Subsea power distribution assembly

Abstract

A subsea power distribution assembly (1) comprising a distribution part (5) with a distribution arrangement (7), a plurality of collection terminals (9) and an export terminal (11) connected to subsea cables (39) with high-voltage dry-mate connectors (31, 131) It further comprises collection connectors (20) and export connectors (30), being high-voltage wet-mate connectors, that connect the collection terminals (9) and export terminal (11) to the distribution arrangement (7) with a jumperless connection.

Description

SUBSEA POWER DISTRIBUTION ASSEMBLYTechnical Field

[0001] The present invention relates to a subsea power distribution assembly configured for distribution of electric power at a subsea location.Background Art

[0002] When installing large and heavy subsea power distribution assemblies, it is known to land a main arrangement on a pre-installed structure, for instance a mudmat, and thereafter connect subsea cables. When connecting the subsea cables, one must use wet-mate type connectors that enable electric connection when surrounded by water. Moreover, to enable movement of the connectors into and out of their connected state, it is common to use a bent cable portion to allow for the movement.

[0003] US9343880 relates to a subsea electric distribution system with a circuit breaker assembly, wherein wet-mate connectors are moved between connected and disconnected positions. To enable movement of the connectors, the cables have an S-shape. While the S-shape is arranged on one side of the connectors, an additional set of cables are used to connect the connectors to the circuit breaker system, which is arranged below the said connectors. This configuration demands a large footprint and several connectors.

[0004] Publication WO2015199550 discloses a wet-mate connector assembly. In one of its embodiments, the connector part has a 90° bend between the cable and the axial direction of the connector part.

[0005] An object of the present invention may be to provide a subsea power distribution assembly that has a reduced footprint.

[0006] Another object may be to provide a more reliable and / or a less complex subsea power distribution assembly.

[0007] Further objects will appear from the following disclosure.Summary of invention

[0008] According to a first aspect of the present invention, there is provided a subsea power distribution assembly comprising collection connectors with a first connector part and a second connector part, wherein the collection connectors are high-voltage wet-mate connectors. The assembly further has export connectors with a first connector part and a second connector part, wherein the export connectors also are high-voltage wet-mate connectors. It further has a distribution part comprising a distribution arrangement, the first connector parts of the collection connectors and the first connection parts of the export connectors. The distribution arrangement can for instance be a switchgear arrangement, a transformer, or other high-voltage electric distribution arrangement. The assembly further has a plurality of collection terminals comprising the second connector parts of the collection connectors, and an export terminal comprising the second connector parts of the export connectors. The respective collection terminals comprise a dry-mate connector part, a collection cable extending from a lower cable end connected to the dry-mate connector part to an upper cable end connected to the second connector part of the collection connector. The lower cable end has a horizontal or inclined nonvertical orientation. The second connector part of the collection connector has a connector body with a horizontal or inclined non-vertical orientation. Moreover, the upper cable end has a vertical or inclined non-horizontal orientation.

[0009] With the term high-voltage wet-mate connectors is meant connectors configured for being made up (connected) when surrounded by water at a subsea location, and which are configured or rated for transmitting electric power at voltages above 12 kV (phase-phase voltage). The wet-mate connectors could in some embodiments be configured for voltages above 24 kV, 36 kV, or even above 60 kV.

[0010] The lower cable end is the part of the cable that extends out from the drymate connector part, while the upper cable end is the part of the cable that extends out from the second connector part of the collection connector or export connector.

[0011] A curved portion of the cable extends between the upper and lower cable ends. As the terms imply, the lower cable end is below the upper cable end.]

[0012] The collection cable may in some embodiments comprise a cable angle between the direction of the lower cable end and the direction of the upper cable end,wherein the cable angle is in the range between 40° and 100°. The cable angle may be between 30° and 100°, or between 50° and 90°.

[0013] The second connector part of the collector connector can comprise a cable body from which the upper cable end extends along a cable axis. The connector body can be configured to mate with the first connector part of the collector connector by movement along a connection axis. The said second connector part can then comprise a deviation angle between the connection axis and the deviation axis which can be in the range of 60° to 90°.

[0014] In some embodiments, the distribution part can be supported at an elevation above the dry-mate connector parts of the respective collection terminals.

[0015] In such embodiments, there may be a separate support structure that supports the distribution part in said elevated position above the dry-mate connector parts.

[0016] The vertical level of the collection connectors can advantageously coincide with the vertical extension of the distribution arrangement.

[0017] The distribution part can have a distribution arrangement with an enclosure wall, wherein the first connection parts of the collection connectors are rigidly connected to penetrators that extend through the enclosure wall.

[0018] The distribution part can comprise a distribution arrangement in the form of a switchgear arrangement.

[0019] The respective collection terminals can comprise a landing guide and a terminal body in the form of a framework, wherein the framework encircles the landing guide. By arranging the landing guide within the framework, one enables a compact installation of the plurality of collection terminals.

[0020] The collection cable can comprise a cable angle between the direction of the lower cable end and the direction of the upper cable end, wherein the cable angle is in the range of 40° to 90°, and wherein the collection cables curve in only one direction.

[0021] Letting the collection cables curve in only one direction, contrary to for instance an S-shaped cable, contributes to a small footprint of the subsea power distribution assembly.

[0022] The electric connection between the collection terminals and the distribution arrangement can advantageously be a jumperless connection.

[0023] By stating that the electric connection is jumperless is meant that there is no electric jumper or cable that constitute part of the connection between the respective collection terminals and the distribution arrangement.

[0024] In this manner, one obtains a subsea power distribution assembly which is less exposed to malfunction, as it contains less jumpers and subsea connectors.

[0025] There is also disclosed a subsea power distribution assembly comprising a high voltage distribution part with an elongated configuration having two longitudinal sides and two end sides. It further has a plurality of collection terminals and an export terminal connected to the distribution part with collection connectors and export connectors. These connectors are high voltage wet-mate connectors. The collection terminals and export terminal comprise a dry-mate connector part vertically below and connected with collection cables and export cables to the collection connectors and export connectors, respectively. Among the collection terminals and export terminal, a plurality is arranged along each respective longitudinal side and one or more is arranged at an end side. The collection connectors and the export connectors are connected and fixed to penetrators extending through one or more enclosure walls of a distribution arrangement, which is part of the distribution part. Moreover, the distribution part is arranged at a vertical level that is above the drymate connector parts.

[0026] Also disclosed herein is a subsea power distribution assembly comprising a distribution part with a distribution arrangement, a plurality of collection terminals and an export terminal connected to subsea cables with high-voltage dry-mate connectors. It further has collection connectors and export connectors, which are high-voltage wet-mate connectors, and which connect the collection terminals and export terminal to the distribution arrangement with a jumperless connection.

[0027] By stating that the collection and export connectors connect to the distribution arrangement with a jumperless connection, is meant that there is no jumper extending between the said connectors and the distribution arrangement.

[0028] The distribution arrangement can be located vertically above the dry-mate connectors. This facilitates curved cables between the dry-mate connectors and the wet-mate connectors, which allows for the disconnecting and connecting movements of the wet-mate connectors.

[0029] As will be discussed in the detailed example embodiment below, the wetmate connectors can advantageously connect in a fixed manner to penetrators supported by an enclosure wall of the distribution arrangement.

[0030] There is further disclosed a subsea power distribution assembly comprising collection connectors with a first connector part and a second connector part, wherein the collection connectors are high-voltage wet-mate connectors. There are export connectors with a first connector part and a second connector part, wherein the export connectors are high-voltage wet-mate connectors. Furthermore, there is a distribution part comprising a distribution arrangement, the first connector parts of the collection connectors and the first connection parts of the export connectors. A plurality of collection terminals comprises the second connector parts of the collection connectors. An export terminal comprises the second connector parts of the export connectors. Furthermore, the respective collection terminals comprise a collection terminal body and a connector support structure arranged on the collection terminal body. The connector support structure comprises the second connector parts, a drymate connector part, collection cables extending between the dry-mate connector part and the second connector parts. The connector support structure is pivotable with respect to the collection terminal body.

[0031] Advantageously, the connector support structure can be slidingly arranged on the collection terminal body. In this manner, it will be both sliding and pivoting with respect to the collection terminal body.

[0032] In some embodiments, the distribution part can be supported on a mudmat, wherein the mudmat comprises a groove, and wherein a portion of the collection cables are arranged in the groove when the collection connectors are in the connected state.

[0033] Furthermore, in some embodiments the collection cables can extend below the footprint of the collection terminal body when the collection terminal is in its installed state.

[0034] Also disclosed is a method of installing a collection terminal with a collection terminal body on a subsea power distribution assembly on the seabed, wherein the method comprises: at a surface installation, lowering the collection terminal through a moon pool of the surface installation while connected on a subsea cable, landing the collection terminal on the subsea power distribution assembly, and pivoting a connector support structure with respect to the collection terminal body.

[0035] This method makes it possible or at least facilitates moving the collection terminal through the moon pool. It will be understood that the pivoting movement can be performed after or before landing on the subsea power distribution assembly.

[0036] Also disclosed herein is a subsea power distribution assembly comprising collection connectors with a first connector part and a second connector part, wherein the collection connectors are high-voltage wet-mate connectors. There are export connectors with a first connector part and a second connector part, wherein the export connectors are high-voltage wet-mate connectors. Furthermore, a distribution part comprises a distribution arrangement, the first connector parts of the collection connectors and the first connection parts of the export connectors. A plurality of collection terminals comprises the second connector parts of the collection connectors. An export terminal comprises the second connector parts of the export connectors. The respective collection terminals comprise a connector support structure comprising a dry-mate connector part, the second connector parts, and collector cables extending between the dry-mate connector part and the second connector parts. The mutual positions of the second connector parts and the drymate connector part are fixed. Furthermore, there is a collection terminal body with a sliding engagement with the connector support structure.

[0037] In some embodiments, the collector cables can extend substantially horizontally between the dry-mate connector part and the second connector parts.

[0038] In some embodiments, the subsea power distribution assembly can further comprise a mudmat and the connector support structure can comprise a main body with a framework that extends beyond the horizontal extension of the mudmat.

[0039] In some embodiments, the connector support structure can extend backwards beyond the collection terminal body.

[0040] Also disclosed herein is a use of a subsea pipeline horizontal connection system as a collection terminal connected to the end of a subsea cable and installed on a subsea power distribution assembly.

[0041] Also disclosed is a subsea power distribution assembly comprising collection connectors with a first connector part and a second connector part, wherein the collection connectors are high-voltage wet-mate connectors, export connectors with a first connector part and a second connector part, wherein the export connectors are high-voltage wet-mate connectors, a distribution part comprising a distribution arrangement, the first connector parts of the collection connectors and the first connection parts of the export connectors, a plurality of collection terminals comprising the second connector parts of the collection connectors, and an export terminal comprising the second connector parts of the export connectors. The respective collection terminals comprise a main pipe and collection cables extending from a dry-mate connector part through the main pipe towards the second connector parts.

[0042] In some embodiments, the respective collection terminals further comprise a pipe split and collection cable pipes, wherein the collection cables extend from the dry-mate connector part, through the main pipe, pipe split and the respective collection cable pipes.

[0043] It shall be understood that the main pipe and the pipe split can be made as one single component.

[0044] Advantageously, the main pipe can extend with a horizontal orientation. In embodiments including the collection cable pipes, these can also advantageously extend in parallel and with a horizontal orientation.

[0045] Also disclosed is a subsea power distribution assembly comprising collection connectors with a first connector part and a second connector part, wherein the collection connectors are high-voltage wet-mate connectors, export connectors with a first connector part and a second connector part, wherein the export connectors are high-voltage wet-mate connectors, a distribution part comprising a distributionarrangement, the first connector parts of the collection connectors and the first connection parts of the export connectors, a plurality of collection terminals comprising the second connector parts of the collection connectors, an export terminal comprising the second connector parts of the export connectors. The respective collection terminals comprise a connector support structure comprising the second connector parts and vertical guide elements.

[0046] In some embodiments, the second connector parts are fixed to the connector support structure and vertically oriented.

[0047] In this manner, the second connector parts can engage with the oppositely arranged first connector parts when the collection terminal is landed. Hence, no further movement is needed to provide the engagement between the first and second connector parts.

[0048] The vertical guide elements can typically be vertically arranged guide posts or guide funnels.

[0049] In other embodiments the second connector parts are supported by a connector support structure which is movably attached to a collection terminal body.

[0050] There is further disclosed a subsea power distribution assembly comprising collection connectors with a first connector part and a second connector part, wherein the collection connectors are high-voltage wet-mate connectors, export connectors with a first connector part and a second connector part, wherein the export connectors are high-voltage wet-mate connectors, a distribution part comprising a distribution arrangement, the first connector parts of the collection connectors and the first connection parts of the export connectors, a plurality of collection terminals comprising the second connector parts of the collection connectors, an export terminal comprising the second connector parts of the export connectors. The subsea power distribution assembly further comprises an AUV docking station.

[0051] Advantageously, the AUV docking station can comprise an electric contact such that an AUV (autonomous underwater vehicle) can be charged when docked.

[0052] In some embodiments, the subsea power distribution assembly can further comprise a battery that is powered with electric power from the distribution arrangement, e.g. a switchgear arrangement. The battery can function as a UPS(uninterruptable power supply) for monitoring and operating the distribution arrangement.

[0053] The distribution arrangement can for instance be a switchgear arrangement, a transformer assembly, or other high-voltage subsea power distribution arrangement.Detailed description of the invention

[0054] While various features of the invention have been discussed in general terms above, a more detailed and non-limiting example of embodiment is presented in the following with reference to the drawings, in whichFig. 1 is a perspective view of a subsea power distribution assembly;Fig. 2 is a perspective view of a switchgear part that is part of the subsea power distribution assembly shown in Fig. 1 ;Fig. 3 is a side view of the subsea power distribution assembly shown in Fig. 1 ;Fig. 4 is a perspective view of a collection terminal, of which several are shown inFig. 1 and Fig. 3;Fig. 5 is a side view of the collection terminal shown in Fig. 4;Fig. 6, Fig. 7, and Fig. 7a are schematic side-views of collection terminals;Fig. 8 is a schematic view of a second connector part of a collection connector;Fig. 9 is a side-view illustrating a collection connector and its interface with an enclosure wall;Fig. 10 is a top view of a collection terminal;Fig. 11 is a top view of the subsea power distribution assembly shown in Fig. 1 ;Fig. 12 and Fig. 13 depict another embodiment of a collection terminal;Fig. 14 is a perspective view of still another embodiment of a collection terminal;Fig. 15 is a perspective view of the collection terminal shown in Fig. 14, during landing of the collection terminal on a subsea power distribution assembly;Fig. 16 and Fig. 17 depict the collection terminal shown in Fig. 14 and Fig. 15 with a side view and a perspective view;Fig. 18 shows an alternative embodiment of a collection terminal, based on a pipeline tie-in structure;Fig. 19 shows an alternative embodiment of a collection terminal, wherein the electric connection is made up with a vertical movement;Fig. 20 shows the collection terminal of Fig. 18 during landing on the subsea power distribution assembly; andFig. 21 is a schematic view of a subsea power distribution assembly with an AUV docking station.

[0055] Fig. 1 depicts a subsea power distribution assembly 1 . In the shown embodiment, the distribution assembly 1 is landed on a mudmat 3 on the seabed.

[0056] The distribution assembly 1 comprises a distribution part, which in the disclosed embodiment is a switchgear part 5. The switchgear part 5 comprises a distribution arrangement, which in the shown embodiment is a switchgear arrangement 7 with electric high-voltage switchgears (not shown). In other embodiments, the distribution arrangement could comprise a subsea transformer assembly or another high-voltage assembly where electric power is collected from several subsea cables and exported through one or more export cables.

[0057] The distribution assembly 1 further comprises a plurality of collection terminals 9.

[0058] In the shown embodiment, the switchgear part 5 has a longitudinal extension and a plurality of collection terminals 9 are arranged along each longitudinal side 5a of the switchgear part 5. In the embodiment of Fig. 1 , there is space for three collection terminals 9 at each longitudinal side 5a. At the most visible longitudinal side 5a of the switchgear part 5 in Fig. 1 , only two collection terminals 9 are shown for illustrational purpose.

[0059] Also shown in Fig. 1 , at one of the end sides 5b of the switchgear part 5, there is arranged an export terminal 11 .

[0060] A typical application of the distribution assembly 1 , is collection of electric power from offshore wind turbines (not shown) through the collection terminals 9, and export of this electric power through the export terminal 11 .

[0061] Fig. 2 is a perspective view of the switchgear part 5. It comprises a framework 13 with said longitudinal sides 5a and end sides 5b. To the framework 13 there is arranged guide funnels 15 for guiding the switchgear part 5 when being landed on the seabed (such as above the mud mat 3 shown in Fig. 1 ).

[0062] In the shown embodiment, the switchgear arrangement 7 is shown having one enclosure. However, in other embodiments, it could be in the form of a plurality of separate enclosures.

[0063] The switchgear arrangement 7 thus comprise one or more enclosures with enclosure walls 7a.

[0064] To the enclosure walls 7a there is arranged a plurality of first connector parts 20a of collection connectors 20. The collection connectors 20 are shown in Fig. 1 , connecting the collection terminals 9 to the switchgear part 5. Since the subsea switchgear assembly 1 shown is a three-phase system, the collection connectors 20 associated with the respective collection terminals 9 are grouped in three.

[0065] A connector plate 17 connects to three first connector parts 20a. The connector plate 17 has a stroke tool interface 17a for engagement with a stroke tool (not shown).

[0066] At one end side 5b of the switchgear part 5, three first connection parts 30a of respective three export connectors 30 is shown. The export connectors 30 are indicated in Fig. 1 , where the second connection parts 30b also are shown.

[0067] Also shown in Fig. 2 are pressure compensators 19 configured to balance the pressure inside the enclosure(s) of the switchgear arrangement 7. A pair of subsea control modules 21 are also arranged.

[0068] Fig. 3 depicts the subsea power distribution assembly 1 shown in Fig. 1 with a side view. The switchgear part 5 is supported from below on a support structure 23. In this manner, the switchgear arrangement 7 is elevated. In the shown embodiment, the support structure 23 is interposed between the mud mat 3 and the switchgear part 5.

[0069] The support structure 23 comprises a framework. Notably, the support structure 23 does not comprise movable parts or any electric components such as cables or connectors, as it is merely provided for supporting the switchgear part 5 at an elevated position.

[0070] Fig. 4 and Fig. 5 depict one collection terminal 9. It comprises a collection terminal body 25, which in the shown embodiment comprises a framework 25a.

[0071] The second connector parts 20b of the collection connectors 20 are supported with a compliant mount that allows some misalignment between the second connector parts 20b and the first connector parts 20a. Arrangements for allowing such misalignment are known in the art and will not be discussed in further detail herein.

[0072] At an upper portion of the collection terminal body 25, there is arranged three second connector parts 20b of a collection connector 20. As the skilled reader will appreciate, each second connector part 20b are configured to mate with a respective first connector part 20a of the collection connector 20. Hence, in the shown embodiment, each collection terminal 9 comprises three second connector parts 20 of the collection connector 20.

[0073] Corresponding to the said first connector parts 20a, the second connector parts 20b of the collection connector 20 are arranged with a connector plate 27. Moreover, the connector plate 27 comprises a stroke tool interface 27a. The first and second connector parts 20a, 20b of the collection connector 20 can thus be engaged and disengaged (i.e. connected and disconnected) by using a stroke tool (not shown). Such a stroke tool can for instance be operated by an ROV (remotely operated vehicle).

[0074] Referring to Fig. 5, the collection terminal 9 comprises three collection cables 29. Each collection cable 29 is connected to a dry-mate connector part 31 that is arranged at a lower portion of the collection terminal 9. The dry-mate connector part 31 is part of a dry-mate connector (not shown) that connects a subsea cable (not shown) to the collection cables 29.

[0075] Hence, when the collection terminal 9 shall be installed on the seabed, the dry-mate connector is made up at a surface (dry) location, by mating the dry-mateconnector part 31 with its dry-mate counterpart, which is arranged at the end of the subsea cable. The collection terminal 9 is then lowered towards the seabed and landed adjacent the switchgear part 5, as shown in Fig. 1 .

[0076] Still referring to Fig. 5, each collection cable 29 extends from the dry-mate connection part 31 to a second connector part 20b of the collection connector 20. The collection cable 29 thus constitutes the electric connection between the (not shown) subsea cable and the switchgear part 5, when in an installed state.

[0077] Fig. 6 is a schematic illustration of the collection terminal 9. The first connector part 20a of the collection connector 20 is also indicated. In this embodiment, the collection terminal body 25 has a square-shaped overall form. The collection cable 29, of which only one is shown for illustrational purpose, has a lower cable end 29a connected to the dry-mate connection part 31 , and an upper cable end 29b that connects to the second connector part 20b of the collection connector 20. Between the lower and upper cable ends 29a, 29b, the collection cable 29 has a curved portion 29c. The lower cable end 29a has a substantially horizontal orientation and the upper cable end 29b has a substantially vertical orientation. Consequently, there is a cable angle a of 90° between them.

[0078] A similar schematic illustration of the collection terminal 9 is shown in Fig. 7. In this example, the lower cable end 29a has a substantially horizontal orientation, while the upper cable end 29b has an inclined orientation. As in the example shown in Fig. 6, the collection cable 29 has a curved portion 29c between the upper and lower cable ends 29a, 29b. The cable angle a is less than 90°.

[0079] Preferably, the cable angle a is between 70° and 100°.

[0080] While the dry-mate connector part 31 shown in Fig. 6 and Fig. 7 (and in previously discussed figures) and the lower cable end 29a have a horizontal orientation, they could have an inclined orientation.

[0081] Such an embodiment is shown in Fig. 7a, wherein the lower cable end 29a connects to the dry-mate connector 31 with an inclined angle. Due to the inclination of the dry-mate connector 31 , the subsea cable 39 will have a bent portion.

[0082] Fig. 8 is a schematic illustration of the second connector part 20b of the collection connector 20. The second connector part 20b of the collection connector20 has a cable body 201 to which the upper cable end 29b connects and a connector body 203 configured to connect with the first connector part 20a of the collection connector 20. Indicated with a dashed line is a connection axis A. When the second connector part 20b of the collection connector 20 is moved for connection or disconnection, it is moved along the connection axis A.

[0083] In the embodiment shown in Fig. 8, the connector body 203 has a horizontal orientation. In other embodiments, the connector body 203 can have an inclined or non-vertical orientation.

[0084] The cable body 201 has an axial extension along a cable axis B that is parallel with the upper cable end 29b. As indicated in Fig. 8, there is a deviation angle [3 between the connection axis A and the deviation axis B.

[0085] In the embodiment shown in Fig. 6, the deviation angle [3 is 90°. In the embodiment shown in Fig. 7, the deviation angle [3 is less than 90°.

[0086] Advantageously, the deviation angle [3 is substantially 90°, or in the range of 60° to 90°.

[0087] As shown with the schematic views of Fig. 7 and Fig. 8, the collection cables 29 have a J -like shape, wherein the orientation of the lower and upper cable ends 20a, 29b are considerably different.

[0088] Advantageously, the collection cables 29 curve in only one direction. This is contrary to some solutions of the prior art, such as the previously mentioned S- shape, where the cable curves in two opposite directions.

[0089] Fig. 9 illustrates the first and second connector parts 20a, 20b of the collection connector 20 when in a non-mated position. The first connector part 20a is rigidly connected to a penetrator 37 that extends through the enclosure wall 7a of the switchgear arrangement 7.

[0090] As a result of the configuration shown in Fig. 10, wherein the first connector part 20a of the collection connector 20 is rigidly attached to the penetrator 37, one avoids the use of an additional cable between the said first connector part 20a and the penetrator 37.

[0091] Fig. 10 depicts the collection terminal 9 with a top view. As discussed above, the collection terminal body 25 has a framework 25a. The collection terminal 9 comprises vertically extending landing guides arranged within the framework 25a. In the shown embodiment, the landing guides are in the form of guide funnels 33. By arranging the guide funnels 33 within the framework 25a, it is possible to arrange the collection terminals 9 close to each other (cf. Fig. 1 and Fig. 3). In this manner, one reduces the footprint of the subsea power distribution assembly 1 .

[0092] Four lifting eyes 35 are attached to the framework 25a for connection to a lifting harness or similar lifting equipment.

[0093] Referring again to Fig. 1 and Fig. 3, as the skilled reader will appreciate, the export terminal 1 1 has a similar configuration as the collection terminal 9. The export terminal 1 1 has an export terminal body 125, a dry-mate connector part 131 . The drymate connector part 131 connects to a not shown export cable. In some embodiments, the export terminal 1 1 can comprise export connectors 30 that are identical to the collection connectors 20. Thus, the export connectors 30 can have first parts 30a and second parts 30b that are similar or identical to the first and second parts 20a, 20b of the collection connectors 20. As indicated in Fig. 3, the drymate connector part 131 connects to the export connectors 30 with export cables 129.

[0094] Fig. 1 1 illustrates the layout or configuration of the subsea power distribution assembly 1 shown in Fig. 1 with a top view. Three collection terminals 9 are arranged along one of the longitudinal sides 5a of the switchgear part 5, while two collection terminals 9 are arranged along the opposite longitudinal side 5a. While only two collection terminals 9 are shown along that longitudinal side 5a, there is space for three collection terminals 9, such that a total of six collection terminals 9 can be landed next to and connect to the switchgear part 5. In other embodiments, there could be space for two or more than three collection terminals 9 on each side.

[0095] The export terminal 1 1 is arranged at one of the end sides 5b of the switchgear part 5.

[0096] The top view of Fig. 1 1 illustrates well how the collection terminals 9 are arranged close together and close to the switchgear part 5 to make a compact overall configuration.

[0097] In the situation shown in Fig. 11 , the collection connectors 20 and the export connectors 30 are all shown in a landed and non-connected state. In this state it is possible to retrieve or lift the switchgear part 5 to the surface, such as for maintenance.

[0098] In the shown embodiments, the export terminal 11 is arranged at one of the end sides 5b of the switchgear part 5. However, it could also be possible to arrange the export terminal 11 at one of the longitudinal sides, adjacent one or two of the collection terminals 9. It would then be space available for a collection terminal at an end side 5b.

[0099] An alternative embodiment of the collection terminal 9 is depicted in Fig. 12 and Fig. 13. It shall be understood that this embodiment also could apply for the export terminal 11 . This collection terminal 9 comprises a pivoting connector support structure 41 . The connector support structure 41 is pivotable with respect to the framework 25a. To provide this function, a not described hinge arrangement connects the connector support structure 41 to the framework 25a.

[0100] As appears form Fig. 12 and Fig. 13, when in a landed state above the mudmat 3, the connector support structure 41 can slide towards the first connector parts 20a (not shown in Fig. 12 and Fig. 13). The sliding movement can be obtained for instance with a stroke tool.

[0101] A landed and not-connected state is shown in Fig. 12. The connector support structure 41 is in a pivoted state. The collection cables 29, of which only one is shown in Fig. 12, extends between the dry-mate connector part 31 and the first connector parts 20a. The collection cables 29 are free to move during the pivoting movement of the connector support structure 41 . They also allow the sliding movement.

[0102] Notably, when in the state shown in Fig. 12, the collection cables 29 are within the footprint of the framework 25a and connector support structure 41 during landing of the collection terminal 9.

[0103] Fig. 13 depicts the connector support structure 41 in its installed state. In this state, the connector support structure 41 has been pivoted and slid forwards to engage the second connector parts 20b with the first connector parts 20a.

[0104] As a result of the pivoting movement, a portion of the collection cables 29 move downwards. To enable this, the mudmat 3 comprises a groove 3a that receives a portion of the collection cables 29. By providing the groove 3a, the collection terminal 9 can have a relatively short height, while still enable the pivoting movement of the connector support structure 41 .

[0105] Notably, when in the installed state, shown in Fig. 13, a portion of the collection cables 29 extend below the footprint of the collection terminal body 25 (here in the form of the framework 25a).

[0106] As can be appreciated when comparing Fig. 12 and Fig. 13, when the connector support structure 41 has been pivoted to the installed state, the overall height of the collection terminal 9 increases. This makes it easier or makes it possible to convey the collection terminal 9 through a moon pool of a surface installation (not shown). Hence, the collection terminal 9 can be conveyed through the moon pool when the connector support structure 41 is not pivoted, i.e. as shown in Fig. 12. Once conveyed through the moon pool, the connector support structure 41 can be moved to its non-pivoted state, typically after landing of the collection terminal 9.

[0107] Fig. 14 depicts a further embodiment of a collection terminal 9. While Fig. 14 illustrates a collection terminal 9, it could also relate to an export terminal 11 .

[0108] The connector support structure 41 supports the second connector parts 20b and comprises a main body 41 a. In the shown embodiment, the main body 41 a is in the form of a framework.

[0109] The connector support structure 41 is slidingly connected to the collection terminal body 25, which in the shown embodiment comprises a framework 25a. To provide the sliding movement, a stroke tool 101 (Fig. 15) engages a stroke tool interface 17a (Fig. 14). The collection terminal body 25 comprises a slide rail 25b, along which the connector support structure 41 can slide.

[0110] Fig. 15 depicts the collection terminal of Fig. 14 in a landed state. It has landed on a mudmat 3, adjacent a distribution part 5 comprising a distribution arrangement 7. The distribution part 5 and the distribution arrangement 7 is not visible in Fig. 15 but are shown in Fig. 16 and Fig. 17, which depict the same embodiment.[0011 1 ] In the situation shown in Fig. 15, the connector support structure 41 has been slid forward such that the second connector parts 20b are in engagement with the oppositely arranged first connector parts 20a.

[0112] Fig. 16 and Fig. 17 show the same embodiment, with collection terminals 9 and an export terminal 11 in a landed state.

[0113] As is clear from comparing for instance Fig. 3 and Fig. 16, the embodiment shown in Fig. 14 to Fig. 17 has a lower height than the embodiment shown in Fig. 3.

[0114] As also appears from Fig. 16, indicated with the two dashed lines, the connector support structure 41 can extend horizontally beyond the extension of the mudmat 3.

[0115] In this embodiment, the collection cables 29 extend substantially horizontally between the dry-mate connector part 31 and the second connector parts 20b. Furthermore, the collection cables 29 comprises a curvature, but will not move with respect to the connector support structure 41 when the second connector parts 20b engage the first connector parts 20a.

[0116] As appears from fig. 14 and Fig. 16, the horizontal extension of the connector support structure 41 is larger than the horizontal extension of the collection terminal body 25.

[0117] When the connector support structure 41 slides forwards on the collection terminal body 25, the subsea cable 39 will flex to allow the movement. The subsea cable 39 is typically laid with a bend (not shown) near the collection terminal 9 to allow the sliding movement of the connector support structure 41 . The bend can have an S-shape.

[0118] As shown with the export terminal 11 in Fig. 16, a portion of the connector support structure 41 (shown with the corresponding part of the export terminal 1 1 in Fig. 16) can extend beyond the extension of the mudmat 3.

[0119] While the connector support structure 41 in the shown embodiment has a substantially horizontal extension, such that the subsea cable 39 connects to the collection terminal 9 (or export terminal 1 1 ) with a horizontal orientation, the connector support structure 41 could in other embodiments be inclined. In such embodiments, the end of the subsea cable 39 that connects to the connector supportstructure 41 can incline upwards. I.e. the connector support structure 41 can incline downwards toward the seabed.

[0120] Fig. 18 depicts another embodiment. In this embodiment, the subsea cable 39 is terminated at a horizontal connection system (HCS) 301 for a subsea pipeline. Details of such an HCS can be found in publications WO2011043671 A1 and WO201 1043672 A1 . Thus, the collection terminal 9 comprises an HCS 301 . The skilled person will appreciate that the HCS 301 also could be used as an export terminal 11 .

[0121] It is lowered and landed onto the subsea power distribution assembly 1 (e.g. as shown in Fig. 1 and Fig. 17) with a landing tool 401. Moreover, a stroke tool interface 17a is arranged for moving the second connector parts 20b of the collection connectors 20 into engagement with the first connector parts 20a.

[0122] By using the HCS 301 , the power cables 39a of the subsea cable 39 can be protected inside rigid steel pipes of the HCS 301 . The HCS 301 thus provides a collection terminal and / or an export terminal which is lean, robust, and based on proven technology.

[0123] Furthermore, as appears from Fig. 18, the HCS 301 compares to the connector support structures 41 discussed for various embodiments above, as it carries the second connector parts 20b. Notably, in the embodiment shown in Fig.18, the HCS 301 does is not slidingly connected to a collection terminal body 25. It can be landed and installed without the collection terminal body 25 due to the landing tool 401 .

[0124] As the skilled person will appreciate, and as is taught by the said publications WO201 1043671 A1 and WO2011043672 A1 , additional landing and guiding means can be temporarily installed on the subsea power distribution assembly 1 for landing and alignment purposes. However, after landing, such equipment can be removed and re-used for another collection terminal 9. This saves use of material and further provides a compact collection terminal 9 (and export terminal 11 ).

[0125] Still referring to Fig. 18, the HCS 301 comprises a pipe split 305, where a main pipe 307 is split into three collection cable pipes 309. The collection cables 29 thus extend from the dry-mate connector part 31 , through the pipe split 305 and intothe respective collection cable pipes 309. With an electric three-phase system, there will typically be three collection cable pipes 309.

[0126] Typically, the main pipe 307, the pipe split 305, and the collection cable pipes 309 can be manufactured as one component (such as by welding). Once the collection cables 29 are connected to the dry-mate connector part 31 , they can be inserted through the pipes and the main pipe 307 can be attached to the dry-mate connector part 31 .

[0127] Fig. 19 and Fig. 20 depict another embodiment. In this embodiment, the collection terminal 9 (and the export terminal 11 ) comprises second connector parts 20b that are configured to engage with the first connector parts 20a when moved vertically. In particular, the second connector parts 20b moves into engagement with the first connector parts 20a when the connector support structure 41 lands on the the subsea power distribution assembly 1 .

[0128] This embodiment does thus not need a stroke tool, since the engaging movement force is provided by gravity.

[0129] When landing the connector support structure 41 , the second connector parts 20b can connect directly to the distribution arrangement, which in the shown embodiment is a switchgear arrangement 7 with electric high-voltage switchgears (not shown). The electric connection and disconnection can be made with a torque tool, for instance mounted on a remotely operated vehicle (ROV) (not shown).

[0130] The connector support structure 41 comprises vertical guide elements, which in the shown embodiment are in the form of guide funnels 41 b that engage with guide poles 3b (Fig. 20) when landing.

[0131] In another embodiment, similar but somewhat differing from the embodiment discussed with reference to Fig. 19 and Fig. 20, the second connector parts 20b can be supported on a connector support structure 41 that is vertically movable with respect to a collection termination body 25.

[0132] Fig. 21 depicts a schematic perspective view of a subsea power distribution assembly 1 , such as discussed above, which is provided with an AUV docking station 500 (AUV - autonomous underwater vehicle). The AUV docking station 500 is configured to receive an AUV 600. In the shown embodiment, the AUV dockingstation 500 is arranged on top of the distribution arrangement, which in the shown embodiment is a switchgear arrangement 7 with electric high-voltage switchgears (not shown). In other embodiments, the AUV docking station 500 could be arranged on one of the sides of the distribution arrangement.

[0133] Advantageously, the subsea power distribution assembly 1 can comprise a battery 51 . The battery 51 is schematically shown in Fig. 21 on top of the switchgear arrangement 7 but would in a real-life embodiment typically be arranged in a more hidden position. The battery 51 can advantageously be powered with power associated with the distribution arrangement, such as the shown switchgear arrangement 7. In embodiments where the switchgear arrangement 7 is installed to distribute electric power from offshore wind turbines (not shown), the battery 51 could thus be powered and charged with power from a wind turbine.

[0134] The battery 51 provides back-up power for operation and monitoring of the distribution arrangement. Moreover, in the embodiment shown in Fig. 21 , the battery can power the AUV 600 when docked in the AUV docking station 500.

[0135] In some embodiments, the distribution arrangement, e.g. the switchgear arrangement 7, can be installed with structural elements and electrical connections that are prepared for later installation of the AUV docking station 500.

[0136] Furthermore, in some embodiments, a plurality of subsea power distribution assemblies 1 , such as the ones discussed above, can be installed on the seabed with mutual distance(s). By providing these with respective AUV docking stations 500, the range of the AUV 600 can be increased, since it can dock at the needed places for charging.

Claims

Claims1 . A subsea power distribution assembly (1 ) comprising- collection connectors (20) with a first connector part (20a) and a second connector part (20b), wherein the collection connectors (20) are high-voltage wet-mate connectors;- export connectors (30) with a first connector part (30a) and a second connector part (30b), wherein the export connectors (30) are high-voltage wet-mate connectors;- a distribution part (5) comprising a distribution arrangement (7), the first connector parts (20a) of the collection connectors (20) and the first connection parts (30a) of the export connectors (30);- a plurality of collection terminals (9) comprising the second connector parts (20b) of the collection connectors (20);- an export terminal (11 ) comprising the second connector parts (30b) of the export connectors (30); wherein the respective collection terminals (9) comprise- a dry-mate connector part (31 );- a collection cable (29) extending from a lower cable end (29a) connected to the dry-mate connector part (31 ) to an upper cable end (29b) connected to the second connector part (20b) of the collection connector (20); wherein the lower cable end (29a) has a horizontal or inclined non-vertical orientation, wherein the second connector part (20b) of the collection connector (20) has a connector body (203) with a horizontal or inclined non-vertical orientation, and wherein the upper cable end (29b) has a vertical or inclined non-horizontal orientation.

2. A subsea power distribution assembly (1 ) according to claim 1 , wherein the collection cable (29) comprises a cable angle (a) between the direction of the lower cable end (29a) and the direction of the upper cable end (29b), wherein the cable angle (a) is in the range between 40° and 100°.

3. A subsea power distribution assembly (1 ) according to claim 1 or claim 2,wherein the second connector part (20b) of the collector connector (20) comprises- a cable body (201 ) from which the upper cable end (29b) extends along a cable axis (B);- the connector body (203) configured to mate with the first connector part (20a) of the collector connector (20) by movement along a connection axis (A); wherein the said second connector part (20b) comprises a deviation angle ([3) between the connection axis (A) and the deviation axis (B) which is in the range of 60° to 90°.

4. A subsea power distribution assembly (1 ) according to one of the preceding claims, wherein the distribution part (5) is supported at an elevation above the dry-mate connector parts (31 ) of the respective collection terminals (9).

5. A subsea power distribution assembly (1 ) according to one of the preceding claims, wherein the vertical level of the collection connectors (20) coincides with the vertical extension of the distribution arrangement (7).

6. A subsea power distribution assembly (1 ) according to one of the preceding claims, wherein the distribution part (5) comprises a distribution arrangement (7) with an enclosure wall (7a), wherein the first connection parts (20a) of the collection connectors (20) are rigidly connected to penetrators (37) that extend through the enclosure wall (7a).

7. A subsea power distribution assembly (1 ) according to one of the preceding claims, wherein the distribution part (5) comprises a distribution arrangement (7) in the form of a switchgear arrangement.

8. A subsea power distribution assembly (1 ) according to any one of the preceding claims, wherein the respective collection terminals (9) comprise a landing guide (33) and a collection terminal body (25) in the form of a framework (25a), wherein the framework (25a) encircles the landing guide (33).

9. A subsea power distribution assembly (1 ) according to any one of claims 1 and claims 3 to 8, wherein the collection cable (29) comprises a cable angle (a) between the direction of the lower cable end (29a) and the direction of the upper cable end (29b), wherein the cable angle (a) is in the range of 40° to 90°, wherein the collection cables (29) curve in only one direction.

10. A subsea power distribution assembly (1 ) according to one of the preceding claims, wherein the electric connection between the collection terminals (9) and the distribution arrangement (7) is a jumperless connection.11 . A subsea power distribution assembly (1 ) comprising- a high voltage distribution part (5) with an elongated configuration having two longitudinal sides (5a) and two end sides (5b);- a plurality of collection terminals (9) and an export terminal (11 ) connected to the distribution part (5) with collection connectors (20) and export connectors (30), which are high voltage wet-mate connectors, wherein the collection terminals (9) and export terminal (11 ) comprise a dry-mate connector part (31 , 131 ) vertically below and connected with collection cables (29) and export cables (129) to the collection connectors (20) and export connectors (30), respectively; wherein among the collection terminals (9) and export terminal (11 ), a plurality is arranged along each respective longitudinal side (5a) and one or more is arranged at an end side (5b); wherein the collection connectors (20) and the export connectors (30) are connected and fixed to penetrators (37) extending through one or more enclosure walls (7a) of a distribution arrangement (7) being part of the distribution part (5), and wherein the distribution part (5) is arranged at a vertical level that is above the dry-mate connector parts (31 , 131 ).

12. A subsea power distribution assembly (1 ) comprising- a distribution part (5) with a distribution arrangement (7);- a plurality of collection terminals (9) and an export terminal (11 ) connected to subsea cables (39) with high-voltage dry-mate connectors (31 , 131 );- collection connectors (20) and export connectors (30), being high-voltagewet-mate connectors, connecting the collection terminals (9) and export terminal (11 ) to the distribution arrangement (7) with a jumperless connection.

13. A subsea power distribution assembly (1 ) comprising- collection connectors (20) with a first connector part (20a) and a second connector part (20b), wherein the collection connectors (20) are high-voltage wet-mate connectors;- export connectors (30) with a first connector part (30a) and a second connector part (30b), wherein the export connectors (30) are high-voltage wet-mate connectors;- a distribution part (5) comprising a distribution arrangement (7), the first connector parts (20a) of the collection connectors (20) and the first connection parts (30a) of the export connectors (30);- a plurality of collection terminals (9) comprising the second connector parts (20b) of the collection connectors (20);- an export terminal (11 ) comprising the second connector parts (30b) of the export connectors (30); wherein the respective collection terminals (9) comprise- a collection terminal body (25) and a connector support structure (41 ) arranged on the collection terminal body (25), wherein the connector support structure (41 ) comprises the second connector parts (20b);- a dry-mate connector part (31 );- collection cables (29) extending between the dry-mate connector part (31 ) and the second connector parts (20b); wherein the connector support structure (41 ) is pivotable with respect to the collection terminal body (25).

14. A subsea power distribution assembly (1 ) according to claim 13, wherein the distribution part (5) is supported on a mudmat (3), wherein the mudmat (3) comprises a groove (3a), and wherein a portion of the collection cables (29) are arranged in the groove (3a) when the collection connectors (20) are in the connected state.

15. A subsea power distribution assembly (1 ) according to claim 13 or claim 14, wherein the collection cables (29) extend below the footprint of the collection terminal body (25) when the collection terminal (9) is in its installed state.

16. A method of installing a collection terminal (9) with a collection terminal body (25) on a subsea power distribution assembly (1 ) on the seabed, wherein the method comprises- at a surface installation, lowering the collection terminal (9) through a moon pool of the surface installation while connected on a subsea cable (39);- landing the collection terminal (9) on the subsea power distribution assembly (1 );- pivoting a connector support structure (41 ) with respect to the collection terminal body (25).

17. A subsea power distribution assembly (1 ) comprising- collection connectors (20) with a first connector part (20a) and a second connector part (20b), wherein the collection connectors (20) are high-voltage wet-mate connectors;- export connectors (30) with a first connector part (30a) and a second connector part (30b), wherein the export connectors (30) are high-voltage wet-mate connectors;- a distribution part (5) comprising a distribution arrangement (7), the first connector parts (20a) of the collection connectors (20) and the first connection parts (30a) of the export connectors (30);- a plurality of collection terminals (9) comprising the second connector parts (20b) of the collection connectors (20);- an export terminal (11 ) comprising the second connector parts (30b) of the export connectors (30); wherein the respective collection terminals (9) comprise- a connector support structure (41 ) comprising a dry-mate connector part (31 ), the second connector parts (20b), and collector cables (29) extending between the dry-mate connector part (31 ) and the second connector parts (20b), wherein the mutual positions of the second connector parts (20b) andthe dry-mate connector part (31 ) are fixed;- a collection terminal body (25) with a sliding engagement (25b) with the connector support structure (41 ).

18. A subsea power distribution assembly (1 ) according to claim 17, wherein the collector cables (29) extend substantially horizontally between the dry-mate connector part (31) and the second connector parts (20b).

19. A subsea power distribution assembly (1 ) according to claim 17 or claim 18, further comprising a mudmat (3) and wherein the connector support structure (41 ) comprises a main body (41a) with a framework that extends beyond the horizontal extension of the mudmat (3).

20. A subsea power distribution assembly (1 ) according to claim 17, claim 18, or claim 19, wherein the connector support structure (41) extends backwards beyond the collection terminal body (25).

21. Use of a subsea pipeline horizontal connection system (301 ) as a collection terminal (9) connected to the end of a subsea cable (39) and installed on a subsea power distribution assembly (1 ).

22. A subsea power distribution assembly (1 ) comprising- collection connectors (20) with a first connector part (20a) and a second connector part (20b), wherein the collection connectors (20) are high-voltage wet-mate connectors;- export connectors (30) with a first connector part (30a) and a second connector part (30b), wherein the export connectors (30) are high-voltage wet-mate connectors;- a distribution part (5) comprising a distribution arrangement (7), the first connector parts (20a) of the collection connectors (20) and the first connection parts (30a) of the export connectors (30);- a plurality of collection terminals (9) comprising the second connector parts (20b) of the collection connectors (20);- an export terminal (11 ) comprising the second connector parts (30b) of theexport connectors (30); wherein the respective collection terminals (9) comprise- a main pipe (307) and collection cables (29) extending from a dry-mate connector part (31 ) through the main pipe (307) towards the second connector parts (20b).

23. A subsea power distribution assembly (1 ) according to claim 22, wherein the respective collection terminals further comprise a pipe split (305), and collection cable pipes (309), and wherein the collection cables (29) extend from the drymate connector part (31 ), through the main pipe (307), pipe split (305) and the respective collection cable pipes (309).

24. A subsea power distribution assembly (1 ) comprising- collection connectors (20) with a first connector part (20a) and a second connector part (20b), wherein the collection connectors (20) are high-voltage wet-mate connectors;- export connectors (30) with a first connector part (30a) and a second connector part (30b), wherein the export connectors (30) are high-voltage wet-mate connectors;- a distribution part (5) comprising a distribution arrangement (7), the first connector parts (20a) of the collection connectors (20) and the first connection parts (30a) of the export connectors (30);- a plurality of collection terminals (9) comprising the second connector parts (20b) of the collection connectors (20);- an export terminal (11 ) comprising the second connector parts (30b) of the export connectors (30); wherein the respective collection terminals (9) comprise- a connector support structure (41 ) comprising the second connector parts (20b);- vertical guide elements (41 b).

25. A subsea power distribution assembly (1 ) according to claim 24, wherein the second connector parts (20a) are fixed to the connector support structure (41 ) and vertically oriented.

26. A subsea power distribution assembly (1 ) according to claim 24, wherein the second connector parts (20b) are supported by a connector support structure (41 ) which is movably attached to a collection terminal body (25).

27. A subsea power distribution assembly (1 ) comprising- collection connectors (20) with a first connector part (20a) and a second connector part (20b), wherein the collection connectors (20) are high-voltage wet-mate connectors;- export connectors (30) with a first connector part (30a) and a second connector part (30b), wherein the export connectors (30) are high-voltage wet-mate connectors;- a distribution part (5) comprising a distribution arrangement (7), the first connector parts (20a) of the collection connectors (20) and the first connection parts (30a) of the export connectors (30);- a plurality of collection terminals (9) comprising the second connector parts (20b) of the collection connectors (20);- an export terminal (11 ) comprising the second connector parts (30b) of the export connectors (30); wherein the subsea power distribution assembly (1 ) further comprises an AUV docking station (500).

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