JPH01241771A - Connection of low surge impedance conductor - Google Patents

Abstract

PURPOSE:To make it possible to secure a high dielectric breakdown strength to the pulse voltage and to make the connection shorter by providing a thin semiconductive layer to contact to an auxiliary conductor exposing part and a main conductor connection of a low surge impedance conductor to connect. CONSTITUTION:The connection of a low surge impedance conductor has a semiconductive layer 22 to contact to an auxiliary conductor exposing part 21 and a main conductor connection 13 of a low surge impedance conductor to connect. As a result, even when a large potential difference is generated instantly between a main conductor 1 and an auxiliary conductor 3, the potential difference is divided evenly in the longitudinal direction by the resistance of the semiconductive layer 22, generating no large potential gradient immediately above the main conductor 1 accordingly, and the dielectric breakdown value by the impulse voltage is increased compared in the case of no semiconductive layer 22. Therefore, the connection can be made shorter. And since only a thin semiconductive layer 22 is provided, an increase of the outer diameter is very little, and the flexibility of the connection is not be lost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a connection section for a low surge impedance conductor used for grounding a lightning arrester, an overhead ground wire, etc.

[Conventional technology]

Traditionally, 600V vinyl insulated wires have been widely used as grounding conductors for lightning arresters, etc., but in recent years, lower surge impedance of grounding conductors has been studied as part of lightning damage countermeasures for overhead power transmission and distribution lines, and various low-surge impedance wires have been used. Impedance conductors have been proposed.

The invention proposed by the present inventors in Utility Model Application No. 77701/1982 is one such proposal, and contributes to countermeasures against lightning damage.

The gist of the invention of the above utility model registration application is to cover an insulator in a substantially rectangular shape around an inner conductor made of a metal plate, and to place an outer conductor made of a metal plate on at least one side of the insulator as the inner conductor. This is a low surge impedance conductor characterized by being attached in parallel and facing each other, and further having an outer covering provided around it.

Note that the main conductor and sub-conductor in this invention have the same meaning as the inner conductor and outer conductor of the low surge impedance conductor in the invention of the above-mentioned utility model registration application.

By the way, the low surge impedance conductor devised above can be applied to all facilities that are at risk of lightning damage, such as various overhead power transmission and distribution lines and lightning rods, and the required length is 100 m.
There are things that extend to Therefore, if the conductor size is, for example, 10
In the case of a 0 mm2 conductor, this low surge impedance conductor alone weighs as much as 160 kg, and with the added requirement that it is often used in mountainous areas, it requires a great deal of effort to transport.

Therefore, the low surge impedance conductor itself is short (
However, there was a need for a reliable and simple method for connecting at the site of use.

[Problem to be solved by the invention]

However, the low surge impedance conductor itself is a new technical concept, and the connection method and structure of the connection part therefor have not yet been developed.

Generally, the connection parts of electric wires, cables, etc. that have multiple conductors or conductors and shields are wrapped with insulating tape or heat-fused to insulate between the conductor connections or between the conductor connection and the shield connection. The insulator is formed at the connection part by wrapping adhesive tape and then heat molding. However, unlike in the non-connection area, the electric field is uneven and the insulator formation must be done manually. Reinforcement insulation is also applied on the insulator around the conductor connection area to make it thicker than the non-connection area and to make the electric field distribution as uniform as possible, smoothing out the tendency for the outer diameter of the insulator to decrease from the conductor connection area to the non-connection area. Therefore, the length of the entire connection part becomes long.

Therefore, there is a problem in that not only is it time-consuming to form the connection part, but also the flexibility of the connection part is deteriorated, resulting in a reduction in workability in wiring work. In order to simplify such manual work, it is possible to insulate the connections using heat shrink tubing, but connections formed using this method have the problem of insufficient impulse breakdown voltage characteristics. Ta.

In view of the above-mentioned current situation, it is an object of the present invention to provide a connection portion for a low-surge impedance conductor that can be formed reliably and easily without degrading the function of the low-surge impedance conductor.

[Means to solve the problem]

In order to solve the above problems, the present invention covers the outer periphery of a flat main conductor with an insulator in a rectangular shape, and a flat sub-conductor is coated on one side of the main conductor in parallel with the main conductor. At the connection part of the low-surge impedance conductor attached and the outer periphery of which is covered with an outer sheath, the outer sheath, sub-conductor and insulator of the terminal parts of the two low-surge impedance conductors are sequentially peeled off in steps. A main conductor connecting portion formed by connecting the exposed main conductors to each other, a semiconductive layer provided so as to come into contact with the exposed subconductor portions and the main conductor connecting portion on both sides, and a semiconductive layer covering the semiconductive layer. An insulator layer provided on the outer periphery, a sub-conductor connection portion made of a conductor provided on the outer periphery to connect with the sub-conductor exposed portions on both sides and the sub-conductor exposed portions, and a sub-conductor connection portion provided on the outer periphery of the sub-conductor connection portion. The structure includes an outer sheath connection part.

[Effect]

The connecting portion of the low-surge impedance conductor of the present invention having the above-mentioned configuration is provided with a semiconductive layer so as to come into contact with the exposed sub-conductor portion and the main conductor connecting portion of the low-surge impedance conductor to be connected. Even if a large potential difference momentarily occurs between the main conductor and the sub-conductor due to the invasion of lightning surge, the potential difference is divided almost equally in the length direction by the resistance of the semiconductive layer, and therefore the main conductor A large potential gradient is not generated immediately above, and the dielectric breakdown value due to impulse voltage is higher than in the case without this semiconductive layer. In other words, the connecting portion can be shortened.

Moreover, since only a thin semiconductive layer is provided, the increase in the outer diameter is very small and does not impair flexibility.

〔Example〕

FIG. 1 shows an embodiment of the connecting part of a low surge impedance conductor according to the present invention. The arrow view and FIG. 1(C) are the same YY cross-sectional view as the arrow view.

In the illustrated embodiment, the low surge impedance conductor to be connected consists of a main conductor 1 made of a copper strip, covered with a vinyl insulator 2, and a sub-conductor 3 made of a copper tape on one side of the vinyl insulator 2. It is attached parallel to the body 1, and its outer periphery is covered with a vinyl jacket 4.

The connections are formed as described below.

That is, the main conductor exposed portions 11.11 are overlapped by a predetermined length and the flat compression connecting pipe 12 is compressed to form the main conductor connecting portion 13, and the exposed portions of the sub conductors 3 on both sides, that is, the sub conductor exposed portions 21, 2 are
1 is folded back and placed at the peeled ends 41 and 41 of the outer sheaths 4 and 4. This folded back sub-conductor exposed portion 21.21
A semiconductive tape is wound on top, on the insulator 2°2, and on the main conductor connecting portion 13 to form a semiconductive layer 22.

Next, a heat shrinkable tube made of ethylene propylene rubber is used around the outer periphery of the semiconductive layer 22 to cover the insulating layer 22.
form 1. The end portion of the sub-conductor exposed portion 21.degree. 21 is connected to the copper tape 21a attached on one side of the insulating layer 51 by a clamp 23, 23 to form a sub-conductor connecting portion 24.

Further, the outer periphery of the tube is covered with a heat-shrinkable tube 42 made of ethylene propylene rubber, and both ends thereof are sealed with sealing tapes 43, 43 and adhesive tapes 44, 44 to form a jacket connection portion 45.

An impulse breakdown voltage test was conducted on the connection portion of the low surge impedance conductor formed as described above. In this test, three samples were prepared for each of the three types of examples with different interface lengths in Figure 1 ((to)), and for comparison, these examples and the point without a semiconductive layer were prepared. Samples differing only in the following were prepared in the same way.

The test method was to apply a 20 KV twin pulse voltage (impulse waveform is based on JIS C3005) between the main conductor and the sub conductor, then increase the voltage by 10 KV, and apply each three times.

The results are shown in the table below.

In the test results in this table, interfacial flashing refers to the interface between the insulator 2 and the semiconductive layer 22 in the case of the example, and the interface between the insulator 2 and the insulator layer 51 in the case of the comparative example. , a flash short has occurred between the main conductor connection part 13 and the sub-conductor exposed part 21, and dielectric breakdown is the occurrence of dielectric breakdown in the insulator 2 itself without passing through such an interface. .

As is clear from the results in the above table, when the semiconductive layer 22 is not provided, even if the interface length is set to 300 mm, it is still 80 mm.
Although interfacial flashing occurs at voltages below KV, interface flashing does not occur at voltages lower than the dielectric breakdown value by setting the interface length to 250 mm or more in those provided with the semiconductive layer 22.

In the above embodiment, the semiconductive layer 22 was formed using a semiconductive tape, but it can also be formed using a semiconductive heat shrink tube or by applying a conductive paint. Included in invention. In addition, the main conductor connection part 1
3. Sub-conductor connection portion 24, jacket connection portion 45, insulator layer 51
These structures are not limited to the above embodiments.

〔Effect of the invention〕

As explained above, the connection part of the low surge impedance conductor according to the present invention is provided by providing a thin semiconductive layer in contact with the exposed sub-conductor part and the main conductor contact part of the low-surge impedance conductor to be connected. , even if an impulse voltage is applied between the main conductor and the sub-conductor, the potential difference is divided almost equally in the length direction by the resistance of the semiconductive layer.
It is possible to ensure high dielectric breakdown strength against impulse voltage, and therefore the connection portion can be shortened.

Moreover, the increase in outer diameter is very small, and flexibility is not impaired. That is, the connection portion of the low-surge impedance conductor according to the present invention can be formed reliably and easily without deteriorating the function of the low-surge impedance conductor.

[Brief explanation of the drawing]

Fig. 1 shows an embodiment of the low surge impedance conductor according to the present invention, Fig. 1(a) is a longitudinal sectional view, and Fig. 1(c) is a cross-sectional view taken along line X-X in Fig. 1(a). , FIG. 1(C) is a Y-Y cross-sectional view of FIG. Covered, 13... Main conductor connection part, 22
...Semiconductive layer, 24.. Sub-conductor connection portion, 45.. Sheath connection portion.

Claims (1)

[Claims] (1) Cover the outer periphery of a flat main conductor with a rectangular insulator, attach a flat sub-conductor on at least one side of the insulator in parallel with the main conductor, and cover the outer periphery with an outer sheath. In the connecting part of low surge impedance conductors made of: The outer cover, sub conductor and insulator of the terminal parts of two low surge impedance conductors are sequentially stripped off in steps and the exposed main conductors are connected to each other. a main conductor connection part; a semiconductive layer provided so as to be in contact with the sub-conductor exposed parts on both sides and the main conductor connection part; an insulator layer provided on the outer periphery of the semiconductive layer so as to cover it; Furthermore, a sub-conductor connection part made of a conductor provided on the outer periphery of the sub-conductor exposed part on both sides and connected to the sub-conductor exposed part; and an outer sheath connection part provided on the outer periphery of the above-mentioned sub-conductor connection part; A low-surge impedance conductor connection section characterized by: