JPS61164414A - Lightning method of 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 <Industrial Application Field> The present invention relates to a method for grounding an overhead ground wire installed on a power transmission tower, and more particularly, to a lightning protection method for a power transmission line.

<Conventional technology> Generally, one or two overhead ground wires are installed at the top of a power transmission line in an area where lightning occurs to prevent direct lightning strikes, that is, to prevent lightning strikes. It is normal to keep it.

This overhead ground wire is connected to the top of each steel tower whose legs are grounded, and by guiding the lightning charge through the tower body to the ground, it has the effect of blocking lightning on power lines.

However, when a lightning current flows into the overhead ground wire, a potential difference is created between the overhead ground wire and the power line due to the resistance of the overhead ground wire and tower members. Reverse sparkle occurs.

For this reason, many snow-proof designs have been implemented so far, such as multi-stranding the overhead ground wire, bridging the overhead ground wire, unbalanced insulation method, and multiple grounding method for the buried ground wire, but none of them have been sufficiently effective. The reality is that we have not yet achieved this goal.

<Problem to be solved by the invention> This is because the wave front steepness of the lightning current is large, so the overhead ground wire,
The surge impedance of the tower and buried ground wire acts, causing the potential to rise around the lightning strike point, and connections from the overhead ground wire to the tower, between tower members, and from the tower to the buried ground wire.
Because they are surface-connected using bolts and metal fittings, lightning waves reflect at the connections, which prevents the lightning current from propagating smoothly to the end of the buried ground wire.

Means for Solving the Problems> The present invention has been made to solve the above problems, and the details thereof will be described below with reference to FIGS. 1 and 2, which correspond to embodiments.
This will be explained using figures.

Overhead ground wire (1) installed between transmission line towers (3)
The above-mentioned overhead ground wire (1) is insulated and installed on the above-mentioned steel tower (3), and the above-mentioned above-mentioned steel tower (3) is connected to the above-mentioned steel tower (3) at both ends.
Each of the above overhead ground wires (1) is connected to a buried ground wire (5) through a hanging wire (0) insulated from the steel tower (3) and arranged along the tower (3), and the above-mentioned overhead ground wire (1) is connected to each predetermined tower span. At the same time, one end of each of the overhead ground wires (1) and one end of the adjacent overhead ground wire (1) are connected by a jumper wire (8) passing above the top of the steel tower (3). This is a lightning protection method for electric wires.

In this way, the overhead ground wire 1 is insulated and installed on the steel tower 3,
At both ends, each is insulated from the steel tower 3 and connected to a buried ground wire 5 via a hanging wire 4 arranged along the steel tower 3, and the above-mentioned overhead ground wire 1 is erected for each predetermined tower span. At the same time, one end of each overhead ground wire l and one end of the adjacent overhead ground wire 1 are connected to a jumper wire 6 passing above the top of the steel tower 3.
connected to reduce the overall surge impedance from the overhead ground wire 1 to the ground GL, and to alleviate lightning surges due to the capacitance between the hanging wire 4 and the steel tower 3,
Lightning current is transferred from the overhead ground wire 1 to the buried ground wire 5 via the hanging wire 4.
Furthermore, the surge impedance of the steel tower 3 is guided to the ground GL without intervening, thereby reducing the potential rise at the point of lightning strike.

<Effects of the Invention> The lightning protection method for power transmission lines according to this invention is as described above.
It has a significant effect in contributing to stabilizing the power supply by reducing insulator reverse flashover in power lines caused by lightning current, as well as the failure of system protection relays and damage to arresters and circuit breakers due to overcurrent and overvoltage. It is.

<Example> An example of the present invention will be described below with reference to FIGS. 1 to 4.

The lightning protection method of this invention comprises an overhead ground wire l, its retaining clamp 8, a retaining insulator 7, a hanging wire 4 and its supporting insulator 9,
and jumper wire 6 and its supporting insulator 9. This is carried out using a buried ground wire 5 as well as a buried ground wire 5.

The overhead ground wire 1 is formed of a predetermined electric wire, for example, a steel-core No. I aluminum alloy stranded wire or an aluminum wave-tone stranded wire.

This overhead ground wire 1 is held down on one side by a detention clamp 8 that is insulated and supported by a suspension insulator-like detention insulator 7 fixed to the steel tower 3, and similarly held on the other side to a predetermined position. The power line 2 is given a slackness of
It is installed at a predetermined position above.

The hanging wires 4 are continuously formed integrally at both ends of the overhead ground wire l, and are attached to the retaining clamps 8 of the installed overhead ground wire l.
It is arranged in a substantially hanging shape downward from the base.

Each of the hanging lines 4 is supported by a required number of support insulators 9, and is extended at a predetermined interval along the main pillar material 3a of each steel tower 3, and is provided for each hanging line 4. The buried ground wire 5 connected to the buried ground wire 5 is formed by burying a predetermined conductor underground around the legs of the three steel towers, and in this embodiment.

Several 30m long conductors are buried radially to provide low grounding resistance.

In addition, the above-mentioned overhead ground wire 1 and the overhead ground wire 1 for each of a predetermined number of tower spans constructed in the same manner as described above are defined as the distance between the overhead ground wires 1 and 1 of the adjacent tower spans, respectively. The clamps 8. are connected to each other by jumper wires 6 at the 8th part,
Adjacent overhead ground wires 1.1 are formed in a good conductive state. Then, the jumper wire 6 connects the intermediate part to the steel tower 3.
It is supported by a support insulator 9 placed at the top.

Further, the steel tower 3 is connected to the buried ground wire 5 at its tower leg.

The above explanation is for the case where there is one overhead ground wire between the tower spans, but even when there are multiple overhead ground wires between the tower spans, each overhead ground wire has a hanging line and a Of course, it is also possible to implement a lightning protection method for power transmission lines by providing a buried ground wire.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing one embodiment of the present invention, Fig. 2 is an explanatory diagram showing a tower span where an overhead ground wire is installed, and Fig.
This figure is an enlarged front view of the retaining clamp part shown in FIG. 1, and FIG. 4 is an enlarged sectional view of the hanging line support part shown in FIG. 1. 1... Overhead ground wire, 3... Steel tower, 4... Hanging line, 5
... Buried ground wire, 6... Jumper wire. Figure 3 Self-initiated amendment procedure amendment 50.6.29 Showa year, month, day, case description 1985 Patent application No. 003629, title of invention, lightning protection method for power transmission lines, person making the amendment Relationship to this case Special Permit application Name of office: Shirakawa Electric Civil Engineering Co., Ltd., agent, drawings subject to amendment, details of amendment

Claims (1)

[Claims] An overhead ground wire installed between steel towers of a power transmission line, wherein the overhead ground wire is installed insulated from the steel tower, and each end thereof is insulated from the steel tower and arranged along the steel tower. Each of the overhead ground wires is connected to a buried ground wire via a hanging wire, and the overhead ground wire is erected for each predetermined tower span, and one end of each of the overhead ground wires is connected to one end of the adjacent overhead ground wire. A lightning protection method for a power transmission line, characterized in that it is connected by a jumper wire passing above the top of a steel tower.