JPS6276502A - Arrester - 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 [Technical Field of the Invention] The present invention relates to a lightning arrester, and more particularly to improving the explosion-proof function of a lightning arrester for a railroad gear brace installed on a power transmission line.

[Technical background of the invention and its problems]

When a lightning arrester installed directly on a railway line receives an excessive load such as a direct hit and a ground fault or short circuit occurs, the inside of the arrester tube is short-circuited by the arc current, and the internal pressure of the tube increases. Therefore, this type of evacuation device has an explosion-proof structure that prevents the pipe from exploding and scattering.

As its explosion-proof structure, there is a conventional lightning arrester as shown in FIG. (Refer to Japanese Patent Application No. 60-65274) In such a lightning arrester, when a fault current flows due to the termination of the internal element 2, the fusible conductor 3 instantly melts, and both the internal element 2 and the fusible conductor 3 are exposed to an arc. to bridge the gap. In the A chamber 4a and the B chamber 4b in the insulating cylinder 4, the pressure relief plates 5 are activated by the increase in internal pressure due to arc heat, and the burnt gas inside the A chamber 4a and the B chamber 4b is discharged through the pressure relief port 6° and the arc guide 7, respectively. Migrate to the outside via. This released burnout gas has conductivity, so when the pressure is released from the arc guide 7, it becomes an external arc that bridges the upper and lower parts, resulting in a short circuit state, so the fault current supplied from the power supply side becomes an external arc.

By the way, in order to prevent the explosion and scattering of the insulator tube 1 using the pressure relief plate 5, it is necessary to release the internal arc of the insulator tube 1 to the outside of the insulator tube 1 as quickly as possible. be. For this purpose, the time it takes for the high pressure, high temperature ionized gas generated after being short-circuited by an arc inside the peeling tube 1 to eject from the pressure release port 6° arc guide 7 and become an external arc is made as short as possible. There is a need to.

However, in the conventional lightning arrester described above, the ejection angles of the ionized gas ejected from the upper and lower arc guides 7 are different, and the pipe length of the high-rated arrester is longer than that of the low-rated arrester. In some cases, it takes a long time for an arc generated inside the device to become an external arc.

As a result, the pressure inside the insulator tube 1 rises too much, causing the tube to break.Also, the arc stays inside the insulator tube 1 for a long time, causing the arc to come into contact with the inner wall of the insulator tube 1, causing the tube to rupture due to the thermal stress of the arc. There were times when I did.

[Purpose of the invention]

The present invention has been made in consideration of the above points, and its purpose is to provide a lightning arrester that improves the explosion-proof function by shortening the time it takes for ionized gas generated inside the tube to become an external arc. It is about providing.

[Summary of the invention]

In order to achieve such an object, according to the present invention, an internal element and a surge generating section connected in series with the internal element are housed in the paddle tube, and the surge generating section is arranged so that a fusible conductor is passed through the insulating cylinder. By filling the surrounding area with an arc extinguishing agent such as quartz grains and sealing both ends, the fusible conductor melts when the internal element burns out, and when it melts, it generates a high voltage, turning the internal arc into an external arc. It is characterized by shortening the time it takes.

[Embodiments of the invention]

An embodiment of the lightning arrester of the present invention will be described below with reference to FIGS. 1 and 2. An internal element 12 formed of a non-linear resistor element is formed in an insulator tube 11, and a surge generating part is formed by passing a fusible conductor 13 into an insulating tube 14, filling the surrounding area with an arc extinguishing agent 15a such as quartz grains, and sealing both ends. 15 are electrically connected and compressed by a compression spring 19 to be housed.

As shown in the drawing, a pressure relief plate 16 is provided at the lower end of the insulator tube 11 to seal the pressure relief port 17, and an arc guide 1 is provided on the outside of the pressure relief plate 16.
8 are provided, and openings 1 at the top and bottom of this arc guide 18 are provided.
8a is in a closed state. The fusible conductor 13 has a characteristic that it does not melt due to normal leakage current of the arrester and discharge current such as lightning or switching surge that flows during the operation of the arrester, but instantaneously melts due to ground fault current or short circuit current that flows during a surge arrester fault. Materials and dimensions are selected with

The operation of such a lightning arrester according to the present invention will be explained.

When a fault current flows due to the termination of the internal element 12, the fusible conductor 13 instantly melts, and the internal element 12 and the fusible conductor I3
Both bridges end in arcs.

At this time, an arc extinguishing agent 1 such as quartz grains is placed around the fusible conductor 13.
5a is filled to form the surge generator 15, the arc is rapidly cooled, and the voltage across the fusible conductor 13 rises rapidly, just as when a current limiting fuse is cut off.

Inside the straddle tube 11, each pressure relief plate 16 operates due to the increase in internal pressure due to arc heat, and the internal burnout gas is discharged through the pressure relief port 17. It moves to the outside via the arc guide 18.

When the withstand pressure between the upper and lower burnout gases released from the upper and lower arc guides 18 becomes lower than the voltage generated by the fusible conductor 13, the burnout gas on the upper side will bridge before it reaches the burnout gas on the lower side, causing an external arc, that is, disconnection. becomes. After that, the fault current supplied from the power supply side passes through an external arc and no longer flows inside the arrester, so internal burnout can be minimized.

FIG. 2(a) shows the voltage when a short-circuit accident occurs in a conventional lightning arrester, and FIG. 2(b) shows the voltage in the lightning arrester of the present invention equipped with a surge generator 15, and in both cases, the horizontal axis shows time. The voltage waveforms taken are shown, and it can be seen that the time until external flashover, that is, disconnection, was much shorter in Figure 2(b) than in Figure 2(a).

〔Effect of the invention〕

As explained above, according to the present invention, the internal element and the surge generator are housed in the hollow tube in series with the internal element, and the pressure relief holes, pressure relief plates, and arc guides are provided at both ends of the hollow tube.
Since the internal arc generated inside the tube is quickly removed from the external arc, it is possible to provide a lightning arrester with significantly improved explosion-proof function.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the lightning arrester of the present invention, and FIG. 2(a). (b) is a diagram showing the voltage characteristics of the present invention and a conventional lightning arrester, respectively, and FIG. 3 is a sectional view of the conventional lightning arrester. 11... Insulator tube, 12... Internal element, 13... Fusible conductor, 14... Insulating cylinder, 15... Surge generating part, 1
5a. Filler, 16. Pressure relief plate, I7.. Pressure relief hole, 18.. Arc guide, 19.. Compression spring.

Claims (2)

[Claims] (1) An internal element made of a non-linear resistance element and a surge generating part electrically connected in series with this internal element are housed in an insulator tube, and pressure relief holes are provided at both ends of the insulator tube, and the Each of the pressure holes is closed with a pressure relief plate, an arc guide is provided on the outside, and the surge generating part is formed by storing a fusible conductor together with an arc extinguisher in an insulating tube, and sealing both ends of the insulating tube. A lightning arrester characterized by: (2) The lightning arrester according to claim 1, wherein the arc extinguishing agent comprises quartz grains.