JPH11187560A - Crosslinked-polyethylene-insulated power cable joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce maintenance of work execution environment, and the shortening of work execution time, and improve the electrical property of a joint, by winding a specified two-layer structure of tape on a conductor joint, and then, molding it, with an ethylene propylene rubber tape face as conductor joint side, thereby forming a reinforced insulator. SOLUTION: The conductors 1 of cables being led out and stripped in tiers are connected with each other by a conductor connecting pipe 2 and a semiconductive tape 3 is wrapped on the conductor conductive pipe 2 and to the tips of both cable inner semiconductive layers 3 so as to form a semiconductive layer 5 within the joint. Thereon, a two-layer tape 10 consisting of an uncrosslinked polyethylene tape layer wherein an crosslinking agent is projected, and an unvulcanized ethylenepropylene rubber tape layer where in a vulcanizing agent is projected is wound, with the unvulcanized EPR layer inside, so as to form a reinforced insulator 7. Furthermore, a semiconductive fusing tape is wrapped on the reinforced insulator 7 and to the tips of both the cable outer semiconductor layers 5 so as to form a joint outer semiconductor layer 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection portion of a CV cable and a power cable according to the invention, and more particularly to a method of winding a non-crosslinked polyethylene tape containing a cross-linking agent and molding the same to form a reinforcing insulator for the connection portion. And a joint formed by the joint method TMJ.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 5, connection of CV cables used for power transmission and distribution is performed by stripping off both power cables, compressing and connecting a cable conductor 1 by a conductor connection pipe 2, and connecting the conductors by a conductor connection pipe 2. Then, the semiconductive layer 6 is applied to the surface of the conductor connection tube 2. Further, a reinforcing insulator 17 is formed on both cable insulators 4 to insulate them.

After the outer semiconductive layer 8 is formed on the outer peripheral surface of the reinforcing insulator 17, the entire connecting portion is covered with a protective body.

[0004] Conventionally used connection techniques include a joint method (tape joint) in which a self-fusing rubber tape is wound to form a reinforcing insulator 17 at the connection portion, and an uncrosslinked polyethylene tape containing a crosslinking agent. Later, a joint method (TMJ) for molding this to form insulation at the connection portion, a joint method (EMJ) for extruding an uncrosslinked polyethylene resin containing a cross-linking agent and then molding to form a reinforcing insulator 17 at the connection portion, A joint method (PJ) for forming insulation at the connection part by combining a rubber stress cone manufactured in advance with a factory and an epoxy insulation unit
And so on.

[0005]

The above-mentioned tape type joint is widely used for a CV cable of 66 to 77 kV class, since the construction time is short and the cost is the best. However, this joint is low in reliability in terms of insulation performance because the tapes are simply adhered to each other with an adhesive layer, and it has been difficult to apply this joint to a CV cable of 154 kV class or more.

Further, since the above-mentioned connection of TMJ and EMJ uses uncrosslinked polyethylene containing a crosslinking agent, it is necessary to strictly control the cleanliness of the construction environment for forming the reinforcing insulating layer. It took more than that.
Further, a long working time continuous for heating and cooling at the time of molding is required.

[0007] Accordingly, the entire operation takes a long time and the cost is excessive.

On the other hand, in the connection method of the PJ, it is necessary to send the epoxy insulating unit to the CV cable side before connection. However, the epoxy insulated unit was very heavy, and the work of sending it was difficult.

Focusing on TMJ from the above situation,
Although the electrical properties of the above-mentioned TMJ are excellent, as described above, it is necessary to maintain the construction environment, and there is a drawback that management of heating and cooling for a long time is required.

On the other hand, although the electrical characteristics of the ethylene propylene rubber tape (EPR tape) mold joint are slightly inferior, there is no significant decrease in the electrical characteristics due to contamination by foreign matter, and furthermore, the cooling at the time of molding is more difficult. There is an advantage that it is unnecessary and the work time is short.

In view of the above points, the present invention provides a cross-linked polyethylene insulated power cable connecting part which can reduce the construction environment maintenance, shorten the construction time and improve the electrical characteristics of the connecting part in TMJ. The purpose is to provide.

[0012]

According to the present invention, there is provided a method for producing a non-crosslinked cross-linked polyethylene (XLP) on a conductor connecting portion.
E) A two-layer tape consisting of a tape layer and an unvulcanized vulcanizing agent-containing ethylene propylene rubber (EPR) tape layer
After the tape layer surface is wound with the conductor connecting portion side, the reinforcing insulating material is formed by molding.

Further, a layer obtained by winding the two-layer structure tape to a predetermined thickness directly above the conductor connection portion and a layer obtained by winding an unvulcanized EPR tape alone are arranged thereon to form a reinforcing insulator. It is characterized by becoming.

Further, a layer obtained by winding the two-layer structure tape to a predetermined thickness directly on the conductor connection portion is further provided thereon with an uncrosslinked XLP.
It is characterized in that a reinforcing insulator is formed by arranging a layer in which a single E tape is wound.

[0015]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a partial vertical sectional view of a power cable connecting portion for explaining an embodiment of the present invention. In the figure, the conductors 1 of the cable stripped at the outlet are connected by a conductor connection tube 2 and a semiconductive tape is placed on the conductor connection tube 2.
Then, a wrap winding is performed over the distal end portions of both cable internal semiconductive layers 3 to form a connection portion internal semiconductive layer 6. A two-layer tape 10 composed of an unvulcanized EPR layer 11 and an uncrosslinked XLPE layer 12 shown in FIG.
Is wound inside (conductor side) to form the reinforcing insulator 7. The reinforcing insulator 7 is mounted on a mold and vulcanized (crosslinked). Further, a semiconductive fusing tape is wrapped around the reinforcing insulator 7 and over the distal end portions of both cable external semiconductive layers 5 to form a connection part external semiconductive layer 8.
To form

On this, a shielding layer, a protective tube, a waterproof layer and the like (not shown) are applied, and the connection operation is completed.

FIG. 3 is a partial longitudinal sectional view of a power cable connecting portion for explaining a second embodiment of the present invention. Claim 2
In the present invention, the connection portion internal semiconductive layer 6 is formed by the connection procedure described with reference to FIG. On top of that, the two-layer tape 10 shown in FIG. 2 is wound up to a predetermined thickness, with the unvulcanized EPR layer 11 inside (on the conductor side).
The reinforcing insulator 7 is formed by winding the R tape 13 alone. Others are the same as those described in FIG.

FIG. 4 is a partial longitudinal sectional view of a power cable connecting portion for explaining a third embodiment of the present invention. In the third embodiment of the present invention, the connecting portion is connected in the connection procedure described in FIG. The inner semiconductive layer 6 is formed. On top of this, the unvulcanized EPR layer 11 is coated with the two-layer tape 10 shown in FIG.
Is wound inside (conductor side), and the uncrosslinked XLPE tape unit 15 having a predetermined thickness is wound thereon to form the reinforcing insulator 7. Others are the same as those described in FIG.

[0019]

As described above, the present invention has the following effects.

(1) Since the bonding condition between the unvulcanized EPR layer and the cable insulator is easier than that of the unbridged XLPE layer, cooling control during molding is not required. Therefore, the construction time can be reduced.

(2) Since the EPR mold joint does not require any environmental maintenance, the environmental maintenance can be reduced only in the EPR layer, so that the construction time can be shortened.

(3) Since the two-layer tape of EPR and XLPE is wound, the electrical characteristics of the cable connection portion can be improved as compared with the case of winding the EPR tape alone.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional view of a cross-linked polyethylene insulated power cable connecting portion according to claim 1 of the present invention.

FIG. 2 is an explanatory diagram of a two-layer tape according to the present invention.

FIG. 3 is a partial longitudinal sectional view of a cross-linked polyethylene insulated power cable connecting portion according to claim 2 of the present invention.

FIG. 4 is a partial longitudinal sectional view of a cross-linked polyethylene insulated power cable connecting portion according to claim 3 of the present invention.

FIG. 5 is a partial longitudinal sectional view illustrating a conventional cross-linked polyethylene insulated power cable connection portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conductor 2 Conductor connection pipe 3 Cable internal semiconductive layer 4 Cable insulator 5 Cable external semiconductive layer 6 Connection internal semiconductive layer 7,17 Reinforcement insulator 8 Connection external semiconductive layer 10 Two-layer tape 13 Unvulcanized Wound layer of EPR tape 15 Wound layer of uncrosslinked XLPE tape

Claims (3)

[Claims] 1. A connecting portion of a crosslinked polyethylene insulated power cable in which an insulating tape is wound on a conductor connecting portion and then molded to form a reinforced insulator. After winding a two-layer structure tape of a cross-linking agent-containing polyethylene layer and an unvulcanized vulcanizing agent-containing ethylene propylene rubber layer, the ethylene propylene rubber layer surface of the two-layer structure tape is used as a conductor connection portion side, A crosslinked polyethylene insulated power cable connection, characterized by forming a reinforcing insulator by molding. 2. A connecting portion of a cross-linked polyethylene insulated power cable in which an insulating tape is wound on a conductor connecting portion and then molded to form a reinforcing insulator. A two-layer tape wound layer according to claim 1 having a thickness, an unvulcanized vulcanizing agent-containing ethylene propylene rubber tape wound layer is formed thereon, and then molded to form a reinforcing insulator. A cross-linked polyethylene insulated power cable connection, characterized in that: 3. A connecting portion of a cross-linked polyethylene insulated power cable in which an insulating tape is wound around a conductor connecting portion and then molded to form a reinforced insulator. A two-layer tape winding layer according to claim 1 having a thickness, a non-crosslinked polyethylene tape winding layer containing a crosslinking agent is formed thereon, and then molded to form a reinforcing insulator. And cross-linked polyethylene insulated power cable connection.