JPH06261437A - Connection of cv cable - Google Patents

Abstract

PURPOSE:To provide connections of CV cables having excellent voltage enduring characteristics, and capable of lightening regulation for foreign substances, voids, protrusions, etc. at the interfaces of a stress relief cone with an epoxy receiving seat and a cable insulating layer. CONSTITUTION:An electrically negative gas such as SF6, N2, etc. is let in the connections of CV cables, and the periphery of a stress relief cone 3 is filled with the electrically negative gas. On this occasion, a gas sealing member 11 is provided at a cable-conductor 10a exposed part to prevent the gas from leaking out through the cable conductor 10a.

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 using a stress relief cone.

[0002]

2. Description of the Related Art A prefabricated terminal connection has a conical surface formed by attaching a premolded rubber premolded electric field relaxation insulation reinforcing material (stress relief cone) to a CV cable insulation layer on site. A stress relief cone is inserted into the hole of the epoxy seat having the hole to assemble the end portion. This prefabricated termination connection has the advantages of easy construction and high reliability. For this reason, the prefabricated type termination connection part is currently widely used for various CV cables from 6 kV to 154 kV class. The stress relief cone is usually made of ethylene propylene rubber, silicone rubber, or the like.

Prefabricated terminations are mainly 6 kV to 22 kV.
A method of inserting the stress relief cone used for the kV class CV cable into the epoxy seat (insertion type) and pressing the stress relief cone mainly used for the 66 kV to 154 kV class CV cable with a spring or the like. There is a method of compressing (compression).

FIG. 2 is a one-sided sectional view showing a terminating connection portion of a conventional compression type prefabricated CV cable.

The CV cable 10 is stripped of the sheath, insulating layer, etc. at the tip thereof, so that the exposed center conductor 1 is exposed.
0a is joined to the conductor pull-out rod 1. A stress relief cone 3 is fitted on the outer periphery of the insulating layer at the tip of the CV cable 10.
Is inserted into the conical hole of the epoxy seat 2. The epoxy seat 2 supports the above-mentioned conductor lead-out rod 1 and is attached to the equipment bottom plate 16 via the adapter 6.

Between the sheath end of the CV cable 10 and the epoxy seat 2, a cable protection metal fitting 8 and an insulating tube 7 are attached to protect the stripped portion of the sheath. The push pipe 4 and the push fitting 5 are disposed inside the cable protection fitting 8. A spring (not shown) is fitted to the pressing fitting 5, and the elastic force of the spring causes the pressing pipe 4 to press the stress relief cone 3 against the epoxy seat 2.

In the prefabricated type terminal connecting portion thus constructed, the stress relief cone has an effect of relaxing electric field concentration in the connecting portion.

Further, the stress relief cone is used not only in the terminal connection portion but also in the intermediate connection portion.

FIG. 3 is a one-sided sectional view showing an example of the intermediate connecting portion of the CV cable. Also in this case, CV cable 1
0 stress relief cone 3 on the outer circumference of the insulating layer
Then, the stress relief cone 3 is inserted into the conical hole provided in the epoxy seat 12, and the spring 1
3 by stress relief cone 3 epoxy seat 1
It is designed to be pressed against 2.

[0010]

However, the above-described conventional CV cable connecting portion has the following problems. That is, in this type of CV cable connecting portion, the characteristics of the interface between the stress relief cone and the epoxy seat and the cable insulating layer are important. For example, if foreign matter, voids, protrusions, or the like are present at these interfaces, the breakdown voltage characteristics may deteriorate, and discharge may occur, resulting in a breakdown accident. Therefore, conventionally, it is necessary to extremely strictly control the presence of foreign matter, voids, protrusions, and the like at the interface between the stress relief cone, the epoxy seat, and the cable insulating layer.

The present invention has been made in view of the above problems, and has further excellent pressure resistance characteristics as compared with the prior art, and foreign matter, voids, and voids at the interface between the stress relief cone and the epoxy seat and the cable insulating layer. It is an object of the present invention to provide a CV cable connecting portion that can relax restrictions such as protrusions.

[0012]

The connection portion of a CV cable according to the present invention is a connection of a CV cable having a stress relief cone fitted to the outer periphery of a cable insulating layer and a seat into which the stress relief cone is inserted. In the department
An electrically negative gas is filled around the stress relief cone.

[0013]

In the present invention, the stress relief cone is filled with an electrically negative gas such as SF ₆ or N ₂ around the stress relief cone. Since the electrically negative gas has excellent insulation resistance and is less likely to cause sparks, filling the periphery of the stress relief cone with the electrically negative gas increases the partial discharge inception voltage. Therefore, the connection portion of the CV cable according to the present invention has improved withstand voltage characteristics as compared with the conventional CV cable connection portion, and foreign matter, voids or protrusions at the interface between the stress relief cone and the epoxy seat or the cable insulating layer. Regulations can be relaxed.

[0014]

Embodiments of the present invention will now be described with reference to the accompanying drawings.

FIG. 1 is a one-sided sectional view showing a connecting portion of a CV cable according to an embodiment of the present invention.

The present embodiment is different from the conventional one in that the terminal connection portion is filled with an electrically negative gas, and the other construction is basically the same as the conventional one. The same reference numerals are given to the same components, and detailed description thereof will be omitted.

In this embodiment, the gas seal portion 1 is provided on the exposed portion of the central conductor 10a at the tip of the CV cable 10.
1 is provided so as to maintain airtightness at the tip of the cable insulating layer. The gas seal portion can prevent gas leakage from the conductor when the electrically negative gas is filled.

Further, the cable protection fitting 8 is provided with a gas injection port 15 through which an electrically negative gas such as SF ₆ or N ₂ is injected from the gas cylinder 9 into the connection portion. It is like this.

The connection portion of the CV cable according to this embodiment is
After assembling in a conventional manner, the inside of the connection portion is evacuated through the gas injection port, and then the electrically negative gas is filled into the connection portion through the gas injection port to form the structure.

In the present embodiment, since the stress relief cone is filled with an electrically negative gas, the pressure resistance characteristics are improved as compared with the conventional ones. For example, the stress relief cone and the epoxy seat or the cable insulating layer are used. Even if there is a foreign substance, a void, a protrusion, or the like at the interface with, the occurrence of discharge can be avoided.

In the above-mentioned embodiment, the case where an electrically inert gas such as SF ₆ or N ₂ is filled around the stress relief cone has been described. However, these electrically negative gas and fluorocarbon liquid ( C ₈ F ₁₆ O) may be used in combination.

[0022]

As described above, according to the present invention, the electrically negative gas is filled around the stress relief cone, so that the withstand voltage characteristic of the CV cable connecting portion is improved as compared with the conventional one. Generation of discharge can be suppressed. Therefore, it is possible to obtain the effect that the regulation of foreign matter, voids, projections, etc. at the interface between the stress relief cone and the epoxy seat or the cable insulating layer is relaxed.

[Brief description of drawings]

FIG. 1 is a one-sided sectional view showing a connecting portion of a CV cable according to an embodiment of the present invention.

FIG. 2 is a one-sided cross-sectional view showing a terminal connecting portion of a conventional prefabricated CV cable.

FIG. 3 is a one-sided sectional view showing an example of an intermediate connection portion of a CV cable.

[Explanation of symbols]

 1; conductor pull-out rod 2; epoxy seat 3; stress relief cone 4; push pipe 5; push metal fitting 6; adapter 7; insulating tube 8; cable protector 9; gas cylinder 10; CV cable 15; gas inlet

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideki Ikeda 1-5-1, Kiba, Koto-ku, Tokyo Inside Fujikura Stock Company

Claims (1)

[Claims] 1. A connecting portion of a CV cable having a stress relief cone fitted to the outer periphery of a cable insulating layer and a seat into which the stress relief cone is inserted,
A connection part of a CV cable, wherein an electrically negative gas is filled around the stress relief cone.