JPH11341664A - Rubber insulator for power cable termination - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the possibility of occurrence of partial discharge during use and enhance the insulating capability of a power cable terminal, by reducing the size of a gap produced at an end of a cable external semiconductive layer and/or an end of a semiconductive tape. SOLUTION: Horizontal woven hat-shaped fins 1-1 are formed on the surface of the body 1 of a terminal corresponding to an end of a cable external semiconductive layer 11-3 and the vicinity of a semiconductive tape 3. As a result, planar pressure produced at the end of the cable external semiconductive layer 11-3 and the end of the semiconductive tape 3 can be increased, and a gap formed between the cable external semiconductive layer 11-3 and an insulator 11-4 and a gap formed at the end of the semiconductive tape 3 can be reduced. Projections or deeply grooved, woven hat-shaped fins may be formed instead of the horizontal woven hat-shaped fins.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to each power cable,
For example, a cross-linked polyethylene insulated vinyl sheath cable (C
The present invention relates to a rubber insulator used for terminal treatment of a V cable or a rubber sheath cable (hereinafter, these are collectively simply referred to as a cable).

[0002]

2. Description of the Related Art A cable terminal is usually assembled as follows. First, strip the cable. That is, as shown in FIG. 3A, the sheath 11-1, the shielding copper tape 11-2, the cable outer semiconductive layer 11-3, and the insulator 11-4 of the cable 11 are peeled off to desired dimensions.
The cable conductor 11-5 is exposed.

[0003] A grounding wire 11 is attached to the shielding copper tape 11-2.
After attaching -6, the terminal body 1 is attached as shown in FIG. 3B, and the terminal 2 is connected to the cable conductor 11-5 by crimping or the like. An electric field relaxation layer 1a is provided on the inner surface of the terminal body 1.
Are provided, and the cable outer semiconductive layer 11-3 is provided.
And the insulator 11-4 are in contact with the electric field relaxation layer 1
It is positioned at the part a. When the terminal main body is a plug-in type, the inner diameter of the terminal main body 1 is smaller than the outer diameter of each part of the stripped cable 11, and the cable 11 is inserted so as to push the terminal main body 1 apart. Therefore, the terminal body 1
The inner surface of the cable is brought into close contact with the surface of each portion of the stripped cable at a predetermined surface pressure.

[0004]

It is well known that the size of the gap at the end of the cable outer semiconductive layer 11-3 greatly affects the performance of the terminal. FIG. 4 shows the outer semiconductive layer 11 of the cable.
3 is an enlarged view of the vicinity of an end of the cable, and as shown in FIG.
4, there is a step, and if this step is large, a gap 4 is generated in this part when the terminal is assembled as shown in FIG.
Partial discharge occurs even under operating voltage. When a partial discharge occurs, the portion is heated and burnt out, and eventually breaks down. Therefore, it is desirable to reduce the step in this portion.

In order to reduce the level difference, conventionally, as shown in FIG. 5A, a thinner semiconductive tape 3, for example, an ACP tape, is wound around the cable outer semiconductive layer end 11-3. was there. This tape is 0.3 mm thinner than the thickness of the outer semiconductive layer of the cable, which is about 0.5 mm.
As shown in the enlarged view of (b), when the terminal main body 1 is attached, the gap 4 does not always disappear completely. In addition, a large amount of silicone grease is applied to this part, but there is a possibility that the terminal body material may be absorbed during use, so there is no problem at the beginning of use, but during long-term use, I was worried. SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to reduce a gap generated at an end of a cable outer semiconductive layer and / or an end of a semiconductive tape (ACP tape). By doing so, the possibility of occurrence of partial discharge during use is reduced, and the insulation performance of the power cable terminal is improved.

[0006]

According to the present invention, there is provided a rubber insulator used for terminal treatment of a power cable, wherein the rubber insulator is attached to a terminal of the power cable. The deep groove caps provided on the rubber insulator, the roots or protrusions of the horizontal cap-shaped folds,
It is arranged so as to be located near the end of the cable outer semiconductive layer and / or near the end of the semiconductive tape wound near the end of the cable outer semiconductive layer.

[0007] In the present invention, the root or the convex portion of the deep-groove-shape fold or the horizontal-shape fold usually provided on the rubber insulator used for the terminal treatment of the power cable as described above is replaced with the cable outer semiconductive layer. Since it is arranged near the end and / or the end of the semiconductive tape, the surface pressure at that part can be increased. In other words, since the rubber portion is thicker at the portion where the deep groove hatch, the horizontal hatch, or the protrusion is provided, the pressure applied to the cable becomes greater than other portions, and the end and / or the half of the cable outer semiconductive layer. The surface pressure near the end of the conductive tape can be increased.
For this reason, the gap at the end of the cable outer semiconductive layer and / or the end of the semiconductive tape can be reduced, the possibility of occurrence of partial discharge during use can be reduced, and the insulation performance can be improved. .

[0008]

FIG. 1 is a view showing a first embodiment of the present invention. The upper half of FIG. 1 shows a cross section, and the lower half shows an appearance. In FIG. 1, reference numeral 1 denotes a substantially cylindrical terminal body formed of a rubber molded body. An electric field relaxation layer 1 a is provided on an inner surface of the terminal body 1, and a plurality of horizontal hatched folds are provided on the terminal body 1. 1-1 is provided. In addition, terminal body 1
Is provided with a terminal 2 at one end and the other end is open, from which a cable 11 stripped to a desired size is inserted. 11 is the above-mentioned cable, 11-1 is a cable sheath, 11-2 is a shielded copper tape, 11-3 is a cable outer semiconductive layer, 11-4 is an insulator, 11-5 is a cable conductor, and 11-6 is grounded. In this embodiment, a semiconductive tape (ACP tape) 3 is wound on the cable outer semiconductive layer.

In this embodiment, the above-mentioned horizontal hatched fold 1-
1 is provided on the end of the cable external semiconductive layer 11-3 and on the surface of the terminal body 1 near the semiconductive tape 3. By providing the horizontal cap-shaped folds 1-1 at the positions as described above, it is possible to increase the surface pressure generated at the end of the cable external semiconductive layer 11-3 and the end of the semiconductive tape 3. The gap formed between the cable outer semiconductive layer 11-3 and the insulator 11-4 and at the end of the semiconductive tape 3 can be reduced, and the insulation performance can be improved.

FIG. 2 is a view showing a second embodiment of the present invention. In this embodiment, the end of the cable outer semiconductive layer 11-3 and the surface of the terminal body 1 near the semiconductive tape 3 are shown. 2 shows a case where a convex portion is provided. In FIG. 2, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and in the present embodiment,
A convex portion 1-2 is provided in addition to the horizontal cap-shaped fold 1-1. The convex portion 1-2 is provided on the end of the cable outer semiconductive layer 11-3 and on the surface of the terminal body 1 near the semiconductive tape 3, as in the first embodiment. Therefore, similarly to the first embodiment, the cable outer semiconductive layer 11-
The gaps formed between the insulator 3 and the insulator 11-4 and at the end of the semiconductive tape 3 can be reduced, and the insulation performance can be improved.

In the above-described embodiment, the case where the horizontal corrugated folds or convex portions are provided on the terminal body 1 has been described. However, the case where the deep groove corrugated folds are provided on the terminal body 1 is the same as above. The base of the deep groove cap may be located on the end of the cable outer semiconductive layer 11-3 and near the semiconductive tape 3. In the above embodiment, the case where the semiconductive tape 3 is wound on the outer semiconductive layer of the cable is described. However, when the semiconductive tape 3 is not wound, the horizontal hatched fold 1-1 is connected to the outer half of the cable. Conductive layer 11-
What is necessary is just to provide on the surface of the terminal main body 1 of the vicinity of the space | gap formed between 3 and the insulator 11-4. The same effect can be obtained even when the electric field relaxation layer 1a described above is a stress cone-shaped conductive layer.

[0012]

As described above, according to the present invention, a horizontal fold, a deep groove fold, or a protrusion is formed on the surface of the terminal body near the end of the cable outer semiconductive layer and / or the end of the semiconductive tape. Is provided, the surface pressure at that portion can be increased, and the gap generated at the end of the cable external semiconductive layer and / or the end of the semiconductive tape (ACP tape) can be reduced. For this reason, the possibility of occurrence of partial discharge during use can be made smaller than it is now, and safety during long-term use can be improved.

[Brief description of the drawings]

FIG. 1 is a view showing a first embodiment of the present invention provided with a horizontal cap-shaped fold.

FIG. 2 is a view showing a second embodiment of the present invention having a convex portion.

FIG. 3 is a diagram showing a state where a cable is stripped and a state where a terminal main body is attached.

FIG. 4 is an enlarged view of an end of the cable semiconductive layer in FIG. 3;

FIG. 5 is a diagram showing a state where a cable is stripped and a semiconductor tape is wound, and a state where a terminal body is attached.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Terminal main body 1a Electric field relaxation layer 1-1 Horizontal hatch fold 1-2 Convex part 2 Terminal 3 Semiconductive tape (ACP tape) 4 Air gap 11 Cable 11-1 Cable sheath 11-2 Shielding copper tape 11-3 Cable outer half Conductive layer 11-4 Cable insulator 11-5 Cable conductor 11-6 Ground wire

Claims (1)

[Claims] 1. A rubber insulator used for terminal treatment of a power cable, wherein the rubber insulator includes a deep groove cap,
When the rubber insulator is attached to the end of the power cable, the deep groove cap, the root or the protrusion of the horizontal cap fold is provided near the end of the cable outer semiconductive layer and when the rubber insulator is attached to the end of the power cable. A rubber insulator for power cable termination, wherein the rubber insulator is disposed so as to be located near an end of a semiconductive tape wound near an end of a cable outer semiconductive layer.