Tip extension for wind turbine rotor blade and method of installing the same

Abstract

The present disclosure relates to a tip extension for a wind turbine rotor blade and a method for installing the same. The method includes removing a removable blade tip of a lightning protection system from a rotor blade so as to expose a down conductor of the lightning protection system. The method also includes securing a conductive extension to the down conductor. Furthermore, the method includes sliding a first end of the tip extension over the conductive extension so as to overlap the rotor blade at the tip end. Additionally, the method includes securing the removable blade tip to the conductive extension at a second end of the tip extension. Additionally, the method includes securing the tip extension to the rotor blade.

Description

Technical Field

[0001] The present disclosure relates generally to wind turbine rotor blades, and more particularly to a tip extension for a wind turbine rotor blade and a method of installing the same that is incorporated into an existing lightning protection system of the wind turbine rotor blade. Background Art

[0002] Wind power is considered to be one of the cleanest and most environmentally friendly energy sources currently available, and wind turbines have received 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 capture the kinetic energy of the wind using the known airfoil principle. The rotor blades transfer the kinetic energy in the form of rotational energy to rotate a shaft that couples the rotor blades to a gearbox, or directly to a generator if a gearbox is not used. The generator then converts the mechanical energy into electrical energy that can be deployed to a utility grid.

[0003] In many cases, accessory components are attached to the rotor blades of a wind turbine to perform a variety of functions during the operation of the wind turbine. For example, it is known to change the aerodynamic properties of a wind turbine rotor blade by adding protrusions or other structures to the surface of the blade in order to increase the energy conversion efficiency during normal operation of the wind turbine by increasing the lift of the blade while reducing drag. Such components include, for example, winglets, tip extensions, and vortex generators. The purpose and operating principles of these devices are well understood by those skilled in the art.

[0004] Installation techniques and systems for attaching conventional add-on components can be expensive and time consuming, particularly for field installation. For example, typical field installation techniques require the use of attachment fixtures and a significant amount of downtime for curing the attachment adhesive. Furthermore, particularly for the addition of tip extensions, a popular conventional approach involves cutting off the existing blade tip in order to integrate the extension with the internal blade structure. Such a process can be time consuming, expensive, and can damage the main blade structure. Furthermore, such a process can compromise the structural integrity and / or durability of the rotor blade, as well as its aerodynamic performance. Furthermore, certain tip extensions can increase noise in the surrounding area above acceptable limits.

[0005] Additionally, wind turbines are susceptible to lightning strikes, and in this regard, it is common practice to provide turbine blades with lightning receptors spaced along the longitudinal length of the blades to capture and conduct the lightning strikes to the ground. As such, additional challenges associated with installing a tip extension onto an existing rotor blade may include maintaining the lightning protection system functionality of the existing rotor blade.

[0006] Accordingly, the industry continues to seek improved methods for installing a tip extension for a wind turbine rotor blade that is incorporated into an existing lightning protection system for the wind turbine rotor blade. Summary of the invention

[0007] Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

[0008] In one aspect, the present disclosure relates to a method for mounting a tip extension onto a tip end of a rotor blade of a wind turbine. The wind turbine includes a lightning protection system mounted thereon. The lightning protection system includes at least a down conductor associated with the rotor blade and a removable conductive blade tip. In addition, the tip extension has a first end, a second end, a closed leading edge, and an at least partially separated trailing edge. Therefore, the method includes removing the conductive blade tip of the lightning protection system so as to expose the down conductor. The method also includes securing the conductive extension to the down conductor. In addition, the method includes sliding the first end of the tip extension over the conductive extension so as to overlap the rotor blade at the tip end. In addition, the method includes securing the previously removed conductive blade tip to the conductive extension at the second end of the tip extension. Then, the method includes securing the tip extension to the tip end of the rotor blade.

[0009] In one embodiment, the down conductor of the lightning protection system may include a down conductor component, a down conductor cable, or any other down conductor of the lightning protection system. In addition, the conductive extension may include a first end and a second end. As such, in a certain embodiment, the step of securing the conductive extension to the down conductor may include securing the down conductor component to the first end of the conductive extension within a groove of the conductive extension.

[0010] In another embodiment, the tip extension may include one or more internal structural members. More specifically, in certain embodiments, the internal structural member(s) may include a transition region structural support or an internal structural channel. In such an embodiment, the step of sliding the first end of the tip extension over the conductive extension may include inserting the tip end of the rotor blade into the transition region structural support (e.g., between ribs of the structural support) and inserting the conductive extension into the internal structural channel.

[0011] In further embodiments, securing the conductive blade tip to the conductive extension at the second end of the tip extension may include inserting the second end of the conductive extension into a recess of the conductive blade tip and securing one or more fasteners through the conductive blade tip and the second end of the conductive extension.

[0012] In additional embodiments, the step of securing the tip extension to the rotor blade may include attaching an adhesive side of one or more strips of double-sided tape to either or both of a pressure side surface or a suction side surface of the rotor blade adjacent the tip end or to an inner surface of the tip extension. The tape strips have a release liner on opposite exposed sides thereof, and each of the tape strips has an extension tail from the release liner that extends beyond a first end of the tip extension when the tip extension is slid onto the tip end of the rotor blade. As such, the step of securing the tip extension to the rotor blade may further include, with the tip extension held in place, sequentially pulling, starting with the strap farthest from the at least partially separated trailing edge, the extended tails of the respective straps and the release liner past the trailing edge and away from the tip extension at an angle such that the release liner is removed along the length of the strap while maintaining the position of the tip extension against the rotor blade to attach the exposed adhesive from beneath the release liner to either or both of the pressure side surface or the suction side surface of the rotor blade or the inner surface of the tip extension.

[0013] In another embodiment, the at least partially separated trailing edge may include a pressure side edge and a suction side edge, each of which extends past the trailing edge of the rotor blade. Furthermore, the pressure side edge and the suction side edge may extend past the trailing edge of the rotor blade by a substantially equal distance, or one of the edges may be offset relative to the other. As such, the method may further include bonding the pressure side edge and the suction side edge together after removing the release liner.

[0014] In further embodiments, the method may include positioning one or more additional components between or with portions of the pressure and suction side edges of the at least partially separated trailing edge, or to one or more surfaces of the tip extension.

[0015] In another aspect, the present disclosure relates to a method for mounting a tip extension to a tip end of a rotor blade of a wind turbine. The wind turbine has a lightning protection system mounted thereon. The lightning protection system has a down conductor and a conductive blade tip fixed to the down conductor associated with the rotor blade. In addition, the tip extension has a closed leading edge and an at least partially separated trailing edge. Therefore, the method includes fixing the conductive extension to the conductive blade tip. The method also includes sliding a first portion of the tip extension over the conductive blade tip so as to overlap the rotor blade at the tip end. In addition, the method includes sliding a second portion of the tip extension over the conductive extension. In addition, the method includes fixing the first portion of the tip extension to the rotor blade. In addition, the method includes fixing the second portion of the tip extension to the first portion.

[0016] In one embodiment, the method may further include securing the extended conductive blade tip to the conductive extension such that the extended conductive blade tip extends beyond the second portion of the tip extension. It should be understood that the method may further include any of the additional steps and / or features as described herein.

[0017] In yet another aspect, the present disclosure relates to a rotor blade assembly. The rotor blade assembly includes a rotor blade having a root end, a tip end, and a pressure side surface and a suction side surface extending between a leading edge and a trailing edge. In addition, the rotor blade assembly includes a lightning protection system mounted to or within the rotor blade. The lightning protection system includes at least a down conductor, a conductive blade tip, and at least one lightning receptor located on either the pressure side surface or the suction side surface. In addition, the rotor blade assembly includes a tip extension having a first end, a second end, a closed leading edge, and a trailing edge defined by at least partially separated pressure side edges and suction side edges, the pressure side edges and the suction side edges being combined and extending beyond the trailing edge of the rotor blade in a chord direction. In addition, the tip extension includes a conductive extension configured between the first end and the second end of the tip extension, the conductive extension electrically coupling the down conductor to at least one of the conductive blade tip and / or the at least one lightning receptor so as to maintain the functionality of the lightning protection system. In addition, the first end of the tip extension overlaps the tip end of the rotor blade.

[0018] In one embodiment, the down conductor of the lightning protection system may include a down conductor component, a down conductor cable, or any other suitable down conductor. In another embodiment, the conductive extension extends between a first end and a second end. As such, the first end of the conductive extension may include a side edge forming a groove. In such an embodiment, the down conductor component may be fixed in the groove. In addition, the second end of the conductive extension may be free of side edges and fixed in a recess of the conductive blade tip. In addition, the conductive blade tip may be configured at the second end of the tip extension so as to provide a conductive extension root end of the rotor blade.

[0019] In an alternative embodiment, the down conductor component may be fixed within a recess of the conductive blade tip, and the first end of the conductive extension may be fixed to the conductive blade tip. In such an embodiment, the conductive blade tip may be configured within the tip extension between the first end and the second end of the tip extension (i.e., rather than being relocated to the tip end of the rotor blade). As such, the lightning receptor(s) may be electrically coupled to the second end of the conductive extension. In additional embodiments, the rotor blade assembly may further include an extended conductive blade tip electrically coupled to the second end of the conductive extension.

[0020] In other embodiments, the tip extension may have a one-piece body or a two-piece body. More specifically, the two-piece body may include a first portion and a second portion. In such embodiments, the first portion may cover the down conductor component and the conductive vane tip, while the second portion may cover at least a portion of the conductive extension. Furthermore, the first portion of the two-piece body may have a separated trailing edge, while the second portion may not have a separated trailing edge.

[0021] In additional embodiments, as mentioned, the tip extension may include one or more internal structural components, including, for example, a transition region structural support and / or an internal structural channel. As such, the tip end of the rotor blade may be configured to fit within the transition region structural support, and the conductive extension may be configured to fit within the internal structural channel. Such internal structural components are configured to provide an enhanced structure to the rotor blade.

[0022] In further embodiments, the rotor blade assembly may further include an adhesive and / or one or more double-sided tapes configured for securing the tip extension to the tip end of the rotor blade and / or for securing the first portion and the second portion of the tip extension together.

[0023] In yet another embodiment, the tip extension may include one or more additional components that are configured between or with portions of the pressure side edge and the suction side edge of the separated trailing edge and / or with one or more surfaces of the tip extension. For example, in certain embodiments, the additional component(s) may include a serrated edge, a band recess (e.g., for a leading edge protection band), an air flow conditioning element (such as a vortex generator), a mounting feature, a drainage hole, or any other suitable blade additional component that may be mounted to or integrated with the tip extension.

[0024] In still other embodiments, the conductive extension and / or the conductive blade tip may be formed via a metal or a metal alloy. For example, in certain embodiments, the metal or metal alloy may include aluminum.

[0025] These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims.The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] A complete and enabling disclosure of the invention, including the best mode thereof, to one of ordinary skill in the art is set forth in the specification with reference to the accompanying drawings, in which:

[0027] Figure 1 illustrates a perspective view of a conventional wind turbine;

[0028] Figure 2 illustrates a perspective view of one embodiment of a rotor blade for a wind turbine according to the present disclosure, the rotor blade having a tip extension configured with a tip end thereof;

[0029] Figure 3 illustrates a perspective view of one embodiment of a wind turbine according to the present disclosure, and in particular illustrates a lightning protection system constructed therewith;

[0030] Figure 4 illustrates a span-wise view of one embodiment of a rotor blade of a wind turbine according to the present disclosure, and in particular illustrates various components of a lightning protection system constructed therewith;

[0031] Figure 5 illustrates a perspective view of one embodiment of a one-piece tip extension according to the present disclosure;

[0032] Figure 6 Pictured Figure 5 A top view of a one-piece tip extension of FIG. 1 , particularly illustrating a transparent tip extension to further illustrate its internal components;

[0033] Figure 7 Pictured Figure 6 A perspective detailed view of a one-piece distal extension;

[0034] Figure 8 Pictured Figure 5 A perspective cross-sectional view of the one-piece tip extension along line 8-8;

[0035] Fig. 9 Pictured Figure 5 A cross-sectional view of the one-piece tip extension along line 9-9;

[0036] Fig.10 The diagram shows the structure Figure 5 A perspective view of one embodiment of a conductive member within a distal extension of the device;

[0037] Fig.11 The diagram shows the structure Figure 5 A perspective view of one embodiment of a conductive extension within a distal extension of;

[0038] Fig.12 illustrates a perspective view of one embodiment of a two-piece tip extension according to the present disclosure;

[0039] Fig.13 Pictured Fig.12 A top view of a two-piece tip extension of FIG. 1 , particularly illustrating a transparent tip extension to further illustrate its internal components;

[0040] Fig.14 Pictured Fig.13 A perspective detailed view of a two-piece tip extension;

[0041] Fig.15 Pictured Fig.13 a perspective cross-sectional view of the two-piece tip extension along line 15-15;

[0042] Fig.16 Pictured Fig.13 a side cross-sectional view of the two-piece tip extension along line 15-15;

[0043] Fig.17 Pictured Fig.12 a partial perspective view of a tip extension of the embodiment of the present invention, particularly illustrating an extended conductive blade tip connected to the conductive extension and extending from a second portion of the tip extension;

[0044] Fig.18 Pictured Fig.12 a partial perspective view of a tip extension of FIG. 1 , particularly illustrating a down conductor member constructed within a recess of an existing conductive blade tip, wherein the conductive extension is attached to the down conductor member and extends into a second portion of the tip extension;

[0045] Fig.19 Pictured Fig.12 a partial perspective view of a second portion of the distal extension of the embodiment of the present invention, particularly illustrating the internal structural channel constructed therein;

[0046] Fig. 20 The diagram shows the structure Fig.12 A perspective view of a conductive member within a distal extension of the device;

[0047] Fig.21 illustrates a perspective view of another embodiment of a two-piece tip extension according to the present disclosure;

[0048] Fig. 22 Pictured Fig.21 a perspective detailed view of a two-piece tip extension of FIG. 1 , particularly illustrating a transparent tip extension to further illustrate internal components thereof;

[0049] Fig.23 Pictured Fig. 22 a partial perspective view of a tip extension of FIG. 1 , particularly illustrating a down conductor member constructed within a recess of an existing conductive blade tip, wherein the conductive extension is attached to the down conductor member and extends into a second portion of the tip extension;

[0050] Fig.24 Pictured Fig. 22 A side cross-sectional view of the one-piece distal extension along line 24-24;

[0051] Fig.25 Pictured Fig. 22 A detailed cross-sectional view of a lightning receptor at a distal extension of the device;

[0052] Fig.26 The diagram shows the structure Fig. 22 A perspective view of a conductive member within a distal extension of the device;

[0053] Fig. 27 A flow chart illustrating one embodiment of a method for mounting a tip extension to a tip end of a rotor blade of a wind turbine according to the present disclosure;

[0054] Fig.28 illustrates a partial top view of one embodiment of a rotor blade for a wind turbine according to the present disclosure, wherein a tip extension is slid onto the tip end of the rotor blade;

[0055] Fig.29 The diagram shows the tip extension after it has been slid into position on the tip end of the rotor blade. Fig.28 A partial top view of an embodiment of the present invention;

[0056] Fig.30 Pictured Fig.29 A partial top view of an embodiment of , depicting peeling the release liner from the tape by the separated trailing edge of the distal extension;

[0057] Fig.31 Pictured Fig.30 A partial top view of an embodiment of , depicting peeling the final release liner from the tape by the separated trailing edge of the distal extension; and

[0058] Fig.32 A flow chart illustrating another embodiment of a method for mounting a tip extension to a tip end of a rotor blade of a wind turbine according to the present disclosure is illustrated. DETAILED DESCRIPTION

[0059] 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 rather than by way of limitation of the present invention. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made in the present invention without departing from the scope or spirit of the present invention. For example, a feature illustrated or described as part of one embodiment may be used together with another embodiment to produce yet another additional embodiment. Therefore, it is intended that the present invention encompasses such modifications and variations as fall within the scope of the appended claims and their equivalents.

[0060] Now referring to the accompanying drawings, Figure 1A wind turbine 10 of conventional construction is illustrated. As shown, wind turbine 10 includes a tower 12 on which is mounted a nacelle 14. A plurality of blades 16 are mounted to a rotor hub 18, which in turn is connected to a main flange that rotates a main rotor shaft (not shown). Wind turbine power generation and control components are housed within nacelle 14. Figure 1 The views of FIG. 1 are for illustrative purposes only, to place the invention in an exemplary field of use. It should be appreciated that the invention is not limited to any particular type of wind turbine configuration.

[0061] refer to Figure 2 , according to the present disclosure, a rotor blade assembly 100 for a wind turbine 10 is illustrated having a tip extension 102 attached to a surface 24 (e.g., a suction side surface) of a rotor blade 16. As shown, the rotor blade 16 has a pressure side 22 and a suction side 24 extending between a leading edge 26 and a trailing edge 28, and extends from a root end 34 to a tip end 32. The rotor blade 16 further defines a rotor blade 16 with respect to the rotor hub 18 ( Figure 1 ) and extending through the center of the root end 34, which is typically perpendicular to the rotor hub 18 and the root end 34. The pitch angle or blade pitch of the rotor blade 16 (i.e., the angle that determines the viewing angle of the rotor blade 16 relative to the air flow passing through the wind turbine 10) can be defined by the rotation of the rotor blade 16 about the pitch axis 40. In addition, the rotor blade assembly 100 defines a chord 42 and a span 44. For example, as Figure 2 As shown in , the chord 42 may vary across the span 44 of the rotor blade 16. Thus, a local chord may be defined for the blade 16 at any point along the span 44 on the blade 16.

[0062] Reference now Figure 3 and Figure 4 , the rotor blade assembly 100 may also include a lightning protection system 50 constructed therewith. For example, as shown, according to the present disclosure, a schematic diagram of various components of an embodiment of the lightning protection system 50 is illustrated. More specifically, Figure 3 A perspective view of one embodiment of a lightning protection system 50 configured with a wind turbine 10 is shown. Figure 4 Illustrated is a cross-sectional view of one of the rotor blades 16 of the wind turbine 10 with portions of a lightning protection system 50 configured therein.

[0063] As shown, the lightning protection system 50 includes one or more conductive loops 52 configured at least partially within the interior cavity 36 of one or more of the rotor blades 16 of the wind turbine 10. Figure 4As shown in , each of the conductive loops 52 may include one or more down conductors 55, a conductive blade tip 59, and at least one lightning receptor 54 located on either the pressure side surface 22 or the suction side surface 24 of the rotor blade 16. For example, as shown in the illustrated embodiment, the down conductor(s) 55 of the lightning protection system 50 may include a down conductor component 57 (e.g., a down conductor fork or other suitable component), a down conductor cable 56, or any other suitable down conductor. Further, as shown, the lightning receptors 54 are disposed on both the pressure side 22 and the suction side 24. In alternative embodiments, the lightning receptors 54 may be disposed on only one of the sides of the rotor blade 16. It should be understood that the lightning receptors 54 may be configured differently within the scope and spirit of the present invention and may include any metal or metalized member (i.e., a metal screen, a metal rod or tip, a metal fastener, and / or the like) mounted on the pressure side 22 and / or the suction side 24 of the rotor blade 16 for the purpose of conducting a lightning impulse to the ground. Additionally, as shown Figure 4 , the lightning receptors 54 may be connected via one or more lightning conductors or conductive cables 56 configured within the interior cavity 36 of the rotor blade 16. As such, the conductive cables 56 may have specifications suitable for defining a conductive leg for transmitting a lightning impulse on any of the receptors 54 to the ground. Furthermore, the conductive cable(s) 56 may be connected to an outer surface or an inner surface of the rotor blade(s) 16. Additionally, each of the rotor blades 16 may be configured in a similar manner.

[0064] Still reference Figure 3 and Figure 4 , a respective lightning conductive loop 52 for each of the rotor blades 16 may include a terminal 58 extending through the root end 34 of the rotor blade 16 and individually connected to a grounding system 60 within the rotor hub 18. The grounding system 60 may be configured differently, as is well known in the art. For example, the grounding system 60 may include any conductive path defined by a mechanical or supporting structure of the wind turbine (including blade bearings, mechanical bedplates, tower structures, and the like) that defines any suitable grounding conductive path 62 from the rotor blade 16 through the tower 12 via a grounding cable 72 to a grounding rod 64, or other suitable electrical grounding path. In other embodiments, the conductive loop 52 may be defined by a member embedded in the rotor blade 16 or external to the rotor blade 16, such as along the outer surface 22, 24 of the rotor blade 16.

[0065] Special reference Figure 4, each rotor blade 16 may include a single conductive loop 52, as depicted, wherein each of the lightning receptors 54 is configured in series within the single loop 52. In alternative embodiments, each of the rotor blades 16 may include multiple loops 52, wherein each of the lightning receptors 54 is configured in one of the respective loops 52. In still other embodiments, the receptors 54 may be connected via conductive cable(s) 56 in any suitable manner, and it should be understood that Figure 3 and Figure 4 The embodiments are provided for the purpose of illustration only and are not intended to be limiting.

[0066] Reference now Figures 5 to 11 , according to the present disclosure, an embodiment of the tip extension 102 of the present disclosure is illustrated. More specifically, Figures 5 to 11 The embodiment of FIG. 1 illustrates a tip extension 102 that utilizes the existing conductive blade tip 59 of the lightning protection system 50 at its outermost position. Figure 5 As shown in , the tip extension 102 has a generally hollow body 108 having a first end 103, a second end 109, a closed leading edge 104, and a trailing edge 106, which is defined by a separate pressure side edge 107 and a suction side edge 105 that are bonded together and extend chord-wise beyond the trailing edge 28 of the rotor blade 16 when mounted to the trailing edge 28 of the rotor blade 16. In addition, the trailing edge 106 is separate in that the suction side edge 105 and the pressure side edge 107 are not bonded or sealed together along at least a portion of the length of the trailing edge 106, which allows the pressure and suction sides of the tip extension 102 to be pulled apart to the extent necessary to slide the tip extension 102 onto the tip end 32 of the rotor blade 16. In certain embodiments as depicted in the figures, the trailing edge 106 is separate along substantially the entire length of the trailing edge, however this is not a requirement for all embodiments. In addition, as shown in the figures, the trailing edge 106 is separate along substantially the entire length of the trailing edge, however this is not a requirement for all embodiments. Figure 2 and Figure 6 to Figure 7 , the first end 103 of the tip extension 102 is configured to overlap the tip end 32 of the rotor blade 16. As such, the rotor blade assembly 100 may further include an adhesive or one or more double-sided tapes configured to secure the tip extension 102 to the tip end 32 of the rotor blade 16 when mounted thereto, as will be described in greater detail below.

[0067] In additional embodiments, the tip extension 102 of the present disclosure may be formed using any suitable manufacturing process. For example, in certain embodiments, the tip extension 102 described herein may be formed via three-dimensional (3D) printing. As such, the tip extension 102 may be constructed as a single component or a limited number of components, such as the two components described herein. 3D printing provides many advantages to the tip extension 102, including but not limited to the ability to have a solid and very thin trailing edge at the outermost portion of the extension and a separated trailing edge further inboard to facilitate installation (which is described in more detail below). In addition, 3D printing of the tip extension 102 provides an automated and economical manufacturing process that produces a desired shape that can be easily customized for a variety of lengths, sizes, and internal geometries to match existing blade surfaces for bonding using adhesives.

[0068] More specifically, if Figures 6 to 9 , the tip extension 102 may be readily designed with one or more internal structural members 136, including, for example, a transition region structural support 138 and / or an internal structural channel 140. As such, the structural member(s) 136 are configured to house and electrically insulate the conductive members described herein. For example, the tip end 32 of the rotor blade 16 may be configured to fit within the transition region structural support 138, while the conductive extension 115 may be configured to fit within the internal structural channel 140. Furthermore, the internal structural members 136 of the tip extension 102 may include internal ribs and / or additional structures to support the original tip end 32 of the rotor blade 16 for additional support.

[0069] Generally speaking Figures 6 to 11 , the tip extension 102 also includes a conductive extension 115 configured between the first end 103 and the second end 109 of the tip extension 102. Therefore, as shown in the illustrated embodiment, the conductive extension 115 is configured to electrically couple the down conductor component 57 of the lightning protection system 50 to the removable conductive blade tip 59. More specifically, as shown in FIG. Fig.11 As shown in FIG. 1 , the conductive extension 115 may include a first end 117 and a second end 119. In addition, as shown, the first end 117 of the conductive extension 115 may include a side edge 121 forming a groove 123. Fig.10 As shown in FIG. 1 , the down conductor member 57 can be fixed in the groove 123 of the conductive extension 115. Figure 10 to Figure 11 As shown in , the second end 119 of the conductive extension 115 may not have a side edge 121, so that the second end 119 can be fixed in the recess 125 of the conductive blade tip 59. Figures 5 to 8As shown in , conductive blade tip 59 is also configured at second end 109 of tip extension 102 when conductive blade tip 59 is secured to second end 119 of conductive extension 115 to provide an extended root end 126 of rotor blade 16 .

[0070] Reference now Figures 12 to 20 , illustrates another embodiment of the tip extension 102 according to the present disclosure. More specifically, as shown, Figures 12 to 20 The embodiment of FIG. 1 illustrates a tip extension 102 that leaves the existing conductive blade tip 59 unchanged, but instead attaches the conductive extension 115 and the additional extended conductive blade tip 132 to the existing conductive blade tip 59 to maintain the functionality of the lightning protection system 50. Figures 5 to 11 As shown in the embodiment shown in FIG. Figures 12 to 20 The tip extension 102 of the rotor blade 16 has a generally hollow body 108 having a first end 103, a second end 109, a closed leading edge 104, and a trailing edge 106 defined by separate pressure side edge 107 and suction side edge 105 that are joined together and extend beyond the trailing edge 28 of the rotor blade 16 in the chord direction when mounted to the trailing edge 28 of the rotor blade 16. However, unlike Figures 5 to 11 , the tip extension 102 has a two-piece body including a first portion 128 and a second portion 130. In addition, the down conductor component 57 is fixed within the recess 125 of the conductive blade tip 59 (i.e., rather than within the groove 123 of the conductive extension 115). In addition, the first end 117 of the conductive extension 115 is fixed to the existing conductive blade tip 59, and the second end 119 of the conductive extension 115 is fixed to the extended conductive blade tip 132 (e.g., via one or more fasteners 134, which can also be configured as lightning receptors).

[0071] Therefore, if Figures 12 to 20 As shown in the illustrated embodiment of , the conductive extension 115 is configured to electrically couple the existing conductive blade tip 59 to the extended conductive blade tip 132. In other words, the existing conductive blade tip 59 remains at the tip end 32 of the rotor blade 16, with the tip extension 102 mounted to the tip end 32. In such an embodiment, the conductive blade tip 59 may be configured within the tip extension 102 between the first end 103 and the second end 109 of the tip extension 102. In addition, as Figures 13 to 16 As shown in FIG. 1 , the first portion 128 may cover the down conductor member 57 and the conductive vane tip 59 , while the second portion 130 may cover at least a portion of the conductive extension 115 .

[0072] Specifically refer to Figures 13 to 16 and Figure 18 to Figure 19 As mentioned, the tip extension 102 may include one or more internal structural members 136. For example, as shown, the internal structural member 136 includes a transition region structural support 138 and an internal structural channel 140. As such, the tip end 32 of the rotor blade 16 may be configured to fit within the transition region structural support 138, and the conductive extension 115 may be configured to fit within the internal structural channel 140.

[0073] In additional embodiments, the conductive members described herein may be formed of any suitable material. For example, in certain embodiments, the conductive extension 115 and / or the conductive blade tip 59 may be constructed of a metal or metal alloy. More specifically, in certain embodiments, the metal or metal alloy may include aluminum.

[0074] Reference now Figure 21 to Figure 26 , illustrates another embodiment of the tip extension 102 according to the present disclosure. More specifically, as shown, Figure 21 to Figure 26 The embodiment of FIG. 5 illustrates a tip extension 102 that leaves the existing conductive blade tip 59 unchanged, but attaches a conductive extension 115 having at least one lightning receptor 134 to the existing conductive blade tip 59 to maintain the functionality of the lightning protection system 50. Figures 12 to 20 As in the embodiment illustrated in FIG. 1 , the tip extension 102 has a generally hollow body 108 having a first end 103, a second end 109, a closed leading edge 104, and a trailing edge 106 defined by separate pressure side edge 107 and suction side edge 105 that are joined together and extend beyond the trailing edge 28 of the rotor blade 16 in the chord direction when mounted to the trailing edge 28 of the rotor blade 16. In addition, as Figures 12 to 20 As in the embodiment illustrated in FIG. 1 , the tip extension 102 has a two-piece body including a first portion 128 and a second portion 130. In addition, as shown, the down conductor member 57 is secured within the recess 125 of the conductive vane tip 59. In addition, the first end 117 of the conductive extension 115 is secured to the existing conductive vane tip 59. However, unlike Figures 12 to 20 In contrast to the embodiment of the present invention, the second end 119 of the conductive extension 115 includes at least one lightning receptor 134 ( Figure 21 to Figure 24 ) (rather than connecting the extended conductive blade tip 132 to the second end 119). In such an embodiment, Fig.25 As shown in FIG. , the lightning receptor 134 may be extended longer than, for example, Figures 13 to 16 and Figures 18 to 20The lightning receptor 134 is a longer fastener, and the lightning receptor 134 is recessed within the distal extension 102 .

[0075] In addition, if Figure 21 to Figure 23 , the tip extension 102 may include one or more optional additional components 142 that are configured between or with portions of the pressure side edge 107 and the suction side edge 105 of the separated trailing edge 106 and / or with one or more surfaces of the tip extension 102. For example, as shown, the additional component(s) 102 may include a serrated edge 144 (e.g., for noise reduction), a belt recess (e.g., for a leading edge protection band), an air flow conditioning element (such as a vortex generator 146), a mounting feature (e.g., for an air flow conditioning element), a winglet, a drain hole 148, or any other suitable blade additional component that may be mounted to or integral with the tip extension 102.

[0076] More specifically, if the pressure side edge 107 and the suction side edge 105 are not offset, the additional feature 142 may be defined (e.g., by laser cutting) into the combination of the joined surfaces 105, 107. In an alternative embodiment, to reduce the thickness of the additional feature 142, the feature may be defined in one of the edges 105, 107 that extends beyond the other edge in the chord direction. For example, in Figure 21 to Figure 23 In the embodiment depicted in FIG, the suction side surface edge 105 of the separated trailing edge 106 extends past the pressure side surface edge 107, wherein the additional member 142 is defined in the suction side surface edge 105 in the form of a sawtooth edge 144. It should be appreciated that the additional member 142 is depicted as a sawtooth profile for illustrative purposes only, and any design of the additional member 142 is within the scope and spirit of the present invention. In alternative embodiments, the suction surface edge 105 and the pressure surface edge 107 may extend equally beyond the trailing edge 28, and the additional member 142 may be incorporated between the suction surface edge 105 and the pressure surface edge 107.

[0077] Reference now Figures 27 to 31 , illustrates one embodiment of a method 200 for installing the tip extension 102 of the present disclosure onto the tip end 32 of the rotor blade 16 of the wind turbine 10. As shown at 202, the method 200 includes removing an existing conductive blade tip 59 of the lightning protection system 50 to expose the down conductor 55 of the lightning protection system 50. For example, in certain embodiments, as mentioned, the down conductor 55 corresponds to the down conductor component 57. In such embodiments, when the conductive blade tip 59 is removed, the down conductor component 57 is exposed.

[0078] Thus, as shown at 204, the method 200 also includes securing the conductive extension 115 to the down conductor 55 (i.e., the down conductor 57). Additionally, as shown at 206, the method 200 includes sliding the first end 103 of the tip extension 102 over the conductive extension 115 so as to overlap the rotor blade 16 at the tip end 32 of the rotor blade 16. For example, Fig.28 An embodiment is shown in which the first end 103 of the tip extension 102 slides over the tip end 32 of the rotor blade 16. In addition, the invention is generally described in U.S. Patent Application Serial No. 14 / 706,024 filed on May 7, 2015. Figure 28 to Figure 31 The present invention relates to an embodiment of an embodiment of a wind turbine blade, which is entitled "Attachment Method and System to Install Components, such as Tip Extensions and Winglets, to a Wind Turbine Blade", which is incorporated herein by reference in its entirety. Fig.28 The tip extension 102 is depicted (via arrows) as sliding linearly in the spanwise direction onto the rotor blade 16, but it should be appreciated that such sliding motion may include a chordwise direction component that is aided by the breakaway nature of the trailing edge 106. More specifically, in certain embodiments, the step of sliding the first end 103 of the tip extension 102 over the conductive extension 115 may include inserting the tip end 32 of the rotor blade 16 into the transition region structural support 138 and inserting the conductive extension 115 into the internal structural channel 140.

[0079] Additionally, as shown at 208, method 200 includes securing conductive blade tip 59 to conductive extension 115 at second end 109 of tip extension 102. For example, in certain embodiments, securing conductive blade tip 59 to conductive extension 115 at second end 109 of tip extension 102 may include inserting second end 119 of conductive extension 115 into recess 125 of conductive blade tip 59 and securing one or more fasteners through conductive blade tip 59 and second end 119 of conductive extension 115.

[0080] Additionally, as shown at 210, method 200 includes securing tip extension 102 to rotor blade 16. More specifically, as shown at 210, Figure 28 to Figure 31As shown in , the step of securing the tip extension 102 to the rotor blade 16 may include attaching the adhesive side of one or more strips of double-sided tape 110 in any desired pattern or configuration to either or both of the pressure side surface or the suction side surface of the rotor blade 16 adjacent the tip end 32 or to the inner surface of the tip extension 102. It should be appreciated that a single larger strip 110 may also be utilized in place of multiple strips. Although not depicted in the figures, the strips of tape may also be adhered to the pressure side surface 22. As shown in FIG. Fig.28 As depicted in , the pattern of strips 110 may be span-wise oriented and spaced apart. It should be appreciated that the strips 110 may be applied to either or both of the blade surfaces 22 , 24 .

[0081] In addition, if Fig.28 and Fig.29 , the straps 110 have a release liner 112 on opposite exposed sides thereof, and each of the straps 110 has an extension tail 113 from the release liner 112 that extends beyond the first end 103 of the tip extension 102 when the tip extension 102 is slid onto the tip end 32 of the rotor blade 16. The length of the extension tail 113 may vary. For example, the straps 110 farthest from the trailing edge 106 may have a longer extension tail 113 than the straps 110 closest to the trailing edge 106 to facilitate pulling the extension tail 113 past the trailing edge 106. Alternatively, the extension tail 113 may comprise any other material or member attached to the straps, such as a wire, a string, a ribbon, etc. In the case of the illustrated embodiment, because the extended tail 113 is composed of the release liner 112 and the adhesive below, after removing the release liner 112, the remaining adhesive layer 111 of the tape strip remains, as shown in FIG. Fig.30 and Fig.31 as depicted and may require trimming.

[0082] As such, the step of securing tip extension 102 to rotor blade 16 may further include, with tip extension 102 held in place, sequentially pulling, starting with strap 110 farthest from separated trailing edge 106, extended tails 113 and release liners 112 of corresponding straps 110 through separated trailing edge 106 and away from tip extension 102 at an angle such that release liners 112 are removed along the length of straps 110 while maintaining the position of tip extension 102 against rotor blade 16 to attach exposed adhesive 110 from below release liners 112 to either or both of the pressure side surface or suction side surface of rotor blade 16 or the inner surface ( Figure 29 to Figure 31 ). In addition, Fig.28In an embodiment of the present invention, tape 110 is initially adhered to blade surface 24, wherein tip extension 102 is then held or otherwise maintained in a desired position on rotor blade 16 (e.g., by being pressed against tape 110) for subsequent removal of release liner 112 from between the underside of tip extension 102 and tape 110. It should be appreciated that there may be a certain degree of inherent “play” or movement of tip extension 102 at the desired position on rotor blade 16 as release liner 112 is removed.

[0083] In an alternative embodiment, the tape 110 can be applied to the inner surface of the tip extension 102 in the same pattern discussed above, and then the inner surface is pressed against the blade surface 24, 22 for subsequent removal of the release liner 112 from the opposite side of the tape 110. It should be appreciated that the method described herein can be implemented using many different commercially available double-sided tapes. These tapes generally have a lower shear modulus than the tip extension 102 to allow shear slip between the tip extension 102 and the underlying blade surface. For example, the tape can be a foam-based strip component with an adhesive on its opposite interface side, such as ultra-high tack tape (VHB tape). TM ) or SAFT (Solar Acrylic Foam Tape) based strip materials.

[0084] Fig.28 Additional aspects are also depicted that may be incorporated into any of the other embodiments described herein. In particular, adhesive 116 is depicted as being beneath tape strip 110. In certain embodiments, it may be desirable to coat the surface of rotor blade 16 where tip extension 102 will be placed with a liquid or paste adhesive (e.g., and epoxy) 116 prior to positioning tape strip 110 on blade surface 24, for example to compensate for any surface irregularities or mismatches between blade surface and tip extension 102, for example due to machining tolerances. Tape strip 110 and tip extension 102 may then be attached prior to curing of adhesive 116, which provides a degree of positioning adjustment of tip extension 102 due to the fact that adhesive 116 is still in liquid or paste form. Alternatively, adhesive 116 (with the tape strip attached to adhesive 116) may be allowed to cure prior to placement of tip extension 102. In either case, this particular embodiment also offers the advantages of the strong bond provided by adhesive 116 and the shear stress reduction provided by strip 110.

[0085] In another embodiment, as mentioned, the separated trailing edge 106 may include a pressure side edge 107 and a suction side edge 105, each of which extends past the trailing edge 28 of the rotor blade 16 to provide a chord-wise extension aspect to the tip extension 102. As such, the method 200 may also include joining the pressure side edge 107 and the suction side edge 105 together after removing the release liner 112 and after attaching the tip extension 102 to the rotor blade 16. The edges 105, 107 may extend an equal chord-wise distance past the blade trailing edge 28, or the edges 105, 107 may be offset, with one of the edges extending past the other. The dashed line indicating the pressure side surface edge 107 is intended to depict both of these configurations.

[0086] In further embodiments, as mentioned, the method 200 may include attaching one or more additional components 142 ( Figure 21 to Figure 23 ) is positioned between portions of the pressure side edge 107 and the suction side edge 105 of the separated trailing edge 106 and / or to one or more surfaces of the tip extension 102.

[0087] Reference now Fig.32 , illustrates a flow chart of another embodiment of a method 300 for installing a tip extension 102 onto a tip end portion 32 of a rotor blade 16 of a wind turbine 10. More specifically, in certain embodiments, Fig.32 The method 300 can be applied to Figures 12 to 20 , the tip extension 102 illustrated in the embodiment of . Thus, as shown at 302, the method 300 includes securing the conductive extension 115 to the conductive blade tip 59. As shown at 304, the method 300 includes sliding the first portion 128 of the tip extension 102 over the conductive blade tip 59 so as to overlap the rotor blade 16 at the tip end 32 of the rotor blade 16. As shown at 306, the method 300 includes sliding the second portion 130 of the tip extension 102 over the conductive extension 115. As shown at 308, the method 300 includes securing the extended conductive blade tip 132 to the conductive extension 115 such that the extended conductive blade tip 132 extends beyond the second portion 130 of the tip extension 102. As shown at 310, the method 300 includes attaching the conductive blade tip 132 to the conductive extension 115, for example, using any suitable attachment method (such as Figure 28 to Figure 31 3 ). The method 300 also includes securing the second portion 130 of the tip extension 102 to the first portion 128 , as shown at 312 .

[0088] This written description uses examples to disclose the invention (including the best mode), and also to enable any person skilled in the art to practice the invention (including making and using any devices or systems, and performing any incorporated methods). The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that are not different from the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims.

Claims

1. A method for mounting a tip extension to a tip end of a rotor blade of a wind turbine having a lightning protection system mounted thereon, the lightning protection system having at least a downconductor associated with the rotor blade and a removable conductive blade tip, the tip extension having a first end, a second end, a closed leading edge and an at least partially separated trailing edge, the method comprising: removing the conductive blade tip of the lightning protection system to expose the down conductor; securing a conductive extension to the down conductor; sliding the first end of the tip extension over the conductive extension so as to overlap the rotor blade at the tip end; securing the conductive blade tip to the conductive extension at the second end of the tip extension; as well as The tip extension is secured to the tip end of the rotor blade.

2. The method according to claim 1, characterized in that The down conductor of the lightning protection system includes a down conductor component, and the conductive extension includes a first end and a second end, and wherein fixing the conductive extension to the down conductor further includes fixing the down conductor component to the first end of the conductive extension within a groove of the conductive extension.

3. The method according to claim 1, characterized in that The tip extension further includes one or more internal structural components including at least one of a transition region structural support or an internal structural channel.

4. The method according to claim 3, characterized in that The sliding further includes inserting the tip end of the rotor blade into the transition region structural support and inserting the conductive extension into the internal structural channel.

5. The method according to claim 2, characterized in that: Securing the conductive blade tip to the conductive extension at the second end of the tip extension further comprises: inserting the second end of the conductive extension into the recess of the conductive blade tip; and One or more fasteners are secured through the conductive blade tip and the second end of the conductive extension.

6. The method according to claim 5, characterized in that The conductive blade tip is configured at the second end of the tip extension to provide an extended root end of the rotor blade.

7. The method according to claim 1, characterized in that Securing the tip extension to the rotor blade further comprises: attaching the adhesive side of one or more double-sided tape strips to either or both of the pressure side surface or the suction side surface of the rotor blade adjacent the tip end or to the inner surface of the tip extension, the tape strips having release liners on opposite exposed sides thereof, each of the tape strips having an extension tail from the release liner that extends beyond the first end of the tip extension when the tip extension is slid onto the tip end of the rotor blade; and With the tip extension held in place, starting with the strap farthest from the detached trailing edge, the extension tails of the respective straps and the release liner are sequentially pulled past the detached trailing edge and away from the tip extension at an angle so that the release liner is removed along the length of the strap while maintaining the position of the tip extension against the rotor blade to attach the exposed adhesive from beneath the release liner to either or both of the pressure side surface or the suction side surface of the rotor blade or the inner surface of the tip extension.

8. The method according to claim 7, characterized in that The separated trailing edge includes a pressure side edge and a suction side edge, the pressure side edge and the suction side edge each extending past the trailing edge of the rotor blade, and the method further includes bonding the pressure side edge and the suction side edge together after removing the release liner.

9. The method according to claim 8, characterized in that Further comprising positioning one or more additional components between or with portions of the pressure and suction side edges of the separated trailing edge, or to one or more surfaces of the tip extension.

10. A method for mounting a tip extension to a tip end of a rotor blade of a wind turbine having a lightning protection system mounted thereon, the lightning protection system having at least a down conductor and a conductive blade tip secured to the down conductor associated with the rotor blade, the tip extension having a closed leading edge and an at least partially separated trailing edge, the method comprising: fixing a conductive extension to a tip of the conductive blade; sliding a first portion of the tip extension over the conductive blade tip to overlap the rotor blade at the tip end; sliding a second portion of the distal extension over the conductive extension; securing the first portion of the tip extension to the rotor blade; as well as The second portion of the distal extension is secured to the first portion.

11. The method according to claim 10, characterized in that Further comprising securing an extended conductive blade tip to the conductive extension such that the extended conductive blade tip extends beyond the second portion of the tip extension.

12. A rotor blade assembly comprising: a rotor blade including a root end, a tip end, a pressure side surface extending between a leading edge and a trailing edge, and a suction side surface; a lightning protection system mounted to the rotor blade, the lightning protection system comprising a downconductor, a conductive blade tip, and at least one lightning receptor located on either the pressure side surface or the suction side surface; as well as a tip extension including a first end and a second end, a closed leading edge, a trailing edge defined by at least partially separated pressure side edge and suction side edge, the pressure side edge and the suction side edge being joined together and extending in a chord direction beyond the trailing edge of the rotor blade, the conductive extension being configured between the first end and the second end of the tip extension, the first end of the tip extension overlapping the tip end of the rotor blade, the conductive extension electrically coupling the down conductor to at least one of the conductive blade tip or the at least one lightning receptor; Wherein, the tip extension further includes one or more internal structural components, and the one or more internal structural components include at least one of a transition region structural support or an internal structural channel, the tip end of the rotor blade is configured to fit within the transition region structural support, and the conductive extension is configured to fit within the internal structural channel.

13. The rotor blade assembly according to claim 12, characterized in that The down conductor of the lightning protection system includes at least one of a down conductor component or a down conductor cable.

14. The rotor blade assembly according to claim 13, characterized in that The conductive extension includes a first end and a second end, the first end of the conductive extension including a side edge forming a groove, the down conductor component is fixed in the groove, the second end of the conductive extension is free of the side edge and is fixed in a recess of the conductive blade tip, the conductive blade tip is configured at the second end of the tip extension to provide an extended root end of the rotor blade.

15. The rotor blade assembly according to claim 13, wherein: The conductive extension includes a first end and a second end, the down conductor component is fixed in a recess of the conductive blade tip, the first end of the conductive extension is fixed to the conductive blade tip, and the conductive blade tip is constructed in the tip extension between the first end and the second end of the tip extension, wherein the at least one lightning receptor is electrically connected to the second end of the conductive extension.

16. The rotor blade assembly according to claim 15, characterized in that Further included is an extended conductive blade tip electrically coupled to the second end of the conductive extension.

17. The rotor blade assembly according to claim 16, wherein: The tip extension includes a two-piece body having a first portion covering at least a portion of the down conductor component and the conductive vane tip and a second portion covering at least a portion of the conductive extension.

18. The rotor blade assembly of claim 12, wherein: Further included is at least one of an adhesive or one or more double-sided tapes configured to secure the tip extension to the tip end of the rotor blade.

19. The rotor blade assembly of claim 12, wherein: The tip extension further includes one or more additional components, which are constructed between or with portions of the pressure side edge and the suction side edge of the separated trailing edge or with one or more surfaces of the tip extension, and the one or more additional components include at least one of a serrated edge, a belt recess, an air flow conditioning element, a mounting feature, or a drainage hole.

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