JPH07118237B2 - Lightning arrester - Google Patents

Abstract

A lightening arresting insulator with a pressure-release mechanism for releasing pressure when a lightening surge flows in a power transmission line is disclosed. The arresting insulator has a plurality of slits formed in the outer wall of an insulating cylinder formed from a material having a high voltage resistance. The slits extend lengthwise to form thin wall portions in the insulating cylinder. An elastic insulator is filled in each of the slits.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when a lightning surge current flows through a transmission line or a distribution line, quickly discharges it to the ground and suppresses and interrupts the subsequent commercial frequency current. It is related to the possible lightning arrester.

[0002]

2. Description of the Related Art As a conventional lightning protection insulator of this type, there is known one having a structure as shown in Japanese Patent Publication No. 2-3241 and Japanese Utility Model Publication No. 1-96739. In the former configuration, the metal fittings on the grounding side and the charging side are connected and fixed to both ends of the withstand voltage insulating cylinder, and the current limiting element having a non-linear voltage-current characteristic is housed in the withstand voltage insulating cylinder. The electrode fitting and the both ends of the current limiting element are electrically connected to each other, and an insulating jacket having a large number of insulating folds is provided on the outer periphery of the withstand voltage insulating cylinder. Further, a plurality of pressure relief holes penetrating therethrough are formed on the peripheral surface of the pressure-resistant insulating cylinder, and the insulator is filled together with the inside through the pressure relief holes at the time of molding the insulation outer casing, and is integrally formed with the insulation outer casing. ing.

On the other hand, in the latter construction, the metal fittings on the grounding side and the charging side are connected and fixed to both ends of the pleated insulating porcelain tube made of a polymer material, and the voltage inside the porcelain porcelain-
A current limiting element having a non-linear current characteristic is accommodated, and the electrode fitting and both ends of the current limiting element are electrically connected. or,
A plurality of recesses are provided on the outer periphery of the insulating porcelain tube, and the recesses form a thin portion for releasing pressure.

[0004]

However, in the former conventional structure, a plurality of pressure relief holes are formed in the peripheral surface of the pressure-proof insulating cylinder, so that the structure in which the insulating gas is enclosed is not provided. Moisture easily enters through the material, and if there is an insulating filler inside, and if there is a pinhole in the insulating jacket or the insulator inside the pressure release hole during the manufacturing process, moisture will enter through it. However, there is a problem that the dielectric strength decreases.

In the latter conventional construction, the pressure-resistant insulating tube is not provided and only the insulating porcelain tube is used. Since the thin wall portion for releasing pressure is formed on the peripheral surface of the insulating porcelain tube, the fouling condition is particularly severe. When it is used for a long time in an environment, there is a problem that erosion due to leakage current, pinholes are generated due to corona, etc., and moisture penetrates into the pinholes to lower the dielectric strength. Further, in this conventional configuration, since the thin wall portion is exposed and formed on the outer periphery of the insulating porcelain pipe, a worker may collide with the thin wall portion in the manufacturing process with a tool or the like, and the bird may stick the thin wall portion during use. There is a problem that the insulating porcelain tube may be broken due to the movement of the insulating porcelain and dust and the like may be accumulated in the concave portion forming the thin wall portion during use, and the dielectric strength is lowered.

The present invention has been made by paying attention to the problems existing in such a conventional technique, and the purpose thereof is to keep the airtightness and the water contained in the outside air penetrates into the inside. It is an object of the present invention to provide a lightning protection insulator that can prevent the occurrence of damage, improve the dielectric strength, and prevent damage to the pressure release portion during the manufacturing process or use.

[0007]

In order to achieve the above object, according to the present invention, the ground-side and voltage-applying side electrode fittings are connected and fixed to both ends of the withstand voltage insulating cylinder, and a voltage is applied inside the withstand voltage insulating tube. -A current limiting element having a non-linear current characteristic is accommodated, the electrode fitting and the both ends of the current limiting element are electrically connected, and an insulating jacket having a large number of insulating folds is provided on the outer periphery of the withstand voltage insulating cylinder. In the lightning insulator formed as described above, a plurality of slits extending in the longitudinal direction are provided on the outer periphery of the pressure-resistant insulating cylinder to form a thin portion for pressure release, and an elastic insulator such as rubber is loaded in the slit. .

[0008]

[Operation] In the lightning protection insulator of the present invention, since a plurality of slits are formed in the outer periphery of the pressure-proof insulating cylinder without forming a pressure-releasing through hole, even in a structure in which gas is sealed inside, The airtightness can be maintained and the moisture contained in the outside air can be prevented from entering the inside. or,
Since the elastic insulator such as rubber is loaded in the slit on the outer periphery of the pressure-proof insulating cylinder, there is no possibility that the pressure releasing portion will be broken during the manufacturing process or during use.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a lightning arrester embodying the present invention will be described in detail below with reference to FIGS. As shown in FIG. 2, the pressure-resistant insulating cylinder 1 is formed in a cylindrical shape from a reinforced resin (for example, epoxy resin-impregnated FRP) having excellent weather resistance. The ground-side electrode fitting 2 is fitted and fixed to the upper end of the pressure-resistant insulating cylinder 1, and the flange portion 3 is integrally formed on the outer periphery thereof. Then, the lightning protection insulator is attached via the flange portion 3 to a mounting adapter provided on a support arm of an unillustrated steel tower.

The bottomed cylindrical electrode-side metal fitting 4 is fitted and fixed to the lower end of the pressure-resistant insulating cylinder 1, and a bracket 5 is integrally provided on the lower surface of the metal fitting 4. Then, the grounding side arc horn is attached to the bracket 5 so as to face the charging side arc horn provided on the transmission line side (not shown) with a predetermined air discharge gap. The fitting tubular portion 6 is formed on the inner bottom surface of the electrode fitting 4 on the voltage applying side, and the conductor fitting 7 on the power applying side is fitted and fixed to the fitting tubular portion 6.
The current limiting element 8 mainly composed of zinc oxide having a non-linear voltage-current characteristic is stacked in series on the upper surface of the conductive metal fitting 7 on the power-supply side, and has a bottomed cylindrical spring receiver at the upper end thereof. The ground-side conductor fitting 9 which is also used is supported.

The tightening ring 10 is the electrode fitting 2 on the ground side.
This tightening ring 1 is screwed into the threaded portion 11 on the inner circumference of the upper end of
A coil spring 1 having a shunt 13 for energization between the intermediate conductor 12 fitted in 0 and the conductor fitting 9 on the ground side.
4 is installed. The current limiting element 8 is pressed and fixed between the current-carrying side conductor fitting 7 and the ground-side conductor fitting 9 by the biasing force of the coil spring 14.

The insulating cap 15 is attached to the upper end of the ground-side electrode fitting 2 and the upper end opening of the ground-side electrode fitting 2 is sealed by the insulating cap 15. The insulating layer 16 is formed in a closed space between the pressure-resistant insulating cylinder 1 and the current limiting element 8, and is formed by filling a room temperature curing type silicone rubber in this embodiment. As shown in FIGS. 1 to 4, a plurality of slits 17 extending in the longitudinal direction are provided at two locations on the outer periphery of the pressure-resistant insulating cylinder 1 in a state where three slits 17 are arranged in the longitudinal direction, and the slits 17 allow the pressure-resistant insulating cylinder 1 to be aligned.
A thin portion 18 for releasing pressure is formed on the peripheral surface of the. The elastic insulator 19 is loaded in each slit 17, and is formed by filling room temperature curable rubber in this embodiment.

An insulating jacket 20 made of high temperature curing type silicone rubber is formed on the outer circumference of the pressure-proof insulating cylinder 1 by coating, and a large number of insulating folds 21 are formed on the outer circumference thereof. In this embodiment, the upper and lower end portions of the insulating jacket 20 extend to the outer peripheral surfaces of the ground-side and power-supply-side electrode fittings 2 and 4,
Airtightness with both electrode fittings 2 and 4 is secured. next,
The operation of the lightning protection insulator configured as described above will be described.

When a lightning surge current flows through the power transmission line with the lightning protection insulator attached to the support arm of the tower, the current is attached to the lower end of the lightning protection insulator from the arc horn on the power transmission line side (not shown). Flashover to an arc horn (not shown). Then, this current passes through the electrode-side metal fitting 4, the conductor-side metal fitting 7, the current limiting element 8, the ground-side conductor metal 9, the shunt 13, the intermediate conductor 12 and the tightening ring 10, and the ground-side electrode. It flows to the metal fitting 2 and further to a steel tower through a mounting adapter (not shown) to be discharged to the ground. Further, the subsequent current generated thereafter is suppressed and blocked by the arc horn and the current limiting element 8.

Further, in the unlikely event that a large-scale lightning surge current flows through this lightning protection insulator, the current limiting element 8 becomes conductive and a high-temperature, high-voltage arc is generated inside the lightning protection insulator. Occurs. This arc is propagated to the pressure-reducing thin-walled portion 18 of the pressure-resistant insulating cylinder 1 through the insulating layer 16 provided in the closed space between the pressure-resistant insulating cylinder 1 and the current limiting element 8, and the thin-walled portion 18 and the insulating jacket are provided. It breaks a part of the body 20 and is rapidly released to the outside. Therefore, the entire lightning protection insulator is not destroyed.

As described above, in the lightning protection insulator of this embodiment, since a plurality of slits 17 are provided on the outer circumference of the pressure-proof insulating cylinder 1 to form the thin portion 18 for releasing pressure, the circumference of the pressure-proof insulating cylinder is formed. Unlike the conventional structure in which the pressure release hole is formed on the surface, the airtightness in the pressure-resistant insulating cylinder 1 can be maintained, and the moisture contained in the outside air can prevent the moisture contained in the outside air from the pinhole of the insulating jacket and the insulator in the pressure release hole. Penetration through the pinhole,
It is possible to surely prevent the dielectric strength from decreasing.

Further, in the lightning protection insulator of this embodiment, since the elastic insulator 19 made of rubber is loaded in the slit 17 on the outer periphery of the withstand voltage insulating cylinder 1, the thin portion 18 for releasing pressure is provided in the withstand voltage insulating tube 1. It is not directly exposed to the outer circumference. Therefore, unlike the conventional structure in which a pressure-resistant insulating tube is not provided and only a high-pressure insulating tube made of a polymer material is used, and a thin-walled portion for pressure release is formed on the peripheral surface of the high-pressure insulating tube, a thin-walled portion 18 for pressure release is provided. It is possible to reliably prevent the risk of being destroyed by a collision of a tool or the like in the manufacturing process or being destroyed by being caught by a bird during use.

Further, in the lightning protection insulator of this embodiment, since the pressure-resistant insulating cylinder 1 is provided with the slit 17, the thin portion 18 for releasing pressure is formed.
7 can be easily cut and formed on the outer periphery of the withstand voltage insulating cylinder 1 by post-processing, and the withstand voltage insulating tube 1 can be easily manufactured. The present invention is not limited to the configuration of the above-mentioned embodiment, and within the scope of the present invention,
It is also possible to change and embody it as follows.

(1) As shown in FIG. 5, the slit 17 is formed in one straight line without being divided in the longitudinal direction. In this configuration, when the thin portion 18 for releasing pressure is broken and the internal pressure is released, the slit 17 may open greatly and the current limiting element 8 and the like may pop out from the inside of the pressure-proof insulating cylinder 1. As shown in, an auxiliary ring 22 made of glass cloth impregnated with an epoxy resin or a phenol resin may be provided on the outer periphery of the pressure-resistant insulating cylinder 1 to regulate the amount of expansion of the pressure-resistant insulating cylinder 1.

(2) Slits 17 are provided at one location on the outer circumference of the pressure-proof insulating cylinder 1 or at a plurality of locations, three or more locations. (3) The elastic insulator 19 is integrally formed in the slit 17 on the outer circumference of the pressure-proof insulating cylinder 1 when the insulating outer jacket 20 is formed over the outer circumference of the pressure-proof insulating cylinder 1. (4) In the sealed space between the pressure-resistant insulating cylinder 1 and the current limiting element 8,
Enclose a gas with excellent insulating properties such as sulfur hexafluoride (SF ₆ ).

(5) The insulating jacket 20 is made of ethylene propylene rubber (EPDM). When the insulating jacket 20 is made of high temperature curing type silicone rubber as in the above embodiment, even when the lightning protection insulator is used outdoors for a long time, compared to the case where it is made of ethylene propylene rubber. It is possible to improve the antifouling property without losing the water repellency and increasing the length of the insulating jacket 20.

[0022]

Since the present invention is configured as described above, it is possible to maintain the airtightness and prevent the moisture contained in the outside air from entering the inside, and improve the dielectric strength. At the same time, it is possible to prevent the pressure release portion from breaking during the manufacturing process or during use.

Further, in the present invention, the slit can be easily formed by cutting on the outer periphery of the pressure-proof insulating cylinder by post-processing, and the pressure relief portion can be easily formed on the peripheral side of the pressure-proof insulating cylinder.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing an embodiment of a lightning protection insulator embodying the present invention.

FIG. 2 is a half sectional view showing the entire lightning protection insulator.

FIG. 3 is a partial perspective view showing the withstand voltage insulating cylinder.

4 is a cross-sectional view taken along the line AA of FIG.

FIG. 5 is a partial perspective view showing another embodiment of the withstand voltage insulating cylinder.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Withstand voltage insulating cylinder, 2 Grounding side electrode metal fittings, 4 Electric charging side electrode metal fittings, 8 Current limiting element, 17 Slits, 18 Pressure release thin wall parts, 19 Elastic insulators, 20 Insulation jackets, 2
1 insulation folds

Claims (1)

[Claims] 1. A voltage-current characteristic is non-linear in the withstand voltage insulating cylinder (1) by connecting and fixing electrode fittings (2, 4) on the grounding side and the charging side to both ends of the withstand voltage insulating tube (1). Accommodating the current limiting element (8), which has a flexible property, the electrode fittings (2, 4) and the current limiting element (8)
Of the withstand voltage insulating cylinder (1) and a plurality of insulating folds (21) on the outer periphery of the withstand voltage insulating cylinder (1).
0) is provided, a plurality of slits (1) extending in the longitudinal direction are formed on the outer periphery of the withstand voltage insulating cylinder (1).
7) is provided to form a thin portion (18) for pressure release, and an elastic insulator (19) such as rubber is loaded in the slit (17) of the lightning protection insulator.