JPH06162851A - Lightning protection insulator device - Google Patents

Abstract

PURPOSE:To provide a lightning protection insulator device, having less responsibility for an element at the time of lightning attack, and capable of reducing the size and cost of a current-limiting element. CONSTITUTION:This lightning protection insulator device is provided with a support insulator 3 suspended by the supporting arm 2 of an iron tower, and lightning protection insulators 17 incorporating a current-limiting element 18 having the nonlinearity of a voltage-current characteristic. A charge side discharge electrode 13 is mounted on the charge side of the support insulator 3. An earth side discharge electrode 24 is connected to the charge side of the lightning protection insulators 17 to form a series gap G2 oppositely to the charge side discharge electrode 13. At least one side of the charge side discharge electrode 13 of the supported insulator 3 or the earth side discharge electrode 24 of the lightning protection insulators 17 is made coil 14 and 25 shapes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightning protection system which, when a lightning surge current flows through a transmission line, quickly discharges it to the ground and suppresses and interrupts the subsequent current that occurs to prevent a ground fault. The present invention relates to an insulator device.

[0002]

2. Description of the Related Art Conventionally, in order to reduce accidents due to lightning, a lightning arrester device has been used in which a series gap is formed between a discharge electrode on the charging insulator side and a grounding discharge electrode on the lightning insulator. A plurality of current limiting elements having non-linear voltage-current characteristics are housed between the grounding side and the voltage applying side of this lightning protection insulator. In the case of this lightning insulator, due to its characteristics, the current limiting element made of zinc oxide discharges the lightning surge current at the time of a lightning stroke to the ground and suppresses and interrupts the subsequent current to prevent a ground fault accident. Further, in this gap type lightning arrester, the current limiting element is destroyed, and even if it should break down due to a lightning stroke exceeding the design, power can be transmitted by reclosing it.

When there is a lightning strike to this lightning protection insulator, in the case of a lightning stroke with a high wave front steepness and a high crest value and a lightning stroke with a high crest value such as multiple lightning, the influence on the element is large, and the lightning protection insulator is destroyed. Or, there was a fear of performance deterioration. For this reason, a lightning protection insulator has been proposed in which a resistor is inserted between the current limiting element and the discharge electrode to reduce the duty of the current limiting element.

[0004]

However, in the above-mentioned prior art, although the resistance can share the responsibility to some extent, in the case of a lightning current having a steep peak 30a such as multiple lightning shown in FIG. Could not be suppressed, and there was a risk of pressure release breakdown or performance degradation. Alternatively, even if a resistor is provided, most of the lightning surge current is absorbed by the current limiting element, and therefore a large-capacity current limiting element having a large capacitance must be used, which leads to an increase in size as a whole. Further, there is a problem that the winding resistance is apt to be deteriorated due to repeated weather changes and needs to be molded, resulting in an increase in cost.

The present invention has been made by paying attention to the problems existing in such a conventional technique, and its purpose is to reduce the responsibility of the element at the time of a lightning stroke, to reduce the size of the current limiting element and An object is to provide a lightning protection insulator device that can reduce costs.

[0006]

In order to achieve the above object, in the present invention, a support insulator suspended in a support arm of a steel tower and a current limiting element having a non-linear voltage-current characteristic are built in, Having a lightning arrester suspended on the support arm,
A discharge side discharge electrode is fixed to the charge side of the supporting insulator, a ground side discharge electrode is connected to the charge side of the lightning arrestor, and the ground side discharge electrode and the charge side discharge electrode are connected. In the lightning arrester device in which a series gap is formed in, the gist is that at least one of the charge-side discharge electrode of the support insulator and the ground-side discharge electrode of the lightning insulator is coiled.

[0007]

With the above structure, the lightning surge current generated at the time of a lightning strike is flashed over from the discharge electrode on the charging side of the supporting insulator to the discharge electrode on the ground side via the coil. In addition, the lightning surge current flows to the discharge electrode on the ground side,
It is discharged from the tower to the ground via the support arm. At this time,
The self-inductance of the coil can absorb a steep surge current and reduce the duty on the current limiting element.

[0008]

An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG.
Is fixed to the tip of the support arm 2 of the steel tower, and the suspension insulator string 3 is supported via the U-clevis link 4 and the upper horn mounting bracket 5 so as to be swingable in the line direction and the orthogonal direction. The suspension insulator series 3 is configured by connecting a plurality of suspension insulators 6 in series, and the suspension insulator series 3 constitutes a support insulator. The electric wire clamp 8 for gripping the power transmission line 7 is connected to the lower horn mounting metal fitting 9 at the lower end of the suspension insulator string 3 by a connecting link 10.
Supported through. The arc horns 11 and 12 for suppressing the damage of the surface flashover of the suspension insulator series 3 are the suspension insulator series 3.
Are attached to the lower and upper horn mounting brackets 9 and 5, and a protective gap G1 is formed between them. Further, the discharge electrode 13 on the charging side is fixed to the horn mounting member 9 separately from the arc horn 11.

The discharge electrode 13 on the charging side is fixed to the lower horn mounting member 9. The lightning surge absorbing coil 14 is formed on the tip side of the discharge electrode 13. The mounting adapter 15 is fixed to the tip of the support arm 2 by a bolt 16, and the lightning protection insulator 1 is attached to the lower surface of the tip of the adapter 15.
7 is suspended and fixed with an electrode fitting 20 on the ground side. The mounting adapter 15 is formed by bending upward so that a series gap G2 described later maintains a predetermined gap length.

The lightning protection insulator 17 is provided with an insulating cylinder (not shown) formed in a cylindrical shape from a tension-resistant material such as FRP, and the current limiting element 18 is housed in series inside the insulating cylinder. Cap-shaped electrode fittings 19 and 20 on the charging side and the grounding side are fitted to both ends of the insulating cylinder, and a rubber mold 21 is integrally formed on the outer circumference of the insulating cylinder. Note that the arc rings 22 and 23 reduce the damage at the time of the surface flashing of the rubber mold 21, in order to reduce the damage.
It is attached to 0 respectively.

The discharge electrode 24 on the ground side is fixed to the electrode metal fitting 19 on the charging side located at the lower end of the lightning protection insulator 17, and a coil 25 for absorbing lightning surge is formed on the discharge electrode 24 over its entire length. Has been done. The ground-side lightning surge absorbing coil 25 is disposed so as to face the power-supply-side coil 14, and a series gap G2 is formed between them. The number of turns of the coil 14 of this embodiment is 10, the coil diameter is about 20 cm, and the impedance in this state is about 3 to 4 ohms.

Next, the operation of the embodiment configured as described above will be described. Now, as shown in FIG. 3, when a lightning surge current 26 flows through the power transmission line 7 due to multiple lightning strikes,
This current is flashed over from the wire clamp 8 and the lightning surge absorbing coil 14 of the charging side discharge electrode 13 to the coil 25 of the ground side discharge electrode 24 through the series gap G2. Further, it flows from the electrode fitting 19 to the current limiting element 18, then flows to the support arm 2 via the electrode fitting 20 on the ground side and the mounting adapter 15, and is discharged from the tower body (not shown) to the ground.

At this time, since the waveform of the lightning surge current is multiple lightning, it has many steep peaks 26a. If the current changes like this peak 26a, the coil 1
The magnetic flux passing through the inside of the coils 4, 25 also changes, and electromotive force is generated in the coils 14, 25 by the inductance. In the equivalent circuit shown in FIG. 2, the voltages V _L1 and V _L2 induced in the coils 14 and 25 are represented by the following equations, where L is the inductance of the coils 14 and 25, respectively. When the series gap G2 is flashed over, the gap G2 is short-circuited.

[0014]

[Equation 1] V _L1 = V _L2 = L (dI / dt) The electromotive forces V _L1 and V _L2 are larger as the peak 26 a is steeper, and the electromotive force V _L1 and V _L2 are directed toward the direction of the change of the current 27 a. Acts to suppress. Therefore,
The discharge current 27 passing through the coils 14 and 25 is changed to a flat current having almost no peak 27a as shown in FIG.

As described above, in the lightning arrester device of this embodiment, the peak 2 is caused by the coils 14 and 25 during a lightning stroke.
7a can be absorbed, and the duty to the current limiting element 18 can be reduced. Therefore, it is possible to reduce the size of the entire insulator device with less pressure breakdown or performance deterioration. Also, unlike resistance, there is no risk of deterioration due to the environment.

The present invention is not limited to the configuration of the above embodiment, and may be applied to, for example, a suspended type lightning arrester device as well as a long type lightning arrester device. Further, the coil may be formed only on the charging side discharge electrode, or may be formed only on the ground side discharge electrode, and may be arbitrarily modified and embodied without departing from the spirit of the present invention. .

[0017]

According to the present invention, since the coil is formed in the arc horn, a steep surge current such as multiple lightning can be absorbed, and the withstanding capacity of the current limiting element can be suppressed and the size and cost can be reduced. Play.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a lightning protection insulator device embodying the present invention.

FIG. 2 is an equivalent circuit diagram showing a state of the lightning arrester device during a lightning stroke.

FIG. 3 is a characteristic diagram showing a lightning current waveform of multiple lightning.

FIG. 4 is a characteristic diagram showing a discharge current waveform of multiple lightning.

FIG. 5 is a characteristic diagram showing a discharge current waveform of multiple lightning in the conventional lightning arrester device.

[Explanation of symbols]

2 support arms, 3 suspension insulators constituting a support insulator,
13 charge side discharge electrode, 14 charge side coil, 17 lightning protection insulator, 18 current limiting element, 24 ground side discharge electrode, 25
Ground side coil.

Claims (1)

[Claims] 1. A support insulator suspended from a support arm of a steel tower, and a lightning protection insulator having a built-in current limiting element having a non-linear voltage-current characteristic and suspended from the support arm. The discharge side discharge electrode is fixed to the charge side of the support insulator, the ground side discharge electrode is connected to the charge side of the lightning arrestor, and the ground side discharge electrode and the charge side discharge electrode are provided. A lightning arrester device in which a series gap is formed, wherein at least one of a charge-side discharge electrode of the support insulator or a ground-side discharge electrode of the lightning insulator is formed into a coil shape.