Interconnected power cables and cable connection structures

Abstract

To improve the reliability of a cable connection portion.SOLUTION: A connection power cable includes a plurality of power cables and at least one cable connection portion connecting a pair of power cables of the plurality of power cables. The cable connection portion has a conductor connection portion connecting conductors on each of the pair of power cables, an inner semiconductive layer provided to cover the outer periphery of the conductor connection portion and having semiconductivity, an insulating layer provided to cover the outer periphery of the inner semiconductive layer and having insulating properties, an outer semiconductive layer provided to cover the outer periphery of the insulating layer and having semiconductivity, a metal tube made of metal and provided to cover the outer periphery of the outer semiconductive layer, and an anticorrosion layer made of resin and provided to cover the outer periphery of the metal tube.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a linking power cable, a cable connection structure, and a method for manufacturing a linking power cable. [Background technology]

[0002] When manufacturing a power cable that will be laid over a long distance, multiple power cables may be connected in a factory to produce a linked power cable having a desired distance. The cable connection in this case is called a "factory joint (FJ)" (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-56039 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to improve the reliability of cable connections. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, A plurality of power cables; at least one cable connection portion that connects a pair of power cables among the plurality of power cables; Equipped with The cable connection portion is a conductor connection portion connecting the conductors of the pair of power cables; an inner semiconductive layer that is provided so as to cover an outer periphery of the conductor connection portion and has semiconductivity; an insulating layer having insulating properties and provided so as to cover an outer periphery of the internal semiconducting layer; an outer semiconductive layer that is provided so as to cover the outer periphery of the insulating layer and has semiconductivity; a metal tube made of metal and provided so as to cover an outer periphery of the outer semiconductive layer; a corrosion protection layer made of resin and provided to cover the outer periphery of the metal pipe; have A connecting power cable is provided.

[0006] According to another aspect of the present disclosure, a conductor connection portion connecting the conductors of the pair of power cables; an inner semiconductive layer that is provided so as to cover an outer periphery of the conductor connection portion and has semiconductivity; an insulating layer having insulating properties and provided so as to cover an outer periphery of the internal semiconducting layer; an outer semiconductive layer that is provided so as to cover the outer periphery of the insulating layer and has semiconductivity; a metal tube made of metal and provided so as to cover an outer periphery of the outer semiconductive layer; a corrosion protection layer made of resin and provided to cover the outer periphery of the metal pipe; Equipped with A cable connection structure is provided.

[0007] According to yet another aspect of the present disclosure, providing a plurality of power cables; forming at least one cable connection portion by connecting a pair of power cables among the plurality of power cables; Equipped with The step of forming the cable connection portion includes: forming a conductor connection portion by connecting the conductors of the pair of power cables; forming an inner semiconductive layer having semiconductivity so as to cover an outer periphery of the conductor connection portion; forming an insulating layer having insulating properties so as to cover an outer periphery of the internal semiconducting layer; forming an outer semiconductive layer having semiconductivity so as to cover an outer periphery of the insulating layer; forming a metal tube made of metal so as to cover an outer periphery of the outer semiconductive layer; forming a corrosion protection layer made of resin so as to cover an outer periphery of the metal pipe; have A method for manufacturing a concatenated power cable is provided. [Effects of the Invention]

[0008] According to the present disclosure, the reliability of the cable connection portion can be improved. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a cable connection portion according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic enlarged view of the tip portion of the power cable in FIG. [Figure 3] FIG. 3 is a schematic enlarged view of the welded portion of the metal pipe in FIG. [Figure 4] FIG. 4 is a flowchart illustrating a method for manufacturing a linked power cable according to one embodiment of the present disclosure. [Figure 5A] FIG. 5A is a schematic diagram showing a first method of the conductor connecting step. [Figure 5B] FIG. 5B is a schematic diagram showing a second method of the conductor connecting step. [Figure 5C] FIG. 5C is a schematic diagram showing a third method of the conductor connecting step. [Figure 6] FIG. 6 is a schematic diagram showing the cross-linking process. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Description of the embodiments of the present disclosure] <Knowledge gained by the inventors> First, the findings of the inventors will be explained.

[0011] As mentioned above, an example of a power cable that is laid over a long distance is a submarine cable (underwater cable). The power cables that make up a submarine cable can only be manufactured to a finite length based on the manufacturing capacity of the factory. For this reason, as mentioned above, a linked power cable of the required length is manufactured as a submarine cable by connecting multiple power cables in the factory. The linked power cable is then loaded onto a cable laying ship.

[0012] Such a connecting power cable is subjected to bending stress during winding onto a turntable, transportation, extension, installation, etc. Therefore, the connecting power cable is required to have, for example, flexibility, and therefore it is desirable that the outer diameter of the cable connection part is approximately the same as the outer diameter of the power cable.

[0013] Furthermore, the connecting power cable is subjected to tensile forces during extension and installation, or when a current occurs after installation. For this reason, the connecting power cable is required to have, for example, tensile strength. Therefore, it is desirable that the connection strength between the power cables at the cable connection section be high.

[0014] Furthermore, when the interconnected power cable is laid on the seabed, for example, water may enter the cable joint, causing corrosion of the conductors, etc. For this reason, the interconnected power cable is required to be, for example, water-resistant (waterproof), and therefore, high sealing performance is desired at the cable joint.

[0015] The present disclosure is based on the above findings made by the present inventors.

[0016] <Embodiments of the present disclosure> Next, embodiments of the present disclosure will be listed and described.

[0017] [1] A connecting power cable according to one embodiment of the present disclosure includes: A plurality of power cables; at least one cable connection portion that connects a pair of power cables among the plurality of power cables; Equipped with The cable connection portion is a conductor connection portion connecting the conductors of the pair of power cables; an inner semiconductive layer that is provided so as to cover an outer periphery of the conductor connection portion and has semiconductivity; an insulating layer having insulating properties and provided so as to cover an outer periphery of the internal semiconducting layer; an outer semiconductive layer that is provided so as to cover the outer periphery of the insulating layer and has semiconductivity; a metal tube made of metal and provided so as to cover an outer periphery of the outer semiconductive layer; a corrosion protection layer made of resin and provided to cover the outer periphery of the metal pipe; It has. This configuration can improve the reliability of the cable connection portion.

[0018] [2] In the connecting power cable described in [1] above, The outermost diameter of the anticorrosion layer in a cross section that includes the conductor connection portion and is perpendicular to the axis of the power cable is +15 mm or less relative to the outermost diameter of the power cable. This configuration can improve the flexibility of the connecting power cable.

[0019] [3] In the connecting power cable according to [1] or [2] above, In the conductor connection portion, the conductors are directly welded to each other without a metal tube being provided around the outer periphery of the conductors. This configuration can improve the connection strength between the power cables.

[0020] [4] In the connecting power cable according to any one of [1] to [3] above, The internal semiconductive layer is made of semiconductive tape wrapped around the outer periphery of the conductor connection portion. According to this configuration, the internal semiconductive layer can be formed to fit the outer shape of the area inside the internal semiconductive layer.

[0021] [5] In the connecting power cable according to any one of [1] to [4] above, The insulating layer is made of an insulating tape wrapped around the outer periphery of the inner semiconductive layer. According to this configuration, the insulating layer can be formed to fit the complex outer shape inside the insulating layer.

[0022] [6] In the connecting power cable according to any one of [1] to [5] above, The outer semiconductive layer is formed of a semiconductive tube that covers the outer periphery of the insulating layer. According to this configuration, even if the layer inside the outer semiconductive layer is made of tape, the surface of the outer semiconductive layer can be made smooth.

[0023] [7] In the connecting power cable according to any one of [1] to [6] above, The cable connection further includes a water-absorbing tape layer provided between the outer semiconductive layer and the metal tube. With this configuration, even if water enters the metal pipe, the propagation of the water can be suppressed.

[0024] [8] The connecting power cable according to any one of [1] to [7] above, The metal tube is narrowed so as to contact the outer circumferential surface of the layer located inside the metal tube. This configuration allows the outermost diameter of the cable connection portion to be reduced.

[0025] [9] In the connecting power cable described in [8] above, The metal tube has traces of having been reduced in diameter. This configuration allows the outermost diameter of the cable connection portion to be reduced.

[0026]

[10] In the connecting power cable according to any one of [1] to [9] above, The anticorrosion layer is provided in a plurality of layers in the radial direction of the conductor. This configuration can improve the corrosion resistance and reliability of the corrosion protection layer.

[0027]

[11] The connecting power cable according to any one of [1] to

[10] above, Each of the pair of power cables includes, from a central axis side to an outer periphery side, the conductor, a cable inner semiconductive layer, a cable insulating layer, a cable outer semiconductive layer, a cable metal tube, and a cable sheath, In each of the pair of power cables, the cable inner semiconductive layer, the cable insulating layer, the cable outer semiconductive layer, the cable metal tube, and the cable sheath are stripped in stages from the tip of the conductor toward the opposite side. According to this configuration, the power cables can be connected to each other in order from the central axis side toward the outer periphery side.

[0028]

[12] In the connecting power cable according to

[11] above, The cable insulation layer has a peel surface that is inclined at a taper angle of 5.2° to 8.6° relative to the axis of the conductor. According to this configuration, it is possible to prevent the cable connection portion from becoming excessively large, and to improve the reliability of the cable connection portion.

[0029]

[13] The connecting power cable according to

[11] or

[12] above, The cable connection portion is a welded portion formed by welding an axial end of the metal pipe to an axial end of the cable metal pipe; a heat insulating portion provided between the welded portion and the outer semiconductive layer and having heat insulating properties; It further has: According to this configuration, thermal degradation of the cable core can be suppressed when welding the welded portion.

[0030]

[14] The connecting power cable according to

[13] above, The cable connection portion further includes a reinforcing portion that covers the outer periphery of the welded portion and suppresses cracks in the welded portion. This configuration can suppress the occurrence of cracks at the end of the welded portion.

[0031]

[15] In the connecting power cable according to any one of

[11] to

[14] above, The cable connection portion further includes a filling portion that fills a step between the exposed portion of the cable metal tube and the cable sheath. According to this configuration, the anticorrosion layer 260 can be smoothly coated between the exposed portion of the cable metal tube and the cable sheath.

[0032]

[16] In the connecting power cable according to any one of

[11] to

[15] above, The anticorrosion layer is formed of a tube that covers the outer periphery of the metal pipe and a part of the outer periphery of the cable sheath. With this configuration, the outer periphery of the metal pipe can be easily covered.

[0033]

[17] In the connecting power cable according to

[16] above, The anticorrosion layer has a bulge on the outer periphery of the cable sheath. This configuration makes it possible to stably prevent water from entering the cable core.

[0034]

[18] The connecting power cable according to

[17] above, The outermost diameter in a cross section perpendicular to the axis of the power cable and including the bulge is greater than the outermost diameter of the power cable by +5 mm or more and +20 mm or less. This configuration can improve the flexibility of the connecting power cable.

[0035]

[19] A cable connection structure according to another aspect of the present disclosure includes: a conductor connection portion connecting the conductors of the pair of power cables; an inner semiconductive layer that is provided so as to cover an outer periphery of the conductor connection portion and has semiconductivity; an insulating layer having insulating properties and provided so as to cover an outer periphery of the internal semiconducting layer; an outer semiconductive layer that is provided so as to cover the outer periphery of the insulating layer and has semiconductivity; a metal tube made of metal and provided so as to cover an outer periphery of the outer semiconductive layer; a corrosion protection layer made of resin and provided to cover the outer periphery of the metal pipe; Equipped with. This configuration can improve the reliability of the cable connection portion.

[0036]

[20] A method for manufacturing a linked power cable according to yet another aspect of the present disclosure includes: providing a plurality of power cables; forming at least one cable connection portion by connecting a pair of power cables among the plurality of power cables; Equipped with The step of forming the cable connection portion includes: forming a conductor connection portion by connecting the conductors of the pair of power cables; forming an inner semiconductive layer having semiconductivity so as to cover an outer periphery of the conductor connection portion; forming an insulating layer having insulating properties so as to cover an outer periphery of the internal semiconducting layer; forming an outer semiconductive layer having semiconductivity so as to cover an outer periphery of the insulating layer; forming a metal tube made of metal so as to cover an outer periphery of the outer semiconductive layer; forming a corrosion protection layer made of resin so as to cover an outer periphery of the metal pipe; It has. This configuration can improve the reliability of the cable connection portion.

[0037] [Details of the embodiments of the present disclosure] Next, an embodiment of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0038] <One embodiment of the present disclosure> (1) Connecting power cables and cable connections A coupled power cable 10 and a cable connection portion (cable connection structure) 20 according to an embodiment of the present disclosure will be described with reference to Figs. 1 to 3. Fig. 1 is a schematic cross-sectional view showing the cable connection portion according to the present embodiment. Fig. 2 is a schematic enlarged view of the tip portion of the power cable in Fig. 1. Fig. 3 is a schematic enlarged view of the welded portion of the metal pipe in Fig. 1.

[0039] In Fig. 1, the side of the power cable 100 is shown after being stripped in stages. Since Figs. 1 to 3 are merely schematic diagrams, the thickness, spacing, shape, etc. of each part shown in each figure may differ from the actual shape. In addition, the lower side of each of Figs. 1 to 3 is omitted.

[0040] As shown in FIG. 1, the connecting power cable 10 of this embodiment is configured as an underwater cable laid on the bottom of the water (ocean bottom), and includes a plurality of power cables 100 and at least one cable connection part 20.

[0041] In the following, the "axial direction" of the power cable 100 or the like refers to the direction along the central axis of the power cable 100 or the like, and can be rephrased as the longitudinal direction of the power cable 100 or the like. The "radial direction" of the power cable 100 or the like refers to the direction perpendicular to the axial direction of the power cable 100 or the like, and can be rephrased as the lateral direction of the power cable 100 or the like in some cases. The "circumferential direction" of the power cable 100 or the like refers to the direction along the outer periphery of the power cable 100 or the like.

[0042] [Power cable] The power cable 100 is configured as a solid insulated cable (CE cable: Crosslinked polyethylene (PE) insulated PE sheathed cable, also called an XLPE cable) which is a high-voltage power transmission cable.

[0043] The power cable 100 has, for example, from the central axis side to the outer periphery, a conductor 110, a cable inner semiconductive layer 120, a cable insulating layer 130, a cable outer semiconductive layer 140, a water absorbing layer (not shown), a cable metal tube 150, and a cable sheath 160. Note that the portion of the power cable 100 from the conductor 110 to the cable outer semiconductive layer 140 is sometimes referred to as the "cable core."

[0044] 1 and 2, the conductor 110 has, for example, a plurality of conductor strand layers 114 formed by helically twisting together a plurality of conductor strands 112. The conductor strands 112 are made of, for example, copper, a copper alloy, aluminum, or an aluminum alloy.

[0045] The power cable 100 is stripped in stages from the tip of the conductor 110 to the opposite side (so-called "stage stripping"). That is, the conductor 110, the cable inner semiconductive layer 120, the cable insulating layer 130, the cable outer semiconductive layer 140, the cable metal pipe 150, and the cable sheath 160 are exposed in this order from the tip side of the conductor 110 to the opposite side. Hereinafter, each stage-stripped portion may be referred to as an "exposed portion." With this configuration, power cables 100 can be connected to each other in order from the central axis side to the outer periphery side.

[0046] The conductor 110, the cable inner semiconductive layer 120, the cable insulating layer 130, the cable outer semiconductive layer 140, and the cable metal tube 150 are cut obliquely with respect to the axis of the conductor 110. In other words, the power cable 100 is processed into, for example, a pencil shape, and has a conical peeled surface (reference numeral not shown) whose diameter expands from the tip of the conductor 110 toward the opposite side.

[0047] 2, the cable insulating layer 130 has a peeled surface that is inclined at a predetermined taper angle θ with respect to the axis of the conductor 110. The taper angle θ of the peeled surface of the cable insulating layer 130 is, for example, 5.2° or more and 8.6° or less with respect to the axis of the conductor 110. Setting the taper angle θ to 5.2° or more can prevent the length of the cable connection portion 20 in the axial direction of the conductor 110 from becoming excessively long. On the other hand, setting the taper angle θ to 8.6° or less can alleviate the electric field around the exposed cable insulating layer 130 while ensuring workability.

[0048] As shown in Fig. 1, a plurality of power cables 100 are provided. Of the plurality of power cables 100, a pair of power cables 100 are butted together with the axes of their conductors 110 aligned. In the following, one power cable 100 of the pair of power cables 100 may be referred to as a "first power cable 100a," and the other power cable 100 may be referred to as a "second power cable 100b."

[0049] [Cable connection] As shown in FIG. 1, the cable connection portion 20 includes, for example, a conductor connection portion 210, an inner semiconductive layer 220, an insulating layer 230, an outer semiconductive layer 240, a water-absorbing tape layer 242, a metal tube (protective tube) 250, and a corrosion-resistant layer (connection portion sheath) 260.

[0050] (conductor connection part) The conductors 110 of the pair of power cables 100 are connected at the conductor connection portion 210. The conductor connection portion 210 has, for example, exposed portions (reference numerals not shown) of the pair of conductors 110 and a welded portion 212.

[0051] Details of the conductor connecting step will be described later with reference to Figures 5A to 5C. In the welded portion 212 of the conductor connecting portion 210 of this embodiment, for example, the conductors 110 are directly welded to each other without a metal tube (so-called conductor sleeve) being provided around the outer periphery of the conductors 110. In the welded portion 212, as will be described later, a plurality of conductor wires 112 are welded to each of a plurality of conductor wire layers 114 of the conductor 110. Furthermore, the conductor connecting portion 210 is compressed, for example, in the radial direction of the conductor 110. With this configuration, the outer diameter of the conductor connecting portion 210 is approximately equal to the outer diameter of the conductor 110 of the power cable 100.

[0052] (internal semiconductive layer) 1 and 2, the internal semiconductive layer 220 is provided so as to cover the outer periphery of the conductor connection portion 210. The internal semiconductive layer 220 has semiconductivity, which can alleviate electric field concentration near the surface of the conductor connection portion 210.

[0053] In this embodiment, the internal semiconductive layer 220 is formed, for example, by a semiconductive tape wrapped around the outer periphery of the conductor connection portion 210. The semiconductive tape is, for example, a cloth tape such as nylon or Tetron (registered trademark) coated with semiconductive rubber, or a tape made of a semiconductive resin material similar to that of the cable internal semiconductive layer 120 of the power cable 100 and containing a crosslinking agent, and is crosslinked by a crosslinking process described below. Furthermore, the semiconductive tape contains a crosslinking agent before manufacturing, and is crosslinked by a crosslinking process described below. By forming the internal semiconductive layer 220 from such a semiconductive tape, the internal semiconductive layer 220 can be formed to match the outer shape and length of the conductor connection portion 210.

[0054] (insulating layer) 1, the insulating layer 230 is provided so as to cover the outer periphery of the internal semiconductive layer 220. The insulating layer 230 has insulating properties, thereby ensuring insulation on the outside of the conductor connection portion 210.

[0055] In this embodiment, the insulating layer 230 covers, for example, the inner semiconducting layer 220 and the exposed portion of the cable insulating layer 130. The insulating layer 230 has, for example, a conical surface whose diameter increases from the end of the insulating layer 230 toward the center in the axial direction of the conductor 110.

[0056] In this embodiment, the insulating layer 230 is formed, for example, by an insulating tape wrapped around the outer periphery of the exposed portions of the internal semiconductive layer 220 and the cable insulating layer 130. The insulating tape is, for example, a tape made of the same insulating resin material as the cable insulating layer 130 of the power cable 100 and containing a cross-linking agent, and is cross-linked by a cross-linking process described below. Furthermore, the insulating tape contains a cross-linking agent before manufacturing, and is cross-linked by a cross-linking process described below. By forming the insulating layer 230 using such an insulating tape, the insulating layer 230 can be formed to fit the complex outer shapes of the exposed portions of the internal semiconductive layer 220 and the cable insulating layer 130.

[0057] (Outer semiconductive layer) 1, the outer semiconductive layer 240 is provided so as to cover the outer periphery of the insulating layer 230. The outer semiconductive layer 240 has semiconductivity, which makes it possible to reduce electric field concentration near the outside of the insulating layer 230.

[0058] In this embodiment, the outer semiconductive layer 240 is formed, for example, by a semiconductive tube that covers the outer periphery of the cable insulating layer 130. Examples of materials for the semiconductive tube include resin materials containing carbon black and the like. The semiconductive tube is heat-shrinkable. The semiconductive tube is cross-linked during manufacturing using a method such as electron beam irradiation, and is fused and integrated with the insulating layer in a cross-linking process described below. By forming the outer semiconductive layer 240 using such a semiconductive tube, the surface of the outer semiconductive layer 240 can be made smooth, even if the layers inside the outer semiconductive layer 240 are formed of tape.

[0059] In this embodiment, the outer semiconductive layer 240 covers the outer periphery of the insulating layer 230 and is in contact with the exposed end of the cable outer semiconductive layer 140. This makes the outer semiconductive layer 240 and the cable outer semiconductive layer 140 electrically equipotential.

[0060] (Water-absorbing tape layer) 1, the water-absorbing tape layer 242 is preferably provided so as to cover the outer periphery of the outer semiconductive layer 240, i.e., provided between the outer semiconductive layer 240 and the metal pipe 250 described below. The water-absorbing tape layer 242 has a similar structure to the water-absorbing layer of the power cable 100, and is, for example, a tape made of a polyester base fabric coated with semiconductive rubber and to which a water-absorbing polymer is attached. By providing such a water-absorbing tape layer 242, it is possible to suppress the propagation of water (i.e., water running) even if water penetrates into the metal pipe 250.

[0061] (metal tube) As shown in Fig. 1, the metal tube 250 is provided so as to cover the outer periphery of the outer semiconductive layer 240 (water-absorbing tape layer 242). The metal tube 250 is made of a rigid metal. Examples of metals that form the metal tube 250 include lead and aluminum. By providing such a metal tube 250, the impact resistance of the cable connection part 20 can be improved.

[0062] In this embodiment, the metal tube 250 is narrowed so as to contact the outer circumferential surface of the layer located inside the metal tube 250 (i.e., the water-absorbent tape layer 242). Therefore, the metal tube 250 has, for example, traces of narrowing. With this configuration, the outermost diameter of the cable connection part 20 can be reduced.

[0063] 3, the axial end of the metal pipe 250 and the axial end of the cable metal pipe 150 are welded together by a weld 252. This prevents water from seeping in between the metal pipe 250 and the cable metal pipe 150, and makes them electrically equipotential.

[0064] In this embodiment, it is preferable that a heat insulating portion 244 having heat insulating properties is provided between the welded portion 252 and the cable outer semiconductive layer 140. This makes it possible to suppress thermal deterioration of the cable core when the welded portion 252 is welded.

[0065] Furthermore, in this embodiment, a reinforcing portion 254 is provided so as to cover the outer periphery of the welded portion 252. Specifically, the reinforcing portion 254 has, for example, epoxy resin, glass tape soaked in epoxy resin, and adhesive PET (Polyethylene Terephthalate) tape covering these. This makes it possible to suppress the occurrence of cracks at the end of the welded portion 252.

[0066] (Anti-corrosion layer) As shown in Fig. 1, the anticorrosion layer 260 is provided to cover the outer periphery of the metal pipe 250 and the exposed portion of the cable metal pipe 150. The anticorrosion layer 260 is made of a resin having anticorrosive properties. Examples of anticorrosive resins include polyethylene blends. This can suppress corrosion of the cable core.

[0067] In this embodiment, the anticorrosion layer 260 is configured, for example, by a tube that covers the outer periphery of the metal pipe 250, the exposed portion of the cable metal pipe 150, and part of the outer periphery of the cable sheath 160. The tube of the anticorrosion layer 260 can easily cover the outer periphery of the metal pipe 250. In addition, the outer periphery surface of the anticorrosion layer 260 can be made smooth.

[0068] The anticorrosion layer 260 covers part of the outer periphery of the cable sheath 160, and therefore has a bulge 260a on the outer periphery of the cable sheath 160. The bulge 260a can stably prevent water from entering the cable core.

[0069] In this embodiment, the anticorrosion layer 260 may be provided in multiple layers in the radial direction of the conductor 110. This can improve the anticorrosion properties and reliability of the anticorrosion layer 260.

[0070] Specifically, the first corrosion protection layer 262 is provided so as to cover the outer periphery of the metal pipe 250, the exposed portion of the cable metal pipe 150, and part of the outer periphery of the cable sheath 160. The first corrosion protection part 263 is provided so as to cover the step between the axial end of the first corrosion protection layer 262 and the cable sheath 160. The first corrosion protection part 263 is made of, for example, a heated and melted polyethylene (PE) tape.

[0071] Furthermore, the second corrosion protection layer 264 is provided so as to cover the outer periphery of the first corrosion protection layer 262, the first corrosion protection portion 263, and part of the outer periphery of the cable sheath 160. The second corrosion protection portion 265 is provided so as to cover the step between the axial end of the second corrosion protection layer 264 and the cable sheath 160. The second corrosion protection portion 265 is made of, for example, a heated and melted PE tape.

[0072] With this configuration, the corrosion resistance and reliability of the corrosion protection layer 260 can be improved.

[0073] 1, in this embodiment, a filling portion 256 is preferably provided so as to fill the step between the exposed portion of the cable metal pipe 150 and the cable sheath 160. The filling portion 256 is made of, for example, an adhesive PE tape and an adhesive PET tape. This allows the anticorrosion layer 260 to smoothly cover the area between the exposed portion of the cable metal pipe 150 and the cable sheath 160.

[0074] (Cover part) In this embodiment, a cover portion 270 is preferably provided so as to cover the axial end portion (second corrosion protection portion 265) of the corrosion protection layer 260. The cover portion 270 is made of, for example, an adhesive PE tape and an adhesive PET tape. This makes it possible to smooth out any irregularities near the axial end portion of the corrosion protection layer 260.

[0075] (others) In this embodiment, the connecting power cable 10 preferably has a mark indicating the position of the cable connection part 20. The mark is configured, for example, by colored tape attached to the outer peripheral surface of the power cable 100 or the cable connection part 20. The mark may also be configured as a pattern printed or applied on the outer peripheral surface of the power cable 100. The mark may be located at either end or the center of the cable connection part 20. This allows the position of the cable connection part 20 to be easily recognized visually.

[0076] (Specific dimensions, etc.) The outermost diameter of the cable connection part 20 in this embodiment is, for example, approximately equal to the outermost diameter of the power cable 100. Specifically, the outermost diameter of the corrosion protection layer 260 in a cross section that includes the conductor connection part 210 and is perpendicular to the axis of the power cable 100 is, for example, +5 mm to +15 mm greater than the outermost diameter of the power cable 100.

[0077] In this embodiment, the outermost diameter of the cable connection part 20 is suppressed even at the position where the bulge 260a of the anticorrosion layer 260 is formed. Specifically, the outermost diameter in a cross section perpendicular to the axis of the power cable 100 and including the bulge 260a is, for example, +5 mm to +20 mm greater than the outermost diameter of the power cable 100.

[0078] (2) Manufacturing method of linked power cables (cable connection method) Next, a method for manufacturing a linked power cable according to this embodiment will be described with reference to Figs. 1 to 6. Fig. 4 is a flowchart showing the method for manufacturing a linked power cable according to this embodiment. Note that steps are abbreviated as "S." Figs. 5A to 5C are schematic diagrams showing first to third methods of the conductor connecting step, respectively. Fig. 6 is a schematic diagram showing the cross-linking step.

[0079] As shown in FIG. 4, the method for manufacturing the linked power cable 10 of this embodiment includes, for example, a preparation step S100 and a cable connection step S200.

[0080] [S100: Preparation process] First, a plurality of power cables 100 are prepared.

[0081] Specifically, the power cable 100 is peeled in stages from the tip of the conductor 110 toward the opposite side. At this time, the power cable 100 is processed into a pencil shape, and a conical peeled surface is formed that expands in diameter from the tip of the conductor 110 toward the opposite side.

[0082] 2, the cable insulating layer 130 has a peeled surface that is inclined at a predetermined taper angle θ with respect to the axis of the conductor 110. The taper angle θ of the peeled surface of the cable insulating layer 130 is set to, for example, 5.2° or more and 8.6° or less.

[0083] After the step stripping of each of the pair of power cables 100 is completed, the first power cable 100a is inserted into, for example, the semiconductive tube that constitutes the outer semiconductive layer 240, the group of pressure tubes used in the second cross-linking step S244, the metal tube 250, and the tube that constitutes the corrosion protection layer 260.

[0084] Next, the power cable 100 is straightened (so-called "direct drawing" is performed). Specifically, a heater is wrapped around the conductor 110, the cable-internal semiconductive layer 120, the cable insulating layer 130, and the exposed portions of the cable-external semiconductive layer 140 to cover them, and the heater is heated to a predetermined temperature for a predetermined time. Once heating is complete, the heater and the like are removed. Next, the exposed portions of the conductor 110, the cable-internal semiconductive layer 120, the cable insulating layer 130, and the cable-external semiconductive layer 140 are fixed along a fixing jig. In this state, the exposed portions of the conductor 110, the cable-internal semiconductive layer 120, the cable insulating layer 130, and the cable-external semiconductive layer 140 are cooled. This allows the power cable 100 to be straightened.

[0085] [S200: Cable connection process] After the preparation step S100 is completed, the cable connection step S200 is performed. The cable connection step S200 includes, for example, a conductor connection step S210, an inner semiconductive layer formation step S220, a first cross-linking step S224, an insulating layer formation step S230, an outer semiconductive layer formation step S240, a second cross-linking step S244, an inspection step S250, a metal pipe formation step S260, a corrosion protection layer formation step S270, and a post-treatment step S280.

[0086] (S210: Conductor connection process) A conductor connection section 210 is formed by connecting the conductors 110 of the pair of power cables 100 together.

[0087] Specifically, three methods are possible, as shown in FIGS. 5A to 5C.

[0088] 5A, in a first method, for example, the conductors 110 of a pair of power cables 100 are exposed. After the conductors 110 are exposed, the tip of each conductor 110 is tapered in a direction oblique to the axis of the conductor 110. Next, with a predetermined gap between the pair of conductors 110, the pair of conductors 110 are butted together in a straight line so that their axes coincide and their tapered surfaces form a V shape.

[0089] Next, the conductors 110 are welded together in the following procedure. Examples of methods for welding the conductors 110 include gas welding using propane gas or acetylene gas and oxygen gas. A brazing material (copper brazing, silver brazing, etc.) is melted into the gap between the pair of conductors 110 to weld the conductors together and integrate them.

[0090] A ring 320 is attached to prevent the cable core from overheating due to heat during welding. The ring 320 is preferably made of a material with good thermal conductivity (such as copper or aluminum). During and after welding, cooling air is supplied to the conductor 110 from an air nozzle 310 to cool the welded portion 212 of the conductor 110. Alternatively, a cooling method may be used in which a cooling water flow path is formed inside the ring 320 attached to the outer periphery of the conductor 110 and cooling water is passed through the flow path. After cooling, the welded portion 212 is shaped using a belt sander and sandpaper to form the conductor connection portion 210.

[0091] Thereafter, a predetermined conductor compression device or compression tool is used to compress and shape the conductor connection portion 210. By compressing and shaping, the outer diameter of the conductor connection portion 210 is made substantially equal to the outer diameter of the conductor 110, and any bends in the conductor connection portion 210 are corrected.

[0092] Alternatively, a second method may be employed, as shown in Figure 5B. For example, after the conductors 110 are exposed, the tip of each conductor 110 is processed into a conical shape with a tapered diameter toward the tip. Next, with a predetermined gap between the pair of conductors 110, the pair of conductors 110 are butted together in a straight line so that their axes and the apexes of their cones are aligned. The subsequent steps are the same as those in the first method.

[0093] Alternatively, a third method may be adopted, as shown in Fig. 5C. For example, the conductor wires 112 are welded together starting from the inner conductor wire layer 114 that constitutes the conductor 110, and the welded portions 212 are then ground to finish. A similar procedure is repeated sequentially for the outer conductor wire layers 114. Subsequent steps are the same as those in the first method.

[0094] (S220: Internal semiconducting layer formation process) After the conductor connecting step S210, an internal semiconductive layer 220 having semiconductivity is formed so as to cover the outer periphery of the conductor connecting portion 210.

[0095] Specifically, the pair of power cables 100 are pulled in opposite directions to maintain a straight line. In this state, a semiconductive tape is wound around the conductor connection portion 210 to cover the outer periphery of the conductor connection portion 210. This forms the inner semiconductive layer 220.

[0096] (S224: 1st crosslinking step) After the internal semiconductive layer forming step S220, in this embodiment, the internal semiconductive layer 220 is crosslinked.

[0097] Specifically, a group of pressure tapes is wrapped around the exposed portions of the inner semiconductive layer 220, the cable inner semiconductive layer 120, the cable insulating layer 130, and the cable outer semiconductive layer 140. A thermocouple, aluminum foil, and a heater are then attached, and the heating area is heated to a predetermined temperature for a predetermined time. This crosslinks the inner semiconductive layer 220. Once crosslinking is complete, the heater and the group of pressure tapes are sequentially removed. After crosslinking is complete, the surfaces of the inner semiconductive layer 220, the cable inner semiconductive layer 120, the cable insulating layer 130, and the cable outer semiconductive layer 140 are scraped to achieve the specified outer diameter.

[0098] (S230: Insulation layer formation process) After the first cross-linking step S224, an insulating layer 230 having insulating properties is formed so as to cover the outer peripheries of the inner semiconductive layer 220, the cable inner semiconductive layer 120 and the cable insulating layer .

[0099] Specifically, insulating tape is wrapped around the inner semiconducting layer 220 and the exposed portions of the cable insulating layer 130 by hand or by using a taping device in a clean booth that is kept clean, thereby forming the insulating layer 230.

[0100] (S240: Outer semiconducting layer formation process) After the insulating layer forming step S230, an outer semiconductive layer 240 having semiconductivity is formed so as to cover the outer periphery of the insulating layer 230.

[0101] Specifically, a semiconductive tube that has been previously passed through the first power cable 100a is placed on the outer periphery of the cable insulating layer 130. After the semiconductive tube is placed, it is heat-shrunk. The excess length of the semiconductive tube is then cut off. This forms the outer semiconductive layer 240 so as to cover the outer periphery of the insulating layer 230 and to contact the exposed end of the cable outer semiconductive layer 140.

[0102] (S244: 2nd crosslinking step) After the outer semiconductive layer forming step S240, the cable core is heated to crosslink the insulating layer 230 and fuse the inner semiconductive layer 220, the insulating layer 230 and the outer semiconductive layer 240 together to form an integrated body.

[0103] First, the outer periphery of the outer semiconductive layer 240 is covered with a presser tube and a group of presser tapes.

[0104] Next, as shown in FIG. 6, the cable core covered with the presser tube group is set in a bridging device 50.

[0105] The cross-linking device 50 includes, for example, a heating furnace (mold furnace) 510, a heater 520, and a gas supply line 530. The heating furnace 510 is configured as a cylindrical body having a hollow portion into which a cable core is inserted. The heater 520 is provided in the heating furnace 510 and configured to heat the cable core in the hollow portion of the heating furnace 510. The gas supply line 530 is provided in the hollow portion of the heating furnace 510 along the axial direction of the heating furnace 510. The gas supply line 530 has the ability to seal and pressurize a gas such as nitrogen gas or air.

[0106] After the cable core is set in the cross-linking device 50, a gas such as nitrogen gas or air is supplied from a gas supply line 530 to the cable core in the hollow portion of the heating furnace 510 to pressurize it, while the cable core is heated by a heater 520. By heating the cable core for a predetermined time at a predetermined temperature and pressure, the insulating layer 230 is cross-linked.

[0107] After cross-linking, the cable core is removed from the cross-linking device 50. Next, the group of presser tubes that have been covering the cable core are removed.

[0108] (S250: Inspection process) After the second cross-linking step S244, the cable connection portion 20 is inspected by X-ray to check for the presence of foreign matter and to measure the insulation thickness.

[0109] (S260: Metal tube forming process) If it is confirmed in the inspection step S250 that there are no abnormalities, as shown in FIG. 1, a metal tube 250 made of metal is formed so as to cover the outer periphery of the outer semiconductive layer 240 as follows.

[0110] First, a water-absorbing tape is wound around the outer periphery of the outer semiconductive layer 240 to cover it, thereby forming a water-absorbing tape layer 242.

[0111] Next, as shown in FIG. 3, a heat insulating portion 244 having heat insulating properties is formed at a position directly below a welded portion 252, which will be described later.

[0112] After the heat insulating portion 244 is formed, the metal pipe 250 that has been passed through the first power cable 100 a in advance is moved, and the outer periphery of the outer semiconductive layer 240 is covered with the metal pipe 250 .

[0113] After the metal tube 250 is placed, a swaging device is used to reduce the diameter of the metal tube 250 so that it comes into contact with the outer circumferential surface of the layer located inside the metal tube 250 .

[0114] 3, the axial end of the metal pipe 250 and the axial end of the cable metal pipe 150 are welded together at a welded portion 252. Examples of a method for welding the metal pipe 250 include gas welding using hydrogen gas and oxygen gas.

[0115] After welding, a reinforcing portion 254 is formed to cover the outer periphery of the welded portion 252. Specifically, epoxy resin is applied to the outer periphery of the welded portion 252, and glass tape soaked in epoxy resin is wound around it. Furthermore, adhesive PET tape is wound around it to cover these. In this way, the reinforcing portion 254 is formed.

[0116] 1, an adhesive PE tape and an adhesive PET tape are wound in this order so as to fill in the step between the exposed portion of the cable metal tube 150 and the cable sheath 160. In this way, a filling portion 256 is formed.

[0117] (S270: Anti-corrosion layer formation process) After the metal pipe forming step S260, as shown in FIG. 1, a corrosion prevention layer 260 made of resin is formed so as to cover the outer periphery of the metal pipe 250 as follows.

[0118] First, a PE tube that has been passed through the first power cable 100a in advance is used to cover the outer periphery of the metal pipe 250, the exposed portion of the cable metal pipe 150, and part of the outer periphery of the cable sheath 160. After covering the metal pipe 250, the PE tube is thermally shrunk. This forms the first anticorrosion layer 262.

[0119] After the first corrosion protection layer 262 is formed, PE tape is wrapped around and heated to melt so as to cover the step between the axial end of the first corrosion protection layer 262 and the cable sheath 160, as shown in Fig. 1. This forms the first corrosion protection part 263.

[0120] Next, the PE tube that has been passed through the first power cable 100a in advance is used to cover the outer periphery of the first corrosion protection layer 262, the first corrosion protection portion 263, and part of the outer periphery of the cable sheath 160. After covering them, the PE tube is heat-shrunk. This forms the second corrosion protection layer 264.

[0121] After the second corrosion protection layer 264 is formed, PE tape is wrapped around and heated to melt so as to cover the step between the axial end of the second corrosion protection layer 264 and the cable sheath 160, as shown in Fig. 1. This forms the second corrosion protection part 265.

[0122] (S280: Post-processing process) After the anticorrosion layer forming step S270, the following post-treatments may be carried out as necessary.

[0123] 1, adhesive PE tape or the like is wound around the end (second corrosion protection portion 265) in the axial direction of the corrosion protection layer 260 so as to cover it, thereby forming the cover portion 270.

[0124] In this manner, the linked power cable 10 of this embodiment is manufactured.

[0125] (3) Effects of this embodiment According to this embodiment, one or more of the following effects are achieved.

[0126] (a) In the connected power cable 10 of this embodiment, multiple power cables 100 are connected via a cable connection portion 20. The cable connection portion 20 has, for example, a conductor connection portion 210, an inner semiconductive layer 220, an insulating layer 230, an outer semiconductive layer 240, a metal pipe 250, and an anticorrosion layer 260. This configuration can improve the reliability of the cable connection portion 20.

[0127] (b) The configuration of this embodiment allows the outermost diameter of the cable connection portion 20 to be approximately equal to the outermost diameter of the power cable 100. Specifically, the outermost diameter of the corrosion protection layer 260 in a cross section that includes the conductor connection portion 210 and is perpendicular to the axis of the power cable 100 can be set to be +15 mm or less greater than the outermost diameter of the power cable 100.

[0128] By making the outermost diameter of the cable connection portion 20 approximately equal to the outermost diameter of the power cable 100 in this way, it is possible to improve the flexibility of the connecting power cable 10. This makes it possible to improve the resistance of the connecting power cable 10 to bending stresses that it receives when it is wound onto a turntable, transported, extended, and installed.

[0129] (c) The configuration of this embodiment can improve the connection strength between the power cables 100 at the cable connection portion 20. This can improve the resistance of the linked power cable 10 to the tensile force it receives when extending and laying the linked power cable 10, or when a tidal current occurs after laying the linked power cable 10.

[0130] (d) The configuration of this embodiment can improve the sealing performance of the cable connection part 20. This can prevent water from entering the cable connection part 20 when the connecting power cable 10 is laid on the seabed, and can prevent corrosion of the conductors 110 and the like.

[0131] (e) In the welded portion 212 of the conductor connection portion 210 of this embodiment, the conductors 110 are directly welded to each other without a metal tube (so-called conductor sleeve) being provided around the outer periphery of the conductors 110. With this configuration, the outer diameter of the conductor connection portion 210 can be made substantially equal to the outer diameter of the conductor 110 of the power cable 100. As a result, it is possible to easily make the outermost diameter of the cable connection portion 20 substantially equal to the outermost diameter of the power cable 100.

[0132] Furthermore, by directly welding the conductors 110 together, the connection strength between the power cables 100 at the cable connection portion 20 can be stably improved.

[0133] (f) In this embodiment, the cable insulating layer 130 of the power cable 100 forms a peel surface that is inclined at a predetermined taper angle θ with respect to the axis of the conductor 110. The taper angle θ of the peel surface of the cable insulating layer 130 is, for example, 5.2° or more and 8.6° or less. By setting the taper angle θ to 5.2° or more, it is possible to prevent the length of the cable connection portion 20 in the axial direction of the conductor 110 from becoming excessively long. On the other hand, by setting the taper angle θ to 8.6° or less, it is possible to alleviate the electric field around the exposed cable insulating layer 130 while ensuring workability. In this way, it is possible to improve the reliability of the cable connection portion 20 while preventing the cable connection portion 20 from becoming excessively large.

[0134] (g) In this embodiment, the insulating layer 230 is made of insulating tape wrapped around the outer periphery of the internal semiconductive layer 220 and the exposed portion of the cable insulating layer 130. This allows the insulating layer 230 to be formed to fit the complex outer shapes of the internal semiconductive layer 220 and the exposed portion of the cable insulating layer 130.

[0135] Furthermore, the outer semiconductive layer 240 is formed, for example, from a semiconductive tube that covers the outer periphery of the cable insulating layer 130. This allows the surface of the outer semiconductive layer 240 to be smooth even if the layer inside the outer semiconductive layer 240 is formed from tape.

[0136] Consider a case where the insulating layer and the outer semiconductive layer are each made of tape. In this case, if a second crosslinking step is performed to simultaneously crosslink the insulating layer and the outer semiconductive layer, the surface of the outer semiconductive layer may not be smooth due to the complex shapes of the exposed portions of the inner semiconductive layer and the cable insulating layer and the unevenness of the tapes in both the insulating layer and the outer semiconductive layer.

[0137] In contrast, in this embodiment, by configuring the insulating layer 230 using tape and the outer semiconductive layer 240 using a tube, the tape-wrap surface of the insulating layer 230, which is formed to fit the complex contours of the inner semiconductive layer 220 and the exposed portion of the cable insulating layer 130, can be smoothly covered with the tube of the outer semiconductive layer 240. This makes it easy to achieve both adaptability to complex contours and a smooth surface of the outer semiconductive layer 240. Furthermore, configuring the outer semiconductive layer 240 using a tube can also shorten the work time.

[0138] (h) In this embodiment, the metal pipe 250 is narrowed so as to contact the outer circumferential surface of the layer located inside the metal pipe 250 (i.e., the water-absorbing tape layer 242). Therefore, the metal pipe 250 has traces of narrowing. With this configuration, the metal pipe 250 can be formed to fit the complex outer shapes of the outer semiconductive layer 240 and the exposed portion of the stepped stripped cable core. As a result, the outermost diameter of the cable connection part 20 can be reduced.

[0139] (i) In this embodiment, a heat insulating portion 244 having heat insulating properties is provided between the welded portion 252 and the outer semiconductive layer 240. This makes it possible to suppress thermal deterioration of the cable core when welding the welded portion 252. Furthermore, by suppressing heat transfer to the cable core using the heat insulating portion 244, the welding process can be carried out reliably, and the welded portion 252 can be firmly welded. As a result, it is possible to improve the reliability of the connected power cable 10 as a whole.

[0140] (j) In this embodiment, the reinforcing portion 254 is provided so as to cover the outer periphery of the welded portion 252. This makes it possible to suppress the occurrence of cracks at the end of the welded portion 252. As a result, it is possible to improve the water resistance of the cable connection portion 20.

[0141] (k) In this embodiment, the filling portion 256 is provided so as to fill the step between the exposed portion of the cable metal pipe 150 and the cable sheath 160. This allows the anticorrosion layer 260 to smoothly cover the area between the exposed portion of the cable metal pipe 150 and the cable sheath 160. From this perspective as well, it is possible to improve the water penetration resistance of the cable connection portion 20.

[0142] (l) In this embodiment, the corrosion protection layer 260 is configured by a tube that covers the outer periphery of the metal pipe 250, the exposed portion of the cable metal pipe 150, and part of the outer periphery of the cable sheath 160. This allows the tube of the corrosion protection layer 260 to easily cover the outer periphery of the metal pipe 250. In addition, the outer periphery of the corrosion protection layer 260 can be made smooth. As a result, the corrosion protection provided by the corrosion protection layer 260 can be improved.

[0143] (m) In this embodiment, the corrosion protection and reliability of the corrosion protection layer 260 can be improved. Even if part of the second corrosion protection layer 264 is torn and water seeps in, the first corrosion protection layer 262 remains intact, thereby reliably preventing water from seeping into the cable core inside the first corrosion protection layer 262. As a result, the reliability of the cable connection part 20 can be stably improved.

[0144] <Other Embodiments of the Present Disclosure> Although the embodiments of the present disclosure have been specifically described above, the present disclosure is not limited to the above-described embodiments and can be modified in various ways without departing from the spirit of the present disclosure.

[0145] In the above embodiment, the case where the connecting power cable 10 is configured as an underwater cable has been described, but the connecting power cable 10 may also be configured to be laid underground or above ground.

[0146] In the above embodiment, the linking power cable 10 has one cable connection portion 20 , but the linking power cable 10 may have a plurality of cable connection portions 20 .

[0147] In the above embodiment, the conductors 110 are directly welded to each other at the conductor connection portion 210, but the conductors 110 may also be connected to each other by compressing a conductor sleeve that surrounds the outer periphery of the conductors 110 at the conductor connection portion 210. However, from the viewpoint of reducing the outer diameter of the conductor connection portion 210 and improving connection strength, it is preferable that the conductors 110 are directly welded to each other.

[0148] In the above-described embodiment, the case where the filling portion 256 is provided between the exposed portion of the cable metal tube 150 and the cable sheath 160 has been described, but the end of the cable sheath 160 may also be cut in a tapered shape.

[0149] In the above embodiment, the anticorrosion layer 260 is provided in a plurality of layers in the radial direction of the conductor 110, but the anticorrosion layer 260 may be a single layer as long as corrosion resistance can be ensured.

[0150] In the above embodiment, the anticorrosion layer 260 is made of a tube, but the anticorrosion layer 260 may be made of a tape. The anticorrosion layer 260 may be either insulating or semi-conductive.

[0151] <Preferred aspects of the present disclosure> Preferred aspects of the present disclosure are described below.

[0152] (Appendix 1) A plurality of power cables; at least one cable connection portion that connects a pair of power cables among the plurality of power cables; Equipped with The cable connection portion is a conductor connection portion connecting the conductors of the pair of power cables; an inner semiconductive layer that is provided so as to cover an outer periphery of the conductor connection portion and has semiconductivity; an insulating layer having insulating properties and provided so as to cover an outer periphery of the internal semiconducting layer; an outer semiconductive layer that is provided so as to cover the outer periphery of the insulating layer and has semiconductivity; a metal tube made of metal and provided so as to cover an outer periphery of the outer semiconductive layer; a corrosion protection layer made of resin and provided to cover the outer periphery of the metal pipe; have Interlocking power cable.

[0153] (Appendix 2) The outermost diameter of the anticorrosion layer in a cross section that includes the conductor connection portion and is perpendicular to the axis of the power cable is +15 mm or less relative to the outermost diameter of the power cable. 1. A connecting power cable as described in Appendix 1.

[0154] (Appendix 3) In the conductor connection portion, the conductors are directly welded to each other without a metal tube being provided around the periphery of the conductors. 1. A connecting power cable according to claim 1 or 2.

[0155] (Appendix 4) the conductor has a plurality of conductor strand layers including a plurality of conductor strands; In the conductor connection portion, the plurality of conductor wires are welded to each other at the plurality of conductor wire layers. 1. A connecting power cable as described in Appendix 3.

[0156] (Appendix 5) The inner semiconductive layer is formed of a semiconductive tape wrapped around the outer periphery of the conductor connection portion. 5. The interconnected power cable of any one of claims 1 to 4.

[0157] (Appendix 6) The insulating layer is formed of an insulating tape wrapped around the outer periphery of the inner semiconducting layer. 6. The interconnected power cable of any one of claims 1 to 5.

[0158] (Appendix 7) The outer semiconductive layer is formed of a semiconductive tube that covers the outer periphery of the insulating layer. 7. The interconnected power cable of any one of claims 1 to 6.

[0159] (Appendix 8) The cable connection portion further includes a water-absorbing tape layer provided between the outer semiconductive layer and the metal pipe. 8. The interconnected power cable of any one of claims 1 to 7.

[0160] (Appendix 9) The metal tube is reduced in diameter so as to contact the outer circumferential surface of the layer located inside the metal tube. 9. The interconnected power cable of any one of claims 1 to 8.

[0161] (Appendix 10) The metal tube has traces of being reduced in diameter. 10. The interconnected power cable of claim 9.

[0162] (Appendix 11) The anticorrosion layer is provided in a plurality of layers in the radial direction of the conductor. 11. The interconnected power cable of any one of claims 1 to 10.

[0163] (Appendix 12) Each of the pair of power cables includes, from a central axis side to an outer periphery side, the conductor, a cable inner semiconductive layer, a cable insulating layer, a cable outer semiconductive layer, a cable metal tube, and a cable sheath, In each of the pair of power cables, the cable inner semiconductive layer, the cable insulating layer, the cable outer semiconductive layer, the cable metal tube, and the cable sheath are stripped stepwise from the tip of the conductor toward the opposite side. 12. The interconnected power cable of any one of claims 1 to 11.

[0164] (Appendix 13) The cable insulation layer has a peel surface that is inclined at a taper angle of 5.2° to 8.6° relative to the axis of the conductor. 13. The interconnected power cable of claim 12.

[0165] (Appendix 14) The cable connection portion is a welded portion formed by welding an axial end of the metal pipe to an axial end of the cable metal pipe; a heat insulating portion provided between the welded portion and the outer semiconductive layer and having heat insulating properties; Further having 14. The interconnected power cable of claim 12 or 13.

[0166] (Appendix 15) The cable connection portion further includes a reinforcing portion that covers the outer periphery of the welded portion and suppresses cracks in the welded portion. 15. The interconnected power cable of claim 14.

[0167] (Appendix 16) The cable connection portion further includes a filling portion that fills a step between the exposed portion of the cable metal tube and the cable sheath. 16. The interconnected power cable of any one of claims 12 to 15.

[0168] (Appendix 17) The anticorrosion layer is formed of a tube that covers the outer periphery of the metal pipe and a part of the outer periphery of the cable sheath. 17. The interconnected power cable of any one of claims 12 to 16.

[0169] (Appendix 18) The anticorrosion layer has a bulge on the outer periphery of the cable sheath. 18. The interconnected power cable of claim 17.

[0170] (Appendix 19) The outermost diameter in a cross section perpendicular to the axis of the power cable and including the bulge portion is greater than or equal to +5 mm and less than or equal to +20 mm with respect to the outermost diameter of the power cable. 19. The interconnected power cable of claim 18.

[0171] (Appendix 20) The cable connecting portion further includes a mark indicating the position of the cable connecting portion. 19. The interconnected power cable of any one of claims 1 to 19.

[0172] (Appendix 21) a conductor connection portion connecting the conductors of the pair of power cables; an inner semiconductive layer that is provided so as to cover an outer periphery of the conductor connection portion and has semiconductivity; an insulating layer having insulating properties and provided so as to cover an outer periphery of the internal semiconducting layer; an outer semiconductive layer that is provided so as to cover the outer periphery of the insulating layer and has semiconductivity; a metal tube made of metal and provided so as to cover an outer periphery of the outer semiconductive layer; a corrosion protection layer made of resin and provided to cover the outer periphery of the metal pipe; Equipped with Cable connection structure.

[0173] (Appendix 22) providing a plurality of power cables; forming at least one cable connection portion by connecting a pair of power cables among the plurality of power cables; Equipped with The step of forming the cable connection portion includes: forming a conductor connection portion by connecting the conductors of the pair of power cables; forming an inner semiconductive layer having semiconductivity so as to cover an outer periphery of the conductor connection portion; forming an insulating layer having insulating properties so as to cover an outer periphery of the internal semiconducting layer; forming an outer semiconductive layer having semiconductivity so as to cover an outer periphery of the insulating layer; forming a metal tube made of metal so as to cover an outer periphery of the outer semiconductive layer; forming a corrosion protection layer made of resin so as to cover an outer periphery of the metal pipe; have Method for manufacturing interlocking power cables. [Explanation of symbols]

[0174] 10 Connecting power cable 20 Cable connection 50 Crosslinking equipment 100 Power Cable 100a First power cable 100b Second power cable 110 Conductor 112 Conductor wire 114(114a~114f) Conductor wire layer 120 Cable inner semiconductive layer 130 Cable insulation layer 140 Cable outer semiconductive layer 150 Cable Metal Tube 160 Cable sheath 210 Conductor connection 212 Welded parts 220 Internal semiconductive layer 230 Insulating layer 240 outer semiconductive layer 242 Water-absorbing tape layer 244 Insulation section 250 metal tube 252 Welded parts 254 Reinforcement 256 Filling section 260 Anti-corrosion layer 260a Bulge 262 First anti-corrosion layer 263 First Corrosion Prevention Department 264 Second anti-corrosion layer 265 Second Corrosion Prevention Department 270 Cover 310 Air Nozzle 320 Ring 510 Heating Furnace 520 Heater 530 Gas Supply Line

Claims

1. A plurality of power cables; at least one cable connection portion connecting a pair of power cables among the plurality of power cables; Equipped with The cable connection portion is a conductor connection portion connecting the conductors of the pair of power cables; an inner semiconductive layer that is provided so as to cover an outer periphery of the conductor connection portion and has semiconductivity; an insulating layer having insulating properties and provided so as to cover an outer periphery of the internal semiconducting layer; an outer semiconductive layer that is provided so as to cover the outer periphery of the insulating layer and has semiconductivity; a metal tube made of metal and provided so as to cover an outer periphery of the outer semiconductive layer; a water-absorbing tape layer provided between the outer semiconductive layer and the metal pipe; a corrosion protection layer made of resin and provided to cover the outer periphery of the metal pipe; have Interlocking power cable.

2. The metal tube is reduced in diameter so as to contact the outer circumferential surface of the layer located inside the metal tube. The interconnected power cable of claim 1 .

3. A plurality of power cables; at least one cable connection portion connecting a pair of power cables among the plurality of power cables; Equipped with The cable connection portion is a conductor connection portion connecting the conductors of the pair of power cables; an inner semiconductive layer that is provided so as to cover an outer periphery of the conductor connection portion and has semiconductivity; an insulating layer having insulating properties and provided so as to cover an outer periphery of the internal semiconducting layer; an outer semiconductive layer that is provided so as to cover the outer periphery of the insulating layer and has semiconductivity; a metal tube made of metal and provided so as to cover an outer periphery of the outer semiconductive layer; a corrosion protection layer made of resin and provided to cover the outer periphery of the metal pipe; and The metal tube is reduced in diameter so as to contact the outer circumferential surface of the layer located inside the metal tube. Interlocking power cable.

4. The metal tube has traces of being reduced in diameter. The interconnecting power cable according to claim 2 or 3.

5. Each of the pair of power cables includes, from a central axis side to an outer periphery side, the conductor, a cable inner semiconductive layer, a cable insulating layer, a cable outer semiconductive layer, a cable metal tube, and a cable sheath, In each of the pair of power cables, the cable inner semiconductive layer, the cable insulating layer, the cable outer semiconductive layer, the cable metal tube, and the cable sheath are stripped stepwise from the tip of the conductor toward the opposite side. The interconnecting power cable according to any one of claims 1 to 4.

6. The cable connection portion is a welded portion formed by welding an axial end of the metal pipe to an axial end of the cable metal pipe; a heat insulating portion provided between the welded portion and the outer semiconductive layer and having heat insulating properties; Further having 6. The interconnecting power cable of claim 5.

7. A plurality of power cables; at least one cable connection portion connecting a pair of power cables among the plurality of power cables; Equipped with Each of the pair of power cables has, from a central axis side to an outer periphery side, a conductor, a cable inner semiconductive layer, a cable insulating layer, a cable outer semiconductive layer, a cable metal tube, and a cable sheath, In each of the pair of power cables, the cable inner semiconductive layer, the cable insulating layer, the cable outer semiconductive layer, the cable metal tube, and the cable sheath are stripped stepwise from a tip of the conductor toward the opposite side, The cable connection portion is a conductor connection portion connecting the conductors of the pair of power cables; an inner semiconductive layer that is provided so as to cover an outer periphery of the conductor connection portion and has semiconductivity; an insulating layer having insulating properties and provided so as to cover an outer periphery of the internal semiconducting layer; an outer semiconductive layer that is provided so as to cover the outer periphery of the insulating layer and has semiconductivity; a metal tube made of metal and provided so as to cover an outer periphery of the outer semiconductive layer; a corrosion protection layer made of resin and provided to cover the outer periphery of the metal pipe; a welded portion formed by welding an axial end of the metal pipe to an axial end of the cable metal pipe; a heat insulating portion provided between the welded portion and the outer semiconductive layer and having heat insulating properties; have Interlocking power cable.

8. The cable connection portion further includes a reinforcing portion that covers the outer periphery of the welded portion and suppresses cracks in the welded portion.

8. The interconnecting power cable of claim 6 or claim 7.

9. The cable connection portion further includes a filling portion that fills a step between the exposed portion of the cable metal tube and the cable sheath. The interconnecting power cable according to any one of claims 5 to 8.

10. A plurality of power cables; at least one cable connection portion connecting a pair of power cables among the plurality of power cables; Equipped with Each of the pair of power cables has, from a central axis side to an outer periphery side, a conductor, a cable inner semiconductive layer, a cable insulating layer, a cable outer semiconductive layer, a cable metal tube, and a cable sheath, In each of the pair of power cables, the cable inner semiconductive layer, the cable insulating layer, the cable outer semiconductive layer, the cable metal tube, and the cable sheath are stripped stepwise from a tip of the conductor toward the opposite side, The cable connection portion is a conductor connection portion connecting the conductors of the pair of power cables; an inner semiconductive layer that is provided so as to cover an outer periphery of the conductor connection portion and has semiconductivity; an insulating layer having insulating properties and provided so as to cover an outer periphery of the internal semiconducting layer; an outer semiconductive layer that is provided so as to cover the outer periphery of the insulating layer and has semiconductivity; a metal tube made of metal and provided so as to cover an outer periphery of the outer semiconductive layer; a corrosion protection layer made of resin and provided to cover the outer periphery of the metal pipe; a filling portion that fills a step between the exposed portion of the cable metal tube and the cable sheath; have Interlocking power cable.

11. The cable insulation layer has a peel surface that is inclined at a taper angle of 5.2° to 8.6° relative to the axis of the conductor. The interconnecting power cable of any one of claims 5 to 10.

12. The anticorrosion layer is formed of a tube that covers the outer periphery of the metal pipe and a part of the outer periphery of the cable sheath. A connecting power cable according to any one of claims 5 to 11.

13. The anticorrosion layer has a bulge on the outer periphery of the cable sheath.

13. The interconnecting power cable of claim 12.

14. The outermost diameter in a cross section perpendicular to the axis of the power cable and including the bulge portion is greater than or equal to +5 mm and less than or equal to +20 mm with respect to the outermost diameter of the power cable.

14. The interconnecting power cable of claim 13.

15. The outermost diameter of the anticorrosion layer in a cross section that includes the conductor connection portion and is perpendicular to the axis of the power cable is +15 mm or less relative to the outermost diameter of the power cable. A connecting power cable according to any one of claims 1 to 14.

16. In the conductor connection portion, the conductors are directly welded to each other without a metal tube being provided around the periphery of the conductors.

16. A connecting power cable according to any one of claims 1 to 15.

17. The inner semiconductive layer is formed of a semiconductive tape wrapped around the outer periphery of the conductor connection portion.

17. A connecting power cable according to any one of claims 1 to 16.

18. The insulating layer is formed of an insulating tape wrapped around the outer periphery of the inner semiconducting layer.

18. A connecting power cable according to any one of claims 1 to 17.

19. The outer semiconductive layer is formed of a semiconductive tube that covers the outer periphery of the insulating layer.

19. The interconnecting power cable of any one of claims 1 to 18.

20. The anticorrosion layer is provided in a plurality of layers in the radial direction of the conductor.

20. The interconnecting power cable of any one of claims 1 to 19.

21. The cable connection part is configured as the cable connection part provided in the connecting power cable according to any one of claims 1 to 20. Cable connection structure.

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