JPH01241772A - Terminal of low surge impedance conductor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a terminal portion of 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 that an insulator is coated around an inner conductor made of a metal plate in a substantially rectangular shape, and an outer conductor made of a metal plate is placed on at least one side of the insulator parallel to the inner conductor. This is a low surge impedance conductor characterized by being attached oppositely to each other and having an outer sheath 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 can be connected to the ground side of an overhead ground wire or lightning arrester. used. Accordingly, there has been a need for a terminal portion of a low-surge impedance conductor that can be simply terminal-treated so as not to cause flashover failure or damage to characteristics.

[Problem to be solved by the invention]

However, the low surge impedance conductor itself is a new technical concept, and the terminal processing method and structure of the terminal portion thereof have not yet been developed.

Generally, the terminals of electric wires, cables, etc. that have multiple conductors or conductors and shields are wrapped with insulating tape to insulate between the terminals of the multiple conductors or between the terminals of the conductor and the shield terminal. The insulator is formed at the end by wrapping heat-adhesive tape and then heat-molding it, but unlike the middle part, we took into account that the electric field would be uneven and that the insulator would have to be formed manually. In order to make the insulator layer thicker than the middle part, and to make the electric field distribution as uniform as possible, reinforcement insulation is applied between the conductor terminal parts or between the shield and the conductor, and the outer diameter of the insulator is reduced from the conductor terminal part to the middle part. The tendency is smoothed out, and as a result, the length of the entire terminal section becomes longer.

Therefore, there is a problem in that not only is it time-consuming to form the terminal portion, but also the flexibility of the terminal portion is deteriorated, resulting in a reduction in workability in wiring work. In order to simplify such manual work, it is possible to treat the terminals using heat-shrinkable tubes, but there is a problem in that the terminals formed by this method have insufficient impulse breakdown voltage characteristics. .

In view of the above-mentioned current situation, it is an object of the present invention to provide a terminal portion of a low-surge impedance conductor that can be formed reliably and easily without deteriorating 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 substantially rectangular shape, and adds a flat sub-conductor on at least one side of the insulator in parallel with the main conductor. At the terminal part of the low surge impedance conductor, which is made of a low-surge impedance conductor whose outer periphery is coated with an outer sheath, the outer sheath, sub-conductor and insulator are sequentially peeled off stepwise to expose the sub-conductor, the exposed insulator and the main conductor. a semiconductive layer provided in contact with the exposed portion;
An insulating layer is provided on the outer periphery of the semiconductive layer so as to cover the semiconductive layer.

[Effect]

Since the terminal portion of the low surge impedance conductor of the present invention having the above configuration is provided with a semiconductive layer so as to come into contact with the sub conductor exposed portion and the main conductor connection 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 directly above, and the dielectric breakdown value due to the impulse voltage is higher than in the case where the semiconductivity does not reach. In other words, the terminal 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 terminal part of a low surge impedance conductor according to the present invention, FIG. a) X-X
Cross-sectional view, FIG. 1 (φ is the Y-Y cross-sectional view, FIG.

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

The terminal section of this embodiment is formed as described below. That is, a bolt hole 12 is formed in the main conductor terminal part 11 by peeling off the vinyl insulator 2, the sub-conductor 3 and the vinyl jacket 4 at the end of the low surge impedance conductor, and the main conductor exposed part 1 is removed.
3, the sub conductor 3 and the vinyl jacket 4 are peeled off over a predetermined length l from the inner end of the main conductor exposed part 13, and the insulator exposed part 2 is removed.
Set to 1. In this case, the sub-conductor 3 is left slightly longer than the stripped end 41 of the vinyl jacket 4 to form the sub-conductor exposed portion 31,
Fold back at the peeled edge 41.

Next, after wrapping the sealing tape 5 around the outer end of the insulator exposed portion 21 (the boundary with the main conductor exposed portion 13) and slightly inside the folded end 41 of the outer sheath 4, The semiconductive layer 22 is formed by wrapping a semiconductive self-adhesive tape around the exposed conductor portion 31, the exposed insulator portion 21, and the inner end of the exposed main conductor portion 13. After that, the semiconductive layer 22
An insulating layer 51 is formed on the outer periphery of the insulating layer 51 using a heat shrinkable tube made of ethylene propylene rubber so as to cover it. Furthermore, after that, an adhesive polyethylene tape 6 is wrapped around both ends of the insulating layer 51, and an adhesive vinyl tape 7 is further wrapped on top of the adhesive polyethylene tape 6.

An impulse breakdown voltage test was conducted on the terminal portion of the low surge impedance conductor formed as described above. In this test, the sample has an interfacial length l in Fig. 1(a).
Three samples were prepared for each of the three types of examples in which the
For comparison, samples were prepared in the same manner as in these examples, except that they did not have a semiconductive layer. The test results are shown in the table on the next page.

The test method was to apply an impulse voltage of 20 KV (impulse waveform according to JIS 03005) between the main conductor and the sub-conductor, then increase the voltage by 10 KV, and apply each three times. In the test results shown 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. As a result, flash shorting occurs between the exposed main conductor portion 13 and the exposed sub-conductor portion 31, and dielectric breakdown is when dielectric breakdown occurs in the insulator 2 itself without passing through such an interface. It is.

As is clear from the test results in this table, the semiconductive layer 2
If the semiconductive layer 22 is not provided, even if the interface length l is set to 300 m, interface flashing will still occur at 80 KV or less, but the semiconductive layer 22
By setting the interface length to 250++n or more, interfacial flash shorting will not occur at a voltage lower than the dielectric breakdown value.

In the above embodiment, the semiconductive layer 23 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 exposed portion 1
3. The structure and shape of the sub-conductor exposed portion 31, the insulator layer 51, etc. are not limited to the above embodiments.

〔Effect of the invention〕

As explained above, the terminal portion of the low-surge impedance conductor according to the present invention is made to contact the exposed sub-conductor portion, exposed insulator portion, and main conductor connection portion of the low-surge impedance conductor to be terminal-treated to form a thin semiconducting material. Because the layer is provided, 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, resulting in a voltage that is higher than the impulse voltage. Dielectric breakdown strength can be ensured, and therefore the terminal portion can be shortened. Moreover, the increase in outer diameter is very small, and flexibility is not impaired. That is, the terminal 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 terminal part of the low surge impedance conductor according to the present invention, and FIG.
Figure 1 (h is a cross-sectional view taken along the line X-X in Figure 1 (a), and Figure 1 (C) is a cross-sectional view taken along the Y-Y line in Figure 1 (a). 1...Main conductor, 2...Insulator, 3...Subconductor, 4...Vinyl jacket, 11...Main conductor terminal part, 13...Main conductor exposed part, 21...Insulation Exposed body part, 22
...Semiconductive layer, 31.. Sub-conductor exposed portion, 51.. Insulator layer. Patent applicant: Kansai Chick Co., Ltd.
Nikkin Denko Co., Ltd.
Yutsuta Electric Cable Co., Ltd. Agent Bunji Kamata (a) Figure 1

Claims (1)

[Claims] (1) Cover the outer periphery of a flat main conductor with an insulator in a substantially rectangular shape, attach a flat sub-conductor on at least one side of the insulator in parallel with the main conductor, and cover the outer periphery of the sub-conductor. At the terminal part of a coated low-surge impedance conductor: The outer sheath, sub-conductor and insulator are sequentially peeled off in steps, and the terminal is placed so as to contact the exposed sub-conductor, exposed insulator and exposed part of the main conductor. A terminal portion of a low surge impedance conductor, comprising: a semiconductive layer; and an insulating layer provided on the outer periphery of the semiconductive layer so as to cover the semiconductive layer.