KR20240081426A - Submarine cable having a shielding layer considering dynamic characteristics - Google Patents

Abstract

The present invention relates to a submarine cable equipped with a shielding layer taking dynamic characteristics into account. Specifically, the present invention considers the dynamic characteristics of continuously being deformed by external forces in an energized state, and provides a shielding layer that can sufficiently perform the passage and shielding function of the fault current while realizing excellent durability in a dynamic environment such as the seabed. This is about the submarine cable provided.

Description

Submarine cable having a shielding layer considering dynamic characteristics}

The present invention relates to a submarine cable equipped with a shielding layer taking dynamic characteristics into account. Specifically, the present invention considers the dynamic characteristics of continuously being deformed by external forces in an energized state, and provides a shielding layer that can sufficiently perform the passage and shielding function of the fault current while realizing excellent durability in a dynamic environment such as the seabed. This is about the submarine cable provided.

Submarine cables have been installed for a long time for power transmission in island areas and communication connections between continents. They can be fixed and laid on the ground under the sea for each section, or they can be separated from the ground on the sea floor and connected to offshore wind turbines or offshore substations. Submarine cables installed in sections separated from the ground are subject to bending loads due to movement or bending due to ocean currents or waves. These sections of the submarine cable are especially called dynamic sections, and the above-mentioned movement or bending must be guaranteed in this dynamic section. It is difficult to apply a metal sheath shielding layer such as soft skin that prevents movement or bending of submarine cables.

Figure 1 schematically shows one or more cores included in a conventional submarine cable.

As shown in Figure 1, the core includes a conductor 31, an internal semiconducting layer 32 surrounding the conductor 31, an insulating layer 33 surrounding the internal semiconducting layer 33, and an insulating layer surrounding the insulating layer. It may include an external semiconducting layer 34, a water blocking layer 35 surrounding the external semiconducting layer 34, and a metal shielding layer 36 surrounding the water blocking layer 35.

The metal shielding layer 36 is made up of a plurality of metal wires 36a spaced apart, so it is advantageous to the movement or bending of the submarine cable compared to the soft metal shielding layer, but when a fault current occurs, the cable is grounded only through one adjacent wire 36a. Since the current cannot flow to the end and effectively perform the function of passing the fault current, a metal tape 36b is used to energize the entire metal wire 36a in order to distribute the fault current to the entire wire and sufficiently perform the function of passing the fault current. may be additionally provided.

Here, the metal tape 36b may be made of, for example, a copper tape. The metal shielding layer 36 of this structure is formed by the metal wire 36a and the metal tape 36b by repetitive bending or tensioning of the submarine cable. are strongly bound to each other, causing a problem in which the metal wire 36a is disconnected or the metal tape 36b is broken, and as a result, the metal shielding layer 36 cannot perform the function of passing and shielding the fault current.

Therefore, considering the dynamic characteristics of continuously being deformed by external forces in an energized state, a shielding layer that can sufficiently perform the passage and shielding function of the fault current while realizing excellent durability in a dynamic environment such as the dynamic section of a submarine cable There is an urgent need for these undersea cables.

The present invention considers the dynamic characteristics of continuously being deformed by external forces in an energized state, and provides a shield that can sufficiently perform the function of passing and shielding the fault current while realizing excellent durability in a dynamic environment such as a dynamic section of a submarine cable. The purpose is to provide a submarine cable with a layer.

In order to solve the above problems, the present invention,

A submarine cable, comprising: at least one core including a conductor, an inner semiconducting layer surrounding the conductor, an insulating layer surrounding the inner semiconducting layer, an outer semiconducting layer surrounding the insulating layer, and a metal shielding layer surrounding the outer semiconducting layer; and a cable protection layer surrounding the outside of the one or more cores, wherein the metal shielding layer includes a plurality of braids in which several strands of metal wires are woven into braided lines twisted together, and the plurality of braids do not overlap each other. It provides a submarine cable that is formed by winding each side without

Here, each of the plurality of braided bodies provides a submarine cable, characterized in that both end sides in the width direction are at least partially in contact with the side surfaces of other adjacent braided bodies.

In addition, a submarine cable is provided, wherein each of the plurality of braided bodies has a thickness of 1 to 2 mm.

Furthermore, the cross-sectional area of the plurality of braids as a whole is 0.5 to 8 mm ² , the cross-sectional area of one braided line constituting the braid is 0.08 to 0.26 mm ² , and the twist pitch length of the braided line is 5 to 100. Provides a submarine cable characterized in that it is mm.

Here, a submarine cable is provided, characterized in that a metal tape layer in electrical contact with each of the plurality of braids is additionally provided below or above the metal shielding layer.

Meanwhile, the metal tape layer provides a submarine cable, wherein the metal tape layer is formed by horizontal winding of a wire, tape, or braid made of a metal material.

Here, the core is provided between the outer semiconducting layer and the metal shielding layer and includes an inner water blocking tape layer surrounding the outer semiconducting layer, an outer water blocking tape layer surrounding the metal shielding layer, and a core jacket surrounding the outer water blocking tape layer. An undersea cable is provided, characterized in that it additionally includes.

In addition, the inner water-order tape layer or the outer water-order taping layer is characterized in that it includes at least one selected from the group consisting of powders containing super absorbent polymer (SAP), tapes, coating layers, and films. We provide submarine cables.

Meanwhile, a submarine cable is provided, characterized in that it includes a plurality of cores and an intervening cable is provided in the area between the cores.

In addition, the cable protection layer includes a binding taping layer for finishing the plurality of cores and the cable intervening in a circular shape; A bedding layer formed outside the binding taping layer and including polypropylene yarn; An armor layer provided outside the bedding layer; and an outermost layer formed outside the armor layer and containing a polymer resin material.

The submarine cable according to the present invention is equipped with a shielding layer of a new structure, thereby realizing excellent durability in a dynamic environment such as the seabed, taking into account the dynamic characteristics of continuously being deformed by external forces in an energized state, while simultaneously blocking and shielding the passage of fault currents. It shows excellent effectiveness in fully performing its function.

Figure 1 schematically shows one or more cores included in a conventional submarine cable.
Figure 2 is a cross-sectional view of one embodiment of a submarine cable according to the present invention.
FIG. 3 schematically shows one embodiment of one core included in the submarine cable shown in FIG. 2.
FIG. 4 schematically shows another embodiment of one core included in the submarine cable shown in FIG. 2.
Figure 5 shows an embodiment of a metal shielding layer in the core shown in Figure 3.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosure will be thorough and complete, and so that the spirit of the invention can be sufficiently conveyed to those skilled in the art. Like reference numerals refer to like elements throughout the specification.

Figure 2 is a cross-sectional view of one embodiment of the submarine cable according to the present invention, and Figure 3 schematically shows one embodiment of one core included in the submarine cable shown in Figure 2.

The submarine cable 1000 according to the present invention may be a three-phase AC power cable in which three cores 300a, 300b, and 300c are arranged in a triangle shape, as shown in FIG. 2. In order to configure the three cores (300a, 300b, 300c) in a circular shape, a cable interposer (400) is disposed in the area between adjacent cores and includes interposers (400a, 400b, 400c) made of plastic material. You can. At least one of the interpositions 400a, 400b, and 400c of the cable intervening 400 will be provided with an optical fiber receiving portion (a) in which at least one optical unit 100 having a plurality of optical fibers can be accommodated and mounted. You can.

Here, the optical unit 100 may include at least one optical fiber 110 and a tube 120 that accommodates the optical fiber 110. Each optical unit 100 includes a predetermined number of optical fibers 110 mounted with filler in a tube 120, and the tube may be made of a rigid material such as stainless steel. The optical unit 100 may further include a sheath 130 surrounding the tube 120.

The cable insert 400 is generally made of plastic material, preferably foam plastic material. When forming a submarine cable by combining the cores 300a, 300b, and 300c with optical units and intervening elements, they can be combined in a circular shape at a predetermined pitch.

In addition, the submarine cable according to the present invention is provided with a cable protection layer surrounding the one or more cores, and according to the embodiment of the present invention in Figure 2, the cable protection layer includes a binding tape layer 500, a bedding layer 600, and an armor. It may include a layer 700 and an outermost layer 800.

That is, a binding tape layer 500 may be provided to finish the three cores 300a, 300b, and 300c and the cable insert 400 in a circular shape.

A bedding layer 600 may be provided outside the binding taping layer 500. The bedding layer 600 may serve to provide a mounting surface on which the armor layer 700 provided outside the bedding layer 600 is mounted.

Here, the bedding layer 600 may be composed of polypropylene (PP) yarn. An armor layer 700 may be provided on the outside of the bedding layer 600, and the armor layer 700 may have an armor wire 710 disposed thereto, which may perform the function of protecting the submarine cable in a rough underwater environment. , may be formed of a plurality of layers including a lower layer 700a and an upper layer 700b.

Outside the armor layer 700, an outermost layer 800 containing a polymer resin material is provided to complete the submarine cable for offshore wind power.

As shown in Figures 2 and 3, the core 300 sequentially includes a conductor 310, an inner semiconducting layer 320, an insulating layer 330, an outer semiconducting layer 340, and an inner order tape layer 350. ), a metal shielding layer 360, an external water-order tape layer 370, and a core jacket 390.

The conductor 310 serves as a path through which current flows to transmit power, and is made of a metal material, such as copper or aluminum, that has excellent conductivity to minimize power loss and has appropriate strength and flexibility for cable manufacturing and use. etc. can be achieved.

The conductor 310 may be a circular compressed conductor in which a plurality of circular wires are stranded and compressed into a circle, and is provided with a circular center wire and a square wire layer composed of a square wire stranded to surround the circular center wire, and has an overall circular shape. It may be a rectangular conductor with a cross-section of, and the rectangular conductor has a relatively high space factor compared to a circular compressed conductor, so it has the advantage of being able to reduce the outer diameter of the cable.

However, the surface of the conductor 310 is not smooth, so the electric field may be non-uniform, and corona discharge is likely to occur locally. Additionally, if a gap is created between the surface of the conductor 310 and the insulating layer 330, which will be described later, an electric field may be concentrated in the gap, thereby deteriorating the insulation performance.

Accordingly, an internal semiconducting layer 320 may be provided outside the conductor 310. The internal semiconducting layer 320 may have semiconductivity by adding conductive particles such as carbon black, carbon nanotubes, carbon nanoplates, and graphite to an insulating material.

The internal semiconducting layer 320 functions to stabilize insulation performance by preventing sudden changes in electric field between the conductor 310 and the insulating layer 330, which will be described later. In addition, by suppressing non-uniform charge distribution on the conductor surface, the electric field can be made uniform and the formation of voids between the conductor 310 and the insulating layer 330 can be prevented, thereby suppressing corona discharge, insulation breakdown, etc.

The insulating layer 330 is provided outside the internal semiconducting layer 320 to electrically insulate it from the outside to prevent current from leaking to the outside along the conductor 310. In general, the insulating layer 330 must have a high breakdown voltage and maintain its insulating performance stably for a long period of time. Furthermore, it must have low dielectric loss and have heat resistance properties such as heat resistance. Therefore, the insulating layer 330 may be made of polyolefin resin such as polyethylene and polypropylene, and polyethylene resin is preferred. Here, the polyethylene resin may be composed of XLPE, a crosslinked resin.

An external semiconducting layer 340 may be provided outside the insulating layer 330. The outer semiconducting layer 340, like the inner semiconducting layer 320, is formed of a semiconducting material by adding conductive particles, such as carbon black, carbon nanotubes, carbon nanoplates, and graphite, to an insulating material, Insulating performance is stabilized by suppressing non-uniform charge distribution between the insulating layer 330 and the metal shielding layer 360 described later. In addition, the external semiconducting layer 340 smoothes the surface of the insulating layer 330 in the cable to alleviate electric field concentration to prevent corona discharge, and also performs the function of physically protecting the insulating layer 330. You can.

A metal shielding layer 360 may be provided outside the external semiconducting layer 340. The metal shielding layer 360 is grounded at the end of the cable and serves as a passage through which fault current flows when an accident such as a ground fault or short circuit occurs, and can perform a shielding function to prevent electric fields from being discharged outside the cable.

As shown in FIG. 3, the metal shielding layer 360 is composed of a plurality of braided bodies in which several strands of copper wires with high electrical conductivity are twisted together to smoothly perform the fault current passage and shielding function. It may be formed by winding horizontally over the lower structure of the core 300, for example, the outer semiconducting layer 340, without overlapping.

The plurality of divided braids constituting the metal shielding layer 360 behave separately during repeated bending or tensioning of the submarine cable, thereby ensuring not only bending or movement of the submarine cable due to ocean currents or waves in a dynamic environment such as the seabed. In addition, unlike the combination of metal wire and metal tape that forms the conventional metal shielding layer, excellent durability in a dynamic environment can be achieved.

Here, the plurality of braids do not overlap each other when transversely wound, thereby preventing local uneven thickness of the metal shielding layer 360 due to overlap and subsequent compression or damage to the lower structure, but each braid is oriented in the width direction. Since the sides of both ends are at least partially in contact with the side of another adjacent braid, when a fault current occurs, the fault current is shared throughout the metal shielding layer 360, so that the passage function of the fault current can be performed more smoothly.

FIG. 4 schematically shows another embodiment of one core included in the submarine cable shown in FIG. 2.

As shown in FIG. 4, below or above the metal shielding layer 360, for example, between the inner water blocking tape layer 350 and the metal shielding layer 360, or between the metal shielding layer 360 ) and the outer order taping layer 370 may be additionally provided with a metal tape layer 380 in direct electrical contact with the metal shielding layer 360. When the plurality of braided bodies constituting the metal shielding layer 360 are not in contact with each other on the side due to the bending or other behavior of the submarine cable, when a fault current occurs, the fault current is not shared throughout the metal shielding layer 360. The metal shielding layer 360 cannot smoothly perform the function of passing the fault current.

Therefore, by additionally providing the metal tape layer 380 in contact with each of the plurality of braids constituting the metal shielding layer 360 below or above the metal shielding layer 360, the metal shielding layer ( Even when the plurality of braided bodies constituting 360) are not in contact with each other on the side, fault current may be shared throughout the metal shielding layer 360.

Specifically, the metal tape layer 380 may be formed by crossing the inner order tape layer 350 with a wire, tape, braid, etc. made of a metal material with excellent electrical conductivity such as copper. In addition, the lateral winding direction of the metal wire forming the metal tape layer 380 may be the same as or different from the lateral winding direction of the plurality of braids constituting the metal shielding layer 360. FIG. 5 is similar to FIG. 3. An embodiment of the metal shielding layer in the illustrated core is shown.

The metal shielding layer 360 may be divided into two braids 361 and 362 as shown in FIG. 5A, and may be divided into three braids 363, 364 and 365 as shown in FIG. 5B, As shown in FIG. 5C, it can be divided into four braids (366, 367, 368, and 369).

The larger the number of divided braids, the more advantageous it is to ensure the bending or tension of the submarine cable, but it is disadvantageous in terms of sharing the accident current that occurs, so the braid is divided in consideration of the structure of the submarine cable, such as the outer diameter or number of cores (300). The number can be appropriately selected.

In particular, the thickness of each of the plurality of braids constituting the metal shielding layer 360 may be 1 to 2 mm, preferably 1.5 to 2 mm. Here, if the thickness of the braid is less than 1 mm, the durability of the metal shielding layer 360 is reduced, so it may be easily damaged when bending or stretching the submarine cable, and the passage function of the fault current may be insufficiently performed due to an increase in overall resistance. On the other hand, if the thickness of the braid is more than 2 mm, the thickness of the braid is unnecessarily thick, which unnecessarily increases the outer diameter and weight of the submarine cable, and increases the copper wires forming the braid, making it difficult to manufacture the submarine cable. There is a problem of increasing costs.

For example, the cross-sectional area of the entire plurality of braids, each having the above thickness, is 0.5 to 8.0 mm ² , the cross-sectional area of the braided lines constituting the braided body is 0.08 to 0.26 mm ² , and the twist pitch length of the braided lines That is, the twist pitch length of the plurality of wires constituting one braided line is 5 to 100 mm, and the number of braided lines constituting the braid considering the total cross-sectional area of the braid, the cross-sectional area of the braid, and the twist pitch length. The number of strokes of the phosphorus braid may be appropriately selected.

In addition, the core 300 may further include at least one water absorption taping layer outside the external semiconducting layer 340. The order taping layer may be provided at least one of the inside and outside of the above-described metal shielding layer 360. In the embodiment shown in Figures 2 and 3, the order taping layer is shown as having an inner order taping layer 350 and an outer order taping layer 370 inside and outside the metal shielding layer 360. , Since moisture mainly penetrates from the outside, only an external water-water taping layer 370 may be provided.

The order tape constituting the order taping layer is a powder or tape containing super absorbent polymer (SAP), which has a high rate of absorbing moisture penetrating into the cable and has an excellent ability to maintain the absorption state in a swollen state. , it is composed of a coating layer or a film, and serves to prevent moisture from penetrating along the length of the cable. The order taping layer may also have semiconductivity to prevent sudden changes in electric field. The order taping layer may be comprised of 0.2 millimeters (mm) to 1.4 millimeters (mm).

A core jacket 390 may be provided outside the outer water taping layer 370. The core jacket 390 constitutes the outermost part of the core and improves corrosion resistance, water resistance, etc., and protects against various environmental factors such as moisture penetration, mechanical trauma, corrosion, and fault current that may affect the power transmission performance of the cable. It can play a role in protecting the cable core from. Meanwhile, the core jacket 390 may be made of a resin such as polyethylene.

Although this specification has been described with reference to preferred embodiments of the present invention, those skilled in the art can make various modifications and changes to the present invention without departing from the spirit and scope of the present invention as set forth in the claims described below. It will be possible to implement it. Therefore, if the modified implementation basically includes the elements of the claims of the present invention, it should be considered to be included in the technical scope of the present invention.

1000: Undersea cable
100: optical unit
300: core
400: Intervention for cable
500: Binding taping layer
600: Bedding layer
700: Armor layer
800: Outermost layer

Claims (10)

As a submarine cable,
At least one core including a conductor, an inner semiconducting layer surrounding the conductor, an insulating layer surrounding the inner semiconducting layer, an outer semiconducting layer surrounding the insulating layer, and a metal shielding layer surrounding the outer semiconducting layer; and
Comprising a cable protection layer surrounding the outside of the one or more cores,
The metal shielding layer includes a plurality of braided bodies in which several strands of metal wires are woven into braided lines twisted together,
A submarine cable formed by each of the plurality of braids being wound horizontally without overlapping each other. According to paragraph 1,
A submarine cable, characterized in that each of the plurality of braided bodies has both end sides in the width direction in at least partial contact with the side surfaces of other adjacent braided bodies. According to paragraph 1,
A submarine cable, characterized in that each of the plurality of braided bodies has a thickness of 1 to 2 mm. According to paragraph 3,
The cross-sectional area of the plurality of braids is 0.5 to 8 mm ² ,
The cross-sectional area of one braided wire constituting the braid is 0.08 to 0.26 mm ² ,
A submarine cable, characterized in that the twist pitch length of the braided line is 5 to 100 mm. According to paragraph 1,
A submarine cable, characterized in that a metal tape layer in electrical contact with each of the plurality of braids is additionally provided below or above the metal shielding layer. According to clause 5,
A submarine cable, characterized in that the metal tape layer is formed by horizontal winding of a wire, tape, or braid made of a metal material. According to paragraph 1,
The core is provided between the outer semiconducting layer and the metal shielding layer and further includes an inner water blocking tape layer surrounding the outer semiconducting layer, an outer water blocking tape layer surrounding the metal shielding layer, and a core jacket surrounding the outer water blocking tape layer. A submarine cable, characterized in that it includes. In clause 7,
The inner order tape layer or the outer order taping layer is a submarine cable, characterized in that it includes at least one selected from the group consisting of powder containing super absorbent polymer (SAP), tape, coating layer, and film. . According to claim 1 or 2,
comprising a plurality of cores,
A submarine cable, characterized in that an intervening cable is provided in the area between the cores. According to clause 9,
The cable protection layer is,
A binding taping layer for finishing a plurality of cores and cable inserts in a circular shape;
A bedding layer formed outside the binding taping layer and including polypropylene yarn;
An armor layer provided outside the bedding layer; and
A submarine cable formed outside the armor layer and comprising an outermost layer containing a polymer resin material.