JPS6137724B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultra-high voltage OF cable, particularly to the structure of its thin layer.

In conventional OF cables, a thin and thin structure as illustrated in FIG. 1 or 2 has been applied. The figure particularly conceptually shows a partial cross section of the cable in the length direction.

In FIG. 1, an insulating layer 1 is formed on the conductor, two carbon paper tapes of one or two pieces are wound on it, and a hard aluminum tape 3 is placed on top of it.
and carbon paper tape 4 are wound together to form a laminated layer, and a copper wire woven cloth tape 5 is wound thereon, and this copper wire woven cloth tape 5 is in partial contact with the aluminum sheath 6. During charging, a charging current is passed through the aluminum sheath 6. A metallized carbon paper tape may be used instead of the hard aluminum tape 3 in the laminated layer. For example, metallized carbon paper is 5~
It is made by gluing aluminum foil of about 20 μm to kraft paper of about 70 to 100 μm, and is wound with the metal side facing outward. On the other hand, in the one shown in FIG. 2, a metallized carbon paper tape 7 is gap-wound on a layer formed by one or two carbon paper tapes 2 with the metal surface facing outward at intervals. On top of that, copper wire woven cloth tape 5
is wound, and the layer made of the copper wire woven cloth tape 5 is in partial contact with the aluminum sheath 6. Note that between the insulating layer 1 and the carbon paper 2, a single layer of metallized paper with the metal side on one side may be gap-wound, and a cloth tape 5 woven with copper wire under the aluminum sheath 6 may be used. In some cases, the aluminum sheath 6 is omitted, and in some cases, the aluminum sheath 6 is replaced with a lead sheath or stainless steel sheath, but as shown in Figures 1 and 2 below, there is a carbon paper 2 on top of the insulating layer 1. The case where a copper wire woven cloth tape 5 is also included and an aluminum sheath 6 is covered will be described as a representative case.

By the way, when considering the flow of charging current in the case shown in FIG. 1, the charging current flows from the copper wire woven cloth tape 5 to the aluminum sheath 6. The area of the metal surface of the tape 3 or the metallized carbon paper tape 7 is not so large due to the presence of the double-wound carbon paper tape 4.

Further, in the case shown in FIG. 2, since the metallized carbon paper tape 7 is bonded with an adhesive, the resistance at the bonding boundary becomes large.

In this way, in the devices shown in Figures 1 and 2, the resistance to the charging current increases, and heat generation due to Joule loss (also called Watt loss) increases in this part, so equivalently, the resistance to the charging current increases. tan
This is equivalent to an increase in δ (dielectric loss).

Generally, when forming the insulating layer 1 by winding, kraft paper or a composite of kraft paper and polyolefin film is used, and polyolefin films are alternately used. It is known that an effective means of suppressing the increase in thickness due to film swelling in insulating oil is to use kraft paper that has been pre-humidified during production (Japanese Patent Publication No. 1973-
No. 38237). When the insulating layer 1 is formed by winding the moisture-adjusted material, and the hard aluminum tape 3 is wound together with the carbon paper tape 4 as explained with reference to FIG. Wrinkles occur on three sides of the aluminum tape, and there is a risk that it will not follow the internal swelling after being immersed in oil.

On the other hand, the tape using the metallized carbon paper tape explained in connection with Fig. 2 is made of, for example, aluminum foil of about 5 to 20 μm and kraft paper of about 70 to 100 μm, which are bonded together as described above. Therefore, it has the advantage of being able to sufficiently follow the aforementioned swelling.

As explained above, the stiffness layer of the conventional OF cable takes into consideration the flow of charging current, but this is not always sufficient, and in the present invention, these The OF cable shown in the figure is further improved to have a thin layer with extremely low resistance to charging current.
It provides cables.

The embodiment of the present invention shown in FIG. 3 will be described below.

Although not shown, an insulating layer 11 is formed on the conductor. For the insulating layer 11, the above-described kraft paper tape, polyolefin plastic tape, composite tape of kraft paper and polyolefin plastic film, etc. are used, and each layer is usually formed into a gap-wound layer. The kraft paper tape and the composite tape of kraft paper and polyolefin plastic are pre-humidified.

One or two sheets of carbon paper tape 12 are wound on top of this insulating layer 11, and a metallized carbon paper tape 13 is wound on top of that. As already explained, the metallized carbon paper tape 13 is made by bonding a metal foil, for example, an aluminum foil 14, and a carbon paper 15.
The aluminum foils 14 are rolled together so that the surfaces of the aluminum foils 14 are in contact with each other, and the surfaces of the aluminum foils 14 appear wide when viewed from the outside. Normally, the overlapping ratio is about 1/4 of the tape width.

After this double winding, a copper wire woven cloth tape 16 is wound, and then a spiral or corrugated metal sheath 17 made of aluminum, for example, is covered. During manufacture, it is then dried and impregnated with insulating oil.

With the configuration shown in FIG.
3', that is, the aluminum foil 14' of the metallized carbon paper tape 13' with the metal surface facing the direction of the insulating layer 11, enters the aluminum foil 14 of the metallized carbon paper tape 13 that is in contact with this, and the aluminum foil Enter the copper wire of the copper wire woven cloth tape 16 from the surface of 14 and insert the aluminum sheath 1
Passed 7. This path provides significantly lower resistance.

At the same time, the charging current is
Then, the carbon paper 15 of the metallized carbon paper tape 13 with the carbon paper surface facing the direction of the insulating layer 11 passes through the aluminum foil 14, enters the copper wire of the copper wire woven cloth tape 16 in contact with this, and enters the aluminum sheath 17. Since the metallized carbon paper tape 13 has its metal surface facing the direction of the insulating layer 11, the carbon paper tape 12 and the aluminum foil 14 of the metallized carbon paper tape 13 have the metal surface facing the direction of the insulating layer 11. The copper wire of the cloth tape 16 with copper wire woven through the carbon paper 15 of the metallized carbon paper tape 13 that passes through the paper 15 and faces this carbon paper 15, passes through the same aluminum foil 14,
There is also a path leading to the aluminum sheath 16, which also reduces resistance.

As explained above, according to the present invention, the problem of increased resistance caused by metallized carbon paper is solved by its clever construction, and it can be applied in place of the conventional hard aluminum tape-containing damping layer. can. In particular, as explained above, when the insulating layer is formed by winding a composite tape of polyolefin plastic film and kraft paper, or by alternately wrapping a polyolefin plastic film tape and kraft paper tape, the winding is usually done after adjusting the humidity. Then, I try to deal with the subsequent drying and oil soaking. That is, unlike the application of hard aluminum tape, the application of metallized carbon paper to the flexible layer on the insulating layer closely follows the shrinkage of the insulating layer due to drying and the swelling of the insulating layer after immersion in oil. Therefore, it is excellent because it does not cause wrinkles, but the present invention is a practical solution to the increased resistance of metallized carbon paper.
By reducing the Joule loss due to the increased resistance of the charging current path in the insulation layer, it is possible to provide an OF cable with equivalently small tanσ.

[Brief explanation of the drawing]

Both FIG. 1 and FIG. 2 are diagrams conceptually illustrating a partial cross section in the length direction of a conventional OF cable. FIG. 3 is a diagram conceptually showing an embodiment of the OF cable of the present invention in a partial longitudinal section. 1, 11... Insulating layer, 2, 12... Carbon paper, 3
...Hard aluminum tape, 4...Carbon paper tape, 5,16...Copper wire woven cloth tape, 6,17...
Aluminum sheath, 7,13,13'...Metalized carbon paper tape, 14,14'...Aluminum foil, 15,15'...Carbon paper.

Claims (1)

[Claims] 1. An OF characterized in that two metallized carbon paper tapes are wound together on an insulating layer formed on a conductor with the metal surfaces facing each other, and a metal sheath is placed on the outside of the tape. cable. 2. OF as set forth in claim 1, characterized in that when two metallized carbon paper tapes are wound together with their metal surfaces facing each other, the metal surfaces are rolled together so that the width appears wider when viewed from the outside. cable. 3. The OF cable according to claim 1 or 2, characterized in that a copper wire woven cloth tape is wound between the laminated layer of two metallized carbon paper tapes and the metal sheath.