JPH11122792A - Intermediate connection section for cv cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control partial discharging from a defective area such as external flow on the core surface, by coating or impregnating the conductive tape or an insulation tape thereon with residual element such as acetphenone, α- methylstylene, cumylalcohol or the like or alkylphenylketon. SOLUTION: An internal semi-conductive layer 2 is provided on a common conductor connecting section 1 with CV cables completely the terminated such as peeling of insulator and penciling or the like, and a reinforcing insulator 3 is also provided by the projection mold. Moreover, a conductive tape 5 and an insulation tape 6 are wound thereon bridging over the external conductive layers 4 of both CV cables, and then it is covered with a metal protection conduit 8 from the external side. Here, the conductive tape 5 or the insulation tape 6 is coated or impregnated with residual element such as acetphenone, α-methylstylene and cumylalcohol or the like or alkylphenylketon. As a result, partial discharge from a defective area such as external damage on the core surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intermediate joint for a CV cable such as an extrusion mold joint or a tape wound mold joint of a CV cable for a power line.

[0002]

2. Description of the Related Art An intermediate connecting portion of a CV cable, such as an extrusion mold joint or a tape wound mold joint,
As can be seen with reference to FIG. 1, an inner semiconductive layer and a reinforcing insulator 3 are applied on the conductor connection portion 1 between the CV cables which have been subjected to end treatment such as stepping off of the coating and pencilling,
A conductive tape 5 and an insulating tape 6 are wrapped around the outer semiconductive layer 4 of both CV cables, and a metal protective tube 8 is covered from the outside. still,
The waterproof compound 7 is injected into the protective tube 8. In FIG. 1, reference numeral 10 denotes a metal shielding layer, 11 denotes an insulating cylinder, 12 denotes an anticorrosion layer, 13 denotes a cable conductor, and 14 denotes a cable insulator.

In the above structure, the conductive tape 5
The insulating tape 6 is electrically connected to the metal shielding layer 10 on the cable body side to become an external semiconductive layer.
Functions as a holding tape that protects the outside of the unit.

The procedure for installing the intermediate connecting portion having the above structure is as follows. After the conductor connecting operation, the inner semiconductive layer and the reinforcing insulator are sequentially formed, and then the conductive tape 5 and the insulating material for protection and holding are provided. The tape 6 is wound, the protective tube 8 is covered, and finally the waterproof compound 7 is injected into the protective tube.

[0005]

The prior art C described above.
According to the V-cable intermediate connection part, as a factor of insulation performance deterioration, defects such as voids and foreign matter in the cable insulator and damage to the cable core are considered.

[0006] The above-mentioned construction work of the intermediate connection portion is carried out under sufficient control. However, if there is a trauma not found during the assembly work, or fine irregularities are formed on the core surface. If it has, a partial discharge will occur from that part, and the insulation performance may be reduced. Further, when a load is actually applied after the completion test after assembly, a partial discharge may be generated from the core surface due to a decrease in the discharge starting voltage due to an increase in the temperature of the connection portion.

Therefore, the problems to be solved by the present invention (objects)
Can suppress occurrence of partial discharge from a traumatic defect on the core surface at an intermediate connection portion such as an extrusion mold joint or a tape wound mold joint of a CV cable.
It is to provide an intermediate connection for a V cable.

[0008]

The C provided by the present invention
The intermediate connection part for the V cable is formed of a conductive tape applied on a reinforcing insulator by extrusion molding or tape winding molding or an insulating tape on the conductive tape, such as acetophenone, α-methylstyrene, cumyl alcohol, etc. Or an alkyl phenyl ketone having a phenyl group and a ketone group in the molecule.

Among the above, alkyl phenyl ketones having a phenyl group and a ketone group in the molecule include acetophenone, n-octanophenone, n-decanophenone, laurophenone, n-tetradecanophenone, and n-hexadecanophenone. , N-heptadecanophenone, 4'-n-
Octyl acetophenone, 4-n-octanoylbiphenyl, 1,9-diphenyl-1,3,6,8-nonatetraen-5-one, 2-isopropoxy-1,2-diphenylethanone, and the like. They can be used alone or in combination of two or more.

[0010]

FIG. 1 schematically shows an embodiment of an intermediate connecting portion for a CV cable according to the present invention.

As shown in FIG. 1, the intermediate connection portion for the CV cable of this embodiment is provided on the conductor connection portion 1 between the CV cables which have been subjected to end treatment such as stripping of the coating and pencilling. An inner semiconductive layer is applied, on which a reinforcing insulator 3 by extrusion molding or tape winding mold is applied, and a conductive tape 5 and an insulating tape 6 are further applied to the outer semiconductive layer 4 of both CV cables. It is wrapped around and is covered with a protective tube 8 made of metal from the outside. Note that a waterproof compound 7 is provided inside the protective tube 8.
Has been injected. In FIG. 1, reference numeral 10 denotes a metal shielding layer, 11 denotes an insulating cylinder, 12 denotes an anticorrosion layer, 13 denotes a cable conductor, and 14 denotes a cable insulator.

In the above structure, the conductive tape 5
The insulating tape 6 is electrically connected to the metal shielding layer 10 on the cable body side to become an external semiconductive layer.
Functions as a holding tape that protects the outside of the unit.

In the intermediate connection portion for a CV cable having the above-mentioned structure, in the present invention, the conductive tape 5 or the insulating tape 6 is used with respect to a residual component such as acetophenone, α-methylstyrene, cumyl alcohol or the like. It is formed by coating or impregnating an alkyl phenyl ketone having a phenyl group and a ketone group in the molecule.

Hereinafter, in the intermediate connection portion for a CV cable having the structure shown in FIG. 1, a traumatic defect is intentionally formed on the external semiconductive layer, and a partial discharge starting voltage is measured. A comparison was made with the partial discharge starting voltage from the same traumatic defect in the conventional intermediate connection portion where no component or the like was applied.

As a specific sample, an extrusion molded joint for a 275 kV class CV cable was used. In the test sample,
As a wound defect, a needle punch wound as indicated by reference numeral 9 in FIG. 2 was used, and a needle having a tip radius of curvature of 0.5 mm and 0.5 mm was used as the needle.

The conductive tape 5 and the insulating tape 6
As a sample 1, a conventional product not coated with a residue component or the like was used, a sample 2 coated with acetophenone was used, a sample 3 was coated with α-methylstyrene, and a sample 4 was cumyl alcohol. The sample coated with n-octanophenone was used as sample 5.

The following Table 1 shows the measurement results of the partial discharge generation voltage from the needle punch defect 9 when the above-mentioned samples 1 to 5 were applied to the structure shown in FIG.

[0018]

[Table 1]

As apparent from Table 1, the conductive tape 5
And, as the insulating tape 6, a sample in which a residue component or a kind of alkyl phenyl ketone having a phenyl group and a ketone group is applied in a molecule is used. Samples 2 to 5 have a phenyl group in the residue component or molecule. It can be seen that the partial discharge generation voltage is higher than that of Sample 1 not coated with the alkylphenyl ketone having a ketone group. As a result,
The former samples 2 to 5 indicate that the occurrence of partial discharge from a traumatic defect can be suppressed.

[0020]

According to the present invention as described above, C
Expected problem (objective) of providing an intermediate connection portion for a CV cable that can suppress occurrence of partial discharge from a traumatic defect on the core surface at an intermediate connection portion such as an extrusion mold joint or a tape wound mold joint of a V cable.
Can be achieved, and a highly reliable intermediate connection portion for CV cables can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory longitudinal sectional view showing a schematic structure of an intermediate connecting portion for a CV cable according to an embodiment of the present invention.

FIG. 2 is a test example of an intermediate connection portion for a CV cable according to the present invention;
FIG. 4 is a longitudinal sectional explanatory view showing a schematic structure of an intermediate connection portion for a 275 kV class CV cable for a partial discharge generation voltage measurement test.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conductor connection part 2 Internal semiconductive layer 3 Reinforcement insulator 4 External semiconductive layer 5 Conductive tape 6 Insulating tape 7 Waterproof compound 8 Metal protective tube 9 Needle removal defect 10 Metal shielding layer 11 Insulation cylinder 12 Corrosion protection layer 13 Cable Conductor 14 Cable insulator

Claims (1)

[Claims] 1. A conductive tape or a conductive tape applied on a reinforcing insulator by an extrusion mold or a tape winding mold at an intermediate connection portion such as an extrusion mold joint or a tape winding mold joint of a CV cable. An intermediate connection portion for a CV cable, which is obtained by applying or impregnating an insulating tape with a residue component such as acetophenone, α-methylstyrene, cumyl alcohol, or an alkylphenyl ketone having a phenyl group and a ketone group in a molecule.