JP2000115977A - Taping winding type linear connected part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the breakdown strength by setting the void level of the interface between a cable insulator at the inclined peeled-off part of the cable insulator and a reinforcement insulating layer rubber tape at the level equivalent to that of any other interface even in a short heating period. 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, and press-wound layer 8 are formed in order. In such a taping linear connected part, the reinforcement insulating layer 5 is formed out of vulcanized rubber, and an insulating tape layer 5a consisting of unvulcanized or nonvulcanized rubber is formed at the interface between the reinforcement insulating layer 5 and the cable insulator 2.

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. 2, 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 wrapped around the outside to form an internal semiconductive layer 4, and a vulcanized or semivulcanized insulating rubber tape is wrapped around the outside to form a reinforcing insulating layer 5. Further, a vulcanized semiconductive rubber tape is wrapped around the outside to form an external semiconductive layer 6, and a shielding metal layer 7 such as a shield mesh tape is wrapped.

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 void remains as it is, when a voltage is applied, a discharge is generated in the void portion, and an electric tree is further generated, resulting in deterioration of insulation performance and further breakdown. On the other hand, by increasing the adhesion at the interface by the above-mentioned pressurizing force or by promoting fusion by self-fusion or heating, the voids are crushed to reduce the size, and the number of voids is reduced, thereby improving the withstand voltage performance. Is to be maintained.

[0004]

However, in the above-mentioned conventional tape-wound type linear connection portion, the temperature of the inclined peeling portion of the cable insulator takes a long time to rise by heating from the outside, and it takes a long time. Otherwise, the cable insulator and the rubber tape of the reinforcing insulating layer 5 at this portion may not be fused. In the case where fusion is not performed, there is a problem that the void level in that portion is deteriorated, and the possibility of deteriorating the withstand voltage performance is increased.

The present invention solves such a problem and reduces the void level at the interface between the cable insulator and the rubber tape of the reinforcing insulating layer 5 at the inclined peeling portion of the cable insulator even with a short heating time. The purpose is to improve the withstand voltage performance at the same level.

[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. In a tape-winding type linear connection portion for a rubber / plastic insulated power cable having a conductive layer, a reinforcing insulating layer, an outer semiconductive layer, and a presser winding layer, the reinforcing insulating layer is formed of vulcanized rubber, and the reinforcing insulating layer is formed. An insulating tape layer made of unvulcanized or unvulcanized rubber is provided at an interface between the layer and the cable insulator. In this case, the void level at the interface between the cable insulator and the reinforcing insulating layer becomes equal to that at the other interface, and the withstand voltage performance is improved.

According to a second aspect of the present invention, there is provided a tape-winding linear connecting portion, wherein an insulating tape layer made of the unvulcanized or non-vulcanized rubber is provided so as to cover a part of the cable inner processing portion. It is characterized by the following. By doing so, the void level at the interface between the cable inner conductive portion and the reinforcing insulating layer can be reduced, and the withstand voltage performance is further improved.

[0008]

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. 2, 2a is an inclined peeling portion of the cable insulator 2, and 5a is an insulating tape layer made of unvulcanized or non-vulcanized rubber.

In the conventional tape-wound type linear connection part, the cable insulator 2 at the end of both cables to be connected is inclined and peeled off, and the inner semiconductive layer 4 is formed outside the connected conductor, and the outside thereof is formed. The reinforcing insulating layer 5 is formed by winding a vulcanized or semi-vulcanized insulating rubber tape on the inclined peeling portion 2a of the cable insulator 2 in the present invention. The reinforcing insulating layer 5 is formed by winding a vulcanized or semi-vulcanized insulating rubber tape thereon. As these rubbers, ethylene propylene rubber can be used.

[0010] Here, the unvulcanized rubber means a rubber to which a vulcanizing agent is added but which has not been vulcanized yet when the tape is wound, and which is first vulcanized by an external heat treatment after the tape is wound. are doing. In addition, the non-vulcanized rubber means a rubber that has not been vulcanized, has no vulcanizing agent added thereto, and is not vulcanized by an external heat treatment after winding the tape. .

The inside of the reinforcing insulating layer 5 using vulcanized rubber or semi-vulcanized rubber includes a heater for pressurizing and external heating by the presser winding layer 8 including the cable insulator interface (excluding the inclined peeling portion) (FIG. (Not shown) to fuse, and the void level is sufficiently reduced. On the other hand, the interface between the cable insulator 2 and the inclined peeling portion 2a is far from the external heating heater, so that the temperature does not easily rise. In this regard, in the present invention, the unvulcanized or non-vulcanized insulating tape layer 5a is provided on the inclined peeling portion 2a, and the unvulcanized or non-vulcanized rubber tape is not vulcanized. Since it is easily deformed by external pressure or heat treatment, the deformation easily causes the void at the interface between the inclined peeling portion 2a of the cable insulator 2 and the reinforcing insulating layer 5 to be crushed.

However, if unvulcanized or non-vulcanized rubber is used for the entire reinforcing insulating layer, the slope will be deformed, and the outer semiconductive layer 6 in this portion will have large irregularities, and will tend to be protruding. An electric field concentrates at the tip, and the withstand voltage characteristics are significantly reduced. Therefore, unvulcanized or unvulcanized rubber cannot be used for the entire reinforcing insulating layer. As described above, in the present invention, the locations where the vulcanized or semi-vulcanized rubber and the unvulcanized or non-vulcanized rubber are used are arranged by utilizing the characteristics of the respective rubbers.

By the way, in such a tape-wrapped linear connection portion, a semiconductive layer inside the cable provided immediately above the cable conductor of the rubber / plastic insulated power cable is provided between the cable conductor 1 and the cable insulator 2. 20 ~
The inner semiconductive layer 4 of the connection portion is formed so as to be partially overlapped with the inner conductive portion by 30 mm.
At that time, since the inner semiconductive layer 4 needs to be formed so as to minimize a step with the inner conductive portion, a part of the inner conductive portion remains exposed. If the reinforcing insulating layer 5 made of vulcanized rubber or semi-vulcanized rubber is directly provided thereon, voids tend to remain like the interface with the inclined peeling portion 2a of the cable insulator 2. Therefore, it is desirable that the insulating tape layer made of the unvulcanized or non-vulcanized rubber is formed so as to cover a part of the cable inner processing portion. By doing so, the withstand voltage performance of the tape-wound linear connection part is improved.

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

[0015]

[Table 1]

This data is obtained from a sample having a cable insulation thickness of 9 mm, a conductor size of 200 sq, and a slope rising angle of 6 ° on the outer surface of the reinforcing insulation layer 5. The thickness of the reinforcing insulating layer on the conductor connection part was 20 mm. The breakdown field is the breakdown voltage 破 壊
The thickness of the reinforcing insulating layer is set to 20 mm, and the unit is indicated by (kV / mm). From Table 1, it can be seen that the AC breakdown electric field and the lightning impulse breakdown characteristics of the product of the present invention are all improved by about 20% compared to the conventional example.

[0017]

Since the present invention is configured as described above, it has the following effects. That is, the tape-wound linear connecting portion according to claim 1 forms the reinforcing insulating layer with a vulcanized rubber, and forms an interface between the reinforcing insulating layer and the cable insulator from unvulcanized or non-vulcanized rubber. Since the insulating tape layer is provided, the void level at the interface between the cable insulator and the reinforcing insulating layer is reduced to a level equivalent to that at the other interface, and the withstand voltage performance is improved.

In the tape-winding linear connecting portion according to the present invention, the insulating tape layer made of the unvulcanized or non-vulcanized rubber is provided so as to cover a part of the cable inner processing portion. Therefore, the void level at the interface between the cable inner conduction processing portion and the reinforcing insulating layer can be reduced, and the withstand voltage performance is further improved.

[Brief description of the drawings]

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

FIG. 2 is a view showing a conventional tape-wound linear connection 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 BA02 BA12 BA17 CA22 5G375 AA02 BA26 BB45 CA02 CA13 CB03 CB04 CB17 DB11

Claims (2)

[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,
An outer semiconductive layer, a rubber-plastic insulated power cable formed with a press-winding layer, and a tape-winding type linear connection portion, wherein the reinforcing insulating layer is formed of vulcanized rubber, and the reinforcing insulating layer and the cable insulator are connected to each other. Characterized in that an insulating tape layer made of unvulcanized or non-vulcanized rubber is provided at the interface of (1). 2. The tape-wound straight line according to claim 1, wherein the insulating tape layer made of the unvulcanized or non-vulcanized rubber is provided so as to cover a part of the cable inner processing part. Connection.