JPS61114483A - Lightning arrestor for power transmission line - 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] [Field of application of the invention] The present invention relates to improvements in lightning arresters for power transmission lines.

[Background of the invention]

As a conventional lightning arrester for power transmission lines, for example, JP-A-54-12
The one shown in Japanese Patent No. 421 is known. This type of lightning arrester is configured to be disconnected from the grid using the ground fault current flowing through the grid when the arrester becomes defective.

However, this arrester had the following drawbacks. It is expected that a lightning arrester cannot be installed on the lower phase transmission line supported at the bottom of the tower, and that the connection wire on the transmission line side of the disconnected lightning arrester will dangle under its own weight. However, there were problems such as concerns about insulation and the inability to promptly restart power transmission.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a surge arrester for a power transmission line that can reliably disconnect the surge arrester from the system and maintain sufficient insulation when a ground fault current flows through a faulty surge arrester.

[Summary of the invention]

In the present invention, a lightning arrester with one end rotatably connected to an arm of a steel tower is arranged diagonally, a power transmission line is connected to the other end, and when the connection on the power transmission line side is disconnected, the lightning arrester uses the end connected to the arm as a fulcrum. The glaze is defined as the act of moving a predetermined distance away from the power line under its own weight.

[Embodiments of the invention]

The present invention will be explained below with reference to embodiments shown in the drawings.

Figure 1 is a front view showing the installation of a lightning arrester.The transmission line tower 1 has an arm 2 stretched out in the horizontal direction, and the lower end of the suspension insulator 4 is fixed to this arm 2 at one end and hangs down. One end of a lightning arrester 6 is connected to a position 5 of the arm 2 diagonally above when viewed from the power transmission line 3 from which the power transmission line 3 is suspended, and the power transmission line 3 is connected to the other end. In this way, the lightning arrester 6 is disposed obliquely between the arm 2 and the power transmission line 3. A disconnection device 8 is provided on the power transmission line 3 side of the lightning arrester 6 to disconnect the connection line 7 if the lightning arrester 6 is defective and a ground fault current flows. When this separation device 8 operates,
The lightning arrester 6 is suspended by its own weight on a hinge 9 with the fulcrum at the position 5 as shown by the dotted line.

Looking at the insulation between the lightning arrester 10 and the power transmission line 3 shown by this dotted line, the metal fittings at both ends of the lightning arrester 100 (similar to those of the lightning arrester 6 in a steady state) are also sufficiently far away from the power transmission line 3, so there is a gap between the two. The insulation of the transmission line 3 is maintained well, and the operation of the power transmission line 3 can be promptly resumed.

FIG. 2 is a longitudinal cross-sectional view of the lightning arrester 6, and shows an insulator 2 such as an insulator tube.
A plurality of zinc oxide elements 21 are stacked inside the insulator 20, and both ends of the insulator 20 are sealed with an explosion-proof device 22. This explosion-proof device 22 includes a pressure release plate 26 that ruptures when the pressure inside the insulator 20 increases and reaches a predetermined pressure;
A pressure relief port 25 is provided to guide internal pressure to the outside. A connection line 7 connected to the power transmission line 3 is connected across the pressure relief port 25. Shields 23 are attached to both ends of insulator 200 to improve voltage sharing of zinc oxide element 21.

Now, if the zinc oxide element 21 becomes defective for some reason and the specified performance cannot be obtained, the ground fault current will cause an arc inside the insulator 20, and the inside of the insulator 20 will be under pressure. rises. When the pressure rises to a predetermined set pressure, the pressure relief plate 26 is ruptured and the pressure is released from the pressure relief port 25, and the above-mentioned internal arc becomes an external arc. The arc heat released from the pressure relief port 25 at this time melts the connection wire 7. In this way, the lightning arrester 6 in FIG. 1 hangs down as shown by the dotted line.

Next, the connection structure between the lightning arrester 6 and the arm 2 will be explained using FIG.

8 rods 30 connected perpendicularly to the arm 2 are insulators 31
The end tube 33 of the connecting wire 32 is rotatably fitted to the outer periphery of the insulator 31. One end of a flexible conductor 34 is connected to the middle of the connection line 32, and the other end of this flexible conductor 34 is connected to the 8 rod 30 or the arm 2.

Because of this configuration, the ground fault current flowing through the lightning arrester 6 does not flow through the end tube 33. Therefore, the circuit portion is not welded to prevent it from rotating due to the ground fault current, and can always move like the lightning arrester 10 indicated by the dotted line in FIG. The rotatable structure of the arm 2 side of the lightning arrester 6 is preferably designed to quickly attenuate the swing of the lightning arrester 10 and to avoid collision with the steel tower 1. In this way, the lightning arrester 6 is connected to the arm 2 for suspending and supporting the power transmission line 3, so this embodiment is applied to all three-phase power transmission lines that are vertically arranged and supported on the steel tower 1. be able to.

In the above embodiment, the disconnecting device 8 was configured to fuse the connecting wire 7 by using the arc heat generated by the internal arc generated within the insulator 20, but as shown in FIG. Instead, the disconnection device 40 can be used to disconnect the lightning arrester 6 by electromagnetic force caused by a ground fault current that flows when the lightning arrester 6 is defective.

〔Effect of the invention〕

As explained above, the present invention has one end connected to a power transmission line, the other end of the lightning arrester is rotatably connected to an arm diagonally above the power transmission line, and the surge arrester is disconnected from the power transmission line side end. Because of the structure of the device, if the arrester malfunctions and a ground fault current flows, the disconnection device will operate, causing the arrester to hang down under its own weight around the arm end, ensuring a sufficient insulation distance from the power line. This will enable the transmission line to resume operation promptly.

[Brief explanation of drawings]

FIG. 1 is a front view of a lightning arrester for power transmission lines according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view showing an example of the lightning arrester of FIG. 1, and FIG. 3 is an enlarged perspective view of the main parts of FIG. FIG. 4 is a front view of main parts showing another example of the lightning arrester shown in FIG. 1. 1... Steel tower, 2... Arm, 3... Power line, 6...
... Lightning arrester, 7... Connection line, 8... Disconnection device.

Claims (1)

[Claims] 1. Supporting a power transmission line via a suspension insulator on the arm of a steel tower,
In a lightning arrester for a power transmission line comprising a lightning arrester connected between the power transmission line and the arm, the lightning arrester is arranged diagonally and one end thereof is rotatably connected to the arm diagonally above the power transmission line, and A lightning arrester for a power transmission line, wherein the other end is connected to the power transmission line via a disconnection device that is disconnected by a ground fault current flowing when the lightning arrester is defective. 2. The lightning arrester for power transmission lines according to claim 1, wherein the lightning arrester is formed by stacking zinc oxide elements. 3. In the item described in claim 1 above, the lightning arrester has an explosion-proof device, and the disconnection device uses fusing caused by arc heat during operation of the explosion-proof device. Lightning arrester for power transmission lines. 4. In the above claim 1, the rotatable connection of the lightning arrester to the arm includes a rotatable mechanical connection electrically insulating between the lightning arrester and the arm; A lightning arrester for a power transmission line, comprising a lightning arrester and an electrical connection between the arms using a flexible conductor.