Lightning protection system for wind turbine rotor blades

Abstract

A rotor blade assembly includes a first blade segment and a second blade segment extending in opposite directions from a chordwise joint. Each of the first and second blade segments includes at least one shell member defining an airfoil surface and an internal support structure. The inner support structure of the first blade segment comprises a longitudinally extending beam structure which is structurally connected to the inner support structure of the second blade segment via a receiving section. The rotor blade assembly also includes a lightning protection system having a first conductive cage integrated with the beam structure and a second conductive cage integrated with the receiving section and electrically connected to the first conductive cage via an electrical connection. Further, the first and second conductive cages are grounded.

Description

Technical Field

[0001] The present disclosure generally relates to wind turbine rotor blades and, more particularly, to a lightning protection system for a wind turbine rotor blade. Background Art

[0002] Wind energy is considered to be one of the cleanest and most environmentally friendly energy sources currently available, and wind turbines are attracting increasing attention in this regard. Modern wind turbines typically include a tower, a generator, a gearbox, a nacelle, and one or more rotor blades. The rotor blades utilize the known airfoil principle to capture kinetic energy from the wind and transfer the kinetic energy as rotational energy to rotate a shaft that couples the rotor blades to the gearbox or, if no gearbox is used, directly to the generator. The generator then converts the mechanical energy into electrical energy that can be deployed to the public power grid.

[0003] A wind turbine rotor blade generally includes a main body shell formed of a composite laminate. Generally, the main body shell is relatively light and has structural properties (such as stiffness, buckling resistance, and strength) that are not configured to withstand the bending moments and other loads applied to the rotor blade during operation. To increase the stiffness, buckling resistance, and strength of the rotor blade, the main body shell is typically reinforced using spar caps that engage the inner surface of the shell. The spar caps can be composed of various materials, including but not limited to fiberglass laminate composites and / or carbon fiber laminate composites.

[0004] During the service life of a wind turbine, the rotor blade is particularly vulnerable to lightning strikes. In particular, when carbon fibers are used in the main body shell, lightning can attach to these fibers, causing severe damage to the main body shell. Therefore, due to the sharp edges and insulating properties of wind turbine blades, a lightning protection system is crucial for protecting wind turbine blades. Modern lightning protection systems typically include one or more lightning receivers disposed on the exterior of the rotor blade, and lightning conductors or cable wires that are coupled to the lightning receivers and extend from the blade tip to the blade root through the main body shell and through other components until they are grounded down through the tower to a ground position. Thus, when lightning strikes the rotor blade, the current flows through the lightning receiver and is conducted through the lightning system to the ground. However, when a lightning strike occurs, an unwanted internal arc can occur from the spar cap to the lightning conductor, which can cause significant damage to the rotor blade.

[0005] Accordingly, there is a continuing search in the art for new and improved lightning protection systems for wind turbine rotor blades. Summary of the Invention

[0006] Aspects and advantages of the invention will be set forth in part in the description which follows, or may be obvious from the description, or may be learned by practice of the invention.

[0007] In one aspect, the present disclosure relates to a rotor blade assembly. The rotor blade assembly includes a first blade segment and a second blade segment extending in opposite directions from a chord joint. Each of the first and second blade segments includes at least one shell member defining an airfoil surface and an internal support structure. The internal support structure of the first blade segment includes a longitudinally extending beam structure, which is structurally connected to the internal support structure of the second blade segment via a receiving section. The rotor blade assembly includes a lightning protection system having a first conductive cage integrated with the beam structure and a second conductive cage integrated with the receiving section and electrically connected to the first conductive cage via an electrical connection, and the first and second conductive cages are grounded.

[0008] In another aspect, the present disclosure relates to a method of assembling a rotor blade of a wind turbine. The method includes providing a first blade segment and a second blade segment. Each of the first and second blade segments has at least one shell member defining an airfoil surface and an internal support structure. The internal support structure of the first blade segment includes a longitudinally extending beam structure, which is structurally connected to the internal support structure of the second blade segment via a receiving section. The method further includes integrating a first conductive cage with the beam structure, and integrating a second conductive cage with the receiving section. Further, the method includes electrically connecting the first conductive cage to the second conductive cage via an electrical connection. In addition, the method includes electrically connecting the first and second conductive cages to ground. In addition, the method includes arranging the first blade segment and the second blade segment in opposite directions from the chord joint, and securing the first and second blade segments together.

[0009] In yet another aspect, the present disclosure relates to a rotor blade assembly having at least one blade segment having at least one shell member defining an airfoil surface and an internal support structure. The internal support structure includes a longitudinally extending spar structure. The spar structure includes an upper conductive beam and a lower conductive beam integrated therein. The upper conductive beam and the lower conductive beam each define a perimeter. The rotor blade assembly further includes a lightning protection system having a conductive cage integrated with the spar structure. The conductive cage only surrounds a part of the perimeter of each of the upper conductive beam and the lower conductive beam. Further, the lightning protection system includes at least one conductor cable disposed in at least one blade segment and grounded, and the conductive cage is electrically connected to the at least one conductor cable.

[0010] These and other features, aspects, and advantages of the present invention will become better understood with reference to the following specification and the appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] For a person of ordinary skill in the art, the specification sets forth a complete and enabling disclosure of the invention, including its best mode, with reference to the accompanying drawings, in which:

[0012] Figure 1 A perspective view showing an embodiment of a wind turbine according to the present disclosure;

[0013] Figure 2 A plan view showing an embodiment of a rotor blade having a first blade segment and a second blade segment according to the present disclosure;

[0014] Figure 3 A perspective view showing a section of an embodiment of a first blade segment according to the present disclosure;

[0015] Figure 4 A perspective view showing a section of an embodiment of a second blade segment at a chordwise joint according to the present disclosure;

[0016] Figure 5 An assembly view showing an embodiment of a rotor blade of a wind turbine according to the present disclosure, the rotor blade having a first blade segment connected to a second blade segment;

[0017] Figure 6 An exploded perspective view showing an embodiment of a plurality of support structures of an assembly of a rotor blade of a wind turbine according to the present disclosure;

[0018] Figure 7 A partial side view showing an embodiment of a lightning protection system according to the present disclosure, the lightning protection system having a first conductive cage integrated with a beam structure of a rotor blade and a second conductive cage integrated with a receiving section of the rotor blade;

[0019] Figure 8 Showing Figure 7 A cross-sectional view along section line 8-8;

[0020] Figure 9 Showing according to the present disclosure Figure 7 A detailed view of an electrical connection member of the lightning protection system;

[0021] Figure 10 Showing Figure 7 A partial perspective view of the lightning protection system, particularly showing a first conductive cage electrically connected to a second conductive cage according to the present disclosure;

[0022] Figure 11 Showing Figure 10 A partial side view of the lightning protection system;

[0023] Figure 12Schematic illustration showing an embodiment of a first conductive cage integrated with a beam structure of a rotor blade and a second conductive cage integrated with a receiving section of the rotor blade and connected to the first conductive cage via an electrical connection member;

[0024] Figure 13 Showing Figure 12 Side view of the schematic illustration;

[0025] Figure 14 Cross-sectional view showing an embodiment of a beam structure of a rotor blade according to the present disclosure, particularly showing the conductive cage integrated with the beam structure;

[0026] Figure 15 Cross-sectional view showing an embodiment of a beam structure of a rotor blade received within a receiving section according to the present disclosure, particularly showing the conductive cage integrated with the receiving section; and

[0027] Figure 16 Flowchart showing an embodiment of a method of assembling a rotor blade of a wind turbine according to the present disclosure. Detailed Description

[0028] Reference will now be made in detail to embodiments of the present invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the present invention and not limitation thereof. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the scope or spirit thereof. For example, features shown or described as part of one embodiment can be combined with another embodiment to yield a still further embodiment. Accordingly, it is intended that the present invention cover such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0029] Now referring to the drawings, Figure 1 Perspective view showing an embodiment of a wind turbine 10 according to the present invention. In the illustrated embodiment, the wind turbine 10 is a horizontal axis wind turbine. Alternatively, the wind turbine 10 can be a vertical axis wind turbine. Further, as shown, the wind turbine 10 can include a tower 12 extending from a support surface 14, a nacelle 16 mounted on the tower 12, a generator 18 positioned within the nacelle 16, a gearbox 20 coupled to the generator 18, and a rotor 22 rotatably coupled to the gearbox 20 by a rotor shaft 24. Further, as shown, the rotor 22 includes a rotatable hub 26 and at least one rotor blade 28 coupled to and extending outwardly from the rotatable hub 26. As shown, the rotor blade 28 includes a blade tip 17 and a blade root 19.

[0030] Now referring to Figure 2 Showing Figure 1Plan view of rotor blade 28. As shown, rotor blade 28 may include a first blade segment 30 and a second blade segment 32. Further, as shown, first blade segment 30 and second blade segment 32 may each extend in opposite directions from chord joint 34. Additionally, as shown, each of blade segments 30, 32 may include at least one housing component, such as a pressure side housing component, a suction side housing component, a leading edge housing component, a trailing edge housing component, and the like. First blade segment 30 and second blade segment 32 are connected by an internal support structure 36 that extends into at least the two blade segments 30, 32 to facilitate connection of the blade segments 30, 32. Arrow 38 shows that in the illustrated example, the segmented rotor blade 28 includes two blade segments 30, 32, and these blade segments 30, 32 are connected by inserting internal support structure 36 into second blade segment 32.

[0031] Now referring to Figure 3 , a perspective view of a section of the first blade segment 30 according to the present disclosure is shown. As shown, first blade segment 30 includes a beam structure 40 that forms part of internal support structure 36 and extends longitudinally for structural connection with second blade segment 32. Further, as shown, beam structure 40 forms at least part of shear web 42 that connects with suction side spar beam 44 and pressure side spar beam 46 (also referred to herein as the lower conductive beam and the upper conductive beam).

[0032] Additionally, as shown, first blade segment 30 may include one or more first pin joints at receiving end 54 of beam structure 40. In one embodiment, the pin joint may include a pin in a tight interference fit with a bushing. More specifically, as shown, the pin joint may include a pin tube 52 that is located on receiving end 54 of beam structure 40. Thus, as shown, pin tube 52 may be oriented in the spanwise direction, i.e., along the span or length of rotor blade 28, which is defined along an axis extending from the blade root to the blade tip of rotor blade 28. Further, first blade segment 30 may also include a pin joint slot 50 that is located on beam structure 40. Additionally, as shown, pin joint slot 50 may be oriented in the chordwise direction, i.e., along the chord of rotor blade 28, which is defined along an axis extending from the leading edge to the trailing edge of rotor blade 28.

[0033] Now referring to Figure 4, showing a perspective view of a section of a second blade segment 32 according to the present disclosure. As shown, the second blade segment 32 includes a receiving segment 60 that extends longitudinally within the second blade segment 32 for receiving the beam structure 40 of the first blade segment 30. Further, as shown, the receiving segment 60 may include a longitudinally extending spar structure 66 for connection to the beam structure 40 of the first blade segment 30. Additionally, as shown, the receiving segment 60 may include a chordal member 48 having a spanwise pin joint slot 56 defined therethrough. Additionally, as shown, the receiving segment 60 may include a chordal pin joint slot 58 defined therethrough, which is aligned with the pin joint slot 50 of the beam structure 40.

[0034] Now referring to Figure 5 , showing an assembly 70 of a rotor blade 28 according to the present disclosure, the assembly having a first blade segment 30 coupled to a second blade segment 32. As shown, the assembly 70 shows a plurality of support structures below the outer housing member of the rotor blade 28. More specifically, as shown, the spanwise extension pin 52 of the receiving end 54 of the beam structure 40 is received within the spanwise pin joint slot 56 of the receiving segment 60 to secure the first blade segment 30 and the second blade segment 32 together. Additionally, as shown, each of the beam structure 40 and the receiving segment 60 may correspondingly define the spar beams 44, 46, 53, 55 of the rotor blade 28.

[0035] Now referring to Figure 6 , showing an exploded perspective view of a plurality of support structures of the assembly 70 towards the blade tip of the rotor blade 28. As shown, the receiving segment 60 is configured to receive the beam structure 40 and may include a chordal pin joint slot 58 that is aligned with the pin joint slot 50 of the beam structure 40, and a chordal extension pin 62 may be inserted through the pin joint slot 50. Further, as shown, the chordal extension pin 62 may be configured to maintain a tight interference fit within the aligned pin joint slots 50, 58 such that the receiving segment 60 and the beam structure 40 are coupled together during assembly. Further, Figure 6 also shown is a chordal member 48 that includes a pin joint slot 56 configured to receive the pin tube 52 of the beam structure 40. Thus, the pin tube 52 is configured to form a tight interference fit joint.

[0036] Now referring to Figures 7 to 15 , showing various views of an embodiment of a rotor blade (such as rotor blade 28) having a lightning protection system 100 according to the present disclosure. Figure 7 Showing a partial side view of the beam structure 40 connected to the receiving segment 60 at the chordal joint 34 of the rotor blade 28. Figure 8 Showing Figure 7 a cross-sectional view taken along section line 8-8. Figure 9Shows a detailed view of the electrical connection member 106 of the lightning protection system 100 according to the present disclosure. Figure 10 Shows at Figure 7 A partial perspective view of the beam structure 40 connected to the receiving section 60 at the chord joint 34 of the rotor blade 28 of Figure 11 Shows at Figure 7 A partial side view of the beam structure 40 connected to the receiving section 60 at the chord joint 34 of the rotor blade 28 of

[0037] In addition, as shown in Figure 7 , the lightning protection system 100 may include a first conductive cage 102 integrated with the beam structure 40, and a second conductive cage 104 integrated with the receiving section 60 and electrically connected to the first conductive cage 102 via the electrical connection member 106. In an embodiment, for example, the first conductive cage 102 and the second conductive cage 104 can be used as a Faraday cage or shield. In addition, as shown in Figure 12 and Figure 13 , in an embodiment, a part of the first conductive cage 102 overlaps with a part of the second conductive cage 104. In addition, Figure 12 Shows a schematic diagram of an embodiment of the first conductive cage 102 integrated with the beam structure 40 and the second conductive cage 104 integrated with the receiving section 60 and electrically connected to the first conductive cage 102 via the electrical connection member 106 according to the present disclosure. Figure 13 Shows Figure 12 A side view of the schematic diagram of. In such an embodiment, for example, the first conductive cage 102 and the second conductive cage 104 can be formed of one of a solid sheet, a wire mesh, a webbing, a netting, or a woven sheet.

[0038] In addition, as shown in Figure 7 and Figure 9 , the lightning protection system 100 further includes at least one conductor cable 108, 110. For example, as shown in Figure 7 and Figures 10 - 12 , the lightning protection system 100 may include a first conductor cable 110 electrically coupled to the first conductive cage 102 and a second conductor cable 108 electrically coupled to the second conductive cage 104. In addition, as shown, the first conductor cable 110 is arranged together with the beam structure 40 and the second conductor cable 108 is arranged together with the receiving section 60. In addition, as shown in Figure 7 and Figure 9 , the first conductor cable 110 and the second conductor cable 108 are electrically connected at the electrical connection member 106. In an embodiment, in addition, the first conductor cable 110 and the second conductor cable 108 can be downlead conductors electrically connected to the first conductive cage 102 and the second conductive cage 104 and grounded. For example, as shown in Figure 7 and Figure 8As shown, the first conductor cable 110 and the second conductor cable 108 can be grounded via the electrical connection 124. More specifically, as shown, the electrical connection 124 is configured to ground any conductor cable described herein.

[0039] In addition, as Figure 7 shown, the lightning protection system 100 can include one or more lightning receivers 120 and / or one or more floating conductors 122, which are arranged together with the beam structure 40 and / or the receiving section 60. In an embodiment, for example, the floating conductor 122 can be made of a carbon fiber reinforced polymer (CFRP) material. More specifically, in such an embodiment, the floating conductor 122 can be the spar beams 44, 46. In another embodiment, for example, the floating conductor 122 can be one of the pin joints described herein and can therefore be made of metal. In addition, in an embodiment, the first conductor cable 110 and the second conductor cable 108 can be electrically connected to each of the one or more lightning receivers 120 and thus ground the lightning receivers 120. However, in contrast, the floating conductor 122 is not electrically connected to the first conductor cable 110 and the second conductor cable 108 and is therefore not grounded. Since floating conductors made of CFRP material can be difficult to ground and floating conductors are sometimes located in areas with limited accessibility of the rotor blade (for which establishing a ground connection is complex), the present disclosure provides the benefit of not having to ground such conductors by using the conductive cages described herein.

[0040] In a further embodiment, as particularly shown in Figure 12 and Figure 13 shown, the first conductive cage 102 and / or the second conductive cage 104 surround the floating conductor 122. Thus, in an embodiment, the first conductive cage 102 and / or the second conductive cage 104 are configured to generate an electric field therein to reduce the potential difference between the down-conductor and the floating conductor 122. Thus, the first conductive cage 102 and the second conductive cage 104, the first conductor cable 110 and the second conductor cable 108, the lightning receivers 120 and / or the floating conductor 122 are configured to control the electric field caused by lightning strikes.

[0041] In such embodiments, the conductive members described herein (such as the first conductive cage 102 and the second conductive cage 104, the first conductor cable 110 and the second conductor cable 108, the lightning receivers 120 and / or the floating conductor 122, etc.) can be any suitable conductive material, for example, such as copper. In addition, such conductive members can have different thicknesses and / or shapes as needed to assist the lightning current.

[0042] Particularly referring to Figure 7 and Figure 9, the electrical connector 106 may include at least one flexible connector 114 that electrically connects the first conductor cable 110 and the second conductor cable 108 together. For example, in an embodiment, the flexible connector 114 may be a flexible circuit, a flexible braided circuit, a flexible bus bar, a flexible cable, a flexible rod, a flexible laminate stack, or a flexible track. In a specific embodiment, as Figure 9 shown, the flexible connector 114 may be, for example, a flexible braided circuit 116 connected between the first conductor cable 110 and the second conductor cable 108. Additionally, as shown, the flexible braided circuit 116 may be attached to the ends of each of the first conductor cable 110 and the second conductor cable 108 using, for example, one or more conductive fasteners 118 that are correspondingly attached to the beam structure 40 and the receiving section 60. In a further embodiment, the flexible braided circuit 116 may be attached to the ends of each of the first conductor cable 110 and the second conductor cable 108 using any suitable means (e.g., such as welding, mechanical fasteners, adhesives, or a combination of both).

[0043] Now referring to Figure 14 and Figure 15 , provided are various cross-sectional views of an embodiment of the beam structure 40 ( Figure 14 ) and the beam structure 40 ( Figure 15 ) received within the receiving section 60. Specifically, as Figure 14 shown, conductive cages (such as the first conductive cage 102 and the second conductive cage 104 described herein) may be integrated into the beam structure 40. In another embodiment, as Figure 15 shown, conductive cages (such as the first conductive cage 102 and the second conductive cage 104 described herein) may be integrated into the receiving section 60. Additionally, as shown, the beam structure 40 includes an upper conductive beam 46 and a lower conductive beam 44 integrated therein, also referred to herein as the suction side and pressure side wing beams 44, 46 and the floating conductor 122. Additionally, as shown, each of the upper conductive beam 46 and the lower conductive beam 44 defines a perimeter that generally refers to a continuous line forming the boundary of each of the suction side and pressure side wing beams 44, 46. Thus, as Figure 14 and Figure 15 shown, the conductive cages 102, 104 only surround a portion of the perimeter of each of the suction side and pressure side wing beams 44, 46. In other words, as shown, the conductive cages 102, 104 extend around the outer surface 126 of the suction side and pressure side wing beams 44, 46 but do not extend around the inner surface 128 of the suction side and pressure side wing beams 44, 46.

[0044] Now referring to Figure 16, a flowchart showing an embodiment of a method 200 for assembling a rotor blade of a wind turbine according to aspects of the present disclosure. Generally, method 200 will be described herein as being implemented using a wind turbine (such as the wind turbine 10 described herein). However, it should be understood that the disclosed method 200 can be implemented using any other wind turbine having any lightning protection system. Additionally, although Figure 16 the steps are depicted in a particular order for purposes of illustration and discussion, the methods described herein are not limited to any particular order or arrangement. Those skilled in the art will understand, using the disclosure provided herein, that the various steps of the method can be omitted, rearranged, combined, and / or adjusted in various ways.

[0045] As shown at (202), method 200 includes providing a first blade segment and a second blade segment. As mentioned, each of the first and second blade segments has at least one shell member defining an airfoil surface and an internal support structure. Additionally, as mentioned, the internal support structure of the first blade segment can include a longitudinally extending beam structure that is structurally connected to the internal support structure of the second blade segment via a receiving section. As shown at (204), method 200 includes integrating a first conductive cage with the beam structure. As shown at (206), method 200 includes integrating a second conductive cage with the receiving section. As shown at (208), method 200 includes electrically connecting the first conductive cage to the second conductive cage via an electrical connection. As shown at (210), method 200 includes electrically connecting a down conductor to the first and second conductive cages and to ground. As shown at (212), method 200 includes arranging the first blade segment and the second blade segment in opposite directions from a chord joint. As shown at (214), method 200 includes securing the first and second blade segments together.

[0046] Aspects and embodiments of the present disclosure are defined by the following numbered clauses:

[0047] A rotor blade assembly, comprising: a first blade segment and a second blade segment extending in opposite directions from a chord joint, each of the first and second blade segments including at least one shell member defining an airfoil surface and an internal support structure, the internal support structure of the first blade segment including a longitudinally extending beam structure that is structurally connected to the internal support structure of the second blade segment via a receiving section; and a lightning protection system, comprising: a first conductive cage integrated with the beam structure; and a second conductive cage integrated with the receiving section and electrically connected to the first conductive cage via an electrical connection, the first and second conductive cages being grounded.

[0048] The rotor blade assembly according to any of the preceding clauses, wherein the first and second conductive cages are grounded via at least one conductor cable.

[0049] The rotor blade assembly according to any one of the preceding clauses, wherein at least one conductor cable includes at least one down-lead conductor electrically connected to the first and second conductive cages.

[0050] The rotor blade assembly according to any one of the preceding clauses, wherein at least one conductor cable includes a first conductor cable electrically coupled to the first conductive cage and a second conductor cable electrically coupled to the second conductive cage, and the first and second conductor cables are electrically connected at an electrical connection member.

[0051] The rotor blade assembly according to any one of the preceding clauses, wherein the first conductor cable is arranged together with the beam structure and the second conductor cable is arranged together with the receiving section.

[0052] The rotor blade assembly according to any one of the preceding clauses, wherein the electrical connection member further includes at least one flexible connector that electrically connects the first and second conductor cables together, and the at least one flexible connector includes at least one of a flexible circuit, a flexible braided circuit, a flexible bus bar, a flexible cable, a flexible rod, a flexible laminate stack, or a flexible track.

[0053] The rotor blade assembly according to any one of the preceding clauses, wherein the lightning protection system further includes one or more lightning receivers, and the first and second conductor cables are electrically connected to each of the one or more lightning receivers.

[0054] The rotor blade assembly according to any one of the preceding clauses, wherein the lightning protection system includes one or more floating conductors arranged together with at least one of the beam structure or the receiving section, wherein at least one of the first conductive cage or the second conductive cage surrounds the one or more floating conductors, and wherein at least one of the first conductive cage or the second conductive cage is configured to generate an electric field therein to reduce the potential difference between at least one conductor cable and the one or more floating conductors.

[0055] The rotor blade assembly according to any one of the preceding clauses, wherein the one or more floating conductors are not electrically connected to at least one conductor cable and are thus not grounded.

[0056] The rotor blade assembly according to any one of the preceding clauses, wherein at least one of the first and second conductive cages is formed of one of a solid sheet, a wire mesh, a webbing, a netting, or a woven sheet.

[0057] The rotor blade assembly according to any one of the preceding clauses, wherein a portion of the first conductive cage overlaps a portion of the second conductive cage.

[0058] The rotor blade assembly according to any one of the preceding clauses, wherein the rotor blade assembly is part of a wind turbine.

[0059] A method of assembling a rotor blade of a wind turbine, the method comprising: providing a first blade segment and a second blade segment, each of the first and second blade segments having at least one shell member defining an airfoil surface and an internal support structure, the internal support structure of the first blade segment including a longitudinally extending beam structure which is structurally connected to the internal support structure of the second blade segment via a receiving section; integrating a first conductive cage with the beam structure; integrating a second conductive cage with the receiving section; electrically connecting the first conductive cage to the second conductive cage via an electrical connection; electrically connecting the first and second conductive cages to ground; arranging the first blade segment and the second blade segment in opposite directions from a chord joint; and securing the first and second blade segments together.

[0060] A rotor blade assembly, comprising: at least one blade segment including at least one shell member defining an airfoil surface and an internal support structure, the internal support structure including a longitudinally extending spar structure, the spar structure including an upper conductive beam and a lower conductive beam integrated therein, the upper conductive beam and the lower conductive beam each defining a perimeter; and a lightning protection system including: a conductive cage integrated with the spar structure, the conductive cage surrounding only a portion of the perimeter of each of the upper conductive beam and the lower conductive beam; and at least one conductor cable arranged in the at least one blade segment and grounded, the conductive cage being electrically connected to the at least one conductor cable.

[0061] The rotor blade assembly according to any one of the preceding clauses, wherein the lightning protection system further includes at least one conductor cable electrically connected to the conductive cage and the electrical connection, and wherein the at least one conductor cable is arranged together with the spar structure.

[0062] The rotor blade assembly according to any one of the preceding clauses, wherein the electrical connection further includes at least one flexible connector, the at least one flexible connector including at least one of a flexible circuit, a flexible braided circuit, a flexible bus bar, a flexible cable, a flexible rod, a flexible laminate stack or a flexible track.

[0063] The rotor blade assembly according to any one of the preceding clauses, wherein the lightning protection system further includes one or more lightning receivers, and at least one conductor cable is electrically connected to each of the one or more lightning receivers.

[0064] The rotor blade assembly according to any one of the preceding clauses, wherein the lightning protection system includes one or more floating conductors arranged together with the spar structure, wherein the conductive cage surrounds the one or more floating conductors, and wherein the conductive cage is configured to generate an electric field therein to reduce the potential difference between the at least one conductor cable and the one or more floating conductors.

[0065] The rotor blade assembly according to any one of the preceding clauses, wherein the one or more floating conductors are not electrically connected to the at least one conductor cable and are thus not grounded.

[0066] The rotor blade assembly according to any of the preceding clauses, wherein the conductive cage is constituted by one of a solid sheet, a wire mesh, a woven tape, a netting, or a knitted sheet.

[0067] This written description uses examples to disclose the invention (including the best mode), 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 method. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. If such other examples include structural elements that are not different from the literal language of the claims, or they include equivalent structural elements that have no substantial difference from the literal language of the claims, then they are intended to fall within the scope of the claims.

Claims

1. A rotor blade assembly, comprising: a first blade segment and a second blade segment extending in opposite directions from a chordwise joint, each of the first blade segment and the second blade segment including at least one shell component defining an airfoil surface and an internal support structure, the internal support structure of the first blade segment including a longitudinally extending beam structure which is structurally connected to the internal support structure of the second blade segment via a receiving section; and a lightning protection system, comprising: a first conductive cage integrated with the beam structure; and a second conductive cage integrated with the receiving section and electrically connected to the first conductive cage via an electrical connector, the first conductive cage and the second conductive cage being grounded.

2. The rotor blade assembly according to claim 1, wherein, The first conductive cage and the second conductive cage are grounded via at least one conductor cable.

3. The rotor blade assembly according to claim 2, wherein, The at least one conductor cable includes at least one down-conductor electrically connected to the first conductive cage and the second conductive cage.

4. The rotor blade assembly according to claim 2, wherein, The at least one conductor cable includes a first conductor cable electrically coupled to the first conductive cage and a second conductor cable electrically coupled to the second conductive cage, the first conductor cable and the second conductor cable being electrically connected at the electrical connector.

5. The rotor blade assembly according to claim 4, wherein, The first conductor cable is arranged together with the beam structure and the second conductor cable is arranged together with the receiving section.

6. The rotor blade assembly according to claim 4, wherein, The electrical connector further includes at least one flexible connector which electrically connects the first conductor cable and the second conductor cable together, the at least one flexible connector including at least one of a flexible circuit, a flexible braided circuit, a flexible bus bar, a flexible cable, a flexible rod, a flexible laminated stack or a flexible track.

7. The rotor blade assembly according to claim 4, wherein, The lightning protection system further includes one or more lightning receivers, the first conductor cable and the second conductor cable being electrically connected to each of the one or more lightning receivers.

8. The rotor blade assembly according to claim 2, wherein, The lightning protection system includes one or more floating conductors arranged together with at least one of the beam structure or the receiving section, wherein at least one of the first conductive cage or the second conductive cage surrounds the one or more floating conductors, and wherein at least one of the first conductive cage or the second conductive cage is configured to generate an electric field therein to reduce the potential difference between the at least one conductor cable and the one or more floating conductors.

9. The rotor blade assembly according to claim 8, wherein, The one or more floating conductors are not electrically connected to the at least one conductor cable and are thus not grounded.

10. The rotor blade assembly according to claim 1, wherein, At least one of the first conductive cage and the second conductive cage is constituted by one of a solid sheet, a wire mesh, a webbing, a net or a knitted sheet.

11. The rotor blade assembly according to claim 1, wherein, A part of the first conductive cage overlaps with a part of the second conductive cage.

12. The rotor blade assembly according to claim 1, wherein, The rotor blade assembly is part of a wind turbine.

13. A method of assembling a rotor blade of a wind turbine, the method comprising: providing a first blade segment and a second blade segment, each of the first blade segment and the second blade segment having at least one shell component defining an airfoil surface and an internal support structure, the internal support structure of the first blade segment including a longitudinally extending beam structure which is structurally connected to the internal support structure of the second blade segment via a receiving section; Integrate the first conductive cage with the beam structure; Integrate the second conductive cage with the receiving section; Electrically connect the first conductive cage to the second conductive cage via an electrical connector; Electrically connect the first conductive cage and the second conductive cage to ground; Arrange the first blade segment and the second blade segment in opposite directions from the chordwise joint; And Fix the first blade segment and the second blade segment together.

14. A rotor blade assembly, comprising: At least one blade segment, which includes at least one shell component defining an airfoil surface and an internal support structure, the internal support structure includes a longitudinally extending spar structure, the spar structure includes an upper conductive beam and a lower conductive beam integrated therein, and the upper conductive beam and the lower conductive beam each define a perimeter; And A lightning protection system, comprising: A conductive cage integrated with the spar structure, the conductive cage only surrounds a part of the perimeter of each of the upper conductive beam and the lower conductive beam; And At least one conductor cable, which is arranged in the at least one blade segment and grounded, and the conductive cage is electrically connected to the at least one conductor cable.

15. The rotor blade assembly according to claim 14, wherein, The lightning protection system further includes at least one conductor cable electrically connected to the conductive cage and the electrical connector, wherein the at least one conductor cable is arranged together with the spar structure.

16. The rotor blade assembly according to claim 15, wherein, The electrical connector further includes at least one flexible connector, and the at least one flexible connector includes at least one of a flexible circuit, a flexible braided circuit, a flexible bus bar, a flexible cable, a flexible rod, a flexible laminated stack or a flexible track.

17. The rotor blade assembly according to claim 15, wherein, The lightning protection system further includes one or more lightning receivers, and the at least one conductor cable is electrically connected to each of the one or more lightning receivers.

18. The rotor blade assembly according to claim 14, wherein, The lightning protection system includes one or more floating conductors arranged together with the spar structure, wherein the conductive cage surrounds the one or more floating conductors, and wherein the conductive cage is configured to generate an electric field therein to reduce the potential difference between the at least one conductor cable and the one or more floating conductors.

19. The rotor blade assembly according to claim 18, wherein, The one or more floating conductors are not electrically connected to the at least one conductor cable and are thus not grounded.

20. The rotor blade assembly according to claim 14, wherein, The conductive cage is formed of one of a solid sheet, a wire mesh, a webbing, a mesh or a woven sheet.

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