JP2552041B2 - Lightning arrester device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when an abnormal current due to a lightning strike flows to a transmission line, discharges it rapidly to the ground by a lightning protection function and suppresses and interrupts a follow current to prevent a permanent ground fault. The present invention relates to a lightning arrester device for a suspended steel tower or a tension resistant steel tower, and more particularly to a ground side discharge electrode.

[0002]

2. Description of the Related Art As a conventional lightning protection insulator device, there is known a device for a suspended steel tower having a structure as shown in FIGS.

In this conventional structure, the power transmission line 9 is supported on the support arm 1 of the steel tower through the upper horn mounting bracket 4, the supporting insulator 5 and the lower horn mounting bracket 7, and the supporting arm 1 is provided with the mounting adapter 13. The lightning protection insulator 14 is supported via the lightning protection insulator 14, the lower horn mounting member 7 is provided with a discharge electrode 21 on the charging side, and the lower end portion of the lightning protection insulator 14 has a predetermined air gap relative to the discharging electrode 21 on the charging side. The ground-side discharge electrodes 23 are provided so as to face each other with a discharge gap G, and the lightning surge is flashed between the tip of the discharge-side discharge electrode 21 and the ground-side discharge electrode 23. There is.

Further, the discharge electrode 23 on the ground side has an air discharge gap G against the swing of the support insulator 5 in the direction perpendicular to the line.
And a rod-shaped electrode body 25 formed in a more appropriate shape corresponding to the movement (trajectory) of the discharge electrode 21 on the charging side in order to minimize the change in
5 and a rod-shaped support 26 welded and fixed to the electrode body 25 at the end portion thereof so as to extend in a direction substantially orthogonal to the reference numeral 5.

[0005]

However, in this conventional lightning arrester device, as shown in FIGS. 5 and 6, flashover occurs at the rod tip and the rod side face, so that the flashover voltage with respect to the lightning surge has a positive polarity. However, there is a problem that it depends on the negative polarity. That is, for example, 66 to 77K
In the V insulator device, in response to a positive flashover voltage from the discharge electrode 21 on the charging side to the discharge electrode 23 on the ground side, a negative flash flash from the discharge electrode 23 on the ground side to the discharge electrode 21 on the charging side. Over voltage (Figs. 6 and 7)
However, there is a problem that the lightning protection insulator device cannot be applied because the insulation cooperation characteristic with the supporting insulator 5 is deteriorated and the cooperation becomes impossible in some cases.

The present invention has been made by paying attention to the problems existing in the above-mentioned conventional techniques, and the purpose thereof is to obtain a negative voltage value having a high flashover voltage as much as possible. (EN) Provided is a lightning protection insulator device which can be made to have a small polarity difference by approaching a positive polarity voltage value, can achieve insulation cooperation with a support insulator, and can be easily manufactured to reduce the cost of the device. It is in.

[0007]

In order to achieve the above-mentioned object, the present invention supports a power transmission line on a support arm of a steel tower via a support insulator, and a discharge electrode on a power-supply side connected to the power transmission line. A lightning arrester supported by the supporting arm or a grounding side metal fitting of the supporting insulator, and a discharge on the ground side connected to the tip of the lightning arrestor and facing the discharge electrode on the charging side with a predetermined air discharge gap. In the lightning arrester device including an electrode, the ground-side discharge electrode is formed of a square rod member or a square tube member having a substantially square cross section.

[0008]

According to the lightning arrester device constructed as described above, since the discharge electrode on the ground side is formed in a substantially square cross section, 1 or 2 is formed on the side facing the discharge electrode on the voltage application side.
There are two corners, and electric potential concentration is likely to occur at the corners. Therefore, as compared with a discharge electrode having a circular cross section, discharge of a negative polarity voltage having a high flashover voltage is more likely to occur, and thus a positive polarity is generated. The negative polarity of the lightning impulse flashover voltage of the negative polarity also becomes smaller as it approaches the rod-to-rod discharge electrode, and it is possible to prevent an increase in the insulation level in the air discharge gap and improve the insulation coordination characteristics. .

Further, according to the present invention, since the discharge electrode has a square cross section, the discharge electrode can be easily processed by using a commercially available square rod or tube having a square cross section. The manufacturing cost can be reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a lightning arrester device embodying the present invention will be described below with reference to FIGS.

As shown in FIG. 2, a suspension metal fitting 2 is attached to a support arm 1 of a steel tower, and an upper horn attachment metal fitting 4 is connected to the suspension metal attachment 2 via a U clevis 3.
A support insulator 5 is suspended and supported on the upper horn mounting member 4 so as to be swingable in the line direction and a direction orthogonal to the line direction. In this embodiment, a suspension insulator string is formed by connecting a plurality of suspension insulators 6 in series. ing. A lower horn mounting bracket 7 is connected to the lower end of the support insulator 5, and the lower horn mounting bracket 7
An electric wire clamp 10 for supporting the power transmission line 9 via a connecting link 8 is attached to the. The arcing horns 11 and 12 are attached to the horn mounting brackets 4 and 7, and the arcing horns 11 and 12 reduce damage to the surface flashover of the support insulator 5 during abnormal lightning strikes.

A mounting adapter 13 is fixed in a cantilever manner to the tip of the support arm 1 and extends horizontally in the same direction as the line. On the lower surface of the tip of the mounting adapter 13, a lightning protection insulator 14 is suspended and fixed by bolts. Lightning arrester 1
Reference numeral 4 is a pressure-resistant insulating cylinder (not shown) formed in a cylindrical shape by a tension-resistant material such as FRP, and zinc oxide (ZnO) housed in series inside the cylinder is the main material, and the voltage-current characteristics are non-linear. Of the resistance element 15 and the cap-shaped electrode fittings 1 on the grounding side and the charging side, which are fitted and fixed to both ends of the withstand voltage insulating cylinder.
6 and 17, and a mold rubber 18 provided on the outer periphery of the pressure-resistant insulating cylinder. Arcing rings 19 and 20 are provided so as to oppose each other on both electrode fittings 16 and 17 of the lightning protection insulator 14.
The damage caused by the surface flashing of the molded rubber 18 is reduced by the members 9 and 20.

A discharge electrode 21 on the charging side is attached via a mounting plate 22 to a lower horn mounting bracket 7 on the charging side of the supporting insulator 5. In addition, the grounding side discharge electrode 23 is attached to the charging side electrode fitting 17 at the lower end of the lightning protection insulator 14 by the mounting plate 24.
Is installed through. The discharge electrodes 21 and 23 on the charging side and the grounding side are arranged to face each other with a predetermined air discharge gap G.

As shown in FIGS. 1 and 2, the discharge electrode 23 on the ground side is a rectangular bar-shaped electrode body 25 having a gentle arc shape extending in the horizontal direction substantially orthogonal to the line direction of the power transmission line 9.
And a support body 26 made of a round bar which is welded and fixed so as to extend in the vertical direction substantially orthogonal to the electrode body 25. The rectangular electrode body 25 is formed by cutting a commercially available rectangular bar material having a square cross section such as copper or aluminum into a predetermined length and curving it into a gentle arc shape. Further, the rectangular rod-shaped electrode body 25 is arranged in a convex shape downward, and even when the support insulator 5 sways in a direction orthogonal to the line direction due to wind pressure or the like, the discharge electrode 2 on the voltage application side.
The air discharge gap G between 1 and the discharge electrode 23 on the ground side is kept substantially constant.

Further, as shown in FIG. 3, a pair of left and right corner portions 25a which are the original corner portions of the square rod member are formed in the lower portion of the square rod electrode body 25, and potential concentration occurs at the corner portion 25a. Therefore, compared with a discharge electrode having a circular cross section, discharge of a negative voltage having a high flashover voltage from the ground-side discharge electrode to the charge-side discharge electrode 21 is more likely to occur.

Here, the cross-sectional area of the rectangular rod-shaped electrode body 25 is set so as not to melt even if a short-circuit current level current flows in the event of an accident. For example, in the 66 KV class, one side has 14 sides.
It is a square of mm.

Next, the operation of the lightning arrester device constructed as described above will be described. Now, in this lightning arrester device, when a surge current caused by a lightning strike is applied to the power transmission line 9, the current flows from the wire clamp 10 to the lower horn mounting bracket 7 to cause an air discharge between the discharge electrodes 21 and 23. It is flashed over in the gap G, then flows through the electrode fitting 17, the resistance element 15 in the lightning protection insulator 14, the electrode fitting 16 and the mounting adapter 13 to the support arm 1 of the tower, and is discharged from the tower to the ground. Further, the subsequent flow generated thereafter is the air discharge gap G between the discharge electrodes 21 and 23 and the lightning protection insulator 14
It is suppressed and cut off by the resistance element 15 inside.

In this embodiment, the discharge electrode 23 on the ground side is also used.
Is composed of the rectangular rod-shaped electrode body 25, potential concentration is likely to occur at the corner portion 25a, and discharge of a negative voltage having a high flashover voltage is more likely to occur as compared with a discharge electrode having a circular cross section. Therefore, the polarity difference between the positive polarity and the negative polarity lightning impulse flashover voltage also becomes smaller when approaching the rod-to-rod discharge electrode, and it is possible to prevent an increase in the insulation level of the air discharge gap G, and to improve the insulation coordination characteristics. It is possible to improve.

Further, in the above-mentioned embodiment, since the electrode body 25 constituting the ground-side discharge electrode 23 has a square cross-section, it is easy to use a commercially available square rod having a square cross-section. The body can be processed and the manufacturing cost can be reduced.

The present invention is not limited to the structure of the above-mentioned embodiment, but is applicable to a tension-resistant or V suspension insulator device, or, for example, as shown in FIG. 4, an electrode body of the discharge electrode 23 on the ground side. It is also possible to arrange 25 into a rhombic cross section, or to form the electrode body 25 by a pipe having a square cross section.

[0021]

As described above in detail, the present invention can reduce the polarity difference of the lightning impulse flashover voltage, prevent the insulation level of the air discharge gap from rising, and improve the insulation cooperation characteristic. Further, there is an effect that the manufacturing can be easily performed and the cost of the device can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view showing a discharge electrode of a lightning protection insulator device embodying the present invention.

FIG. 2 is a front view of a lightning arrester insulator device.

FIG. 3 is a cross-sectional view of discharge electrodes on a ground side and a charging side.

FIG. 4 is a cross-sectional view showing another example of the discharge electrode on the ground side.

FIG. 5 is a front view of a conventional lightning protection insulator device.

FIG. 6 is a side view of discharge electrodes on a grounding side and a charging side of a conventional lightning arrester device.

FIG. 7 is a partially enlarged cross-sectional view of discharge electrodes on a ground side and a charging side of a conventional lightning arrester device.

[Explanation of symbols]

1 Steel tower support arm, 4 Upper horn mounting bracket, 5
Support insulator, 7 lower horn mounting bracket, 9 power line, 13
Mounting adapter, 14 lightning protection insulator, 21 discharge side discharge electrode, 23 ground side discharge electrode, 25 square rod electrode body,
26 Support, G Air discharge gap.

Claims (1)

(57) [Claims] 1. A lightning striker in which a power transmission line is supported by a support arm of a steel tower via a support insulator, and a discharge electrode on the power-supply side connected to the power transmission line and a grounding side metal fitting of the support arm or the support insulator are supported. A lightning arrester device comprising an insulator and a grounding side discharge electrode which is connected to a tip end portion of the lightning arrestor and faces the discharge electrode on the charging side with a predetermined air discharge gap. A lightning arrester device, characterized in that the electrode is constituted by a rectangular rod member or a rectangular tube member having a substantially square cross section.