JP2000115976A - Taping winding type linear connected part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the breakdown strength by preventing voids from removing on the interface between an internal semi-conductive layer and a cable insulator, and the interface between a reinforcement insulating layer and an external semi-conductive layer. SOLUTION: A cable insulator 2 at the end of a rubber and plastic insulating power cable is peeled off, to which a cable conductor 1 is jointed. An internal semi-conductive layer 4, a reinforcement insulating layer 5, an external semi- conductive layer 6, a metallic layer 7 for shielding, and a press-wound layer 8 are wound in order. Semi-conductive tape consisting of unvulcanized rubber is used as the internal semi-conductive layer 4 and the external semi-conductive layer 6 of a taping type linear connected part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape-winding type linear connection portion applied to connection of a rubber-plastic insulated power cable.

[0002]

2. Description of the Related Art As shown in FIG. 3, a tape-winding type linear connecting portion for a rubber / plastic insulated power cable, as shown in FIG. 1 is inserted into the conductor sleeve 3, and the conductor sleeve 3 is compressed and connected. Then, a vulcanized semiconductive rubber tape is wound around the outside to form the internal semiconductive layer 10, and an insulating rubber tape is wound around the outside to form the reinforcing insulating layer 5. Further, a vulcanized semiconductive rubber tape is wrapped around the outside to form an external semiconductive layer 11, and a shielding metal layer 7 such as a shield mesh tape is wrapped around the outer semiconductive layer 11.

As the insulating rubber, for example, ethylene propylene rubber having self-fusing property is used, and the insulating rubber tape is wound under tension while being stretched. The adhesive force between the tape layers is favorably maintained by the radially inner pressing force, and the adhesiveness is improved by the self-fusing property of the tapes being fused together over time. In the tape winding type linear connection part, voids are inevitably generated between the tape layers at the beginning of the tape winding. If the voids remain as they are, discharge occurs in the voids when a voltage is applied, and furthermore, an electrical tree is generated, leading to deterioration of withstand voltage performance and further to dielectric breakdown.
On the other hand, by increasing the adhesion at the interface by promoting the fusion by the above-mentioned pressing force or self-fusion or heating,
By crushing the voids to reduce the size thereof and reducing the number of voids, good withstand voltage performance is maintained.

[0004]

However, in the above-mentioned conventional tape-winding type linear connection portion, the internal semiconductive layer 1 is not provided.
A vulcanized semiconductive tape having no self-fusing property was used for the outer semiconductive layer 11 and the outer semiconductive layer 11. Therefore, the inner semiconductive layer 1
0 and the interface between the cable insulator 2 and the interface between the reinforcing insulating layer 5 and the external semiconductive layer 11 are not fused by the heat treatment or the externally applied pressure by the press-winding layer, and voids remain at those interfaces. Thus, there is a problem that a decrease in withstand voltage performance cannot be avoided.

An object of the present invention is to solve such a problem and to improve the withstand voltage performance by preventing voids from remaining at the interface between the semiconductive layer and the insulating layer.

[0006]

According to a first aspect of the present invention, there is provided a tape-connecting linear connection portion according to the first aspect, wherein a cable insulator at an end portion is peeled off, a cable conductor is connected, and an inner half is sequentially connected. A semiconductive tape made of non-vulcanized rubber as the external semiconductive layer in a tape-wound linear connection portion for a rubber / plastic insulated power cable having a conductive layer, a reinforcing insulating layer, an external semiconductive layer, and a press-winding layer formed thereon. Is used. This prevents voids from remaining at the interface between the reinforcing insulating layer and the external semiconductive layer, and improves the withstand voltage performance.

According to a second aspect of the present invention, in the tape winding type linear connecting portion, the outer semiconductive layer is formed by winding a semiconductive tape made of a non-vulcanized rubber, and a semiconductive tape made of a vulcanized rubber outside. The tape is formed by winding, and a shielding metal layer is wound around the tape. This can prevent the shielding metal layer from penetrating into the external semiconductive layer.

[0008] The tape-wound linear connecting portion according to claim 3 is characterized in that a semiconductive tape made of non-vulcanized rubber is used as the internal semiconductive layer. In this case, no void remains at the interface between the internal semiconductive layer and the cable insulator, and the withstand voltage performance is further improved.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing a first embodiment of the present invention. The reference numerals correspond to those in FIG. 3, wherein 4 is an inner semiconductive layer and 6 is an outer semiconductive layer.

[0010] In the conventional tape wound linear connection portion, a semiconductive rubber tape vulcanized on the inner semiconductive layer and the outer semiconductive layer is used. For 6, a semiconductive tape made of non-vulcanized rubber, that is, rubber that is not vulcanized and contains no vulcanizing agent is used. Ethylene propylene rubber can be used as this rubber.

Since the non-vulcanized semiconductive rubber tape is not vulcanized, it has plasticity and is easily deformed by external pressure or heat treatment. Therefore, for example, when the outer semiconductive layer 6 is formed by winding it around the outside of the stepped or uneven reinforcing insulating layer 5, the interface between the reinforcing insulating layer 5 and the non-vulcanized rubber tape or the non-vulcanized Even if voids occur at the interface between the rubber tapes, those voids gradually collapse and eventually disappear. In order to promote the disappearance of the voids, a press-winding layer 8 for applying an appropriate pressing force from outside of the external semiconductive layer 6 is formed, and after the press-winding layer 8 is further formed, the pressure is reduced to about 90 to 150 ° C. Means such as applying a heat treatment of several tens of minutes at a temperature can be used.

Table 1 shows to what extent the withstand voltage performance of the tape-wound linear connection part was improved by the present invention.

[0013]

[Table 1]

This data was obtained at a tape-wrapped linear connection for a cable insulation thickness of 9 mm and a conductor size of 200 sq. The thickness of the reinforcing insulating layer is 30 mm. In the product of the present invention, both the inner semiconductive layer 4 and the outer semiconductive layer 6 have a thickness of 0.
It was formed by winding a non-vulcanized semiconductive ethylene propylene rubber tape having a thickness of 5 mm and a width of 25 mm. The thickness of the semiconductive layer was about 2 mm for the inner semiconductive layer and about 4 mm for the outer semiconductive layer. On the other hand, in the sample of the prior art, both semiconductive layers were formed by winding a vulcanized semiconductive ethylene propylene rubber tape of the same size, and the thickness was adjusted to the above. The withstand voltage performance is represented by an average electric field (kV / mm) with respect to the reinforcing insulation thickness, that is, a value obtained by dividing a partial discharge generation voltage or an AC breakdown voltage by the reinforcing insulation thickness. From Table 1, it is understood that the partial discharge starting electric field and the AC breakdown electric field of the product of the present invention are improved by about 60%, respectively, as compared with the prior art.

By the way, when the shielding metal layer 7 is formed directly on the outer semiconductive layer 6 and its outside is pressed down by the presser winding layer 8, the non-vulcanized semiconductive layer forming the outer semiconductive layer 6 is formed. While the rubber tape is deformed and the void between the insulating layer and the insulating layer is crushed, a phenomenon in which the shielding metal layer 7 made of a shielded mesh tape enters into the soft outer semiconductive layer 6 also progresses. The bite progressed excessively,
When the shielding metal layer 7 penetrates the external semiconductive layer 6 and reaches the reinforcing insulating layer 5, the portion becomes a metal protrusion,
The withstand voltage performance will be significantly reduced. In order to prevent this, in this embodiment, the thickness of the outer semiconductive layer 6 needs to be as thick as, for example, about 4 mm, which is twice the thickness of the inner semiconductive layer 4.

FIG. 2 is a diagram showing a second embodiment of the present invention. The reference numerals correspond to those in FIG. In this embodiment, the external semiconductive layer has a two-layer structure of an external semiconductive layer 6-1 made of non-vulcanized rubber and an external semiconductive layer 6-2 made of vulcanized rubber. The outer semiconductive layer 6-1 is formed by winding a non-vulcanized semiconductive rubber tape around the reinforcing insulating layer 5, and the outer semiconductive layer 6-2 is formed by winding a vulcanized semiconductive rubber tape around the outside. Form. As a result, between the outer semiconductive layer 6-1 made of a non-vulcanized semiconductive rubber tape and the shielding metal layer 7 made of a shield mesh tape or the like,
An external semiconductive layer 6-2 made of a vulcanized semiconductive rubber tape is interposed.

In the first embodiment, the thickness of the outer semiconductive layer 6 is made twice as large as the thickness of the inner semiconductive layer 4 so that the withstand voltage caused by the penetration of the shielding metal layer 7 into the outer semiconductive layer 6. The performance was prevented from lowering. Although this is sufficient as a preventive measure, the problem is that the cost of the semiconductive tape is high and the cost is high. To eliminate that point,
In the second embodiment, the outer semiconductive layer 6-2 made of a hard vulcanized semiconductive rubber tape, which does not penetrate the shield mesh tape and does not penetrate further, is made of a non-vulcanized semiconductive rubber tape. It is formed between the external semiconductive layer 6-1 and the shielding metal layer 7. By doing so, for example, the thickness of the outer semiconductive layer 6-1 made of a non-vulcanized semiconductive rubber tape and the thickness of the outer semiconductive layer 6-2 made of a vulcanized semiconductive rubber tape on each of them are reduced by about 1mm
The cost can be reduced by setting the total to about 2 mm.

[0018]

Since the present invention is configured as described above, it has the following effects. That is, in the tape-wound linear connecting portion according to claim 1, since a semiconductive tape made of non-vulcanized rubber is used as the external semiconductive layer, voids remain at the interface between the reinforcing insulating layer and the external semiconductive layer. And the withstand voltage performance can be improved. By using a non-vulcanized semiconductive tape made of, for example, ethylene propylene rubber for all or part of the inner and outer semiconductive layers that are in contact with the insulating layer, it is necessary to initially wind the tape around the interface between the semiconductive layer and the insulating bird. With the help of external pressure and heat treatment, the voids formed can be eliminated to improve the withstand voltage performance.

According to a second aspect of the present invention, there is provided a tape-connecting linear connecting portion, wherein an external semiconductive layer is formed by winding a semiconductive tape made of a non-vulcanized rubber, and a semiconductive tape made of a vulcanized rubber on the outside thereof. Is formed, and the shielding metal layer is wound around the outside, so that it is possible to prevent the shielding metal layer from biting into the external semiconductive layer.

Further, in the tape wound linear connecting portion according to the third aspect, since the semiconductive tape made of non-vulcanized rubber is used as the internal semiconductive layer, the interface between the internal semiconductive layer and the cable insulator is used. Also, no void remains, and the withstand voltage performance can be further improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a second embodiment of the present invention.

FIG. 3 is a view showing a conventional tape-winding type linear connecting portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cable conductor 2 ... Cable insulator 3 ... Conductor sleeve 4 ... Inner semiconductive layer 5 ... Reinforcement insulating layer 6 ... External semiconductive layer 7 ... Shielding metal layer 8 ... Holding layer

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Toshiya Matsui 4-1 Egasaki-cho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture F-term in the Electric Power Research Laboratory, Tokyo Electric Power Company 5G355 AA03 BA04 BA17 CA22 5G375 AA02 BA26 BB45 CA02 CA13 CB03 CB04 CB17 CB38 CB55 DB11

Claims (3)

[Claims] 1. A cable insulator at an end is peeled off, a cable conductor is connected, and an internal semiconductive layer, a reinforcing insulating layer,
In an external semiconductive layer, a tape-wound linear connection portion for a rubber / plastic insulated power cable having a press-winding layer formed thereon, a semiconductive tape made of non-vulcanized rubber is used as the external semiconductive layer. Tape-wrapped straight connection. 2. The external semiconductive layer is formed by wrapping a semiconductive tape made of non-vulcanized rubber, wrapping a semiconductive tape made of vulcanized rubber around the outside, and forming a shielding metal layer outside the outside. 2. The tape-wound linear connection section according to claim 1, wherein 3. The semiconductor device according to claim 1, wherein a semiconductive tape made of non-vulcanized rubber is used as said internal semiconductive layer.
Or a tape-winding type linear connecting portion according to 2.