each glass fiber pultrusion (221) includes one or more metal conductive layers (223) and pultruded glass fiber portions (224).

9. The wing spar cap structure (110, 220) according to any one of claims 7 to 8, wherein, Each of the metal conductive layers (223) of the glass fiber stack (220) is at least partially overlapped by a connecting portion of one of the conductive yarns (232) of the carbon fiber stack (230, 230a, 230b, 230c).

10. A wind turbine blade (7) extending in a longitudinal direction, the wind turbine blade comprising: Upper blade shell portion (100); The lower blade shell portion (200) is connected to the upper blade shell portion (100). The reinforcing structure (300) between the upper blade shell portion (100) and the lower blade shell portion (200); and The upper blade shell portion (100) and / or the lower blade shell portion (200) include a spar cap structure (110, 220) according to any one of claims 1 to 9.

11. The wind turbine blade (7) according to claim 10, comprising a plurality of lightning receivers (400) housed in the glass fiber stack (120, 220) and electrically connected to a conductive element (222) of the glass fiber stack (120, 220).

12. The wind turbine blade (7) of claim 11, comprising down conductors (410, 410a, 410b) extending substantially parallel to the longitudinal direction (37), wherein the down conductors (410, 410a, 410b) are configured to be electrically connected to the ground, and wherein the plurality of lightning receivers (400) are electrically connected to the down conductors (410, 410a, 410b).

13. The wind turbine blade (7) according to claim 12, wherein, The down conductors (410, 410a, 410b) extend within the reinforcing structure (300) and / or within the glass fiber stack (120, 220).

14. A method (500) for manufacturing a spar cap structure (110, 210), comprising: Stack (510) one or more carbon fiber components in multiple layers to form a row of one or more carbon fiber components to form a carbon fiber stack (130, 230). as well as One or more layers of glass fiber members and conductive elements (222) are arranged (520) near the layers of carbon fiber members to form glass fiber stacks (120, 220), wherein the glass fiber stacks (120, 220) are configured to accommodate a lightning receiver (400) to be electrically connected to the conductive elements (222). Conductive yarn (232) is arranged (530) between two consecutive rows of layers of one or more carbon fiber components, and the conductive element (222) of the glass fiber stack (120, 220) is electrically connected to the conductive yarn (232) of the carbon fiber stack (130, 230). as well as Combined with the glass fiber stack (120, 220) and the carbon fiber stack (130, 230) described in (540).

15. A method (600) for manufacturing a wind turbine blade (7) according to any one of claims 10 to 13, comprising: Forming (610) the upper blade shell portion (100) and the lower blade shell portion (200), wherein forming the upper blade shell portion (100) and / or the lower blade shell portion (200) includes: The spar cap structures (110, 210) are arranged on the outer layer (101, 201) laid in the mold of the blade shell section; and The wing cap structure (110, 210) is attached to the outer layer (101, 201); The reinforcing structure (300) is connected (620) to the upper blade shell portion (100) and to the lower blade shell portion (200) such that the reinforcing structure (300) is arranged between the upper blade shell portion (100) and the lower blade shell portion (200). Connect (630) the upper blade shell portion (100) to the lower blade shell portion (200); and Multiple lightning receivers (400) are inserted into the glass fiber stack (120, 220).

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