GB2602462A

GB2602462A - Floating wind turbine array

Info

Publication number: GB2602462A
Application number: GB2020649.6A
Authority: GB
Inventors: Bekhouche Christophe; Ole Dunserud Jan
Original assignee: Aker Offshore Wind AS
Current assignee: Aker Offshore Wind AS
Priority date: 2020-12-28
Filing date: 2020-12-28
Publication date: 2022-07-06
Also published as: GB202020649D0

Abstract

An array of offshore floating wind turbines comprising at least two floating wind turbine assemblies 212, each assembly having an ingoing and outgoing (242, 244, Fig. 2) electrical connections with respective first 226 and second 228 electrical cables connected, the first and second cables extending from the same lateral side of the floating wind turbine, and the second cable of a first turbine connecting to the ingoing electrical connection of a second wind turbine. The first and second cables may be connected via a junction box to remove a turbine from the array for maintenance. The second cable may be positioned on the seabed in a U-shape or a V-shape. The first and second cable may have a circumferential offset between them of less than 90°, or less than offset between them of less than 90°, or less than 45°, and the cables may be adjacent. The cables may be supported by a single bending stiffener.

Description

Floating Wind Turbine Array

Technical field

The present disclosure relates to arrays of floating wind turbine assemblies and a method for electrical connection of an array of floating power plants, as well as to a method for installation of an array of wind turbine assemblies.

Background

In recent decades, there has been an increasing desire to produce energy by sustainable means, as opposed to relying on the Earth's finite supply of fossil fuels. The goal of sustainable energy production may be achieved in many ways, and today one of the most popular is through the deployment of renewable energy devices, such as wind turbines. Advancements in technology have enabled renewable energy devices such as wind turbines to be located offshore, where they may be able to be larger and better positioned to harness wind, solar, tidal, wave power etc. than their onshore counterparts. The operation of locating a power plant such as a wind turbine or solar panel offshore involves the transport and subsequent installation of the power plant at the offshore location, which can be a complex and expensive operation. Very often, offshore power plants are installed in arrays comprising multiple power plants (e.g. multiple wind turbines, multiple solar panels) , which can be installed and maintained as a group of wind turbines, which may assist to improve the cost-efficiency of the whole process.

The installation of an array of power plants (e.g. an array of wind turbines) may require each power plant to be connected in an electrical network. In the case of an array of wind turbines, the more wind turbines in the array, the more complex this network may become, which may increase the cost of materials required to establish the network, as well as the complexity of the network itself which may lead to complications in cases where a wind turbine is required to be disconnected from the array (e.g. when a turbine is to be repaired or maintained). Such complications are undesirable as they may greatly increase the time and cost associated with operations on such an array.

Summary

It is an object of the present disclosure to mitigate, alleviate or eliminate one or more of the above-identified deficiencies and disadvantages in the prior art and solve at least the above mentioned problem.

It is an object of the present disclosure to mitigate, alleviate or eliminate one or more of the above-identified deficiencies and disadvantages in the prior art and solve at least the above mentioned problem. According to a first aspect there is provided an array of floating wind turbine assemblies, comprising: at least two floating wind turbine assemblies; each of the at least two floating wind turbine assemblies comprising an ingoing and an outgoing electrical connection; a first electrical cable extending from the ingoing connection on one lateral side of a first of the at least two floating wind turbine assemblies; a second electrical cable extending from the outgoing connection on the same lateral side of the first of the at least two floating wind turbine assemblies, the second electrical cable connecting to the ingoing electrical connection of a second of the at least two floating wind turbine assemblies.

According to a second example, the second electrical cable may be positioned on the seabed in a U-shape between the first and the second of the at least two floating wind turbine assemblies. The second electrical cable may extend between two (e.g. any two) of the at least two wind turbine assemblies in a U-shape. According to the third example, the second electrical cable may be positioned on the seabed in a V-shape between the first and the second of the at least two floating wind turbine assemblies. The second electrical cable may extend between two (e.g. any two) of the at least two wind turbine assemblies in a V-shape.

The second electrical cable may be positioned on the seabed, or extend between any two of the at least two wind turbine assemblies in a winding and/or undulating configuration, or in a partially winding and partially straight configuration.

According to a fourth example each of the floating wind turbine assemblies may comprise a vertical axis, and the first electrical cable may extend from the first of the floating wind turbine assemblies at an angle that is circumferentially offset by 90 degrees or fewer from the second electrical cable extending from the first of the floating wind turbine assemblies, relative to the vertical axis of the first of the floating wind turbine assemblies.

According to a fifth example, the first electrical cable may extend from the first of the floating wind turbine assemblies at an angle that is circumferentially offset by 45 degrees or fewer from the second cable extending from the first of the floating wind turbine assemblies, relative to the vertical axis of the first of the floating wind turbine assemblies.

According to a sixth example, the ingoing and outgoing electrical connections may be adjacent. According to a seventh example, the ingoing and outgoing electrical connections may be located on the same lateral side of each wind turbine assembly of the at least two wind turbine assemblies. Such positioning of the ingoing electrical connection relative to the outgoing electrical connection may facilitate the disconnection of each in single operation, as well as the reconnection of the first and second cables to a wind turbine assembly, or to a junction box, for example.

According to an eighth example, the first and second electrical cables may be supported on a first of the at least two wind turbine assemblies by a single bending stiffener adjacent the ingoing and outgoing electrical connection to the floating wind turbine assembly.

According to a ninth example, the floating wind turbine assembly may comprise a buoyant structure, and the first and second electrical cables may be mounted on the buoyant structure.

According to a second aspect there is a method for electrical connection of an array of floating wind turbine assemblies, comprising: providing at least two floating wind turbine assemblies at an offshore location, each of the at least two floating wind turbine assemblies comprising an ingoing and an outgoing electrical connection; connecting a first electrical cable to a first of the at least two floating wind turbine assemblies at the ingoing electrical connection thereof, and connecting a second electrical cable to a second of the at least two floating wind turbine assemblies at the outgoing electrical connection thereof, and extending the first and second electrical cable both from the same lateral side of the first of the at least two floating wind turbine assemblies; connecting the second electrical cable to a second of the at least two floating wind turbine assemblies at the ingoing electrical connection thereof.

According to a second example of the second aspect, the method may comprise positioning the second electrical cable between the first and second of the at least two floating wind turbine assemblies in a U-shape.

According to a third example of the second aspect, the method may comprise disconnecting the first and second cable from at least one of the at least two floating wind turbine assemblies, and connecting the first and second cable to a junction box.

According to a fourth example of the second aspect, the method may comprise connecting a third electrical cable to the second of the at least two wind turbine assemblies at an outgoing electrical connection thereof and to a third wind turbine assembly at an ingoing electrical connection thereof.

According to a third aspect there is provided an array of offshore wind turbine assemblies, comprising: at least two wind turbine assemblies; a common array cable configurable to be secured to a subsea location; each of the at least two wind turbine assemblies being electrically connected to the common array cable by a connection cable.

According to a second example of the third aspect, the connection cable may connect each of the at least two wind turbine assemblies to the common array cable at an axially separated location. Having each of the at least two wind turbine assemblies connected to the common array cable at an axially separated location may assist to permit operations to be performed on any of the wind turbine assemblies while minimising the impact on other wind turbine assemblies in the array. For example, it may allow one wind turbine assembly to be

S

disconnected at the Y-connection and towed away (e.g. for maintenance) while not affecting or disturbing the connection of any other wind turbine assembly in the array.

According to a third example of the third aspect, the connection between the common array cable and the connection cable may be in the form of a branch connection from the common array cable. According to a fourth example of the third aspect, the common array cable may be connected to the connection cable via a branched connector. The branch connection and/or branched connector may facilitate reduced complexity in the connection of the array by permitting each of the wind turbine assemblies to be attached to the array using only one cable, rather than having to have each turbine having an ingoing and an outgoing cable to adjacent wind turbine assemblies.

According to a fifth example of the third aspect, the array may comprise a securing arrangement to secure a portion of each of the connection cables to a subsea location, for example a securing location which may be the seabed, a lakebed, a subsea structure such as an anchor point installed on the seabed or other subsea infrastructure. According to a sixth example of the third aspect, the securing arrangement may comprise an anchor in the form of a weighted component. According to a seventh example of the third aspect, the array may comprise a connection point at the subsea securing location for securing one of the connection cables thereto. Having a portion of each of the connection cables secured at a subsea location may reduce the effect of tidal and wave motion on the array. The connection cable may be connected to the connection point so as it may be easily released and removed if required.

According to an eighth example of the third aspect, at least a portion of the connection cable may be buoyant. According to a ninth example of the third aspect, the connection cable may comprise at least one buoyancy member mounted thereon. According to a tenth example of the third aspect, at least a portion of each of the connection cables may be suspended in a subsea location at a position below a water level, for example such that the portion of connection cable is not in contact with a surface (e.g. the sea bed), and is also submerged below the surface or water level. According to an eleventh example of the third aspect, at least a portion of each of the connection cables may be suspended in a wave formation. Such a formation of connection cable may assist to prevent damage to the cables as a result of horizontal movement of the wind turbine assembly, e.g. due to wave motion, or due to vertical movement e.g. due to tidal motion. Having suspended cable, which may be in a wave formation, may be a convenient way of maintaining slack in a cable, without having cable resting on the seabed or a lake bed, which may risk damage or tangling of the cable.

According to a twelfth example of the third aspect, each of the at least two wind turbine assemblies may be connected to the common array cable by a single connection cable for each one of the at least two floating wind turbine assemblies. In this circumstance, fewer materials may be required to establish the connection than in other configurations.

According to a thirteenth example of the third aspect, the common array cable may have a negative buoyancy, thereby assisting to secure the common array cable in place without the need for specialist equipment.

According to a fourteenth example of the third aspect, the at least two wind turbine assemblies may be directly electrically connected to the common array cable.

According to a fifteenth example of the third aspect, the at least two wind turbine assemblies may be coupled to the common array cable, each by a separate respective connection cable.

According to sixteenth example of the third aspect, the subsea location may be the sea bed.

According to a seventeenth example of the third aspect, the common array cable may be secured to the sea bed.

According to an eighteenth example of the third aspect, the common array may be connected to a second common array cable of a second array of wind turbine assemblies.

A fourth aspect relates to a method for installation of an array of wind turbine assemblies, comprising: providing at least two wind turbine assemblies at an offshore location; connecting a connection cable to each of the at least two wind turbine assemblies; providing a common array cable at an offshore location; securing the connection cable at a subsea location; electrically connecting each of the at least two wind turbine assemblies to the common array cable via the connected connection cable.

According to a second example of the fourth aspect, the method may comprise securing the at least two wind turbine assemblies to the seabed at an offshore location via an anchor arrangement.

According to a third example of the fourth aspect, the method may comprise electrically connection each of the at least two wind turbine assemblies to the common array cable via a floating vessel.

According to a fourth example of the fourth aspect, the method may comprise electrically connecting each of the at least two wind turbine assemblies to the common array cable and securing the connection cable to the subsea location in a single operation.

Hence, it is to be understood that the herein disclosed disclosure is not limited to the particular component parts of the device described or steps of the methods described since such device and method may vary. It is also to be understood that the terminology used herein is for purpose of describing particular embodiments only, and is not intended to be limiting. It should be noted that, as used in the specification and the appended claim, the articles "a", "an", "the", and "said" are intended to mean that there are one or more of the elements unless the context explicitly dictates otherwise. Thus, for example, reference to "a unit" or "the unit" may include several devices, and the like. Furthermore, the words "comprising", "including", "containing" and similar wordings does not exclude other elements or steps.

The present disclosure will become apparent from the detailed description given below. The detailed description and specific examples disclose preferred embodiments of the disclosure by way of illustration only. Those skilled in the art understand from guidance in the detailed description that changes and modifications may be made within the scope of the disclosure.

Brief descriptions of the drawings

The above objects, as well as additional objects, features and advantages of the present disclosure, will be more fully appreciated by reference to the following illustrative and non-limiting detailed description of example embodiments of the present disclosure, when taken in conjunction with the accompanying drawings.

Figure 1 is a schematic illustration of an array of offshore wind turbine assemblies.

Figure 2 is an illustration of an electrical connection to a buoyant structure of a wind turbine assembly.

Figure 3 is an illustration of cables extending from a buoyant structure of a wind turbine assembly.

Figure 4A illustrates an array of wind turbine assemblies in a standard configuration.

Figure 4B is a side view of one of the wind turbine assemblies of Figure 4A.

Figure 5 is a schematic illustration of an example of an array of wind turbine assemblies.

Figures 6 to 9 illustrate steps involved in a method for installing wind turbine assemblies.

Detailed description

The present description provides an improved array of floating wind turbine assemblies and method for electrical connection of array of floating wind turbine assemblies. According to an example embodiment there is provided an array of floating wind turbine assemblies, comprising: at least two floating wind turbine assemblies; each of the at least two floating wind turbine assemblies comprising an ingoing and an outgoing electrical connection; a first electrical cable extending from the ingoing connection on one lateral side of a first of the at least two floating wind turbine assemblies; a second electrical cable extending from the outgoing connection on the same lateral side of the first of the at least two floating wind turbine assemblies, the second electrical cable connecting to the ingoing electrical connection of a second of the at least two floating wind turbine assemblies.

Figure 1 illustrates an illustration of an array of offshore wind turbine assemblies 212, which in this case refers to a wind turbine 215 mounted upon a floating platform 214. Here, three wind turbine assemblies 212 are illustrated, although it should be noted that other examples containing more or fewer wind turbine assemblies 212 are also possible. Further, in this example, each of the offshore wind turbine assemblies 212 are identical, however in other examples there may be differences between each of the wind turbine assemblies 212. For example, the wind turbines 215 may be of different energy-generation capacities, may have more or fewer blades, or be otherwise differently configured.

Although not illustrated in detail, the wind turbine assemblies 212 are located in an offshore location. The offshore location may be in a sea or an ocean, or may be in a lake or similar body of water. As stated, each of the wind turbine assemblies 212 comprises a buoyant structure in the form of a floating platform 214 with a wind turbine 215 mounted thereon. The floating platform 214 supports the weight of each of the wind turbines 215 and permits the wind turbine assemblies 212 to float on the surface of a body of water, in a configuration that is conducive to the production of electricity.

Each of the floating platforms 214 is anchored in position by an anchoring means 220, which in this example comprises three anchoring members 220a-c. In this case, anchoring means 220 comprises three anchoring members that may be cables or chains. However, in other examples, a different anchoring means 220 may be used, for example a fixed structure. Further, more or fewer than three anchoring means 220a-c may be used. The anchoring means is configured to hold the respective floating platform 214 in an offshore location, although may permit the floating platform 214 some degree of movement, for example some degree of vertical movement which may be necessary if the floating platform 214 is in a location affected by tides, and/or some degree of horizontal movement, which may be necessary where the floating platform 214 is affected by wind or tidal motion with a force acting in horizontal direction.

Each of the wind turbine assemblies 212 comprises two electrical cables connected thereto. In Figure 1, the leftmost wind turbine assembly 212 comprises a first electrical cable 226 and a second electrical cable 228 connected thereto. Although described as electrical cables, both may additionally comprise other means of transmission, such as fibre optic cables that permit the transmission of data (e.g. for operation of some feature on the wind turbine assembly). In some examples, the electrical cables 226, 228 may be used for both power and data transmission. The electrical cables 226, 228 may permit an electrical current to flow to and from the wind turbine assemblies 212. In this example, the first electrical cable 226 may be considered to be an ingoing electrical cable (e.g. a cable that permits flow clan electrical current to the wind turbine assembly 212), while the second electrical cable 228 may be considered to be an outgoing electrical cable (e.g. a cable that permits flow clan electrical current from the wind turbine assembly).

As illustrated in Figure 1, each of the floating wind turbine assemblies comprises a central vertical axis 240. The first and second electrical cables 226, 228 are configured such that both the first and second electrical cables 226, 228 extend from one lateral side of the wind turbine assembly 212. Each of the first and second electrical cables 226, 228 may be considered to extend in a radial direction relative to the central vertical axis 240, and may be offset from each other by a relatively small angle (e.g. they may have a relatively small circumferential offset relative to the central vertical axis 240). For example, the circumferential offset between the first and second electrical cables 226, 228 may be fewer than 90 degrees (e.g. an acute angle), fewer than 45 degrees, fewer than 20 degrees, or the like.

Each of the first and second cables 226, 228 may be configured to extend from the wind turbine assembly 212 and towards the seabed, lakebed or other surface located below the wind turbine assembly 212 in a wave configuration, as is illustrated in Figure 1. As such, at least a part of each of the first and second cables 226, 228 may comprise a buoyant member, or buoyant members connected thereto so as to provide at least a part of each of the first and second electrical cables 226, 228 with some buoyancy, thereby assisting to permit each to remain buoyantly suspended in a subsea location. Having such a wave configuration may permit the wind turbine assembly 212 some degree of vertical and/or horizontal motion without the either of the cables 226, 228 being held in tension, which may cause damage to the cables. As the first and second electrical cables 226, 228 are permitted some degree of movement, each cable may be considered to be a dynamic cable, which is some degree of free movement and may be able to move with surrounding water, e.g. as a result of wave or tidal motion, which may assist to prevent damage to the cable as a result of offshore weather conditions. A portion of each of the cables 226, 228 rests on a surface below each of the wind turbine assemblies 212 (e.g. the seabed or lakebed), and each cable 226, 228 has, in this example, a circumferential offset such that there is no overlap between each of the cables. This may avoid the cables becoming tangled or damaged as a result of contact or interference therebetween. In addition, each of the first and second cables 226, 228 may extend from the wind turbine assemblies 212 so as to position each cable 226, 228 away from the anchoring means 220, for example as far as is possible from the anchoring means 220, so as to minimise interference therebetween, and remove any risk of damage to the cables 226, 228. In this example, the first and second cables 226, 228 extend radially from the wind turbine assembly 212 between the second and the third anchoring members 220b, 220c.

Here, the second electrical cable 228 extends from a first wind turbine assembly 212 (here, the leftmost wind turbine assembly) and towards a second wind turbine assembly 212 (in Figure 1, the central wind turbine assembly). The second electrical cable 228 may be an outgoing cable for a first of the wind turbine assemblies 212, and an ingoing cable for a second of the wind turbine assemblies 212. As such, the second electrical cable 228 of the first wind turbine assembly may be considered to function as the first electrical cable 228 of the second of the assemblies 212.

As is illustrated in Figure 1, the cables 226, 228 extend along the lower subsea surface (e.g. the seabed, lakebed, etc.) initially in a direction radially away from the central axis 240 of the wind turbine assembly 212, before then extending in the direction of the next wind turbine assembly 212 in the array (e.g. the cable extends from the first to the second wind turbine assembly 212). In this example, the wind turbine assemblies 212 are in the form of a linear array, and as such, the cable comprises a bend of approximately 90 degrees. However, it should be noted that in other array configurations, the angle may differ. In this example, the cable 226, 228 extends along the lower surface (e.g. seabed, lakebed etc.) in a U-shape or an approximate U-shape. However, it should be noted that other shapes may be envisaged, for example a V-shape. The cable 226, 228 may comprise additional winding sections, where there are illustrated straight sections in Figure 1. For example, the cable may have a winding and/or undulating configuration on the seabed, lakebed, etc. as the cable 226, 228 transitions between each wind turbine assembly 212 in the array, and/or the cable may comprise straight sections as illustrated in Figure 1. Having the cables configured in such a shape may minimise interference between the cables 226, 228 and the anchoring means 220, while at the same time allowing both cables to extend from the wind turbines 212 both on the same lateral side of the wind turbines 212, and while optionally providing enough cable slack at a desired location to permit for some movement of the cable 226, 228 on the seabed, lakebed, etc.. Having the cables both extend laterally from the wind turbine assemblies may permit a user to more easily remove a wind turbine assembly from the array. For example, a wind turbine assembly may be disconnected from the array, and then each of the first and second cables 226, 228 connected to a junction box, thereby allowing continued operation of the array, in a single operation. As such, the configuration may enable better functioning of an array compared to known configurations.

Figure 2 illustrates an electrical connection to a buoyant structure 214 of a wind turbine assembly 212. Here, both the first and second electrical cables 226, 228 are connected to the buoyant structure 214. In this case, the first electrical cable 226 is connected to an ingoing electrical connection 242, while the second electrical cable 228 is connected to an outgoing electrical connection 244. Both the ingoing and outgoing electrical connections 242, 244 are adjacently located, and hang off the buoyant structure 214. Although not illustrated in detail, the first and second electrical cables 226, 228 may extend from the buoyant structure 214 via a bending stiffener, so as to ensure that the cables 226, 228 are not damaged as a result of bending under their own weight at the point of connection to the buoyant structure 214. As both the first and the second electrical cables 226, 228 extend laterally from the same side of the buoyant structure 214, a single bending stiffener may be used, thereby saving cost relative to known methods, which may have cables extending in vastly differing directions, thereby requiring the use of multiple bending stiffeners. In addition, in known methods, an 1-tube may be required in order to wrap around and support an electrical cable connecting to a wind turbine assembly. However, in this example, no I-tube may be necessary.

In the illustration of Figure 2, the buoyant structure 214 is in the form of three columns, connected together to form a buoyant triangular structure. However, the skilled reader will understand that other configurations of buoyant structure may be possible. In this case, a wind turbine is mounted on the buoyant structure 214, which provides power. Figure 3 further illustrates the first and second cables 226, 228 as connected to the buoyant structure 214. In this Figure, the wave formation of each of the cables 226, 228 and the circumferential offset can be clearly seen. In this example, as well as those previous, the cables may be able to be installed (e.g. attached to the buoyant structure 214 and laid on the seabed or lakebed) by a vessel, which may comprise a crane or other installation apparatus for such a purpose.

Various further inventive aspects and embodiments according to the present disclosure will now be outlined in the following numbered clauses: CLAUSE 1. An array of floating wind turbine assemblies, comprising: at least two floating wind turbine assemblies; each of the at least two floating wind turbine assemblies comprising an ingoing and an outgoing electrical connection; a first electrical cable extending from the ingoing connection on one lateral side of a first of the at least two floating wind turbine assemblies; a second electrical cable extending from the outgoing connection on the same lateral side of the first of the at least two floating wind turbine assemblies, the second electrical cable connecting to the ingoing electrical connection of a second of the at least two floating wind turbine assemblies.

CLAUSE 2. The array of clause 1, wherein the second electrical cable is positioned on the seabed in a U-shape between the first and the second of the at least two floating wind turbine assemblies.

CLAUSE 3. The array of clause 1 or 2, wherein the second electrical cable is positioned on the seabed in a V-shape between the first and the second of the at least two floating wind turbine assemblies.

CLAUSE 4. The array of any preceding clause, wherein each of the floating wind turbine assemblies comprises a vertical axis, and the first electrical cable extends from the first of the floating wind turbine assemblies at an angle that is circumferentially offset by 90 degrees or fewer from the second electrical cable extending from the first of the floating wind turbine assemblies, relative to the vertical axis of the first of the floating wind turbine assemblies.

CLAUSE 5. The array of clause 4, wherein the first electrical cable extends from the first of the floating wind turbine assemblies at an angle that is circumferentially offset by 45 degrees or fewer from the second cable extending from the first of the floating wind turbine assemblies, relative to the vertical axis of the first of the floating wind turbine assemblies.

CLAUSE 6. The array of any preceding clause, wherein the ingoing and outgoing electrical connections are adjacent.

CLAUSE 7. The array of any preceding clause, wherein the first and second electrical cables are supported on a first of the at least two wind turbine assemblies by a single bending stiffener adjacent the ingoing and outgoing electrical connection to the floating wind turbine assembly.

CLAUSE 8. The array of any preceding clause, wherein the floating wind turbine assembly comprises a buoyant structure, and the ingoing and outgoing electrical cables are mounted on the buoyant structure.

CLAUSE 9. The array of any preceding clause, wherein each of the floating wind turbine assemblies are floating wind turbines.

CLAUSE 10. A method for electrical connection clan array of floating wind turbine assemblies, comprising: providing at least two floating wind turbine assemblies at an offshore location; connecting an ingoing and an outgoing electrical cable to a first of the at least two floating wind turbine assemblies, and extending the ingoing and outgoing electrical cable both from the same lateral side of the first of the at least two floating wind turbine assemblies; connecting an ingoing and an outgoing electrical cable to a second of the at least two floating wind turbine assemblies, the outgoing cable of the first of the wind turbine assemblies being the same as the ingoing cable of the second of the wind turbine assemblies, and extending the ingoing and outgoing electrical cable both from the same lateral side of the second of the at least two floating wind turbine assemblies.

CLAUSE 11. The method of clause 11, comprising positioning the electrical cable between two of the at least two floating wind turbine assemblies in a U-shape.

CLAUSE 12. The method of clause 11 or 12, comprising disconnecting the ingoing and outgoing cable from at least one of the at least two floating wind turbine assemblies, and connecting the ingoing and outgoing cable to a junction box.

Moving to the description of Figures 4 to 9, there provided an improved array of offshore wind turbine assemblies and method for installation of array of floating wind turbine assemblies. According to an example embodiment there is provided an array of floating wind turbine assemblies, comprising: at least two floating wind turbine assemblies; a common array cable configurable to be secured to a subsea location; each of the at least two floating wind turbine assemblies being electrically connected to the common array cable by a connection cable.

Figure 4A is a schematically illustrated array 10 of wind turbine assemblies 12, according to a known array structure, while Figure 4B illustrates an individual wind turbine assembly 12 shown from a side view in order to further illustrate the configuration of the associated cabling. In this example, four wind turbine assemblies 12 are illustrated, each being substantially identical. Each of the wind turbine assemblies 12 comprises a wind turbine 15 located on a floating platform 14 in an offshore location. The offshore location of the wind turbine assemblies 12 is indicated in Figure 4B by waterline 16.

The floating platforms 14 of each wind turbine assembly 12 are held in place by an anchoring means 20. In this case, the anchoring means is in the form of three anchor members 20a-c, which may be chains or cables. Each wind turbine assembly 12 comprises one anchoring means 20, which connects the wind turbine assembly 12 to the seabed 22. Although not illustrated in Figures 4A or 4B, there may be a connection point on the seabed corresponding to each of the securing members 20a-c.

Here, each wind turbine assembly 12 is connected to the array 10 via an array cable 18.

The array cable 18 is connected towards the base of each wind turbine assembly 12 in the array 10, and in use all (or substantially all) of the array cable 18 is located below the waterline 16. In this example, there are four wind turbine assemblies 12 that form the array 10, although the skilled reader will understand that an array can have more or fewer wind turbine assemblies 12 than those illustrated.

Here, the wind turbine assemblies 12 are illustrated as being daisy chained together, meaning that a first wind turbine assembly 12a is connected to a second wind turbine assembly 12b, which in turn is connected to a third wind turbine assembly 12c, as is illustrated. The power generated by each wind turbine assembly 12 may therefore be relayed to a desired location 22 via the array cable 18, with the power from wind turbine assemblies 12 being located further from the desired location 22 being routed through those wind turbine assemblies being located closer to the desired location 22.

While permitting the connection of each of the wind turbine assemblies 12 to an array 10, the illustrated configuration may have drawbacks, particularly when considering the disconnection of one of the turbines, such as the case may be when maintenance or repairs are required. In this instance, the disconnection of a single wind turbine assembly 12 may have an effect on the ability of all of the other turbine assemblies 12 in the array 10 to produce power, as it may disrupt the array network while the turbine assembly is being removed. This is therefore detrimental to the operation of the array, as it creates a period of downtime in which no electrical power is being produced.

Figure 5 illustrates an example of an array 110 of wind turbine assemblies 112 according to the present disclosure. As in the previous Figures 4A and 4B, this array 110 of wind turbine assemblies 112 comprises four wind turbine assemblies 112. Again, the array 110 may comprise more or fewer wind turbine assemblies 112 than those illustrated in this example.

Each of the wind turbine assemblies 112 comprises a wind turbine 115 mounted on a floating platform 114, which supports the wind turbine 115 located thereon on the surface of a body of water, such as the sea, ocean, a lake or the like. The floating platform is, in turn, secured in place by an anchoring means 120. The anchoring means 120 of this example is comprised of three anchor members 120a-c. The securing members may be cables, chains, or the like, and each of the securing members 120a-c may be secured to a fixed point. The fixed point may be on the floor of the sea, ocean, lake, or the like, in which the array 110 of wind turbine assemblies 112 is located. A fixed point may be an anchor which is installed in place, for example by being physically fastened to the floor of the sea, ocean, lake or the like, or an anchor which may be sufficiently heavy so as to not be affected by movement of the wind turbine assembly, for example as a result of waves or tidal motion.

In this example, a common array cable 124 forms part of the array 110. The common array cable 124 is electrically connected to each of the wind turbine assemblies 112 of the array 110 by a connection cable 126. An individual connection cable 126 connects each of the wind turbine assemblies 112 of the array to the common array cable 124. Therefore, in this example, as there are illustrated four wind turbine assemblies 112 forming part of the array 110, then there are four connection cables 126, each corresponding to a respective wind turbine assembly 112. As illustrated, each of the connection cables 126 is positioned in a wave formation, which may assist to provide slack in the cable such that movement of the wind turbine assembly 112 relative to the common array cable 124 does not induce a high tension load in the connection cable 126, and does not result in large forces acting on the common array cable 124, which may cause damage to either cable 124, 126, or to the electrical connection therebetween. The wave formation may be achieved by attaching buoyancy members (not illustrated) to the connection cables 126, by providing a buoyant sheath around all or part of the buoyant connection cables 126 (e.g. whereby the buoyant sheath may have variable buoyancy therealong), to induce a buoyancy of the connection cable 126 relative to the surrounding fluid (e.g. fresh water or seawater), by fabricating all or part of the connection cable 126 from a buoyant material, or the like, or any combination thereof. In such examples, the connection cable 126 may be considered to be a buoyant connection cable 126. The buoyancy of the connection cable 126 may therefore be such that the connection cable 126 (or at least a portion thereof) is buoyantly suspended in the surrounding fluid, e.g. the seawater. The buoyancy of the connection cable 126 may therefore be such that it naturally assumes a wave formation when submerged, for example when electrically connected to both the wind turbine assembly 112 and the common array cable 124, as is illustrated in Figure 5.

A similar wave formation may be seen in Figures 4A and 4B. In line with the disclosure of this example, the array cable 18 of Figures 4A and 4B may be made buoyant by the attachment of buoyancy members thereto. It should be noted that, in the example of Figures 4A and 4B, the array 10 comprises wind turbine assemblies 12 each being connected to an array cable 18 having two wave formations therein. In contrast, the wind turbine assemblies 112 of Figure 5 require connection to one single cable having a wave formation (in this case, the buoyant connection cable 126). As such, in the example of Figure 5, a reduced number of buoyancy members are required as compared to that of Figures 4A and 4B, thereby saving the cost of the buoyancy equipment (e.g. buoyancy members, sheaths, or the like) and their installation. In the case of wind turbine assemblies 112 that must be transported offshore, this additionally reduces the complexity involved with having to transport both cables and buoyancy equipment to the offshore location.

Although in the example illustrated, the connection cable 126 is buoyant and extends from the wind turbine assembly 112 (e.g. the floating platform 114 of the wind turbine assembly 112) to the seabed, in other examples there may be a different configuration. For example, where the wind turbine assembly 112 is not a floating wind turbine assembly, but rather is fixed to the seabed (for example by a support structure such as a pile or a jacket structure) the connection cable may extend along the length of the support structure to the seabed. In such cases, the connection cable 126 may not require to be buoyant, and may have a negative buoyancy, for example. In examples where the wind turbine assembly 112 is fixed to the seabed, lakebed or the like, the connection cable 126 may be fastened to the support structure by any appropriate means, such as ties or clamps. As such, in this case, the connection cable 126 may not have a wave shape.

Illustrated in Detail A of Figure 5 is a securing arrangement 128. In this example, the securing arrangement 128 assists to secure a portion of the connection cable 126 relative to the common array cable 124, such that movement of the connection cable 126 is prevented or restricted. The securing arrangement 128 may be used to secure the connection cable 126 to a subsea securing point, which may be on the seabed, lakebed, or the like. The remainder of the connection cable 126 may have some degree of freedom of movement (relative to the secured portion held by the securing arrangement 128), and at least some of the remainder of the connection cable 126 may be buoyantly suspended, as is illustrated in Figure 5. The connection cable 126 may be considered to be a dynamic cable, or at least the potion of the buoyant that has some degree of freedom of movement may be considered to be a portion of dynamic cable, as relative movement of the cable is permissible. Having a dynamic cable may permit movement of the cable in response to forces from the surrounding water, thereby assisting to prevent damage to the cables as a result of offshore weather conditions. The portion of the connection cable 126 that is secured by the securing arrangement 128 may be located closer to the common array cable 124 than the wind turbine assembly 112, and may be located adjacent the common array cable 124. The secured portion of the connection cable 126 may extend from a point in the subsea location to the connection with the common array cable 124, or as illustrated, there may be further non-secured section of the connection cable 126 (e.g. a portion of the connection cable 126 that is not secured by the securing arrangement 128) located between the securing arrangement 128 and the connection between the common array cable 124 and the connection cable 126.

The securing arrangement may be any suitable arrangement that restricts movement of the connection cable 126. For example, the securing arrangement 128 may simply be a bag of weighted material (e.g. sand) that is placed over the connection cable 126, or bags of a weighted material, in order to restrict movement thereof. Alternatively or additionally, the securing arrangement 128 may be an anchor point that is installed on the seabed, and to which the connection cable 126 is connected (e.g. coupled or fastened via a cable or coupling). Having a securing arrangement while the array 110 is in use may assist to reduce or remove forces incident on the junction between the common array cable 128 and the connection cable 126 as a result of movement of the connection cable 126, for example due to wave or tidal motion, subsea or underwater currents, movement of the wind turbine assembly 112, or the like.

The electrical connection between the connection cable 126 and the common array cable 124 may be a direct electrical connection, as is schematically illustrated in Figure 5, or the connection may alternatively be via at least one additional component, such as a further section of spooled or spare cable, a further electrical component, or the like.

Illustrated in Detail B is further detail surrounding the connection between the connection cable 126 and the common array cable 124. As illustrated in Detail B, the connection is a branched connection in the form of a Y-type connection, or a Y-type connector. Having a Y-connector or branched connector may permit a simpler connection of each wind turbine assembly 112 to the common array cable 124, by permitting the connection cable 126 to be connected to the common array cable 124 at one point. In addition, having a Y-connector or branched connector in combination with a common array cable may permit a simpler configuration of the array 110. For example, rather than having to have an ingoing and an outgoing array cable to connect each wind turbine assembly to adjacent wind turbine assemblies, having a Y-connector or Y-connection arrangement permits each wind turbine assembly 112 in the array 110 to be connected to the common array cable 124 at a one point (e.g. a single point) and may permit each to share the common array cable 124.

While in Detail B the Y-connector illustrates each cable having a stepped configuration so as to merge into one single cable, it may be the case that one of the cables 124 runs straight, while the other of the cables 126 connects at a right or oblique angle relative thereto.

The common array cable 124 may be secured in place by any appropriate means. For example, the common array cable 124 may be secured in place by a weighted arrangement, for example which may be positioned in contact (e.g. above, or on top of) the common array cable 124 to assist to hold it in place, and which may be a simple and effective method for securing the cable 124 in place. An example of a weighted arrangement (e.g. an anchor arrangement) may be a bag of sand or stones, or a non-buoyant block of material.

Alternatively or additionally, the common array cable 124 may simply be secured under its own weight in cases where the common array cable 124 has a negative buoyancy. Providing the common array cable 124 with a negative buoyancy may have the advantage of permitting the common array cable to be installed more simply and quickly than in other examples. Alternatively or additionally, the common array cable 124 may be affixed to a subsea structure, thereby holding it in place. For example, existing equipment that is located in a subsea location, such as pipework, or equipment that is installed with the specific intention of securing the cable 124, such as anchor points.

In some examples, a trench or structure may be installed or located on the seabed, lakebed, or the like, for positioning of the common array cable 124 therein. This may assist to prevent the array cable from moving from its subsea location without having to provide or install equipment or structures, which may pose logistical and cost challenges.

As illustrated, the connection cable 126 connects each wind turbine assembly 112 to the common array cable 124. The connection cable 126 may connect to the base of the respective wind turbine assembly 112 to permit transfer of power and, in some examples, electrical signalling between an external location (e.g. an onshore location) and the wind turbine assembly 112. The connection cable 126 may be connected to each wind turbine assembly 112 to maximise the distance between the connection cable 126 and the anchoring means 120. For example, where the anchoring means comprises three anchor members 120a-c, the connection cable 126 may be located between two of the anchor members 120a-c. For example, the connection cable 126 may run outwardly from the wind turbine assembly between two of the anchor members 120a-c, also running outwardly from the wind turbine assembly (a illustrated in Figure 5). The connection cable 126 may run outwardly equidistant from two of the anchor members 120a-c. The connection cable 126 may be located approximately angularly centrally between two of the anchor members 120a-c. The location of the connection cable 126 may be selected to minimise interference between the connection cable 126 and the anchor members 120a-c. In addition, in this example, having only a single connection member 126 extending from each turbine, as opposed to two in previous examples, may minimise the likelihood of any interference between each connection member 126 and the anchor members 120a-c.

In Figures 6 to 9, steps in the installation process of the array of wind turbine assemblies is described. In Figure 6, it can be seen that the wind turbine assemblies 112 have been positioned in a desired location for the array 110. Each of the wind turbines 112 is provided on a floating platform 114. In some examples, the floating platform 114 may be first towed to the desired location, for example by a tow vessel. Each wind turbine 112 may be provided and installed on the floating platform thereafter. Once the floating platform 114 has been provided at the desired location, the floating platform 114 may then be secured in the desired location. As previously described, and as illustrated in this example, this may be by the anchoring means 120. Once the floating platform 114 has been secured in place by the anchoring means 120 as previously described, it may be desirable at this stage to install a wind turbine 112 on each floating platform 114.

With the wind turbine assembly 112 in place, the connection cable 126 may be connected thereto. In some examples, the connection cable 126 may be installed entirely after the installation of the wind turbine assembly 112. The connection cable 126 having buoyancy members attached thereto may automatically provide the connection cable 126 with the desired wave formation when installed. In some other examples, adjustment of the buoyancy members on the connection cable 126 may be possible after installation, either by adjusting the buoyancy members in a subsea location, or by bringing at least a portion of the connection cable 126 to the surface, to adjust the buoyancy members at a surface location (e.g. on a vessel).

In order to assist in the installation of the connection cable 126, the securing arrangement 128 may be positioned towards a distal end of the connection cable 126 (relative to the wind turbine 112 and floating platform 114). The securing arrangement 128 secures a portion of the connection cable 126, in this case, to the seabed, lakebed, or the like. The securing arrangement 128 therefore assists in the installation process of the array 110 as it reduces the effect of subsea motion of the connection cable 126 on the installation process, by providing a restriction to such movement.

In Figure 7, there the process of connecting the connection cable 126 to the common array cable 124 is illustrated. In this case, a vessel 130 is used to carry the common array cable 124, and install it in the desired position. As can be more clearly seen in Detail C of Figure 7, a Y-connector 132 is located on the vessel 130 to which both the common array cable 124 and the connection cable 126 are attached. As is illustrated, securing arrangement 128 holds the connection cable 126 in position while the connection cable 126 extends from the securing arrangement 128 (e.g. located on the seabed or lakebed) and to the vessel 130. In having a securing arrangement 128 then it is ensured that the weight of the connection cable 126 located between the securing arrangement 128 and the wind turbine assembly 112 is not being supported by the vessel, which may be damaging to the vessel 130, or in particular to the 11-connector 132 on the vessel, which may otherwise be required to bear a significant weight. Instead, the securing arrangement 128 ensures that the weight of the connection cable 126 is distributed between the wind turbine assembly 112, and the seabed.

In Figure 8, there is a progression of the installation process shown. Here, the common array cable 124 and the connection cable 126 have been connected at the Y-connector 132, also illustrated in Detail D. The vessel 130 has then proceeded to lower the Y-connector from the vessel 130 and towards the seabed or lakebed. In this case, the Y-connector is taking the weight of the length of common array cable 124 and the length of connection cable 126 that is not positioned on the seabed or lakebed. It is desirable to minimise this weight to reduce the stresses on the Y-connector, which may not be designed to withstand very high stresses. The securing arrangement 128 is therefore of increased importance at this stage, as it serves to minimise the length of connection cable 126 that is not resting on the seabed, and the weight thereof that must be supported by the Y-connector 132.

Further progression of the method is illustrated in Figure 9. Here, the connection of one turbine 112 to the array 110 has been completed, and the vessel 130 is then able to continue towards a second wind turbine assembly 112 that is awaiting connection to the array 110. As the vessel 130 moves towards the second wind turbine assembly 112, it continues to lay a length of common array cable 124 on the seabed or lakebed. In addition, the Y-connector 132 that connects the first wind turbine assembly 112 to the array 110 is now positioned on the seabed.

Once the vessel reaches the second wind turbine assembly 112, the buoyant connection cable is retrieved and taken on board the vessel, and the steps of attaching both the common array cable 124 and the connection cable 126 via a Y-connector are repeated, as before. These steps may be continued several times depending on the desired number of wind turbine assemblies to be in the array 110.

As is illustrated in both Figures Sand 9, each of the wind turbine assemblies 112 is attached via the connection cable 126 to the common array cable 124 at different axial locations. Each Y-connector 132 may be spaced along the common array cable at any appropriate distance, for example 100m, 200m, 300m or more. It should also be understood that, if required, it may be possible to electrically connect a first and second wind turbine assembly 112 to the common array cable 124 with a relatively short axial separation, for example lm, Sm, 10m or the like. Any two Y-connectors 132 may be connected to, or form part of, the common array cable 124 with a degree of axial separation.

Various further inventive aspects and embodiments according to the present disclosure will now be outlined in the following numbered clauses: CLAUSE 1. An array (110) of offshore wind turbine assemblies (112), comprising: at least two wind turbine assemblies (112); a common array cable (124) configurable to be secured to a subsea location; each of the at least two wind turbine assemblies (112) being electrically connected to the common array cable (124) by a connection cable (126).

CLAUSE 2. The array (110) of clause 1, wherein the connection cable (126) connects each of the at least two wind turbine assemblies (112) to the common array cable (124) at an axially separated location.

CLAUSE 3. The array (110) of clause 1 or 2, wherein the connection between the common array cable (124) and the connection cable (126) is in the form of a branch connection from the common array cable (124).

CLAUSE 4. The array (110) of any preceding clause, wherein the common array cable (124) is connected to the connection cable (126) via a branched connector.

CLAUSE 5. The array (110) of any preceding clause, comprising a securing arrangement (128) to secure a portion of each of the connection cables (126) of the array at a subsea location.

CLAUSE 6. The array (110) of clause 5, wherein the securing arrangement (128) comprises an anchor in the form of a weighted component.

CLAUSE 7. The array (110) of clause 5 or 6, comprising a connection point at the subsea securing location for securing one of the connection cables (126) thereto.

CLAUSE 8. The array (110) of any preceding clause, wherein at least a portion of the connection cable (126) is buoyant.

CLAUSE 9. The array (110) of any preceding clause, wherein the connection cable (126) comprises at least one buoyancy member mounted thereon.

CLAUSE 10. The array (110) of any preceding clause, wherein at least a portion of each of the connection cables (126) is suspended in a subsea location at a position below a water level.

CLAUSE 11. The array (110) of clause 10, wherein at least a portion of each of the connection cables (126) is suspended in a wave formation.

CLAUSE 12. The array (110) of any preceding clause, wherein each of the at least two wind turbine assemblies (112) are connected to the common array cable (124) by a single connection cable (126) for each one of the at least two wind turbine assemblies (112).

CLAUSE 13. The array (110) of any preceding clause, wherein the common array cable (124) has a negative buoyancy.

CLAUSE 14. The array (110) of any preceding clause, wherein the at least two wind turbine assemblies (112) are directly electrically connected to the common array cable (124).

CLAUSE 15. The array (110) of any preceding clause, wherein the at least two wind turbine assemblies (112) are coupled to the common array cable (124), each by a separate connection cable (126).

CLAUSE 16. The array (110) of any preceding clause, wherein the subsea location is the sea bed.

CLAUSE 17. The array (110)of clause 16, wherein the common array cable (124) is secured to the sea bed.

CLAUSE 18. The array (110) of any preceding clause, wherein the common array cable (124) is connected to a second common array cable of a second array of wind turbine assemblies (112).

CLAUSE 19. A method for installation of an array (110) of offshore wind turbine assemblies (112), comprising: providing at least two wind turbine assemblies (112) at an offshore location; connecting a connection cable (124) to each of the at least two wind turbine assemblies (112); providing a common array cable (124) at an offshore location; securing the connection cable (126) at a subsea location; electrically connecting each of the at least two wind turbine assemblies (112) to the common array cable (124) via the connected connection cable (126).

CLAUSE 20. The method of clause 19, comprising securing the at least two wind turbine assemblies (112) to the seabed at an offshore location via an anchor arrangement.

CLAUSE 21. The method of clause 19 or 20, comprising electrically connecting each of the at least two wind turbine assemblies (112) to the common array cable (124) via a floating vessel (130).

CLAUSE 22. The method of any of clauses 19 to 21, comprising electrically connecting each of the at least two wind turbine assemblies (112) to the common array cable (124) and securing the connection cable (126) to the subsea location in a single operation.

The person skilled in the art will realise that the present disclosure is not limited to the preferred embodiments described above. The person skilled in the art further realises that modifications and variations are possible within the scope of the appended claims. For example, there may be many different possibilities to the described securing and anchoring arrangements, to the number of wind turbine assemblies in the array, to the layout of the described array, or the like. Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed disclosure, from a study of the drawings, the disclosure, and the appended claims.

Claims

CLAIMS1. An array of floating wind turbine assemblies (212), comprising: at least two floating wind turbine assemblies (212); each of the at least two floating wind turbine assemblies (212) comprising an ingoing and an outgoing electrical connection (242, 244); a first electrical cable (226) extending from the ingoing connection (242) on one lateral side of a first of the at least two floating wind turbine assemblies (212); a second electrical cable (228) extending from the outgoing connection (244) on the same lateral side of the first of the at least two floating wind turbine assemblies (212), the second electrical cable (228) connecting to the ingoing electrical connection (244) of a second of the at least two floating wind turbine assemblies (212).
2. The array of claim 1, wherein the second electrical cable (228) is positioned on the seabed in a U-shape between the first and the second of the at least two floating wind turbine assemblies (212).
3. The array of claim 1 or 2, wherein the second electrical cable (228) is positioned on the seabed in a V-shape between the first and the second of the at least two floating wind turbine assemblies (212)
4. The array of any preceding claim, wherein each of the floating wind turbine assemblies comprises a vertical axis (240), and the first electrical cable (226) extends from the first of the floating wind turbine assemblies (212) at an angle that is circumferentially offset by 90 degrees or fewer from the second electrical cable (228) extending from the first of the floating wind turbine assemblies (212), relative to the vertical axis (240) of the first of the floating wind turbine assemblies (212).
5. The array of claim 4, wherein the first electrical cable (226) extends from the first of the floating wind turbine assemblies (212) at an angle that is circumferentially offset by 45 degrees or fewer from the second cable (228) extending from the first of the floating wind turbine assemblies (212), relative to the vertical axis (240) of the first of the floating wind turbine assemblies (212).
6. The array of any preceding claim, wherein the ingoing and outgoing electrical connections (242, 244) are adjacent.
7. The array of any preceding claim, wherein the ingoing and outgoing electrical connections are (242, 244) are located on the same lateral side of each wind turbine assembly (212) of the at least two wind turbine assemblies (212).
8. The array of any preceding claim, wherein the first and second electrical cables (226, 228) are supported on a first of the at least two wind turbine assemblies (212) by a single bending stiffener adjacent the ingoing and outgoing electrical connection (242, 244) to the floating wind turbine assembly (212).
9. The array of any preceding claim, wherein the floating wind turbine assembly (212) comprises a buoyant structure (214), and the first and second electrical cables (226, 228) are mounted on the buoyant structure (214).
10. A method for electrical connection of an array of floating wind turbine assemblies (212), comprising: providing at least two floating wind turbine assemblies (212) at an offshore location, each of the at least two floating wind turbine assemblies (212) comprising an ingoing and an outgoing electrical connection (242, 244); connecting a first electrical cable (226) to a first of the at least two floating wind turbine assemblies (212) at the ingoing electrical connection thereof (242), and connecting a second electrical cable (228) to a second of the at least two floating wind turbine assemblies (212) at the outgoing electrical connection thereof (244), and extending the first and second electrical cable (226, 228) both from the same lateral side of the first of the at least two floating wind turbine assemblies (212); connecting the second electrical cable (226, 228) to a second of the at least two floating wind turbine assemblies (212) at the ingoing electrical connection thereof (242).
11. The method of claim 10, comprising positioning the second electrical cable (228) between the first and second of the at least two floating wind turbine assemblies (212) in a U-shape.
12. The method of claim 10 or 11, comprising disconnecting the first and second cable (226, 228) from at least one of the at least two floating wind turbine assemblies (212), and connecting the first and second cable (226, 228) to a junction box.
13. The method of any of claims 10 to 12, comprising connecting a third electrical cable to the second of the at least two wind turbine assemblies (212) at an outgoing electrical connection (244) thereof and to a third wind turbine assembly at an ingoing electrical connection (242) 10 thereof.