JP2022157329A - Method of forming cable intermediate connection structure and cable intermediate connection structure - Google Patents

Abstract

To provide a method of forming a cable intermediate connection structure and a cable intermediate connection structure that can suppress insulation breakdown and is made quick and simple.SOLUTION: A method of forming a cable intermediate connection structure 1 includes: a first power cable cutting step for forming a first cutting end portion having a waviness width of 6.0 mm or less on one end portion of a first external semiconductor layer 13 and a first cutting inclined portion 41 that extends from the first cutting end portion to the other end portion, and has a rising angle, which is more than 5.00 degrees and equal to or less than 8.00 degrees, while exposing one end side of a first cable conductor 11 and one end side of a first cable insulator 12; a second power cable cutting step by a similar step; a connecting step of connecting the first cable conductor and the end portion on the one end side of a second cable conductor 21; and a mounting step of forming a semiconductor portion 8 around the outer periphery of a conductor connection portion 2 and the outer periphery of the exposed portions of the first cable conductor and the second cable conductor, and mounting a tubular insulating unit 3 over the outer periphery of the exposed portions of a second external semiconductor layer 23 from the first external semiconductor layer.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a method of forming an intermediate cable connection structure and an intermediate cable connection structure.

Conventionally, when forming a cable intermediate connection structure in which the ends of two power cables are connected to each other, an outer semiconductive layer (hereinafter referred to as a , simply referred to as an outer conductor) is required.

In this process, first, the sheath, metal shielding layer, semi-conductive tape layer, etc. are scraped off from the outside of the power cable by hand using a tool, and the one end of the power cable is removed. Expose the outer conductor. Subsequently, for one end of the power cable where the outer conductor is exposed, for example, the outer conductor is manually scraped off using a piece of glass so as to form a slope shape toward the other end of the power cable, It exposes the conductor and insulator at one end of the power cable. The work of scraping off the outer conductor in this way requires a long time in addition to depending on the skill level of the operator who performs the manual work.

In addition, in Patent Document 1, regarding the cable intermediate connection structure, if the rising angle of the scraped end of the outer semi-conductive layer is large, partial discharge is likely to occur. A structure is described in which a scraped end portion of the outer semiconducting layer having a thickness of less than 100°C is produced and pressure is applied from the outer periphery of the rubber block insulator.

Patent No. 4283778

However, in Patent Literature 1, when the outer semiconductive layer having the scraped end portion of the above shape is produced by the outer conductor scraping machine, the dielectric breakdown of the cable intermediate connection structure cannot be sufficiently suppressed in some cases.

An object of the present disclosure is to provide a method for forming an intermediate cable connection structure and a cable intermediate connection structure that can suppress dielectric breakdown and are quick and simple.

[1] A first power cable having at least a first cable conductor, a first cable insulator, and a first outer semi-conductive layer from the center to the outer circumference, and at least a second cable conductor from the center to the outer circumference. A method for forming a cable intermediate connection structure for connecting a cable conductor, a second cable insulation and a second outer semi-conductive layer, the first outer end of the second power cable, the first outer end of the first outer With respect to the first power cable in which the semiconductive layer is exposed, one end side of the first power cable is cut stepwise toward the other end side using a cutter, and the one end side of the first cable conductor is cut. and a first cut end portion exposing one end side of the first cable insulator and having a waviness width of 6.0 mm or less on one end side of the first outer semi-conductive layer, and from the first cut end portion A first power cable cutting step of forming a first cutting inclined portion extending to the other end side and having a rising angle of more than 5.00 degrees and less than or equal to 8.00 degrees; and exposing the second outer semiconductive layer on the one end side. One end side of the second power cable is step-stripped toward the other end side using a cutter for the second power cable, and the one end side of the second cable conductor and the second cable are cut. Exposing one end side of the insulator, a second cut end portion having a waviness width of 6.0 mm or less on one end side of the second outer semi-conductive layer, and extending from the second cut end portion to the other end side , a second power cable cutting step forming a second cut slope portion having a rising angle of more than 5.00 degrees and not more than 8.00 degrees; and one end of the first cable conductor exposed in the first power cable cutting step. a connecting step of connecting the end portion of the side and the end portion of the one end side of the second cable conductor exposed in the second power cable cutting step with a conductor connection portion; A cylindrical semiconducting portion is formed on the outer circumference of the exposed portion of the first cable conductor and the outer circumference of the exposed portion of the second cable conductor, and the second outer semiconducting layer extends from the outer circumference of the exposed portion of the first outer semiconducting layer. and a mounting step of mounting a cylindrical insulation unit over the outer periphery of the exposed portion of the cable intermediate connection structure.
[2] In the mounting step, insulating oil is applied from the outer peripheral surface of the exposed portion of the first external semi-conductive layer to the outer peripheral surface of the exposed portion of the second external semi-conductive layer, and then the insulating unit is attached. The method for forming the cable intermediate connection structure according to the above [1].
[3] The method for forming an intermediate cable connection structure according to [2] above, wherein the insulating oil is fluorine oil.
[4] The insulation unit is made of silicone rubber, and is wound in a spiral shape around the inner peripheral surface of the insulation unit in the mounting step, and is expanded in diameter to hold the inner peripheral surface of the insulation unit. The method for forming a cable intermediate connection structure according to any one of [1] to [3] above, wherein the member is pulled out from the insulation unit and the insulation unit is attached.
[5] The above [1], further comprising, before the mounting step, removing at least one of the other end side stepped portion of the first inclined cutting portion and the other end side stepped portion of the second inclined cutting portion. ] to [4], the method for forming a cable intermediate connection structure.
[6] One end portion of a first power cable comprising at least a first cable conductor, a first cable insulator and a first outer semi-conductive layer from the center to the outer periphery; A cable intermediate connection structure for connecting a cable conductor, a one end portion of a second power cable comprising a second cable insulator and a second outer semi-conductive layer, the one end of the first cable conductor and a conductor connecting portion connecting the portion and the end portion of the second cable conductor on the one end side, and covering from the outer periphery of the first outer semiconductive layer to the outer periphery of the one end side of the second outer semiconductive layer. and an insulating unit, wherein the waviness width of the first cut edge on one end side of the first outer semi-conductive layer covered with the insulation unit is 6.0 mm or less, and the waviness from the first cut edge is 6.0 mm or less. The rising angle of the first cutting inclined portion extending to the end side is more than 5.00 degrees and less than or equal to 8.00 degrees, and the second cutting edge is located on one end side of the second outer semiconductive layer covered with the insulating unit. The waviness width of the portion is 6.0 mm or less, and the rising angle of the second cut inclined portion extending from the second cut end portion to the other end side is more than 5.00 degrees and 8.00 degrees or less. Intermediate connection structure.

Advantageous Effects of Invention According to the present disclosure, it is possible to provide a method for forming a cable intermediate connection structure and a cable intermediate connection structure that are capable of suppressing dielectric breakdown and that are quick and simple.

FIG. 1 is a longitudinal sectional view showing an example of the cable intermediate connection structure of the embodiment. 2 is an enlarged sectional view of the cable intermediate connection structure of FIG. 1; FIG. FIG. 3 is a side view showing an example of one end side of the first power cable obtained in the first power cable cutting step. 4 is an enlarged side view of one end of the first power cable of FIG. 3. FIG. FIG. 5 is a side view showing an example of one end side of the second power cable obtained in the second power cable cutting step. 6 is an enlarged side view of one end of the second power cable of FIG. 5. FIG. FIG. 7 is a side view showing an example of the connection process. FIG. 8 is a cross-sectional view showing an example of a mounting process for mounting an insulation unit having a diameter expansion holding member.

A detailed description will be given below based on the embodiment.

The inventors of the present invention have found that, as in Patent Document 1, when an outer semiconductor layer having a scraped end portion with a rising angle of 5 degrees or less is produced by an outer conductor shaving machine, the outer conductor, which is the starting point of the outer conductor, It has been found that the ends of the outer conductors may vary greatly, which reduces the smoothness of the ends of the outer conductor, and cannot sufficiently suppress the dielectric breakdown of the cable intermediate connection structure. As a result of further intensive research, the present inventors used a cutting tool to step-cut one end of the power cable where the outer semiconductive layer was exposed in order to expose the conductor and the insulator. In this case, if the rising angle of the cut inclined portion of the outer semi-conductive layer is 5.00 degrees or less, the smoothness of the cut edge of the outer semi-conductive layer is poor. Even with covering, the semi-conductive end of the insulating unit cannot cover the cut end of the external semi-conductive layer, and the electric field concentrates on the cut end, which is likely to cause dielectric breakdown in the cable intermediate connection structure. . Furthermore, the present inventors focused on the shape of the cutting edge and cutting slope of the outer semi-conductive layer formed using a cutter, and found that the wavy width of the cutting edge and the rising angle of the cutting slope have a predetermined relationship. It was found that dielectric breakdown of the cable intermediate connection structure is suppressed by satisfying The present disclosure is based on such findings.

A method for forming an intermediate cable connection structure according to an embodiment includes: an end portion on one end side of a first power cable comprising at least a first cable conductor, a first cable insulator and a first outer semi-conductive layer from the center to the outer circumference; A method for forming a cable intermediate connection structure for connecting an end on one end side of a second power cable comprising at least a second cable conductor, a second cable insulator and a second outer semi-conductive layer from the center to the outer circumference. Then, with respect to the first power cable in which the first outer semi-conductive layer on the one end side is exposed, a cutter is used to step-scrape the one end side of the first power cable toward the other end side. , a first cut end portion exposing one end side of the first cable conductor and one end side of the first cable insulator, and having a waviness width of 6.0 mm or less on one end side of the first outer semi-conductive layer; , and a first power cable cutting step that extends from the first cut end to the other end and forms a first cut inclined portion having a rising angle of more than 5.00 degrees and 8.00 degrees or less; With respect to the second power cable in which the second outer semi-conductive layer is exposed, one end side of the second power cable is step-stripped toward the other end side using a cutter, and the second cable is cut. A second cut end portion that exposes one end side of the conductor and one end side of the second cable insulator and has a waviness width of 6.0 mm or less on one end side of the second outer semi-conductive layer, and the second A second power cable cutting step of forming a second cut inclined portion extending from the cut end portion to the other end side and having a rising angle of more than 5.00 degrees and not more than 8.00 degrees; and the first power cable cutting step a connecting step of connecting the exposed end of the first cable conductor and the one end of the second cable conductor exposed in the second power cable cutting step with a conductor connecting portion; A cylindrical semiconductive portion is formed around the outer periphery of the conductor connection portion, the outer periphery of the exposed portion of the first cable conductor, and the outer periphery of the exposed portion of the second cable conductor, and the exposed portion of the first outer semiconductive layer is formed. and a mounting step of mounting a cylindrical insulating unit from the outer periphery to the outer periphery of the exposed portion of the second external semi-conductive layer.

The cable intermediate connection structure of the embodiment comprises: an end portion on one end side of a first power cable comprising at least a first cable conductor, a first cable insulator and a first outer semi-conductive layer from the center to the outer periphery; a cable intermediate connection structure for connecting an end of a second power cable comprising at least a second cable conductor, a second cable insulation and a second outer semi-conductive layer toward the first cable, a conductor connecting portion connecting an end portion of the conductor on the one end side and an end portion of the second cable conductor on the one end side; and an insulation unit that covers up to the outer periphery of the side, and the waviness width of the first cut edge on one end side of the first external semiconductive layer covered with the insulation unit is 6.0 mm or less, and the first The rising angle of the first cutting inclined portion extending from one cutting end to the other end is more than 5.00 degrees and less than or equal to 8.00 degrees, and the one end side of the second outer semiconductive layer covered with the insulating unit. , the waving width of the second cutting end is 6.0 mm or less, and the rising angle of the second cutting inclined portion extending from the second cutting end to the other end is more than 5.00 degrees and 8.00 degrees or less .

First, a method for forming the cable intermediate connection structure of the embodiment will be described.

FIG. 1 is a longitudinal sectional view showing an example of the cable intermediate connection structure of the embodiment. 2 is an enlarged sectional view of the cable intermediate connection structure of FIG. 1; FIG. FIG. 3 is a side view showing an example of one end side of the first power cable obtained in the first power cable cutting step. 4 is an enlarged side view of one end of the first power cable of FIG. 3. FIG. FIG. 5 is a side view showing an example of one end side of the second power cable obtained in the second power cable cutting step. 6 is an enlarged side view of one end of the second power cable of FIG. 5. FIG.

1, the first cable conductor 11, the first cable insulator 12, the first outer semiconductive layer 13, the first semiconductive tape layer 14, the first cable shielding layer 15, the first Cable sheath 16, second cable conductor 21 of second power cable 20, second cable insulation 22, second outer semi-conductive layer 23, second semi-conductive tape layer 24, second cable shield layer 25, second cable Sheath 26 is a side view for convenience. For convenience, FIG. 4 shows a part of the first outer semi-conducting layer 13, FIG. 6 shows a part of the second outer semi-conducting layer 23, and FIG. ing.

The method of forming the cable intermediate connection structure 1 of the embodiment is a method of connecting the end of the first power cable 10 on the one end side and the end of the second power cable 20 on the one end side. The one end side of the first power cable 10 is the side connected to the second power cable 20 when the cable intermediate connection structure 1 is formed, and the other end side of the first power cable 10 is the cable intermediate connection structure 1 It is the side that is not connected to the second power cable 20 when the is formed. Further, the one end side of the second power cable 20 is the side connected to the first power cable 10 when the cable intermediate connection structure 1 is formed, and the other end side of the second power cable 20 is the cable intermediate connection It is the side that is not connected to the first power cable 10 when the structure 1 is formed.

The first power cable 10 comprises at least a first cable conductor 11 , a first cable insulation 12 and a first outer semi-conductive layer 13 from the center to the periphery. The first cable conductor 11 extends in the axial direction (longitudinal direction) of the first power cable 10 . A first cable insulation 12 covers the outside of the first cable conductor 11 . A first outer semi-conductive layer 13 covers the outside of the first cable insulation 12 . The inner peripheral portion of the first cable insulator 12 is provided with an inner semi-conductive layer (not shown). The first power cable 10 also includes a first semiconductive tape layer 14 , a first cable shielding layer 15 and a first cable sheath 16 in this order outside the first outer semiconductive layer 13 .

The first cable conductor 11 is made of highly conductive metal such as copper, copper alloy, aluminum, or aluminum alloy. The first cable insulator 12 is made of a highly electrically insulating resin such as crosslinked polyethylene. The inner semi-conductive layer, the first outer semi-conductive layer 13 and the first semi-conductive tape layer 14 are made of semi-conductive resin or the like. The first cable shielding layer 15 is made of a highly conductive metal such as copper, copper alloy, aluminum, or aluminum alloy. The first cable sheath 16 is made of resin such as polyethylene or polyvinyl chloride.

The second power cable 20 is similar to the first power cable 10 . The first power cable 10, the first cable conductor 11, the first cable insulator 12, the first outer semi-conductive layer 13, the first semi-conductive tape layer 14, the first cable shield layer 15 and the first cable sheath 16 each comprise: , second power cable 20 , second cable conductor 21 , second cable insulator 22 , second outer semiconductive layer 23 , second semiconductive tape layer 24 , second cable shield layer 25 and second cable sheath 26 . shall be

The method for forming the intermediate cable connection structure 1 of the embodiment has a first power cable cutting step, a second power cable cutting step, a connecting step, and a mounting step.

In the first power cable cutting step, the one end side of the first power cable 10 is cut to the other end side using a cutter with respect to the first power cable 10 in which the first outer semi-conductive layer 13 on the one end side is exposed. Cut stepped toward . By step stripping using a cutter, the first power cable 10 is continuously cut from one end of the first power cable 10 toward the other end as follows, and shown in FIGS. A first cutting edge 40 and a first cutting ramp 41 are formed. That is, using a cutter, all the first outer semi-conductive layers 13 and first cable insulators 12 are cut from one end of the first power cable 10 toward the other end to cut the first One end side of the cable conductor 11 is exposed, and then all the first outer semi-conductive layers 13 and a certain amount of the first cable insulation are removed from one end of the first cable insulation 12 to the other end. The body 12 is cut to expose one end side of the first cable insulation 12, and then the first outer semi-conductive layer 13 is cut from one end to the other end of the first outer semi-conductive layer 13. 13, the amount of cutting is gradually reduced, the cutting tool is stopped, and the step peeling cutting is completed.

By step-cutting the one end side of the first power cable 10 with a cutter in this way, the one end side of the first cable conductor 11 and the one end side of the first cable insulator 12 are formed on the one end side of the first power cable 10 . is exposed, and a first cut end portion 40 and a first cut inclined portion 41 are formed on one end side of the first outer semi-conductive layer 13 .

As shown in FIG. 4 , the first cutting edge 40 of the first outer semi-conducting layer 13 is on the side facing the second power cable 20 (front side) and is the leading edge portion of the first outer semi-conducting layer 13 . . When viewed from the radially outer side of first power cable 10 , first cut end portion 40 extends along the circumferential direction of first power cable 10 while meandering to one end side and the other end side of first power cable 10 . It is the undulating shape that exists.

As shown in FIG. 4 , the first power cable 10 is the axial distance of the first power cable 10 between the portion closest to the second power cable 20 and the portion farthest from the second power cable 20 at the first cut end 40 . The waviness width a1 of one cutting end portion 40 is 6.0 mm or less. The waviness width a1 of the first cut end portion 40 is defined by a virtual reference circle c1 passing through the portion of the first cut end portion 40 closest to the second power cable 20 and the distance from the second power cable 20 at the first cut end portion 40 to It is the shortest distance between the virtual reference circle c2 passing through the far part. The virtual reference circles c<b>1 and c<b>2 referred to here refer to outer circumference circles of the first cable insulator 12 on a cross section perpendicular to the central axis of the first power cable 10 .

When the waviness width a1 of the first cut end portion 40 is more than 6.0 mm, the first cut end portion 40 acts as a projection of the first outer semiconductive layer 13 at the rising portion of the stress cone that constitutes the insulation unit 3. may work. At this time, electric field concentration occurs in the vicinity of the first cut end portion 40, and dielectric breakdown of the intermediate cable connection structure 1 is likely to occur. If the waviness width a1 is 6.0 mm or less, electric field concentration in the vicinity of the first cut end portion 40 is suppressed, so dielectric breakdown of the intermediate cable connection structure 1 can be suppressed. From this point of view, the waviness width a1 is 6.0 mm or less, preferably 5.0 mm or less.

As shown in FIG. 4 , the first cut inclined portion 41 of the first outer semi-conductive layer 13 is cut from the first cut end portion 40 , which is the end on one end side of the first outer semi-conductive layer 13 , to the first power cable. 10 extends to the other end side. As described above, in the first power cable cutting step, the cutting amount of the first external semi-conductive layer 13 is gradually reduced from one end of the first external semi-conductive layer 13 toward the other end. , the thickness of the first external semiconducting layer 13 increases stepwise toward the other end at one end of the first external semiconducting layer 13, forming a first cut inclined portion 41 having a rising angle θ1. .

The rising angle θ1 of the first cut slanted portion 41 is determined from the start position P of the first cut slanted portion 41 to the height of the first power cable 10 in a longitudinal section along the axial direction of the intermediate cable connection structure 1 as shown in FIG. A straight line connecting the outer surface position P1 of the first cutting inclined portion 41 20 mm away from the other end side, and a first cutting inclination 20 mm away from the starting position P of the first cutting inclined portion 41 toward the other end side of the first power cable 10 It is an angle formed by a straight line connecting the inner surface position P2 of the portion 41 .

Regarding the first cut end portion 40 and the first cut inclined portion 41 formed by step-cutting the first power cable 10 with a cutter, the waviness width a1 of the first cut end portion 40 and the first cut inclined portion 41 There is a correlation between the rising angle θ1 of . A cutting tool is used to reduce the degree of stepwise reduction of the cutting amount of the first outer semi-conductive layer 13, and when the rising angle θ1 is decreased to form the first cutting inclined portion 41, the first cutting end portion 40 is formed. waving width a1 tends to increase. Further, by increasing the degree of stepwise reduction of the cutting amount of the first outer semi-conductive layer 13 using a cutter and increasing the rising angle θ1 to form the first cutting inclined portion 41, the first cutting edge The waving width a1 of the portion 40 tends to decrease.

The rising angle θ1 of the first cut slope portion 41 in the first outer semi-conductive layer 13 is greater than 5.00 degrees and less than or equal to 8.00 degrees. When the rising angle θ1 of the first cutting inclined portion 41 is more than 8.00 degrees, when the hollow cylindrical insulation unit 3 holding the inner peripheral surface 3a shown in FIG. , the shrinkage of the insulation unit 3 cannot follow the shape of the first cut slope portion 41, and voids are likely to be formed inside the insulation unit 3. When the voltage is applied to the void, it discharges, and the dielectric breakdown of the cable intermediate connection structure 1 is likely to occur. If the rising angle θ1 of the first cut inclined portion 41 is 8.00 degrees or less, the formation of voids inside the insulating unit 3 can be suppressed, so dielectric breakdown of the cable intermediate connection structure 1 can be suppressed. From this point of view, the rising angle θ1 of the first cutting slope portion 41 is 8.00 degrees or less, preferably 7.00 degrees or less.

Further, when the rising angle θ1 of the first cutting inclined portion 41 is 5.00 degrees or less, the waviness width a1 of the first cutting end portion 40 increases, and as a result, the waviness width a1 tends to exceed 6.0 mm. . Therefore, electric field concentration occurs in the vicinity of the first cut end portion 40 , and dielectric breakdown of the intermediate cable connection structure 1 is likely to occur. When the rising angle θ1 of the first cut inclined portion 41 is more than 5.00 degrees, the waviness width a1 of the first cut end portion 40 becomes small, so dielectric breakdown of the intermediate cable connection structure 1 can be suppressed.

Further, as described above, in the stepped stripping using a cutter, if the waviness width a1 of the first cutting end portion 40 is small, the rising angle θ1 of the first cutting slope portion 41 increases, and the first cutting slope If the rising angle θ1 of the portion 41 is too large, voids are formed inside the insulating unit 3, and dielectric breakdown is likely to occur. .

The configuration of the cutter used in the first power cable cutting step is to step-cut one end side of the first power cable 10 where the first outer semiconductive layer 13 is exposed, and cut the first cable conductor 11 and the first cable. It is particularly limited if one end side of the insulator 12 can be exposed and the first cut end portion 40 having the waviness width a1 within the above range and the first cutting inclined portion 41 having the rising angle θ1 within the above range can be formed. Do not mean.

As an example, the cutter used in the first power cable cutting step has a plurality of roller portions arranged along the circumferential direction and a plate-like cutting blade portion. The cutting blade portion is cut into the outer periphery of the first outer semi-conductive layer 13, and the roller portion of the cutter is moved from one end side of the first power cable 10 to the other end side while cutting the cutting blade portion into the first outer semi-conductive layer. By rotating in the circumferential direction of 13, one end side of the first power cable 10 is stepped and cut. In order to form the first cutting end portion 40 and the first cutting inclined portion 41 , the blade surface of the cutting blade portion is inclined at a predetermined angle with respect to the axial direction of the first power cable 10 . Therefore, it is preferable that the type of cutting edge of the cutting edge is a cutting edge.

The first power cable 10, which is prepared in the first power cable cutting step and has the first outer semi-conductive layer 13 on one end side exposed, is cut by cutting the outside of the first power cable 10 using, for example, a sheath cutter or a knife. can be obtained by sequentially removing the first cable sheath 16, the first cable shield layer 15 and the first semiconductive tape layer 14 from the .

The second power cable cutting step is basically the same as the first power cable cutting step. The first power cable 10, the first cable conductor 11, the first cable insulator 12, the first outer semiconductive layer 13, the first semiconductive tape layer 14, the first cable shielding layer 15, the first cable shielding layer 15, and the first cable insulator 12 in the first power cable cutting step. 1 Cable sheath 16, first cut end portion 40, first cut inclined portion 41, waviness width a1, virtual reference circle c1, virtual reference circle c2, rising angle θ1, outer surface position P1, and inner surface position P2 are each arranged at the second power cable 20, second cable conductor 21, second cable insulation 22, second outer semi-conductive layer 23, second semi-conductive tape layer 24, second cable shield layer 25 and second cable sheath 26, second cut end Section 50, second cutting inclined section 51, wave width a2, virtual reference circle c3, virtual reference circle c4, rising angle θ2, outer surface position P3, and inner surface position P4.

The second power cable cutting process shown in FIGS. 5 and 6 may be performed before the first power cable cutting process, may be performed after the first power cable cutting process, or may be performed with the first power cable cutting process. You can go at the same time.

FIG. 7 is a side view showing an example of the connection process. As shown in FIG. 7, in the connection step performed after the first power cable cutting step and the second power cable cutting step, one end of the first cable conductor 11 exposed from the first power cable 10 by the first power cable cutting step The side end and the one end side end of the second cable conductor 21 exposed from the second power cable 20 by the second power cable cutting step are connected at the conductor connection portion 2 .

The exposed end of the first cable conductor 11 on the one end side is inserted into the one end side of the conductor connection portion 2 , and the exposed end of the second cable conductor 21 on the one end side is inserted into the other end of the conductor connection portion 2 . By compressing the conductor connection portion 2 while the conductor connection portion 2 is inserted to the side, the conductor connection portion 2 electrically connects the first cable conductor 11 of the first power cable 10 and the second cable conductor 21 of the second power cable 20. Connecting.

From the viewpoint of high conductivity and compressibility, the conductor connection portion 2 is preferably made of copper, copper alloy, aluminum, or aluminum alloy. The conductor connection portion 2 is cylindrical, for example.

In the mounting step performed after the connecting step, as shown in FIG. 7, at least the outer circumference of the conductor connection portion 2, the outer circumference of the exposed portion of the first cable conductor 11, and the outer circumference of the exposed portion of the second cable conductor 21 are covered with a tubular shape. to form a semiconducting portion 8 of . For example, the semiconductive portion 8 is formed by winding a semiconductive tape. Subsequently, the hollow cylindrical insulating unit 3 is attached from the outer periphery of the exposed portion of the first outer semi-conductive layer 13 to the outer periphery of the exposed portion of the second outer semi-conductive layer 23 . Thus, the cable intermediate connection structure 1 shown in FIG. 1 is formed. Although FIG. 1 shows an example in which the insulating unit 3 covers all the exposed portions of the first external semi-conductive layer 13 and the exposed portions of the second external semi-conductive layer 23, the insulating unit 3 covers the first external It suffices that the exposed portion on the one end side of the semiconductive layer 13 and the exposed portion on the one end side of the second external semiconductive layer 23 are covered, and part of the exposed portion on the other end side is not covered with the insulating unit 3 . may

The insulation unit 3 includes the outer circumference of the semi-conducting portion 8, the outer circumference of the exposed portion on the one end side of the first cable insulator 12, the outer circumference of the exposed portion on the one end side of the first external semi-conductive layer 13, the outer circumference of the second cable insulator 22. It is mounted in close contact with the outer periphery of the exposed portion on the one end side and the outer periphery of the exposed portion on the one end side of the second external semi-conductive layer 23 (hereinafter also referred to as the outer periphery of the connecting portion).

The insulation unit 3 covers the outer periphery of the connecting portion of the first power cable 10 and the second power cable 20 . Such an insulating unit 3 continuously covers from the exposed portion of the first external semi-conductive layer 13 to the exposed portion of the second external semi-conductive layer 23 .

The insulating unit 3 is cylindrical and has radial contractility. Further, the insulating unit 3 is attached while being expanded in diameter, covering the outer periphery of the connecting portion. Therefore, the inner peripheral surface of the insulating unit 3 is attached in close contact with the outer periphery of the connecting portion due to the restoring force of the insulating unit 3 .

The insulating unit 3 includes a main insulating portion 31 , a cylindrical inner peripheral semi-conductive portion 32 provided on the inner peripheral portion of the central portion of the main insulating portion 31 in the axial direction of the intermediate cable connection structure 1 , and both ends of the main insulating portion 31 . and a cylindrical outer semiconductive portion 34 provided on the outer peripheral portion of the central portion in the axial direction of the main insulating portion 31 . The outer semiconductive portion 34 is provided so as to contact at least one (one or both) of the two end semiconductive portions 33 .

As described above, the first power cable cutting step exposes one end side of the first cable conductor 11 and one end side of the first cable insulator 12, and cuts the first cut end portion 40 having the waviness width a1 within the above range. And the formation of the first cutting inclined portion 41 having the rising angle θ1 within the above range can be continuously performed using a cutter. Similarly, in the second power cable cutting step, one end side of the second cable conductor 21 and one end side of the second cable insulator 22 are exposed, and the second cut end portion 50 having the waviness width a2 within the above range and the above The formation of the second cutting inclined portion 51 having the rising angle θ2 within the range can be continuously performed using a cutter. Therefore, the intermediate cable connection structure 1 can be formed easily in a short time.

In addition, after exposing the conductors and insulators on one end of the power cable, the surface of the insulators is polished with sandpaper, and the edges of the outer semi-conductive layers are smoothed to align the edges. The dielectric breakdown of the intermediate cable connection structure 1 can be suppressed even if it is not carried out. Therefore, the cable intermediate connection structure 1 can be formed easily in a short time, and the operator can be made without skill.

In addition, as described above, the waving width of the first cut end portion 40 and the second cut end portion 50 due to the cutting processing of the first outer semiconductive layer 13 and the second outer semiconductive layer 23 using a cutter is conventionally Therefore, even if the steps of polishing the insulator and smoothing the external semi-conductive layer are performed after that, these steps can be simplified.

In addition, the cable intermediate connection structure 1 includes the first cut end portion 40 and the second cut end portion 50 having the waviness width within the above range, and the first cut inclined portion 41 and the second cut end portion 41 having the rising angle within the above range. Since the cable intermediate connection structure 1 has the inclined portion 51, dielectric breakdown can be suppressed.

In addition, as shown in FIGS. 3 and 4, for the end portion on the one end side of the first cable insulator 12 exposed by the step stripping in the first power cable cutting step, the outer circumference, which is the exposed portion of the first cable insulator 12, Surface roughness Ra of surface 12a is preferably 40 μm or less. When the surface roughness Ra of the outer peripheral surface 12a of the first cable insulator 12 is 40 μm or less, the amount of voids formed inside the insulation unit 3 is reduced, thereby further suppressing dielectric breakdown of the cable intermediate connection structure 1. can. The smaller the surface roughness Ra of the outer peripheral surface 12a is, the more the dielectric breakdown of the intermediate cable connection structure 1 can be suppressed. When the surface roughness Ra of the outer peripheral surface 12a is more than 40 μm, the outer peripheral surface 12a may be polished to reduce the surface roughness Ra of the outer peripheral surface 12a.

Further, the surface roughness Ra of the outer peripheral surface 22 a of the second power cable, which is the exposed portion of the second cable insulator 22 , is the same as that of the first power cable 10 .

The surface roughness Ra of the outer peripheral surface 12a of the first cable insulator 12 and the outer peripheral surface 22a of the second cable insulator 22 was measured at several points (0° and 90° directions) in the axial direction using a surface roughness meter. is the average value obtained by

In addition, in the method of forming the cable intermediate connection structure of the embodiment, in the mounting step, from the outer peripheral surface of the exposed portion on the one end side of the first external semi-conductive layer 13 to the exposed portion on the one end side of the second external semi-conductive layer 23 . It is preferable to mount the insulating unit 3 after applying insulating oil over the outer peripheral surface, that is, to the outer peripheral surface of the connecting portion.

When the insulating unit 3 is attached to the outer periphery of the connection part whose surface is coated with insulating oil, even if a void is formed inside the insulating unit 3, the insulating oil fills the void. Therefore, dielectric breakdown of the cable intermediate connection structure 1 is further suppressed.

Furthermore, the applied insulating oil lowers the coefficient of friction of the insulating unit 3 with respect to the outer peripheral surface of the connecting portion. In the mounting process, the insulation unit 3 can be easily moved during mounting, so that the insulation unit 3 can be easily installed at a desired position.

From the above viewpoints, the insulating oil is preferably fluorine oil. Also, the insulating oil may be silicone oil.

Moreover, the dielectric breakdown strength of the insulating oil is preferably 12 kV/mm or more. When the dielectric breakdown strength of the insulating oil is within the above range, the dielectric breakdown of the intermediate cable connection structure 1 is further suppressed.

Also, the kinematic viscosity of the insulating oil is preferably 1000 mm ² /s or more and 1500 mm ² /s or less. When the kinematic viscosity of the insulating oil is 1000 mm ² /s or more, sagging of the insulating oil due to gravity can be suppressed, and when it is 1500 mm ² /s or less, the coating properties of the insulating oil can be improved. The kinematic viscosity of the insulating oil is the kinematic viscosity of the insulating oil at 20°C.

Moreover, FIG. 8 is a schematic diagram showing an example of a mounting process for mounting an insulating unit having a diameter expansion holding member. The insulating unit 3 is made of silicone rubber, and is wound in a spiral shape around the inner peripheral surface 3a of the insulating unit 3 in the mounting process. It is preferable to attach the insulation unit 3 by pulling out the diameter holding member 60 from the insulation unit 3 . The diameter expansion holding member 60 is a spiral core.

In the mounting step shown in FIG. 8 , first, the insulation unit 3 whose inner peripheral surface 3 a is expanded by the diameter expansion holding member 60 is placed at the connection portion of the first power cable 10 and the second power cable 20 . Moving. Subsequently, by pulling out one end of the diameter expansion holding member 60 spirally wound around the inner peripheral surface 3a from the insulation unit 3, the diameter expansion holding member 60 can be easily removed from the insulation unit 3. The diameter of the inner peripheral surface 3a of the insulating unit 3 is reduced so that the insulating unit 3 can be easily mounted in close contact with the outer periphery of the connecting portion. Therefore, the intermediate cable connection structure 1 can be formed more quickly and easily.

In addition, in the method of moving the insulation unit 3 preliminarily attached to the first power cable 10 or the second power cable 20 to the connecting portion, when the attached insulation unit 3 is being moved, foreign matter may enter inside the insulation unit 3. There is an intrusion. On the other hand, in the mounting process shown in FIG. 8, such intrusion of foreign matter can be suppressed.

In this way, the insulation unit 3 , which has been expanded in diameter before attachment, is reduced in diameter and attached in close contact with the outer periphery of the connection portion of the first power cable 10 and the second power cable 20 . When the insulating oil is fluorine oil, the insulating unit 3 is preferably made of silicone rubber, considering the Young's modulus, which is the followability of the insulating unit 3 to the shape of the connecting portion. Moreover, when the insulating oil is silicone oil, the insulating unit 3 is preferably made of ethylene propylene rubber (EP rubber).

3 on the other end of the first inclined cutting portion 41, and the other end of the second inclined cutting portion 51 having a large step shown in FIG. If the side stepped portion 52 exists, a removing step of removing at least one of the other end side stepped portion 42 of the first cut slope portion 41 and the other end side step portion 52 of the second cut slope portion 51 before the mounting step. It is preferable to further have

In the first power cable cutting step, when the cutting tool moving from one end side to the other end side of the first power cable 10 completes the stepped peeling cutting, the cutting edge part of the cutting tool rotating in the circumferential direction The other end side stepped portion 42 may be formed at the stopped position. The other end side stepped portion 42 formed on the other end side of the first cutting inclined portion 41 is not formed over the entire circumferential direction, but is formed locally. Also in the second power cable cutting step, the other end side stepped portion 52 may be formed on the other end side of the second cut inclined portion 51 in the same manner as in the first power cable cutting step.

By removing the other end side stepped portion 42 of the first inclined cutting portion 41 and the other end side stepped portion 52 of the second inclined cutting portion 52, the amount of voids formed inside the insulation unit 3 is reduced. Dielectric breakdown of the intermediate cable connection structure 1 can be further suppressed. For example, the other end side stepped portion 42 and the other end side stepped portion 52 are manually removed by an operator using a piece of glass.

As described above, the other-end-side stepped portion 42 and the other-end-side stepped portion 52 are formed at the stop position of the cutting blade portion. is local and easy to identify. Therefore, the removing process does not depend on the skill level of the operator.

Next, the cable intermediate connection structure of the embodiment will be described.

The intermediate cable connection structure 1 of the embodiment is formed by the method of forming the intermediate cable connection structure of the above embodiment. As shown in FIG. 1 , the cable intermediate connection structure 1 is a connection structure that connects one end of the first power cable 10 and one end of the second power cable. A cable intermediate connection structure 1 includes a conductor connection portion 2 and an insulation unit 3 .

The conductor connection portion 2 constituting the intermediate cable connection structure 1 includes an end portion on one end side of the first cable conductor 11 in the first power cable 10 and an end portion on one end side of the second cable conductor 21 in the second power cable 20. to connect.

The insulating unit 3 is cut from the outer circumference of the first external semi-conductive layer 13 including the first cutting edge 40 and the first cutting slope 41 on the one end side to the second cutting edge including the second cutting edge 50 and the second cutting slope 51 . 2 The outer semiconductive layer 23 is covered up to the outer circumference of one end side.

The waviness width a1 of the first cutting edge 40 covered with the insulating unit 3 is 6.0 mm or less, preferably 5.0 mm or less. When the waviness width a1 of the first cut end portion 40 is 6.0 mm or less, electric field concentration in the vicinity of the first cut end portion 40 is suppressed, so dielectric breakdown of the intermediate cable connection structure 1 can be suppressed.

The rising angle θ1 of the first cutting inclined portion 41 covered with the insulating unit 3 is greater than 5.00 degrees and less than or equal to 8.00 degrees. When the rising angle θ1 of the first cut inclined portion 41 is 8.00 degrees or less, the formation of voids inside the insulating unit 3 can be suppressed, so dielectric breakdown of the cable intermediate connection structure 1 can be suppressed. From this point of view, the rising angle θ1 of the first cutting slope portion 41 is 8.00 degrees or less, preferably 7.00 degrees or less.

If the rising angle θ1 of the first cut inclined portion 41 is more than 5.00 degrees, the waviness width a1 of the first cut end portion 40 formed using a cutter becomes small, so that the insulation of the intermediate cable connection structure 1 is reduced. Destruction can be suppressed. From this point of view, the rising angle θ1 of the first cutting slope portion 41 is more than 5.00 degrees.

The waviness width a<b>2 of the second cutting edge 50 is the same as the waviness width a<b>1 of the first cutting edge 40 . Also, the rising angle θ2 of the second inclined cutting portion 51 is the same as the rising angle θ1 of the first inclined cutting portion 41 .

In addition, as shown in FIG. 1, the cable intermediate connection structure 1 extends from the outer peripheral surface of the exposed portion of the first cable shielding layer 15 to the outer peripheral surface of the exposed portion of the second cable shielding layer 25 on the outside of the insulation unit 3. , a shielding layer 4, a protective layer 5, and a metal tube 7 made of a metal such as copper may be provided in this order from the inside. The inside of the metal tube 7 may be filled with a compound to form a compound portion 6 as shown in FIG. 1, or may be filled with air without being filled with a compound (not shown). In addition, the cable intermediate connection structure 1 includes one end of the metal tube 7 (the end on the first power cable 10 side), the first cable shielding layer 15, and the other end of the metal tube 7 (the end on the second power cable 20 side). A conductor portion 9 made of metal may be provided for connecting the end portion) and the second cable shielding layer 25, respectively. In addition, the cable intermediate connection structure 1 is filled with resin or wrapped with tape so that each opening is sealed between the first cable sheath 16 and the second cable sheath 26 at both ends of the metal tube 7 . Corrosion protection 70 may be provided, which is formed by winding.

In addition, the cable intermediate connection structure 1 includes the first outer semi-conductive layer 13 and the second electric wire in the gap inside the shielding layer 4 near one end of the main insulating portion 31 (near the end on the first power cable 10 side). A semiconductive tape portion 35 may be provided so as to fill the gap while bringing the first semiconductive tape layer 14 and the end semiconductive portion 33 into electrical contact with each other. In the cable intermediate connection structure 1, a semiconductive tape portion 35 is also provided in a gap inside the shielding layer 4 near the other end of the main insulating portion 31 (near the end on the second power cable 20 side). may

The intermediate cable connection structure 1 having such a configuration is preferably a cold shrinkable joint (CSJ), which is required to suppress dielectric breakdown and to be formed easily in a short time. Moreover, the first power cable 10 and the second power cable 20 connected by the cable intermediate connection structure 1 are preferably crosslinked polyethylene insulated vinyl sheath cables (CV cables). Moreover, it is preferable that the withstand voltage value of the first power cable 10 and the second power cable 20 is 154 kV or less.

In addition, although the above describes the application of the present disclosure to the cable intermediate connection structure formation method and cable intermediate connection structure, the present disclosure may be applied to the cable termination connection structure formation method and cable termination connection structure. . Even if the present disclosure is applied to a method for forming a cable termination connection structure and a cable termination connection structure, dielectric breakdown can be suppressed, and the cable termination connection structure can be formed easily in a short time.

According to the embodiment described above, the cable intermediate connection structure can be easily formed in a short time by performing the first power cable cutting step and the second power cable cutting step using the cutter. In addition, dielectric breakdown of the cable intermediate connection structure is suppressed by satisfying a predetermined relationship between the waviness width of the first cut end portion and the second cut end portion and the rising angle of the first inclined cut portion and the second inclined cut portion. can do.

In addition to the first cable conductor 11, the first cable insulator 12 and the first external semi-conductive layer 13, the first power cable 10 includes the first semi-conductive tape layer 14, the first cable shield layer 15 and Although an example comprising a first cable sheath 16 has been shown, if the first power cable 10 comprises at least the first cable conductor 11, the first cable insulation 12 and the first outer semi-conductive layer 13, the first power cable 10 is not particularly limited. For example, first power cable 10 may include first cable conductor 11, first cable insulation 12, first outer semi-conductive layer 13, first semi-conductive tape layer 14 and first cable conductor 11, first cable insulation 12, first outer semi-conductive layer 13, first semi-conductive tape layer 14 and first cable sheath 16 without first cable sheath 16. The structure provided with the cable shielding layer 15 may be sufficient. The same applies to the second power cable 20 as well.

Although the embodiments have been described above, the present invention is not limited to the above embodiments, and includes all aspects included in the concept and claims of the present disclosure, and can be variously modified within the scope of the present disclosure. be able to.

Next, examples and comparative examples will be described, but the present disclosure is not limited to these examples.

(Examples 1-10 and Comparative Examples 1-2)
A 66 kV class cable and an insulation unit are prepared, and a cutter (SH50, manufactured by Hivotec) is used to cut the first power cable with the first outer semiconductive layer exposed on one end side. A first cutting edge portion having a waviness width a1 and a first cutting inclined portion having a rising angle θ1 were formed. Similarly, using a cutter (SH50, manufactured by Hivotec), the second power cable with the second outer semiconductive layer on one end side exposed is stepped and cut, and the second power cable having the waviness width a2 shown in Table 1 is cut. A second cutting ramp was formed having a cutting edge and a rise angle θ2. Subsequently, the first power cable and the second power cable were connected at the conductor connection portion. Subsequently, after the conductor connection portion is covered with the semiconductive portion, the kinematic viscosity at 20° C. extends from the outer peripheral surface of the exposed portion of the first outer semiconductive layer to the outer peripheral surface of the exposed portion of the second outer semiconductive layer. 1300 fluorine oil was applied. Next, I installed the insulation unit. Thus, a cable intermediate connection structure as shown in FIG. 1 was formed.

In Comparative Example 1, the intermediate cable connection structures of Comparative Examples 1-1 and 1-2 were formed in which the waviness width a1 of the first cut end portion was greater than 6.0 mm. Further, in Comparative Example 2, cable intermediate connection structures of Comparative Examples 2-1 and 2-2 were formed in which the rising angle θ1 of the first cut inclined portion was greater than 8.00 degrees.

As a dielectric breakdown test, a commercial frequency alternating voltage (AC) test and a lightning impulse voltage (lightning lmp) test were performed. Table 1 shows the results.

As shown in Table 1, in Examples 1 to 10, the waviness widths of the first cutting edge and the second cutting edge, and the rising angles of the first cutting slope and the second cutting slope satisfy a predetermined relationship. Therefore, the dielectric breakdown of the cable intermediate connection structure could be suppressed.

On the other hand, in Comparative Examples 1 and 2, the waviness widths of the first and second cutting edges and the rising angles of the first and second inclined cutting parts did not satisfy the predetermined relationship. Therefore, the dielectric breakdown of the cable intermediate connection structure cannot be suppressed, and the withstand voltage value of the nominal voltage 66 kV commercial frequency voltage room temperature test and the nominal voltage 66 kV lightning impulse room temperature test described in the standard JEC-3408 of the Institute of Electrical Engineers of Japan. A withstand voltage value of 485 kV could not be achieved. Since the cable intermediate connection structure of Comparative Example 1-1 was destroyed at 120 kV in the commercial frequency alternating voltage (AC) test, the lightning impulse voltage (lightning lmp) test could not be performed. Therefore, as another sample with a similar configuration, a lightning impulse voltage (lightning lmp) test was performed on the cable intermediate connection structure of Comparative Example 1-2, but it was destroyed at 430 kV, so a commercial frequency alternating voltage (AC) test could not be performed. I didn't. Similarly, the cable intermediate connection structure of Comparative Example 2-1 was destroyed at 120 kV in the commercial frequency alternating voltage (AC) test, so the lightning impulse voltage (lightning lmp) test could not be performed. Therefore, as another sample with a similar configuration, a lightning impulse voltage (lightning lmp) test was performed on the cable intermediate connection structure of Comparative Example 2-2, but it was destroyed at 480 kV, so a commercial frequency alternating voltage (AC) test could not be performed. I didn't.

1 Cable Intermediate Connection Structure 2 Conductor Connection Portion 3 Insulation Unit 3a Inner Peripheral Surface of Insulation Unit 4 Shielding Layer 5 Protective Layer 6 Compound Portion 7 Metal Tube 8 Semiconductive Portion 9 Conductor Portion 10 First Power Cable 11 First Cable Conductor 12 Second 1 cable insulator 12a outer peripheral surface of the exposed portion of the first cable insulator 13 first outer semi-conductive layer 14 first semi-conductive tape layer 15 first cable shield layer 16 first cable sheath 20 second power cable 21 second cable Conductor 22 Second cable insulator 22a Outer peripheral surface of exposed portion of second cable insulator 23 Second outer semiconductive layer 24 Second semiconductive tape layer 25 Second cable shield layer 26 Second cable sheath 31 Main insulation 32 Inside Peripheral Semi-Conducting Part 33 End Semi-Conducting Part 34 Peripheral Semi-Conducting Part 35 Semi-Conducting Tape Part 40 First Cutting Edge 41 First Cutting Inclined Part 42 Other End Side Stepped Part 50 Second Cutting Edge 51 Second Cutting Inclined Part 52 Other end side stepped portion 60 Diameter expansion holding member 70 Anticorrosion portion

Claims (6)

one end of a first power cable comprising at least a first cable conductor, a first cable insulation and a first outer semi-conductive layer center-to-perimeter; and at least a second cable conductor center-to-perimeter; A method for forming a cable intermediate connection structure for connecting a second cable insulator and a second outer semi-conductive layer to one end of a second power cable, the method comprising:
With respect to the first power cable in which the first external semiconductive layer on the one end side is exposed, a cutter is used to step-scrape one end side of the first power cable toward the other end side, a first cut end exposing one end side of the first cable conductor and one end side of the first cable insulator and having a waviness width of 6.0 mm or less on one end side of the first outer semi-conductive layer; and a first power cable cutting step of forming a first cut inclined portion extending from the first cut end portion to the other end side and having a rising angle of more than 5.00 degrees and not more than 8.00 degrees;
With respect to the second power cable in which the second external semiconductive layer on the one end side is exposed, a cutter is used to step-scrape one end side of the second power cable toward the other end side, a second cut end exposing one end side of the second cable conductor and one end side of the second cable insulator, and having a waviness width of 6.0 mm or less on one end side of the second outer semi-conductive layer; and a second power cable cutting step of forming a second cut inclined portion extending from the second cut end portion to the other end side and having a rising angle of more than 5.00 degrees and not more than 8.00 degrees;
An end portion of the first cable conductor exposed in the first power cable cutting step and an end portion of the second cable conductor exposed in the second power cable cutting step are connected to a conductor connection portion. a connection step of connecting with
A cylindrical semiconductive portion is formed at least around the outer periphery of the conductor connecting portion, the outer periphery of the exposed portion of the first cable conductor, and the outer periphery of the exposed portion of the second cable conductor, and the exposed portion of the first outer semiconductive layer. a mounting step of mounting a cylindrical insulating unit from the outer periphery of the second outer semi-conductive layer to the outer periphery of the exposed portion of the second outer semi-conductive layer;
A method for forming a cable intermediate connection structure, comprising: In the mounting step, after applying insulating oil from the outer peripheral surface of the exposed portion of the first external semi-conductive layer to the outer peripheral surface of the exposed portion of the second external semi-conductive layer, the insulating unit is mounted. A method for forming a cable intermediate connection structure according to claim 1. 3. The method for forming an intermediate cable connection structure according to claim 2, wherein said insulating oil is fluorine oil. The insulation unit is made of silicone rubber,
In the mounting step, the diameter expansion holding member formed by spirally winding around the inner peripheral surface of the insulating unit and holding the inner peripheral surface of the insulating unit while expanding the diameter thereof is pulled out from the insulating unit to remove the insulating unit. Mounting,
A method for forming a cable intermediate connection structure according to any one of claims 1 to 3. The method according to any one of claims 1 to 4, further comprising a removing step of removing at least one of the other end side stepped portion of the first inclined cutting portion and the other end side stepped portion of the second inclined cutting portion before the mounting step. A method of forming a cable intermediate connection structure according to any one of claims 1 to 3. one end of a first power cable comprising at least a first cable conductor, a first cable insulation and a first outer semi-conductive layer center-to-perimeter; and at least a second cable conductor center-to-perimeter; A cable intermediate connection structure for connecting a second power cable having a second cable insulator and a second outer semi-conductive layer, the end on the one end side of the second power cable, comprising:
a conductor connection portion that connects an end portion on one end side of the first cable conductor and an end portion on one end side of the second cable conductor;
an insulating unit covering from the outer periphery of the first outer semiconductive layer to the outer periphery of the second outer semiconductive layer at one end;
with
The waviness width of the first cutting edge on one end side of the first outer semiconductive layer covered with the insulating unit is 6.0 mm or less, and the first cutting edge extends from the first cutting edge to the other end side. The rising angle of the inclined portion is more than 5.00 degrees and 8.00 degrees or less,
The waviness width of the second cutting edge on one end side of the second outer semiconductive layer covered with the insulating unit is 6.0 mm or less, and the second cutting edge extends from the second cutting edge to the other end side. A cable intermediate connection structure, wherein the rising angle of the inclined portion is more than 5.00 degrees and less than or equal to 8.00 degrees.

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