JPS63205012A - Lightning insulator for 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] Purpose of the Invention (Industrial Field of Application) The present invention provides a method for detecting abnormally large currents flowing through power transmission lines due to lightning strikes.
The present invention relates to a lightning insulator device for power transmission lines that can quickly discharge lightning to the ground through its protection function, suppress and interrupt follow-on current, and prevent permanent ground faults.

(Prior art) Conventionally, as a lightning arrester device for power transmission lines, a power transmission line is supported via a support insulator to the tip of a support arm of a steel tower, and a mounting bracket is horizontally cantilevered to the support arm. A lightning arrester is suspended and fixed on the lower surface of its tip, an arcing horn as a grounding side discharge electrode attached to the lower end of the lightning arrester, and an arcing horn as a energizing side discharge electrode attached to the lower end of the support insulator. The horns were opposed to each other with a predetermined discharge gap.

(Problems to be Solved by the Invention) However, in the conventional lightning arrester device for power transmission lines, during snowfall, snow falling on the support arm converges downward along the inclined frame, that is, at the tip of the support arm. In this way, a large amount accumulates and moves to the horizontal mounting bracket as well as to the lightning arrester.
When used for higher voltages, the bracket becomes larger, and the snow that falls on it similarly moves to the lightning arrester, and this snow pushes out from the mounting bracket to the top of the lightning arrester, wraps the top of the lightning arrester, and covers the creepage insulation distance. There is a risk that it will be impossible to cut off the follow-on current following a lightning strike.

In addition, since a large amount of snow containing dust adheres to the surface of the lightning arrester, the surface is likely to become contaminated, and from this point of view, the creeping insulation strength of the lightning arrester will quickly decrease, reducing its reliability as a lightning arrester device. The problem is that it lacks sex.

Structure of the Invention (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention suspends and supports power transmission lines from support arms of steel towers via support insulators, and also installs lightning protection through mounting brackets. In a lightning arrester device for a power transmission line in which an insulator is supported and a ground side discharge electrode attached to the tip thereof faces a energized side discharge electrode attached to the power transmission line side with a predetermined discharge gap, the mounting A method is adopted in which a snow cover control member having a snow sliding slope extending from the support arm or a position close to the support arm is provided above the bracket.

(Function) By adopting the above-mentioned means, the present invention functions as follows.

Snow falling on the support arm gradually moves to its tip, and without moving to the mounting bracket, the snow cap control means causes the snow to fall so as to avoid the lightning arrester. As a result, snow does not adhere to the lightning arrester, the reduction in the creepage insulation distance of the lightning arrester is suppressed, and the follow-on current following a lightning strike is reliably blocked, improving electrical reliability.

(Example) Hereinafter, an example embodying the present invention will be described based on FIGS. 1 and 2.

A connecting fitting 2 is fixed to the tip of the support arm 1 of the steel tower, and a suspension insulator 5 is connected in series to the connecting fitting 2 via a U clevis link 3 and a horn fitting 4. The insulator chain 6 is supported so as to be swingable in the line direction and in the orthogonal direction. In this embodiment, the connecting fitting 2, the U clevis link 3, and the horn mounting fitting 4 constitute an upper hanging fitting. A wire clamp 10 for supporting a power transmission line 9 is supported by a horn fitting 7 at the lower end of the suspension insulator chain 6 via a connecting link 8. In this embodiment, the horn mounting fitting 7, the connecting link 8, and the wire clamp 10 constitute a lower hanging metallic structure. The horn mounting brackets 4 and 7 are provided with an arcing horn 11. to reduce damage caused by creeping flash to the suspension insulator chain 6 as much as possible.
12 is installed.

A mounting bracket 13 is horizontally fixed to the tip of the support arm 1 by bolts, and a lightning arrester 14 is suspended and fixed by bolts 16 to the lower surface of the tip of the bracket 13 with an electrode fitting 15 on the ground side. . In addition, the lower end of the lightning arrester 14, that is, the electrode fitting 17 on the charging side,
A ground-side discharge electrode 18 having a horn shape is supported.

On the other hand, as shown in FIG. 3, on the horn mounting bracket 7, a discharge electrode 19, which is a horn-shaped energizing example, is supported in a cantilever manner by a bolt in the direction of the line, and the discharge electrode 19 and the discharge electrode 18 are A predetermined air discharge gap G is provided between them. As shown in FIG. 3, the tip of the discharge electrode 18 is formed into an almost circular arc shape when viewed from the direction perpendicular to the line, so that the discharge gap G remains almost constant even when the suspension insulator chain 6 swings in the line direction. I'm trying to keep it.

The lightning arrester 14 includes a voltage-resistant insulating cylinder (shown in the diagram) formed in a cylindrical shape from a tensile material such as FRP, and a voltage-resistant insulating cylinder (shown in the diagram) that is mainly made of zinc oxide (ZnO) housed in series inside the cylinder. A current-limiting element (path shown) with non-linear current characteristics, cap-shaped electrode fittings 17 and 15 on the power supply side and the grounding side that are fitted and fixed to both ends of the voltage-resistant insulating tube, and a voltage-resistant insulating tube. It is formed by a rubber mold 20 provided on the outer periphery of the rubber mold 20.

Incidentally, arcing rings 21, 22 are provided on the electrode fittings 17, 15 on the energizing side and the grounding side of the lightning arrester 14 to reduce damage to the rubber mold 20 during creeping flash.

A snow cover falling gutter 23 as a snow cover control means is attached to the upper side of the mounting bracket 13.

Locking plates 24 and 25 are formed at both ends of the snow-capped gutter 23, and bolts 26 are inserted through the locking holes 24a of the locking plates 24 and tightened and fixed to the inclined frame IA of the support arm 1. ing.

Also, the bolt 26 is inserted from the locking hole 25a of the locking plate 25 at the tip.
is inserted through the mounting bracket 13 and tightened and fixed to the tip of the mounting bracket 13. Then, the bottom surface of the snow-covered snow falling gutter 23 is positioned lower toward the tip to form a snow sliding slope S, and the support arm 1
The snow cap that has been moved from the inclined frame IA is moved along the inclined surface S to the tip and falls.

Further, a snow return plate 27 is vertically welded and fixed in the middle of the mounting bracket 13, and is configured to drop snow that is about to move from the mounting bracket 13 to the lightning arrester 14 side. This snow is part of the snow that was not dropped by the snow capping gutter 23, so the amount is extremely small, but measures are taken to prevent the movement of moisture from the support arm 1 to the lightning arrester 14. It is worn.

Next, the operation of the lightning arrester device for power transmission lines constructed as described above will be explained.

Now, when an abnormally large current that exceeds expectations is applied to the power transmission line 9 due to a large-scale lightning strike, this current is discharged from the wire clamp 10 and discharge electrode 19 to the discharge electrode 18 through the discharge gap G, and from the electrode fitting 17 to the lightning protection It flows to the current limiting element (when shown) in the insulator I4, flows from the electrode fitting 15 of the ground Ip to the support arm 1 via the mounting bracket I-13, and further flows to the steel tower and is discharged to the earth. Subsequent currents that occur thereafter are suppressed and blocked by the current limiting element.

Now, in the embodiment described above, since the snow-covered falling gutter 23 was provided above the mounting bracket 13, the inclined frame IA of the support arm 1
The snow that is about to move from the side toward the mounting bracket 13 is moved to the tip along the slope S of the snow-covered snow falling gutter 23,
The snow is discharged from the gutter 23, therefore, the snow does not move and adhere to the lightning arrester 14, and the surface insulation strength of the lightning arrester 14 is ensured.

Also, although it is a small amount, the snow that has moved to the mounting bracket 1-13 falls from the snow return plate 27, so it
This prevents adhesion to.

Note that the present invention can also be embodied as follows.

(1) As shown in FIG.
As shown in the figure, a mountain-shaped snow cap falling chute 23' may be used.

(2) As shown in FIG. 5, a plurality of snow cap falling rails 29 as a snow cap control means are connected in parallel to the upper surface of the mounting bracket 13 by means of support bins 28, and from the support arm 1 side to the lightning arrester 14 side. Form in a slope that gets lower as you go. Further, as shown in FIG. 6, a semicircular arc-shaped snow-cover rail 30 is attached to the mounting bracket 13 via a support bin 28.
The mounting brackets 13 should be supported at equal intervals and in an inclined state as a whole.

In these other examples, the influence of wind pressure can be reduced.

(3) As shown in FIG. 7, the snow returning board 27 is divided into upper and lower parts, a bracket 31 is welded to each board, and this bracket is fixed to the mounting bracket 13 with bolts 32.

(4) As shown in FIG. 8, a large number of bar-shaped snow returning rods 33 are attached radially to the bracket 31. This alternative example can also reduce the influence of wind pressure.

Effects of the Invention As described in detail above, the present invention is capable of securing the creeping insulation strength of the lightning arrester by using a snow cap control means to prevent snow from moving from the support arm to the lightning arrester through the mounting bracket. This has the effect of reliably blocking the follow-on current following a lightning strike and improving electrical reliability.

[Brief explanation of the drawing]

Fig. 1 is a front view showing the entire lightning arrester device for power transmission lines embodying the present invention, Fig. 2 is an enlarged perspective view of a snow-covered gutter, and Fig. 3
6 are perspective views showing other examples of the snow cover control means, and FIGS. 7 and 8 are perspective views showing other examples of the snow returning member. DESCRIPTION OF SYMBOLS 1... Support arm, 6... Suspension insulator chain as a support insulator, 9... Power transmission line, 13... Mounting bracket 14
... Lightning arrester, 15 (17) ... Electrode fitting on the grounding (power charging) side, 18 (19) ... Discharge electrode on the grounding (power charging) side, 23 ... As snow cover control means Snow-covered gutter, 24
．． 25... Locking plate, 29.30... Snow cap falling rail as snow cap control means.

Claims (1)

[Scope of Claims] 1. A power transmission line is suspended and supported from a support arm of a steel tower via a support insulator, and a lightning arrester is supported via a mounting bracket, and a ground side discharge is attached to the tip of the lightning arrester. In a lightning arrester device for a power transmission line, which faces a discharge electrode on a power-supplying side with an electrode attached to the power transmission line side with a predetermined discharge gap,
A lightning arrester device for a power transmission line, characterized in that a snow cover control member having a snow sliding slope extending from a support arm or a position close to the support arm is provided above the mounting bracket. 2. The snow cover control means arranges a plurality of rods in parallel with each other,
The lightning arrester device for a power transmission line according to claim 1, which is a snow-covered snow drainage gutter that is inclined so as to be positioned lower toward the tip of the mounting bracket. 3. The lightning arrester for power transmission lines according to claim 1, wherein the snow cover control means is a snow cover control plate whose cross section is formed in an inverted U-shape, and whose upper surface is inclined to one side. Insulator device.