FIELD OF THE INVENTION

The present invention relates to a mould tool for forming an adhesive mound, a method of forming said adhesive mound, an adhesive mound obtainable via said method and a wind turbine blade comprising said adhesive mound.

BACKGROUND OF THE INVENTION

In modern wind turbine blades, it is common for electrical components to be provided at, or proximal to, the surface of the wind turbine blade.

One such example is the provision of electro-thermal heating (ETH) elements, which are typically embedded within the wind turbine blade shell to help prevent frozen water from gathering on the surface of the blade. These and other electrically powered auxiliary blade systems, such as sensor systems, may be electrically connected via connectors passing through the blade shell to power or data cables running along the length of the blade internally of the blade.

Also, lightning receptors on the blade shell surface may be electrically connected via connectors passing through the blade shell to lightning conductor cables running along the length of the blade internally of the blade.

A known example of such an assembly is described in WO 2015/055213.

However, it is important that such electrical connector terminals and their relevant cables are properly protected to ensure the electrical connection is not compromised during the blade’s operation throughout its life. This may involve immobilising the cable and connector terminal, particularly at the blade tip, since any loose connectors can increase the risk of corrosion or shearing of the electrical connection.

This may be achieved e.g. by manually applying a mound of glue over the connector and enveloping the connector terminal, i.e. enveloping the joint between the cable and the connector terminal up to the interior surface of the blade shell. However, in performing such operations freehand, it is often difficult to achieve the desired dimensional consistency, particularly when gluing large numbers of such connectors as is typically required for a given blade shell.

SUMMARY OF THE INVENTION

A first aspect of the disclosure provides a mould tool for forming an adhesive mound over an electrical connector projecting from a surface of a wind turbine blade shell and attached to an electrical cable, the mould tool comprising an open base, a body extending upwardly from the base, said body defining an internal cavity sized for receiving an electrical connector, an inlet for permitting the introduction of an adhesive material into the internal cavity of the mould tool, an aperture in the body for accepting an electrical cable to pass from outside the body to the electrical connector in the internal cavity and a slit extending from the base up to at least the aperture so as to permit removal of the mould tool after forming the adhesive mound.

Advantageously, the mould tool according to the first aspect of the disclosure helps users to efficiently and consistently apply adhesive mounds having the desired shape and dimensional accuracy about the electrical connectors of a wind turbine blade shell, and to remove the mould tool over the cable.

The body may be a resiliently deformable body. Advantageously, the resiliently deformable body helps to aid the release of the mould tool from the connector once the adhesive mound has been adequately formed.

The base may be a flared base. The base may comprise a corner radius of at least approximately 5mm. The base may comprise a corner radius of at least approximately 8mm. The base may comprise a corner radius of at least approximately 10mm. Advantageously, the flared base helps to reduce the presence of stress tensors between the adhesive mound and the interior surface of the blade in the finished product, thereby improving the durability of the mound created by the mould tool.

The inlet may be provided at a top of the mould tool. The mould tool may have an open top which constitutes the inlet. The mould tool may be open at both ends. Advantageous, providing an inlet on the top surface of the mould tool helps make it easier for an operator to control and judge the height of the adhesive mound formed using the mould tool.

The slit may comprise a width which is less than a width or diameter of the aperture. Advantageously, making the slit narrower than the aperture helps to reducing spillage of adhesive from within the mould whilst still permitting passage of the electrical cable through the mould tool via the aperture. The slit may comprise a width of less than 5mm. The slit may comprise a width of less than 2mm. The slit may extend beyond the aperture away from the base. Advantageously, this feature helps to further facilitate release of the mould from about the adhesive mound.

The base may have a diameter of approximately 40mm. The base may have a diameter of at least approximately 30mm.

The body may have a height of at least 30mm. The body may have a height in the range of 30mm to 50mm. Advantageously, a mould tool having a height of at least 30mm helps the adhesive mound to more effectively insulate the electrical connector. Furthermore, keeping the mound height below 50mm helps to prevent clashes between adjacent mounds upon assembly of the blade.

The body may have an aspect ratio of at least 0.7. The body may have an aspect ratio of at least 1 . The body may have an aspect ratio of at least 1 .2.

The internal cavity of the mould tool may comprise a hydrophobic interior surface. The hydrophobic interior surface may comprise PTFE. Advantageously, the hydrophobic lining helps to further aid the release of the mould tool.

The body may have a substantially frustoconical shape. Advantageously, the frustoconical shape of the mould helps to further aid release of the mould tool following use.

A second aspect of the disclosure provides a method of forming an adhesive mound over an electrical connector projecting from a surface of a wind turbine blade shell and attached to an electrical cable, the method comprising providing a mould tool as defined in the first aspect of the disclosure, applying the mould tool over an electrical connector projecting from a surface of a wind turbine blade shell such that the electrical connector is received within the internal cavity of the mould tool and such that the electrical cable attached to the electrical connector passes through the aperture in the body of the mould tool, introducing an adhesive material into the internal cavity of the mould tool, at least partially curing the adhesive material to form an adhesive mound having a shape corresponding to that of at least a portion of the internal cavity of the mould tool, thereby securing the electrical cable with respect to the surface of the wind turbine blade shell and then removing the mould tool by lifting the mould tool from the surface of the wind turbine blade shell and passing the electrical cable along the slit to exit the base of the mould tool. In embodiments the electrical cable may be secured to the connector at an end of the electrical cable.

The method may further comprise expanding the base of the body so as to expand the slit width during removal of the mould tool.

The step of curing the adhesive material may be performed at an ambient temperature.

A third aspect of the disclosure provides an adhesive mound formed over an electrical connector projecting from an interior surface of a wind turbine blade shell and attached to an electrical cable, the adhesive mound being obtainable according to the method of the second aspect of the disclosure, said adhesive mound maintaining the electrical cable spaced from the interior surface of the wind turbine blade shell. The adhesive mound may be generally drum-shaped or barrel-shaped and/or may have a generally frustoconical form.

The body portion may comprise at least one wall surrounding the electrical connector. The at least one wall may have a thickness of at least approximately 10mm. The at least one wall may have a thickness of at least approximately 15mm. Advantageously, the provision of at least one wall having a thickness of at least 10mm helps the adhesive mound to more effectively insulate the electrical connector.

The adhesive mound may comprise a body surrounding the electrical connector. The body may have a diameter of at least 30mm. The body may have a diameter of at least 40mm.

The adhesive mound may have a height extending at least 5mm above a height of the electrical connector adhered thereto. Advantageously, the provision of an adhesive mound having a height at least 5mm greater than a height of the electrical connectors also helps the adhesive mound to more effectively insulate the electrical connector.

A fourth aspect of the disclosure provides a wind turbine blade comprising the adhesive mound according to the third aspect of the disclosure.

The wind turbine blade may have a wind turbine blade shell with an electrical component embedded therein or attached thereto, said electrical component being electrically connected to the electrical connector, optionally, wherein said electrical component is electrically connected to said electrical connector at an end of said electrical connector.

The electrical component may be an electrical heating element for an anti-icing system may be another auxiliary blade system. The electrical component may be a lightning receptor.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described with reference to the accompanying drawings, in which:

Figure 1 is a front view illustrating a wind turbine system;

Figure 2 is a cross-sectional view illustrating a respective blade shell of a wind turbine blade featuring an embedded electro-thermal heating (ETH) element;

Figure 3 is a perspective view illustrating a mould tool according to one example;

Figure 4 is a cross-sectional view illustrating the blade shell of Figure 2 after an adhesive mound has been applied;

Figure 5 is a cross-sectional view illustrating a wind turbine blade featuring a lightning protection system;

Figure 6 is a cross-sectional view illustrating a respective blade shell and electrical connector for use with the lightning protection system shown in Figure 5; and

Figure 7 is a cross-sectional view illustrating the blade shell of Figure 6 after an adhesive mound has been applied; and

Figure 8 is a cross-sectional view illustrating a mould tool according to another example. DETAILED DESCRIPTION OF EMBODIMENTS

Figure 1 shows a wind turbine 1 including a nacelle 2 supported on a tower 3 that is mounted on a foundation 4. The wind turbine 1 depicted here is an onshore wind turbine such that the foundation 4 is embedded in the ground, but the wind turbine 1 could be an offshore installation in which case the foundation 4 would be provided by a suitable marine platform.

The nacelle 2 supports a rotor 5 comprising a hub 6 to which three blades 7 are attached. It will be noted that the wind turbine 1 is the common type of horizontal axis wind turbine (HAWT) such that the rotor 5 is mounted at the nacelle 2 to rotate about a substantially horizontal axis defined at the centre at the hub 6. As is known, the blades 7 are acted on by the wind which causes the rotor 5 to rotate about its axis thereby operating generating equipment through a gearbox (not shown) that is housed in the nacelle 2. The generating equipment is not shown in Figure 1 since it is not central to the examples of the invention.

A blade shell 10, suitable for forming a part of a wind turbine blade 7, is shown in Figure 2. The blade shell 10 provides the outer aerodynamic surface of the blade and defines an internal hollow cavity.

The blade shell 10 may be made up of a plurality of composite ply layers including at least one inner shell layer 12, a plurality of core layers 14, at least one outer shell layer 16 and a cover layer 18. The at least one inner shell layer 12 may provide an internal surface of the blade shell 10 and the cover layer 18 may provide an external aerodynamic surface of the blade shell 10.

Various electrical components such as lightning receptors and auxiliary systems such as anti-icing systems may be provided on the blade shell 10 and connected to cables extending along the length of the blade and inside the blade cavity. The electrical components in or on the blade shell may be electrically connected to the cables by electrical terminals passing through the blade shell and protruding into the blade interior cavity.

The blade shell 10 may include an electrical component which is embedded between the outer shell layer 16 and the cover layer 18. In the example illustrated in Figure 2, the electrical component 20 may be an electro-thermal heating (ETH) element, although it shall be appreciated that in other examples, the electrical component 20 may be of a different type.

A heating element may enable the external surface of the blade shell 10, provided by the cover layer 18, to be controllably heated based on the temperature conditions external to the blade, thereby helping to prevent ice from forming on the turbine blade (which can be detrimental to aerodynamic performance).

The electrical component 20, such as a heating element, may be connected to an end of an electrical connector 22 which extends from the electrical component 20 through a thickness (t) of the blade shell 10 to a terminal 24 which is located at the internal surface of the blade shell 10. Typically, the blade shell 10 has a thickness in the region of 5 to 40mm, although it shall be appreciated that other suitable thicknesses may be used. The terminal 24 may be connected to an electrical cable 26, such as a power cable which can be used to provide electrical power to the electrical component 20 during use. Whilst the example shown in Figure 2 only displays a single electrical connector 22, in other examples a given blade shell may comprise a plurality of electrical connectors situated along the blade for connection to one or more electrical components 20.

During use, due to the high rotational speeds and consequent centrifugal forces experienced by components 20 situated on the wind turbine blade 7, particularly at the blade tip region, it is important that any electrical connections, such as an electrical connector 22, are properly immobilised since loose electrical connectors 22 can increase the risk of corrosion or shearing of the electrical connection during operation of the wind turbine.

A mould tool 30 is shown in Figure 3. The mould tool may be used to form an adhesive mound 40 over the electrical connector 22 projecting from the interior surface of the blade shell 10 and attached to one end of the electrical cable 26. The mould tool 30 may be removed once the adhesive is partially or fully cured, leaving the adhesive mound. The adhesive mound can be used to help ensure that electrical connector 22 and the electrical cable 26 are properly immobilised when in use on a wind turbine blade. The mould tool 30 is made up of an open base 31 and a body 32, which extends upwardly from the base 31 to a top 33. The base 31 may be a flared base. The flared base may have a corner radius 38. The corner radius 38 may be of approximately 10mm. The flared base 31 may help to reduce the presence of stress tensors between the adhesive mound (formed using the mould tool 30) and the interior surface of the blade 10 in the finished product, thereby improving the durability of the mound created by the mould tool 30. However, it shall be appreciated that in other examples the flared based may have a different corner radius. For example, some mould tools may comprise a corner radius 38 of approximately 8mm, whereas others may have a corner radius 38 of approximately 5mm. Furthermore, in some examples, the flared base may be omitted.

The body 32 of the mould tool 30 may have a frustoconical shape. The base 31 of the mould tool 30 may have a greater diameter than the top 33 of the mould tool 30. For example, the base 31 of the mould tool 30 may have a diameter (D) of approximately 40mm and the top 33 of the mould tool 30 may have a diameter (d) of approximately 30mm, although it shall be appreciated that other suitable dimensions may be used.

The frustoconical shape of the body 32 helps to aid the release or quick-release of the mould tool 30 from about the adhesive mound 40 after use, as shall be described in greater detail below. However, it shall be appreciated that in other examples, the body may comprise a different shape, such as a cylindrical shape, and so the body need not be frustoconical in shape for all examples.

The body 32 of the mould tool 30 may be integrally formed from a single piece of resiliently deformable material, such as a plastic. The resiliently deformable nature of the material helps to facilitate release of the mould tool 30 since it enables the tool to be deformed by a user. However, in other examples, it shall be appreciated that the mould tool 30 may be formed in multiple sections and, in other examples, may comprise any other suitable material.

The body 32 of the mould tool 30 defines an internal cavity 34 which is sized for receiving an electrical connector. Typically, the body 32 of the mould tool 30 may have a height of at least 30mm, more typically in the range of 30 to 50mm, although it shall be appreciated that in some examples the height of the mould tool may differ from the values specified above. By providing a mould tool 30 having a height in the range of 30mm to 50mm, it has been found that the adhesive mounds formed by the mould tool are able to effectively insulate most electrical connectors that will be found on a typical wind turbine blade, whilst also reducing the number of potential “clashes” between adjacent adhesive mounds upon assembly of the turbine blade. It is important to note that the thickness of a blade shell laminate may vary along the length of the blade. Thereby, the height of different connector terminals, protruding above the blade shell inside surface, may vary. This has a bearing on applying the adhesive mound as it may mean adhesive mounds may be of different heights, depending on the height of a respective electrical connector above the blade shell interior surface.

The internal cavity 34 may also be provided with a hydrophobic interior surface. The internal cavity 34 may be coated with a hydrophobic PTFE coating which may help to further facilitate release of the mould tool 30 following use by helping to reduce the amount of adhesion between the tool 30 and the adhesive applied thereto. However, it will be appreciated that in other examples, a different form of hydrophobic coating may be used or, in further examples, the hydrophobic interior surface of the internal cavity 34 may be omitted. In other examples a liner may be used inside the mould tool. The liner may ease the mould tool's removal after the adhesive mound has been formed. The liner may comprise a hydrophobic material or may have a hydrophobic interior surface. The liner may remain with the adhesive mound after removal of the mould tool, or the liner may be removed from the adhesive mound subsequent to removal of the mould tool. The liner may be a PTFE release paper, for example.

The internal cavity 34 of the mould tool 30 is provided with an inlet 35 to permit the introduction of an adhesive material (such as a glue) into the internal cavity 34 of the mould tool 30 during use. The inlet 35 may be provided as an open top, e.g. as shown in Figure 3, such that the mould tool 30 is open at both ends. In other words, the mould tool 30 has an opening at the base 31 and an opening at the top 33, both of which are in fluid communication with the internal cavity 34 of the mould tool 30. The opening provided at the base 31 enables the adhesive material introduced into the mould tool 30 to bond with the internal surface of the blade shell 10 to help secure the electrical connector 22 into place, whereas the open top allows the adhesive material to be introduced into the internal cavity 34 of mould tool 30.

By providing the inlet 35 as an open top, the mould tool 30 makes it easier for an operator to control and judge the height of the adhesive mound formed via the mould tool 30. However, it shall be appreciated that in other examples, any other suitable type of inlet at any other suitable location on the mould tool may be used. For instance, the inlet may be provided as an aperture or spout extending from or in the side wall of the body of the mould tool in some examples.

The mould tool 30 also comprises an aperture 36, provided in the body 32, to allow the electrical cable 26 to pass from the electrical connector 22, received within the internal cavity 34 of the mould tool, to a location external to the mould tool 30. The aperture 36 has a width W, sufficient to accommodate a conductive lightning cable 26. The width W may be a diameter dimension of the aperture 36. The aperture 36 may be shaped to fit snugly around a lightning conductor cable 36.

A slit 37 is also provided in the body 32, which slit 37 extends from the base 31 of the mould tool 30 to the aperture 36. The slit 37 allows the mould tool 30 to be placed around an electrical connector 22 which has already been connected to one end of an electrical cable 26. The cable 26 can be fed along the slit 37 up from the base 31 by the user during installation of the mould tool 30 about the electrical connector 22 such that the electrical cable 26 is received within the aperture 36. The aperture 36 may be located at a height from the base 31 approximately corresponding to the height of the cable connection to the electrical connector 22 away from the interior surface of the blade shell 10. The slit 37 also aids in the removal of the mould tool 30 following use, as shall be described in greater detail below.

The slit 37 may extend up a majority of the height of the body 32 from the base 31 to the aperture 36. The slit 37 may also extend beyond the aperture 36 to a location proximal to the top 33. However, in other examples, the slit may terminate at the aperture 36.

The slit 37 may have a width (w) which is less than a width (W) or diameter of the aperture 36. This may help to ensure that the electrical cable can be comfortably received within the aperture 36 during use, without risking damage to the electrical cable 26, whilst also helping to prevent adhesive from spilling out from within the internal cavity 34 of the mould tool 30. In particular, the aperture 36, having a width W, may narrow to a slit width w at the intersection between the slit 37 and the aperture 36. The slit 37, having a width w, narrower than the aperture width W, runs into the aperture 36. The width W of the aperture 36 may correspond to a maximum width of said aperture 36. The slit 37 may be provided with a width (w) of less than 5mm, e.g. approximately 2mm. However, in other examples, other slit widths may be used. Furthermore, in some examples, the slit 37 may be provided having a width (w) which is the same as the diameter of the aperture 36. The slit width (w) may be the same or different above and below the aperture 36. A slit 37 may be configured such that its width w is less than the aperture width W of the aperture 36 along substantially all of the length of the slit 37 or along the majority of the length of the slit 37. More than one slit 37 and corresponding aperture 36 may be provided on the mould tool 30, e.g. where multiple electrical cables are coupled to a common electrical connector 22.

The use of the mould tool 30 for forming an adhesive mound over an electrical connector projecting from a surface of a wind turbine blade shell and attached to an end of an electrical cable shall now be described.

In a first step of the method, the mould tool 30 is provided, e.g. as shown in Figure 3.

In a second step, the mould tool 30 is then applied over an electrical connector 22 projecting from a surface of the blade shell 10 such that the base 31 of the mould tool 30 abuts against the interior surface of the blade shell 10 and such that the electrical connector 22 is received within the internal cavity 34 of the tool 30. The mould tool 30 may be applied to the electrical connector 22 after the electrical connector has been linked up with a respective electrical cable 26. As such, during application, the electrical cable 26 can be threaded through the slit 37 to be received within the aperture 36 which allows the electrical cable 26 to pass through the body 32 of the mould tool 30. This allows the mould tool 30 to be applied about an electrical connector 22 without having to disconnect the electrical connector 22 from its respective electrical cable 26. However, in other examples, the electrical cable 26 may be coupled to the connector 22 via the aperture after the mould tool 30 has been applied over the electrical connector 22.

Once the mould tool 30 has been applied about the electrical connector 22, an adhesive material is introduced into the internal cavity 34 via the inlet 35 of the mould tool 30. In some examples, the adhesive material may be a glue, such as Spabond™ Glue (manufactured by Gurit). However, in other examples, other adhesive materials may be used. As has been described previously, the inlet 35 may be provided as an open top of the mould tool 30 and so the adhesive material can simply be poured into the internal cavity 34 of the mould tool 30 via the open top inlet 35. However, in other examples, the adhesive may be applied via injection or any other suitable mechanism. Once the adhesive material has been introduced into the internal cavity 34 of the mould tool 30 the adhesive material will flow, under the influence of gravity, towards the base 31 of the mould tool 30 and into contact with the interior surface of the blade shell 10 on which the mould tool 30 has been placed. As further adhesive material is added to the mould 30, the adhesive introduced thereafter will envelope the electrical connector 22 received within the internal cavity 34. The adhesive material is continually added until the electrical connector 22 is fully enveloped.

Once the electrical connector 22 is fully enveloped, the adhesive material is allowed to cure to form an adhesive mound 40 having a shape corresponding to that of at least a portion of the internal cavity 34 of the mould tool 30 as is illustrated in Figure 4. The adhesive mound 40 may have a generally frusto-conical form. In embodiments, the adhesive mound 40 may be generally barrel-shaped or drum-shaped. In particular, the adhesive mound 40 may have a generally frusto-conical form. The adhesive mound 40 may have a radiused foot at the base of the mound.

The adhesive mound 40 surrounds and insulates the electrical connector 22 and also adheres the electrical connector 22 and power cable 26 to the interior surface of the blade shell 10, thereby maintaining the end of the electrical power cable 26 spaced from the interior surface of the blade shell 10. The adhesive may be left to cure at an ambient temperature, although in some examples the adhesive may be heated to help speed up the curing process.

Once the adhesive mound 40 has been left to cure, the mould tool 30 can be removed from about the electrical connector 22 by lifting the mould tool 30 from the surface of the wind turbine blade shell 10 and passing the electrical cable 26 along the slit 37 and out from the base 31 of the mould tool 30. In some examples, during removal of the mould tool 30, the mould tool 30 can be manually deformed by the user to expand the base 31 and body 32 of the mould tool 30, thereby facilitating more easy release of the tool 30 from about the adhesive mound 40. In other examples, the slit 37 may also be expanded width-wise during removal to help remove the power cable 26 from the mould tool 30. As illustrated in Figure 4, the adhesive mound 40 forms an adhesive body 42 which surrounds the electrical connector 22. In one example, the electrical connector 22 has a diameter of 10mm and the adhesive mound 40 created by the 40mm diameter mould tool 30 has a corresponding adhesive body 42 diameter or cross-sectional dimension of approximately 40mm. As such, in this example, the electrical connector 22 is surrounded by an approximately 15mm thickness of adhesive material of the adhesive body 42. This helps to ensure that the electrical connector 22 is adequately insulated within the adhesive mound 40. However, it shall be appreciated that in other examples, adhesive mounds having different diameters may be envisaged.

Similarly, the adhesive mound 40 has a height (A) which may extend at least 5mm above a height of the electrical connector 22 adhered thereto to help ensure that the electrical connector 22 is adequately insulated. The adhesive mound 40 may have a height (A) of at least 30mm, typically in the range of 30mm to 50mm, when measured from the interior surface of the blade shell 10 to which the mound 40 is adhered. However, it shall be appreciated that in other examples, adhesive mounds with other such heights may be provided.

Furthermore, in examples where a tool 30 having a flared base has been used, a mound 40 having a corresponding corner radius 48 may be provided. The corner radius 48 of the adhesive mound 40 may be of approximately 10mm. This helps to reduce the presence of stress tensors between the adhesive mound 40 and the interior surface of the blade 10 in the finished product, thereby improving the durability of the mound 40. However, it shall be appreciated that in other examples, adhesive mounds having different corner radiuses may be envisaged. For example, some adhesive mounds may comprise a corner radius of approximately 8mm, whereas others may have a corner radius of approximately 5mm depending on the dimensions of the mould tool that has been used to form the mound.

Figure 5 shows a further portion of a wind turbine blade 7 to which an adhesive mound obtainable via the mould tool may be applied.

The blade 7 comprises a root end 71 for connection to the hub 6 of the wind turbine 1 and a tip end 72 which is distal from the hub 6 when in use. The tip end 72 of the turbine blade 7 may have a metal tip 25 which acts as a lightning receptor when in use. The lightning receptor may be connected to a one or more lightning down conductor cables 26a and 26b which extend through the interior of the turbine blade 7.

The blade 7 may also have a metal mesh lightning receptor/down conductor 23. The mesh 23 may be electrically connected to one or more electrical cables, such as the down conductor cables 26a and 26b via a series of electrical connectors 22. The electrical cable 26 may be connected at one end to a terminal of the electrical connector 22.

A close-up via of the blade shell 10 of the turbine blade 7 is shown in Figs. 6 and 7. The electrical connector 22 may extend through the full thickness (t) of the blade shell 10 such that an end of the electrical connector 22 can be coupled to the mesh 23 located at the external surface of the blade shell 10.

The blade 7 may also feature a harness mount 29 which helps to space the electrical cable 26 away from the internal surface of the blade shell 10. The harness may be for additionally immobilising the electrical cable 26 to which the nearby electrical connector 22 is connected. The harness may give additional stability to the connection at the adhesive mound 40 and electrical connector 22 and may help prevent the electrical cable 26 from transmitting high loads to the electrical connector 22 and/or adhesive mound 40, e.g. during operation of the wind turbine blade 7. The harness mount 29 may be provided as a clamping arrangement. However, it shall be appreciated that in other examples, any suitable mounting configuration may be used. Furthermore, in other examples, the harness mount may be omitted. The harness mount 29 may be used similarly with any electrical cable, such as the power cable 26 described above.

An adhesive mound 40 can be applied about the electrical connector 22 in substantially the same manner as has been described above, so as to properly immobilise the electrical connectors 22 and their electrical cables 26a, 26b located along the length of the blade 7.

In some cases, it may be necessary also to connect the ETH power cables 26 to the wind turbine blade lightning protection system. Where the electrical component 20 is an ETH element, this may be done in order to ensure that the power cable 26 to the ETH elements does not act as a lightning conductor in case of a lightning strike. For example, the anti-icing power cable 26 may be connected to the mesh lightning receptor/conductor 23 using an electrical connector 22 of the type described above. These would also require an adhesive mound 40 for protection. A surge protection device at the anti-icing power cable 26 arrangement would ensure that any lightning current in the anti-icing power cable 26 would be dumped via the lightning system. The adhesive mound 40 in this example may be formed in substantially the same way as described above.

After removal of the mould tool 30 for forming an adhesive mound 40 the mould tool 30 may be re-used to form another adhesive mound. Where a liner or coating is used as described above, a fresh liner or re-coating may be applied.

The mould tools 30 may be injection moulded, made by injection moulding e.g. in a mass production.

A mould tool 30 according to another example is also illustrated in Figure 8. The features of the mould tool 30 illustrated in Figure 8 correspond substantially to those denoted in Figure 3. However, in the example illustrated in Figure 8, the mould tool 30 is provided with a pair of apertures 36 and corresponding slits 37 (not shown in Figure 8). This enables the mould tool 30 to be used at an electrical connector 22 to which an electrical cable 26 is connected at a point along the cable’s length rather than at an end thereof. In one embodiment (not shown) the cable 26 may be electrically connected to the connector 22 without interruption in the cable 26. For example, a bracket at the connector 22, such as a clamp type bracket, may electrically conductively fasten an exposed, conducting portion of the cable 26 to a connection terminal at the connector 22. Alternatively, the cable 26 may be connected to the connector 22 at an interruption or break in the cable 26, as illustrated. In both cases two segments of the cable 26 are embedded in the glue mound 40. As such, the mould tool 30 may be used with electrical connectors 22 which receive an electrical through- cable. Such mould tools 30 are typically used for forming adhesive mounds 40 over electrical connectors 22 located within an array of connectors, whereas the mould tool 30 shown in Figure 3 is typically used for electrical connectors 22 at the end of an array, or single connectors 22, to which only one end of an electrical cable 26 is attached. The operation of the mould tool 30 described in Figure 8 is substantially the same as has been described in relation to the previous examples and so, for the sake of conciseness, shall not be repeated. It shall be appreciated however, that in further examples, mould tools 30 featuring a plurality of apertures 36 and corresponding slits 37 may be envisaged. In some examples, the mould tool 30 may have three or more apertures 36 and three or more corresponding slits 37.

Whilst the invention has been described with reference to an electrical heating element and a lightning conduction system, it shall be appreciated that the claimed invention may be used with any suitable type of electrical component and is not solely limited to components for heating and lightning conduction applications.

Although the invention has been described above with reference to one or more preferred embodiments, it will be appreciated that various changes or modifications may be made without departing from the scope of the invention as defined in the appended claims.