JPH01183016A - Lightning protective insulator and lightning protective device equipped with it - Google Patents

Abstract

PURPOSE:To suppress the damage of a shade part to the minimum by providing at least one discharge part sideward at the periphery of a cap fitting and connecting this discharge part and the upper electrode of a lightning protective element through a connecting lead which fully withstands lightning surge and fuses out at connection of a large current. CONSTITUTION:When lightning surge voltage flows to a transmission line L, the current flows to a pin fitting 8 of the lowermost lightning protective insulator 3 and a cap fitting 7 of the right above insulator 3 through a suspended fitting 4, and is earthed to the earth through the fitting 7 repeating it. It is the same even at the time of lightning attack at the top of the steel tower. At this time, a lightning protective element 10 built in an insulator main body 5 promptly decreases a resistance value to discharge a surge current and for the dynamic current, the element 10 recovers immediately the resistance value to restore the insulation. On the other hand, when the element 10 absorbs lightning energy exceeding the amount of designed resistance, it becomes insulation conductive condition and the dynamic current flows the insulator 3 and a dynamic current lead 16 fuses out near a P point and an arc is discharged from the end of a discharge part 15. And the arc connects with both upper and lower discharge parts 15 and discharge is performed and the insulator 3 is not broken.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a suspension insulator-type lightning arrester that has both the functions of a suspension insulator and a lightning arrester, and a lightning arrester equipped with the same.

(Prior Art) Conventionally, it has been considered to introduce lightning arresters to power transmission lines in order to absorb lightning and switching surges and prevent power transmission line ground faults. However, attaching a lightning arrester having only a lightning arresting function to a power transmission line is undesirable because it complicates the structure of the transmission line tower and the insulator device. For this reason, conventional insulators are
Various types of lightning arresters have been proposed that have both the wire support function and the lightning protection function of lightning arresters (for example, Japanese Patent Laid-Open No. 5.5-32
(See Publication No. 308). This lightning arrester had a lightning arrester integrated into the head of the insulator body, and electrically connected the cap and pin fittings to the lightning arrester.

(Problem to be solved by the invention) However, since this lightning arrester has a lightning arrester element built into the head, it is necessary to carry out the lightning protection function and the load-bearing function as a suspension insulator centrally near the central axis, that is, in the head. This not only greatly increases the insulator connection length and makes it difficult to coordinate the lightning protection function and mechanical strength, but also increases the degree of damage to the insulator in the event that the lightning arrester element is destroyed by a large-scale lightning strike. (There was a problem in that mechanical reliability required significant improvement.

In order to solve the above-mentioned problems, the applicant of the present application has already developed a lightning arrester in which a lightning arrester is embedded in an insulating shade part provided vertically through the shade part of the suspension insulator. (Refer to Japanese Utility Model Application No. 59-275110.) However, in this lightning arrester, the lightning arrester element is installed through the cap of the suspension insulator, so in the event of a lightning strike exceeding the design withstand capacity, However, there is a problem in that the lightning arrester is damaged and a short-circuit occurs, causing a short-circuit current of the operating voltage to flow through the lightning arrester, resulting in damage to the insulator.

SUMMARY OF THE INVENTION An object of the present invention is to provide a lightning arrester that solves the above-mentioned problems and a lightning arrester equipped with the same.

(Means for Solving the Problem) In order to achieve the above object, the lightning arrester according to claim 1 is provided. A cap metal fitting is capped and fixed to the head of the insulator body having a cap part and a head part, and a pin fitting is fixed to the inside of the head part, and a lightning arresting element extending in the vertical direction is provided on the cap part, In a lightning arrester in which both electrodes are respectively connected to a cap metal fitting and a pin metal fitting, at least one discharge portion is provided on the outer periphery of the cap metal fitting so as to protrude laterally,
The discharge part and the upper electrode of the lightning protection element are connected via a connection lead that is sufficiently resistant to lightning surges and melts when a large current flows due to an operating voltage short circuit.

Further, in the lightning arrester according to claim 2, in the lightning arrester according to claim 1, the discharge portion is formed into a flat plate shape, and the width thereof is approximately the same as or larger than the diameter of the element housing hole for housing the lightning arrester element. It is set.

Furthermore, in the lightning arrester according to claim 3, a plurality of lightning arresters configured similarly to the invention according to claim 1 are connected to each other so that the discharge parts on their outer peripheries correspond to the upper and lower positions, and the tip of the upper arcing horn is A method is adopted in which the uppermost lightning arrester is disposed facing the outer side of the discharge portion of the lightning arrester, and the tip of the lower arcing horn is disposed opposite to the outer side of the discharge portion of the lowermost lightning arrester.

(Function) According to the lightning arrester of claim 1, when the lightning arrester element becomes conductive and a large current follows, the connecting lead melts and breaks.
The arc generated at the fused portion is emitted outward along the discharge portion, and damage to the cap portion of the insulator body is minimized.

Further, in the lightning arrester of claim 2, when the arc collides with the discharge part, all of the arc is vigorously deflected outward by the discharge part, so that the arc can be quickly and reliably formed between the tip parts of the discharge part. will be migrated.

Furthermore, in the lightning arrester according to claim 3, when the above-mentioned follow current flows, the arc emitted outward from the discharge part of the uppermost lightning arrester moves to the upper arcing horn, and the arc emitted outward from the discharge part of the uppermost lightning arrester insulator moves to the upper arcing horn. The arc emitted outward from the discharge part moves to the lower arcing horn, and the arc continues between the upper and lower arcing horns, thereby more reliably preventing damage to each lightning arrester.

(Example) Hereinafter, an example in which the present invention is embodied in a suspension type lightning arrester will be described with reference to FIGS. 1 to 3.

FIG. 3 shows the entire lightning arrester, in which a large number of suspension insulator type lightning arresters 3 are connected in series and suspended from a support arm 1 provided on a steel tower (not shown) via hanging fittings 2.
A power transmission line is supported at the lowermost end of the lightning arrester 3 via a hanging fitting 4.

As shown in FIG. 1, an insulator body 5 constituting the lightning arrester 3
A cap part 5a, a plurality of folds 5b formed annularly and concentrically on the inner surface of the cap part 5a, and a covered cylindrical part integrally formed at the upper center of the cap part 5a. Head 5
It is integrally molded with c. Further, a cap fitting 7 is fixed to the outer periphery of the head 5c with cement 6,
A fitting recess 7a is formed in the metal fitting 7, so that the pin fitting 8 of the lightning arrester 3 directly above can be engaged with the fitting recess 7a.

The upper part of the pin fitting 8 is fixed inside the head 5c with cement 6, and the lower end is engaged with the fitting recess 7a of the cap fitting 7 of the lightning arrester 3 directly below. In this way, a plurality of lightning arresters 3 are connected in series.

As shown in FIGS. 1 and 2, the folds 5b of the insulator body 5
On the inside of the insulator body 5, a plurality of (three in this embodiment) element storage holes 9 are formed at equal intervals in the circumferential direction, passing through the cap 5a vertically. , its planar shape is a flat arc centered on the axis O of the pin fitting 8. Inside each element storage hole 9, a flat arc-shaped lightning arrester element 10 is placed with an airtight sealant 11 made of glass, resin, rubber, etc.
It is fixed with adhesive. The lightning arrester 10 is mainly made of zinc oxide (ZnO) which exhibits excellent non-linear voltage-current characteristics, and has an upper electrode 13 and a lower electrode 14 made of the same metal at its upper and lower ends. Note that the outer peripheries of the upper electrode 13 and the lower electrode 14 are sealed with solder 12.

A plurality of (
In this embodiment, three discharge portions 15 are integrally formed to protrude laterally. Upper electrode 13 of each lightning arrester element 10
The connecting lead 16 is conductive and can be fused to large currents caused by short-circuit follow-on currents (hereinafter referred to as short-circuit follow-on currents) due to the operating voltage when the insulation of the element is penetrated when the filtered large lightning surge exceeds the design withstand capacity and absorbs large lightning surges. It is fixed by a binding material or the like, and its upper end is connected and fixed to the lower surface of each discharge section 15, respectively. A lead wire 17 is connected to the lower electrode 14 of each lightning arrester lO.
is fixed with a conductive bonding material or the like, and its inner end is connected to the pin fitting 8.
Each connection is fixed. Then, when the lightning arrester 10 becomes conductive due to a lightning strike that exceeds expectations and a large current short-circuit follows, the connecting lead 16 melts near point P in Figure 1, and an arc occurs at the fused portion. is emitted outward from the discharge section 15.

Further, in the lightning arrester shown in FIG. 3, the plurality of lightning arresters 3 are connected to each other in a state in which the discharge portions 15 on their outer peripheries are located vertically corresponding to each other, and discharge from the discharge portions 15 of each lightning arrester 3 is performed. The arcs are connected between corresponding upper and lower discharge parts 15.

Further, the upper arcing horn 18 attached to the support fitting 2 is extended outward from the lower part so that its tip is disposed opposite to the outer side of the discharge part 15 of the uppermost lightning arrester 3. There is. Further, the lower arcing horn 19 attached to the hanging metal fitting 4 has its tip extending toward the outside of the discharge portion 15 of the lowermost lightning arrester 3. When the connection lead 16 is fused, the arc emitted outward from the discharge part 15 of the uppermost lightning arrester 3 moves to the upper part, the arging horn 18, and from the discharge part 15 of the lowermost lightning arrester 3. Released outwards
The arc is transferred to the lower arcing horn 19, and the arcs are connected in both the upper and lower arcing horns 18 and 19. Next, the operation of the lightning arrester constructed as described above will be explained.

When a lightning surge voltage is applied to the power transmission line, the lightning surge current flows through the suspension fitting 4 to the pin fitting 8 of the lowermost lightning arrester 3.1. Lead wire 19-lower electrode 12-lightning arrester 1〇-disc spring 16-upper electrode 11→lead wire 18→
It is transmitted to the cap metal fitting 7. Thereafter, the light is transmitted from the cap fitting 7 to the pin fitting 8 of the lightning arrester 3 directly above it. Similarly, it is transmitted to multiple lightning arresters 3 connected in series,
From the cap metal fitting 7 of the uppermost lightning arrester 3 to the support metal fitting 2,
and is grounded to the ground via the support arm l.

Also, when the top of a steel tower is struck by lightning, the potential of the steel tower arm 1 becomes an excessive voltage with respect to the power transmission line, and a lightning surge current flows in the completely opposite direction. That is, it is transmitted from the support fitting 2 - the camping fitting 7 - the lightning arrester 3 - the pin fitting 8 - the hanging fitting 4 to the power transmission line.

At this time, the lightning arrester element 10 built into the insulator body 5 quickly reduces its resistance value due to its characteristics and discharges the current caused by the lightning surge. Furthermore, in response to the following current of the operating voltage that continues on the lightning strip, the lightning arrester 10 immediately restores its resistance value and restores insulation due to the non-linearity of the voltage and current, so that the following current is suppressed and interrupted. The power line will return to normal.

On the other hand, in this lightning arrester, the lightning arrester element 1 of the lightning arrester 3
0 absorbs lightning surge energy that exceeds the design withstand capacity, the disconnection 8 becomes conductive, and the following current becomes a short-circuited large current following current that flows through the lightning arrester 3, and the following current lead 16 melts near point P in Figure 1. Then, an arc is generated, and a high-temperature, high-pressure arc agent blows out and hits the discharge portion 15, and is emitted outward from its tip. As shown in FIG. 3, the arc emitted from the discharge section 15 continues between the discharging sections 15 correspondingly located above and below, and discharge is performed between both the discharging sections 15. Therefore, the short-circuit large current follow-on current does not continue to flow through the lightning arrester element 10, and the arc is not emitted toward the cap 5a of the insulator main body 5.
Damage to a is minimized.

Furthermore, in this lightning arrester, after the arc continues between the upper and lower discharge parts 15 as described above, it is emitted outward from the discharge part 15 of the uppermost lightning arrester 3, as shown in FIG. As the arc moves to the upper arcing horn 18, the arc emitted outward from the discharge part 15 of the lowermost lightning arrester 3 moves to the lower arcing horn 19, and the arc continues between the upper and lower arcing horns 18 and 19. . Therefore, even if the discharge state continues, the time during which the insulator bodies 5 of each lightning arrester 3 are exposed to the arc is shortened, and damage to the insulator bodies 5 can be more reliably suppressed.

Next, an embodiment of the lightning arrester according to claim 2 will be described based on FIGS. 4 and 5.

In this embodiment, a mounting cap 5d is formed on the cap 5a, and a plurality of lightning arresting elements 10 are fitted in series into the inner peripheral surface of the mounting cap 5d, that is, the through hole 9.

Further, element holding members 23 made of porcelain are respectively fitted into the upper and lower end surfaces of the lightning arrester element 10, and are adhesively fixed together with the lightning arrester element 10 in the element housing hole 9 by an inorganic bonding material 24 such as inorganic glass.

An upper electrode 13 and a lower electrode 14 are fixed by caulking to both upper and lower ends of the mounting cap 5d. A conductive member 25 made of brass is engaged with a through hole 23a provided at the center of the element holding member 23, and a conductive member 25 made of an elastic material is provided between the conductive member 25 and the upper electrode 13 and the lower electrode 14, respectively. A disc spring 26 is interposed. Both upper and lower electrodes 1
The internal space of 3° 14 is filled with an insulating material 27 such as silicone rubber.

On the other hand, on the outer circumferential surface of the cap metal fitting 7, a discharge portion 15 having a horizontally elongated planar rectangular shape is horizontally fixed by welding or the like. The width W of the discharge portion 15 is set to be equal to or larger than the diameter of the element housing hole 9, as shown in FIG. When set in this way, even if an arc ejects from any position on the upper end surface of the lightning arrester 10, all of the arc can be deflected by the discharge part 15, and as a result, some of the arcs can be deflected upward. It is possible to prevent the insulator body 5 of the suspended insulator located from being hit and burnt out, and to facilitate the movement of the arc to the outside. Further, the discharge portion I5 is connected to the upper electrode 13 by a connection lead 16 made of stainless steel mesh.

Furthermore, the distal end portion 15a of the discharge portion 15 is made to protrude a distance from the outer circumferential surface of the upper electrode 13 in the horizontal direction, as shown in FIG. This distance is set to 511 or more. If it is less than 511, the arc tends to be trapped in the space between the upper electrode 13 and the discharge part 15, so it is desirable that it is 5 or more.

Therefore, in this embodiment, when the lightning arrester 10 becomes conductive and the arc collides with the discharge section 15, all of the arc is vigorously deflected outward by the discharge section 15, so that the discharge section can be quickly and reliably The arc can be transferred between the 14 tips.

Note that the present invention is not limited to the above embodiments,
It may be specified as follows.

(1) As shown by the chain line in FIG. 2, a mounting band 2 made of a conductive material is circumferentially fixed around the outer periphery of the cap metal fitting 7, and the outer periphery discharge portion 14 of the mounting band 21 is provided protrudingly.

(2) As shown by the chain line in FIG. 2, the discharge portion 15 is integrally formed on the outer periphery of the cap fitting 7 at a position that does not correspond to each lightning arrester element 10, or is attached and fixed via the mounting band 21.

(3) Attach the lowest discharge section 15 to the pin fitting 8 as shown by the line in FIG.

(4) The discharge section 15 of the embodiment of claim 1 is replaced with the discharge section 15 of the embodiment of claim 2 to cover the entire space above the element storage hole 9.

(5) In FIG. 5, a convex portion (not shown) is provided at the tip of the discharge section 15.

(Effects of the Invention) As detailed above, in the lightning arrester of claim 1, when the lightning arrester element becomes conductive and a large current flows, the connecting lead melts and the arc generated at the melted part It is emitted outward along the discharge portion, and has the effect of minimizing damage to the cap portion of the insulator body.

Further, in the lightning arrester of claim 2, when the arc collides with the discharge part, all of the arc is vigorously deflected outward by the discharge part, so that the arc can be quickly and reliably drawn between the tip parts of the discharge part. Therefore, damage to the lightning arrester can be more reliably prevented.

Furthermore, in the lightning arrester according to claim 3, when the follow current flows, the arc emitted outward from the discharge part of the uppermost lightning arrester moves to the upper arcing horn, and the arc discharged from the discharge part of the lowermost lightning arrester insulator moves to the upper arcing horn. The arc emitted outward is transferred to the lower arcing horn, and the arc is continuous between the upper and lower arcing horns, thereby achieving the effect of more reliably preventing damage to each lightning arrester.

[Brief explanation of the drawing]

FIG. 1 is a half-longitudinal sectional view showing an embodiment of the lightning arrester according to claim 1, FIG. 2 is a sectional view taken along line A-A in FIG. 1, and FIG. FIG. 4 is a half-longitudinal sectional view showing an embodiment of the lightning arrester according to claim 2, and FIG.
The figure is a plan view of FIG. 4. 3... Suspension type lightning arrester, 5... Insulator body, 5a.
...Kasabe, 5c...Head, 5d...Mounting Kasabe, 7.
... Camping fittings, 8... Pin fittings, 9... Element storage holes, 10... Lightning arrester elements, 13... Upper electrodes, 14
...lower electrode, 16.17...connection lead, W...
・Width of discharge part 15, D...Diameter of element housing hole 9, L・
...Protrusion distance in the horizontal direction from the outer circumferential surface of the upper electrode 13 of the discharge section 15.

Claims (3)

[Claims] 1. The insulator body (
A cap fitting (7) is fixed to the head (5c) of 5), and a pin fitting (8) is fitted and fixed inside the head (5c), and a cap fitting (8) is fixed to the head (5c) in the vertical direction. In a lightning arrester insulator which is provided with an extending lightning arrester (10) and whose upper and lower electrodes (13, 14) are respectively connected to a cap metal fitting (7) and a pin metal fitting (8), the outer periphery of the cap metal fitting (7) has at least one Two discharge parts (15) are provided to protrude toward the side, and the discharge parts (15)
) and the upper electrode (13) of the lightning arrester (10) are connected via a connecting lead (16) that is sufficiently resistant to lightning surges and melts when a large current follows. insulator. 2. The discharge section (15) is formed into a flat plate shape, and its width (
2. The lightning arrester according to claim 1, wherein W) is set to be substantially the same as or larger than the diameter (D) of the element housing hole (9) for housing the lightning arrester element (10). 3. The insulator body (
A cap fitting (7) is fixed to the head (5c) of 5), and a pin fitting (8) is fitted and fixed inside the head (5c), and a cap fitting (8) is fixed to the head (5c) in the vertical direction. An extending lightning arrester (10) is provided, the lower electrode (14) of which is connected to a pin fitting (8), and at least one discharge portion (15) and a lightning arrester (10) are provided on the outer periphery of the cap fitting (7). A lightning arrester (3) is constructed by connecting the upper electrode (13) of the lightning insulator (3) to the upper electrode (13) of the lightning insulator (3) through a connection lead (16) that is sufficiently strong against lightning surges and melts when a large current follows. The lightning arresters (3) are connected to each other so that the discharge parts (15) on their outer peripheries correspond to the upper and lower sides, and the upper arcing horn (18
) is arranged facing the outside of the discharge part (15) of the uppermost lightning arrester (3), and the lower arcing horn (
19) to the discharge part (15) of the lowest lightning arrester (3).
) A lightning arrester characterized in that the lightning arrester is arranged oppositely to the outside.