This application claims the benefit of priority from European Patent Application No. 22 307 035.0, filed on Dec. 23, 2022, the entirety of which is incorporated by reference.
The present invention relates to a connector for a high voltage cable.
There are several low-maintenance alternatives for connecting low voltage cables (up to 42 kV) and branching off from a single cable core into multiple cores with minimal space requirement. Such connections have also been realized by means of a factory joint approach with vulcanized insulation layers. These approaches can be very challenging to scale to higher voltage levels.
U.S. Pat. No. 6,227,908 B1 discloses electrical interconnection arrangements provided for connecting together two pieces of electrical equipment. A first connection component includes a first elongate conductive member, which in use is at a relatively high voltage, enclosed within insulating material. A portion of the first conductive member protrudes at one end beyond an end surface of the insulating material. The other end of the first member is arranged for electrical connection with one of the pieces of electrical equipment. One end of the first conductive member has an enlarged radiused region within the insulating material adjacent the protruding portion to provide electrical stress relief at the exposed surface of the insulating material. A second connection component includes a second elongate conductive member enclosed within insulating material which has a socket exposed at an end surface thereof for receiving the protruding end of the first conductive member. The other end of the second member is arranged for electrical connection with the other of the pieces of electrical equipment. A respective conductive layer extends over the surface of the insulating material of each connection component at one end and extends there along towards another end to provide electrical screening, each conductive layer terminating in respective first and second connection portions.
For higher voltage levels, today's solutions require the use of a full gas insulated switchgear (GIS) system to branch cable cores, which is a large assembly and typically not maintenance free.
One objective of the invention is to increase the efficiency of making connections for high voltage cables.
One objective of the invention is to increase the reliability of the joint between the connection and the cable.
The present invention relates to a connector for a high voltage cable, comprising: a metal conductor comprising a first elongated conductor element having a first end, a second end and an intermediate section between the first end and the second end;
As used herein, the term “high voltage cable” is referring to a cable with a nominal voltage rating of 52 kV or more. Typically, voltages in the interval between 52 kV to 245 kV are referred to as high voltage within this area of technology, while the interval between 245 kV to 800 kV is referred to as extra high voltage.
In one aspect, the insulating plastic materials comprise thermoplastics or thermosetting polymers.
In one aspect, the insulation plastic material comprises epoxy, or polyethylene, cross-linked polyethylene, or a thermoplastic polymer.
In one aspect, the connector is placed in a watertight housing.
In one aspect, the connector is a termination connector for a single cable section.
In one aspect, the metal conductor comprises:
In one aspect, the sphere of the spheroid-shaped conductor element is connected to the metal conductor by welding or bolting.
In one aspect, the metal conductor comprises a second elongated conductor element having a first end, a second end and an intermediate section between the first end and the second end;
In one aspect, the two elongated conductor elements are separate elements connected to each other by welding or bolting.
In one aspect, the spheroid-shaped conductor element is connected between the second end of the first elongated conductor element and the second end of the second elongated conductor element.
In one aspect, the metal conductor comprises a third elongated conductor element having a first end, a second end and an intermediate section between the first end and the second end;
In one aspect, the three elongated conductor elements are separate elements connected to each other by welding or bolting.
In one aspect, the second end of the third elongated conductor element is connected to the spheroid-shaped conductor element.
In one aspect, the first, second and third elongated conductor elements are forming a T-shaped structure or a Y-shaped structure.
In one aspect, the first, second and third elongated conductor elements are located in one common plane.
In one aspect, the intermediate sections of the first and second elongated conductor elements are located in a first plane, wherein the first end of the third elongated conductor element is located in a plane different from the first plane.
In one aspect, the metal conductor comprises:
In one aspect, the first and second elongated conductor elements together with the first joining element are forming a U-shaped structure.
In one aspect, the metal conductor comprises a second elongated joining element; wherein the second end of the third elongated conductor element is connected to the second end of the second elongated conductor element via the second elongated joining element;
In one aspect, the first, second and third elongated conductor elements together with the first and second elongated joining elements are forming an E-shaped structure.
In one aspect, the metal conductor is made as one single metal body.
In one aspect, the one single metal body may be machined from one metal piece, it may be made by an additive manufacturing process, etc.
In one aspect, the metal conductor is made from non-ferrous metals such as aluminium or copper.
In one aspect, a transition area between the second ends of the first and second elongated conductor elements is rounded.
In one aspect, the transition area is rounded with a radius Rcp. The radius Rcp will depend on the voltage level of the electrical system in which the connector is used.
According to the above, the electric field in the connector is distributed uniformly.
In one aspect, the connector is a joining element for joining at least two cable sections.
Initially, it is referred to
The connector 1 further comprises an insulating layer 21 moulded as one single body onto the second end 12b and the intermediate section 12c of the first elongated conductor element 12. In this way, the first end 12a is protruding from the insulating layer 21 with a distance referred to as a first insulator distance DI1.
The connector 1 further comprises a semiconductive layer 31 provided outside of the insulating layer 21. The semiconductive layer 31 is provided at a distance referred to as a first semiconductor distance DS1 from the first end 12a of the first elongated conductor element 12.
As shown in
In
Due to the distances DI1, DS1, it is easy to connect the connector 1 to an end of a high voltage cable, either by a joining process or by using a slip-on joint.
It is now referred to
In
It should be noted that the insulating layer 21 is moulded as one single body onto the spheroid-shaped conductor element 19, the second end 12b and the intermediate section 12c of the elongated conductor element 12 in similar way as for the embodiment of
The first end 12a and the intermediate section 12c have a circular cross section with a diameter adapted to the diameter of the cable the connector 1 is being connected to. The thickness of the insulating layer 21 is adapted to the thickness of the insulating layer of the cable the connector 1 is being connected to. The thickness of the semiconductive layer 31 is also adapted to the thickness of the semiconductive layer of the cable the connector 1 is being connected to.
It is now referred to
In addition, the metal conductor 11 here comprises a second elongated conductor element 13 having a first end 13a, a second end 13b and an intermediate section 13c between the first end 13a and the second end 13b.
The metal conductor 11 shown in
The connector 1 comprises an insulating layer 21 moulded as one single body onto the second end 12b and the intermediate section 12c of the first elongated conductor element 12 as described for the first embodiment. In addition, the insulating layer 21 is moulded onto the second end 13b and the intermediate section 13c of the second elongated conductor element 13. In this way, the first end 13a is protruding from the insulating layer 21 with a distance referred to as a second insulator distance DI2.
Connector 1 also comprises a semiconductive layer 31 provided outside of the insulating layer 21 at a first semiconductor distance DS1 from the first end 12a of the first elongated conductor element 12 as described for the first embodiment. In addition, it is also provided at a distance referred to as a second semiconductor distance DS2 from the first end 13a of the second elongated conductor element 13.
The insulating layer 21 is moulded as one single body onto the spheroid-shaped conductor element 19, the second end 12b and the intermediate section 12c of the first elongated conductor element 12 and the second end 13b and the intermediate section 13c of the second elongated conductor element 13 in a similar way as the embodiment shown in
a show a connector 1 with a metal conductor 11 with a first elongated conductor element 12 and a second elongated conductor element 13 as described in the second embodiment above. In addition, the metal conductor 11 comprises a third elongated conductor element 14 having a having a first end 14a, a second end 14b and an intermediate section 14c between the first end 14a and the second end 14b.
The metal conductor 11 shown in
The connector 1 as shown in
Connector 1 also comprises a semiconductive layer 31 provided outside of the insulating layer 21 at a first semiconductor distance DS1 from the first end 12a of the first elongated conductor element 12 and a second semiconductor distance DS2 from the first end 13a of the second elongated conductor element 13 as described for the second embodiment. In addition, the semiconductive layer 31 is also provided at a distance referred to as a third semiconductor distance DS3 from the first end 14a of the third elongated conductor element 14.
The insulating layer 21 is moulded as one single body onto the spheroid-shaped conductor element 19, the second end 12b and the intermediate section 12c of the first elongated conductor element 12 and the second end 13b, the intermediate section 13c of the second elongated conductor element 13 and the second end 14b and the intermediate section 14c of the third elongated conductor element 14 in a similar way as for the embodiment shown in
Also, the semiconductive layer 31 is provided in a similar way as in
A further embodiment of the metal conductor 11 is shown in
In the embodiment shown in
The connector 1 comprises an insulating layer 21 moulded as one single body as described for the second embodiment where in addition the continuous insulating layer is moulded onto the first elongated joining element 16. Hence, the joining element 16 is provided entirely within the insulating layer 21.
The connector 1 comprises an insulating layer 21 moulded as one single body as described for the second embodiment and the U connector where in addition the continuous insulating layer 21 is moulded onto the second elongated joining element 17. Hence, the joining element 16 and the joining element 17 are both provided entirely within the insulating layer 21.
The metal conductor 11 shown in
For all embodiments described above, the second end 12b of the first elongated conductor element 12, the second end 13b of the second elongated conductor element 13, the second end 14b of the third elongated conductor element 14 and the second end 15b of the fourth elongated conductor element 15, as well as the first elongated joining element 16, the second elongated joining element 17 and the spheroid-shaped conductor element 19 are connected by welding or bolting.
Alternatively, the metal conductor 11 may be machined from one metal piece or it may be made by an additive manufacturing process or similar. Typically, the metal conductor 11 is made from non-ferrous metals such as aluminium or copper.
The transition area TA between the first elongated conductor element 12, and the second elongated conductor element 13, and/or the third elongated conductor element 14 and/or the fourth conductor element 15, and/or the first elongated joining element 16, and/or the second elongated joining element 17 and/or the spheroid-shaped conductor element 19 are rounded with a radius Rcp to achieve a better distribution of the electric field strength within the connector 1 by providing a rounded surface when different elements meet, see also
Typically, a sphere features larger field strength over the surface compared to a cylinder, hence; any end or bend will feature a region with a larger radius to limit the field strength. It might be possible to allow also larger field strength in some regions.
In all of the above embodiments, the insulating layer 21 is moulded as one single insulating body using plastic materials such as thermoplastics or thermosetting polymers. The insulation plastic material may comprise epoxy, polyethylene, cross-linked polyethylene, or a thermoplastic polymer.
The semiconductor layer 31 can be sprayed or coated on the insulating layer 21 later during the assembly process or it can be covered with semiconductive self-amalgamating tape followed by copper mesh. A further alternative for a semiconductor layer 31 is to have a metallic outer screen molded into the insulating layer 21 terminated by a rounded screen break within the molded insulating layer 21.
Below, it will be described how the connector 1 is being connected to an end of a cable.
The connector 1 is manufactured and tested in a factory prior to installation. The connector 1 is connected to a corresponding slip-on joint 41 for a high voltage cable 42 as shown in
The connector 1 shown in
The connector 1 shown in
An outer layer of the assembly can feature embodiments such as single or multi-component watertight and pressure resistant barrier for use in submarine applications. Furthermore, for submarine applications, armor clamps can be designed into the housing for load transfer.
The E, Y or T connectors 1 can connect all three phases of a high voltage cable 42 together during post-installation or factory acceptance tests.
Hence, as is apparent from the above, the connector 1 for a high voltage cable simplifies the installation process in the field.
According to the above, it is achieved a connector 1 which provides a connection and branching off solution for high voltage cables that does not require the use of gas insulation. It is aimed at connections for high voltage cables with a voltage rating of 52 kV or more. Typically, voltages in the interval between 52 kV to 245 kV are referred to as high voltage within this area of technology, while the interval between 245 kV to 800 kV is referred to as extra high voltage.
Number | Date | Country | Kind |
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22307035.0 | Dec 2022 | EP | regional |