JPH04262386A - Lighting arrester for power transmission line - Google Patents

Abstract

PURPOSE:To generate the max. effective section area of Zn oxide element by arranging a Zn oxide element in doughnut form in an insulated vessel, and inserting a distant piece in the space on the peripheral side of the Zn oxide element and the vessel, CONSTITUTION:In an insulation cylinder 2 a Zn oxide element 3 having an excellent non-linear voltage-current characteristic is formed by stacking connection plates 11 serially while attached by pressure to a distant piece 30 by a spring 10. At a lightning arrester 1 an arrester vessel is formed by covering another insulation cylinder 65 with Si type rubber 31. Therein the capacity on the bore side can be utilized by embodying the Zn oxide element in doughnut form 3, which allows reducing the rise of the internal pressure.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to the structure of a lightning arrester having a built-in zinc oxide element to form a lightning arrester element, and in particular to a power transmission line for preventing lightning damage to a power transmission line support insulator used in a transmission line tower. This invention relates to a lightning arrester element for a lightning arrester.

0002

[Prior Art] As a conventional lightning arrester without an explosion-proof insulator applied to this type of lightning arrester for power transmission lines, Japanese Patent Application Laid-Open No. 63-4
A device disclosed in Japanese Patent No. 3301 is known, and this is shown in FIG.

FIG. 4 is an internal sectional view of the lightning arrester, showing the elastic rubber 2
A zinc oxide element 27 was placed in a container 25 made of an insulator such as No. 4, and a discharge hole 26 was provided.

However, the space 30 between the zinc oxide element 27 and the insulator 29 constituting the container is small, and in the unlikely event that the zinc oxide element 27 is burned out by excessive lightning, a ground fault current from the grid will flow. The rise in internal pressure due to arcing was large, and the internal pressure could not be withstood, making it impossible to satisfy explosion-proof performance.

[0005]

[Problems to be Solved by the Invention] It is an object of the present invention to provide an explosion-proof insulator-less lightning arrester that has the maximum effective cross-sectional area of a zinc oxide element with respect to the unit cross-sectional area of the container, and The object of the present invention is to form a space with an effective cross-sectional area and form a lightning arrester or a lightning arrester element with excellent explosion-proof performance.

[0006]

[Means for Solving the Problems] In the present invention, a donut-shaped zinc oxide element is arranged inside an insulating container of a lightning arrester, and furthermore, the space between the container and the outer diameter side of the zinc oxide element has an inner diameter side and an outer diameter side. A donut-shaped distance piece with a portion cut out was inserted, and the internal volume of the zinc oxide element was utilized to reduce the rise in internal pressure caused by arcing inside the container.

[0007] Furthermore, in order to improve the adhesive strength of the container, a notch was provided at the end of the insulating cylinder to improve the adhesive strength and strengthen the pressure resistance of the container.

Furthermore, an O-ring is inserted between the insulating cylinder and the metal fittings at both ends of the lightning arrester container, and an airtight test plug is placed on the lower flange to improve the airtight structure, which is a factor in the failure of the lightning arrester. .

[0009]

[Function] By forming a lightning arrester with this configuration, the internal pressure increased by the arc is suppressed by the distant piece that communicates the space on the inside diameter side of the zinc oxide element with the outside diameter side and the inside diameter side of the zinc oxide element. It is possible to construct a lightning arrester that can suppress the pressure within the withstand pressure of the container and has excellent airtight performance.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a structural sectional view of a lightning arrester specifically realized according to the present invention.

As shown in FIG. 1, the lightning arrester 1 includes an insulating tube 2.
Zinc oxide elements 3 having excellent non-linear voltage-current characteristics are stacked in series by crimping a connection plate 11 with a distant piece 30 using a spring 10. Lightning arresters or lightning arrester elements conduct lightning surges during discharge and block follow-on current from the grid due to the voltage-current characteristics of the zinc oxide element.

[0012] Since lightning arresters for power transmission lines are installed on towers of power transmission lines, they are particularly required to be lighter in weight and have improved explosion-proof performance compared to those for power generation and substations. In order to satisfy these two conditions, the lightning arrester or lightning arrester element 1 can be made lightweight by coating the silicone rubber 31 on the insulating tube 65 to form a lightning arrester container. It can also be made resistant to heat shock.

[0013] However, simply stacking zinc oxide elements cannot withstand the internal pressure increase caused by the ground fault current that flows when the zinc oxide elements burn out due to excessive surge. This becomes possible by enlarging the space inside the insulating cylinder 2.

In the present invention, by forming the zinc oxide element into a donut shape 3, the volume on the inner diameter side can be utilized, and an increase in internal pressure can be reduced. Furthermore, in response to the increase in internal pressure when the outer creeping surface of the zinc oxide element flashes, the pressure generated between the partially cut out surface and the surface is guided to the inner diameter side of the zinc oxide element, reducing the pressure increase. . A metal connection plate 8 is provided on both sides of the donut-shaped connection plate 9 as shown in FIG. 2, and is connected to a zinc oxide element. The generated internal pressure ruptures the pressure relief plates at both ends, releases the internal pressure energy to the outside through the discharge hole 5 of the metal fitting 7, and short-circuits both ends of the metal fittings 7 and 12 with an arc to perform a pressure relief operation. As a result, a lightning arrester with excellent explosion resistance can be realized.

FIG. 3 shows grooves 7 in the lightning arrester 1 and metal fittings 7 and 12.
0 and is bonded to the insulating tube 2 with an epoxy material 22, which increases the bonding area and increases the strength of the container. Furthermore, by providing an O-ring 20 between the metal fitting 7 and the insulating tube 2 at the lower part of the container forming the lightning arrester 1, an airtightness test during assembly can be easily performed, thereby improving the airtightness of the insulating tube. be able to. A plug 17 is provided for airtight sealing of the plug portion, and O-rings 18 and 19 are further provided for airtight sealing of the plug portion. In order to prevent the zinc oxide element from collapsing during explosion protection, a disk 24 with punched holes is inserted into the connecting plate 8 and the donut-shaped connecting plate.

[0016]

According to the present invention, a lightning arrester with excellent explosion-proof performance can be constructed, and a lightning arrester with excellent airtight performance can be constructed.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of the present invention.

FIG. 2 is a view taken along arrow II-II in FIG. 1.

FIG. 3 is a cross-sectional view of another embodiment of the invention.

FIG. 4 is a sectional view of a conventional known example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1... Lightning arrester, 2... Insulating tube, 3... Donut-shaped zinc oxide element, 4... Distant piece, 5... Discharge hole, 6... Pressure release plate,
7... Metal fitting, 8... Connection plate, 9... Donut-shaped connection plate, 10...
Connection plate, 11... Spring, 12... Metal fitting, 13... Cover, 14
...Bolt, 15...Washer.

Claims (4)

[Claims] 1. A lightning arrester in which the surface of an insulating cylinder is coated with silicone rubber and a plurality of zinc oxide elements are built inside the insulating cylinder, wherein the shape of the zinc oxide element is a donut shape,
Without placing an insulating rod on the inner diameter side of the zinc oxide element,
A lightning arrester for a power transmission line, characterized in that the zinc oxide elements are stacked with a doughnut-shaped connection plate with at least a portion cut out interposed between them. 2. The lightning arrester for a power transmission line according to claim 1, wherein the metal fitting portion and the end of the insulating cylinder are provided with an O-ring and a cutout groove of the metal fitting. 3. The lightning arrester for power transmission lines according to claim 1, comprising a metal fitting part, an O-ring at the end of the insulating tube, a notched groove lightning arrester in the metal fitting, and an airtight plug on the end face of the lower flange part. Device. 4. In claim 1, between the zinc oxide elements, a donut-shaped connection plate with at least a portion cut out is interposed, and a punched out connection plate is provided between the connection plate and the donut-shaped connection plate. Lightning arrester for power transmission lines equipped with disks.