JPH06105567B2 - Suspended lightning arrester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention promptly discharges an excessive current to the ground when a high voltage due to a lightning surge is applied to a transmission line and an excessive current flows. The present invention relates to a suspension type lightning arrestor that interrupts the subsequent flow that occurs after that to prevent a ground fault and enables power transmission again.

(Prior Art) Conventionally, it has been considered to introduce a lightning arrester into a transmission line in order to absorb lightning and switching surges and prevent a ground fault in the transmission line. However, it is not preferable to attach a lightning arrester having only a lightning protection function to the transmission line because the transmission line tower structure and the insulator device are complicated. Therefore, the insulation of conventional insulators
A suspended lightning arrestor having both a wire support function and a lightning arrester function has been proposed.

As the suspension type lightning protection insulator, the applicant of the present application has proposed a structure in which a current limiting element having a non-linear voltage-current characteristic is attached to the cap portion of the insulator body. This lightning insulator has an inner peripheral surface of the mounting cylinder,
That is, the current limiting element is housed in the through hole, and the metallic upper electrode and lower electrode are fitted and fixed to the upper and lower ends of the mounting cylinder.

Further, as shown in FIG. 5, a cap metal fitting 7 is capped and fixed to the head formed at the upper center of the cap portion 5a, and a pin metal fitting 8 of a lightning arrester directly above is fitted and fixed in the cap metal fitting 7. The upper electrode 12 at the upper end of the current limiting element 9 and the cap fitting 7 were connected by the lead wire 19.

Then, the terminal 31 in the cap metal fitting 7 of the lead wire 19
Was not provided directly below the contact portion P between the cap metal fitting 7 and the pin metal fitting 8. Therefore, an excessive current due to a lightning surge was flowing from the contact portion P to the pin fitting 8 via the terminal 31 and the electric path E.

(Problems to be Solved by the Invention) In the above conventional technique, the upper electrode at the upper end of the current limiting element 9 is used.
Since the 12 and the cap fitting 7 were connected at any position by the lead wire 19, the electric current path of the excessive current due to the lightning surge did not become the shortest distance inside the cast iron cap fitting 7 with a large electric resistance, and The distance to the contact portion P was long. Therefore, the discharge characteristic tends to be poor, and the limiting voltage tends to increase.

Configuration of the Invention (Means for Solving the Problems) In order to solve the problems, the present invention fits and fixes a cap metal fitting to a capped cylindrical head formed in the upper center of the cap portion of the insulator body. Then, a pin metal fitting is fitted and fixed inside the head portion, a current limiting element is embedded in the cap portion, and in the suspension type lightning protection insulator in which an upper electrode and a lower electrode are provided at both upper and lower ends thereof, the cap metal fitting is provided. The configuration is such that a current-carrying terminal to the current limiting element is provided at the lower end of the cap metal fitting below the contact portion between the pin metal fitting and the cap metal fitting on both sides of the opening.

(Operation) By adopting the above configuration, excessive current due to lightning surge flows from the upper electrode to the current-carrying terminal located below the contact part between the pin fitting and the cap fitting through the current limiting element, and further the pin fitting and the cap fitting. The shortest distance from the contact part to the pin fitting.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 4, a large number of suspension type lightning arresters 3 are connected in series via a suspension metal fitting 2 to a support arm 1 provided on a steel tower (not shown), and the lowermost end of the suspension type lightning protection insulator 3 is suspended. The transmission line L is supported by the hanging metal fitting 4.

As shown in FIG. 3, the insulator main body 5 that constitutes the suspended lightning protection insulator 3 includes a cap portion 5a and a plurality of concentric pleats 5b formed in an annular shape on the inner surface of the cap portion 5a. Further, it is integrally molded with a cylindrical head portion 5c with a lid integrally formed on the central upper portion of the cap portion 5a. Further, a cap metal fitting 7 is capped and fixed to the outer periphery of the head 5c by cement 6, and an engaging recess 7a is formed in the metal fitting 7 so that the pin metal fitting 8 of the lightning protection insulator 3 directly above can be engaged. I have to. The upper portion of the pin metal fitting 8 is fixed to the inside of the head portion 5c by cement 6, and the lower end thereof is an engaging recess of the cap metal fitting 7 of the lightning protection insulator 3 directly below.
It is engaged with 7a. In this way, multiple lightning protection insulators 3
Are connected in series.

The cap portion 5a is formed with a plurality of cylindrical mounting portions 5d (four locations in this embodiment) at equal intervals so as to penetrate the cap portion 5a in parallel with the pin fitting 8. .

In the inner peripheral surface of each of the mounting cylinders 5d, that is, in the through holes 5e, a plurality of non-linear cylindrical columns having non-linear voltage-current characteristics, which are mainly made of zinc oxide (ZnO) and have excellent follow-current blocking characteristics, are provided. In the embodiment, two current limiting elements 9 are inserted in series. And
An adhesive layer 10 filled with silicon rubber or low melting point glass between the outer peripheral portion of the current limiting element 9 and the inner peripheral surface of the mounting cylinder portion 5d.
Is provided, and the current limiting element 9 is fixed to the mounting cylinder portion 5d.

Cap-shaped upper electrodes are provided on both upper and lower ends of the mounting cylinder 5d.
12 and the lower electrode 13 are fitted via the solder 14, and the mounting cylinder portion
The upper and lower ends of 5d are crimped.

Metallized layers 15 are provided on the upper and lower end surfaces of the current limiting element 9 by metallikon, silver baking, or another method. On the surface of the metallized layer 15, a metal-made thin protective plate 16 for conduction is provided. A pressing spring 17 having electrical conductivity and thermal conductivity is interposed between the conduction protection plate 16 and the upper and lower electrodes 12 and 13 to electrically connect the current limiting element 9 to the upper electrode 12 and the lower electrode 13. I'm trying to do. Further, the rubber-like adhesive elastic body 18 is enclosed in the inner space of the upper and lower electrodes 12, 13 to improve the airtightness by increasing the adhesive sealing surface.

One end of a lead wire 19 is adhesively fixed to the upper surface of the upper electrode 12, and the other end of the lead wire 19 is connected to the auxiliary electrode 21. Then, as shown in FIG. 1, one end of the connecting conductor 22 is connected to the portion of the auxiliary electrode 21 corresponding to the position below the contact portion P of the pin metal fitting 8 and the cap metal fitting 7 on both sides of the opening of the cap metal fitting 7. The other end of the connecting conductor 22 is connected to a current-carrying terminal 23 provided at the lower end of the cap fitting 7 below the contact portion P.

It should be noted that, as shown in FIG. 2, the current-carrying terminals 23 are provided at two locations on both sides of the contact portion P in this embodiment. Further, the cap fitting 7 is integrally provided with a conductive energization promoting ridge 24 extending from the side of the contact portion P along the surface thereof to the energization terminal 23.

One end of a lead wire 20 is adhesively fixed to the lower surface of the lower electrode 13, and the other end of the lead wire 20 is connected to the pin fitting 8.

Next, the operation and effect of the lightning protection insulator configured as described above will be described.

When an excessive voltage due to a lightning surge is applied to the power transmission line L, the current at this time flows through the hanging metal fitting 4 to the pin metal fitting 8 of the lightning protection insulator 3 on the lowermost side, and the lead wire 20 → lower electrode 13 → pressing spring.
17-> protection plate for conduction 16-> metallization layer 15-> current limiting element 9-> metalization layer 15-> protection plate for conduction 16-> pressing spring 17-> upper electrode
12 → Lead wire 19 → Auxiliary electrode 21 → Connection conductor 22 → Conductive terminal 23
→ The electricity is transmitted to the projection 24 for energization and the inside of the cap fitting 7 in the vicinity thereof → the contact portion P. After that, lightning arrester 3 directly above
Is transmitted to the pin metal fitting 8. Similarly, it is transmitted to a plurality of lightning protection insulators 3 connected in series, and is grounded from the contact portion P of the uppermost lightning protection insulator 3 through the hanging metal fitting 2 and the support arm 1 to the ground.

At this time, the current limiting element 9 built in the insulator main body 5 quickly reduces the resistance value due to its characteristics and discharges a large current due to a lightning surge. Further, the current limiting element 9 immediately restores the resistance value and restores the insulation with respect to the continuous current continuing to the lightning surge, so that the continuous current discharge is suppressed and interrupted and the electric line is normally restored.

Now, in the present embodiment, an excessive current due to a lightning surge passes from the contact portion P to the pin fitting 8 via the energizing terminal 23 as described above.
The contact portion P is a portion where the cap metal fitting 7 and the pin metal fitting 8 come into contact with each other, and is located on both sides of the opening of the cap metal fitting 7, and the energizing terminal 23 is located below the contact portion P of the cap metal fitting 7. Since it is located at the lower end, the electric path in the cap fitting 7 has the shortest distance, and the current flows through the auxiliary electrode 21 which is a conductor and the ridge 24 for energization promotion with little resistance and is discharged. The energization promoting ridge 24 can further reduce the resistance by increasing its cross-sectional area,
The discharge characteristics can be improved.

Further, in this embodiment, the total resistance of the electric circuit can be reduced, so that it is possible to prevent the limit voltage from rising.

The present invention is not limited to the above embodiment, but can be configured as follows.

(1) In the above embodiment, the ridges for energizing electricity are provided on the surface of the cap fitting, but this can be omitted.

In this case, the excessive current due to the lightning surge reaches the current-carrying terminal from the current limiting element, and flows into the pin metal fitting through the cap metal fitting.

(2) Although the annular auxiliary electrode is provided on the surface of the cap portion in the above embodiment, it may be omitted.

In this case, the current-carrying terminal is connected to the current limiting element by a lead wire.

Effect of the Invention In the suspended lightning arrester of the present invention, an overcurrent due to a lightning surge flows from the current limiting element to the pin fitting through the current-carrying terminal to the pin fitting in the shortest distance. It has an excellent effect of preventing the rise.

[Brief description of drawings]

FIG. 1 is a perspective view of a lightning protection insulator showing an embodiment of the present invention, FIG. 2 is a plan view of FIG. 1, FIG. 3 is a sectional view taken along line AA of FIG. 1, and FIG. FIG. 5 is a front view showing a usage state, and FIG. 5 is a perspective view showing a conventional lightning protection insulator. 5 ... Insulator main body, 5a ... Shade part, 5c ... Head part, 7 ... Cap fitting, 8 ... Pin fitting, 9 ... Current limiting element, 12 ... Upper electrode, 13 ...
Lower electrode, 21 ... auxiliary electrode, 23 ... energizing terminal, 24 ... energization promoting ridge, P ... contact part

Claims (3)

[Claims] 1. A cap metal fitting (7) is fitted and fixed to a capped cylindrical head (5c) formed in the central upper part of a cap portion (5a) of an insulator body (5), and the head (5c) is fixed. ), A pin metal fitting (8) is fitted and fixed, and a current limiting element (9) is embedded in the cap portion (5a), and an upper electrode (12) and a lower electrode (13) are provided at both upper and lower ends thereof. In the provided suspension type lightning arrester, the current is limited to the lower end of the cap metal fitting (7) below the contact portion (P) between the pin metal fitting (8) and the cap metal fitting (7) on both sides of the opening of the cap metal fitting (7). A suspended lightning arrester characterized in that a current-carrying terminal (23) is provided to the element. 2. A ridge (24) for energizing electricity from the contact portion (P) to the energizing terminal (23) is formed on the surface of the cap fitting (7). Suspended lightning arrestor described. 3. The upper surface of the cap portion (5a) is the energizing terminal (2
The suspension type lightning protection insulator according to claim 1, further comprising an annular auxiliary electrode (21) connected to (3).