JPH0326887B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lightning arrester device for an overhead power transmission line. More specifically, the present invention relates to a lightning arrester device for an overhead power transmission line that has an insulation recovery function and can retransmit power even if a zinc oxide element built into the lightning arrester fails.

[Conventional technology]

Conventionally, the zinc oxide element built into the lightning insulator of the lightning insulator installed between the steel tower and the overhead power transmission line, which has non-linear voltage-current characteristics, has deteriorated and is struck by lightning, or the zinc oxide element becomes normal. However, if the element is damaged by a large-scale lightning strike, the zinc oxide element becomes conductive due to the follow-on current based on the operating voltage following the lightning surge. As a result, current flows from the overhead power transmission line to the tower via the lightning arrester device, causing a ground fault, which is then interrupted by a circuit breaker at the substation. However, even after the circuit breaker was activated, the insulation of the lightning arrester had not recovered.
Retransmission becomes impossible.

A lightning insulator device for overhead power transmission lines for preventing the occurrence of such abnormal conditions is disclosed in Japanese Patent Laid-Open No. 138202/1983. In this lightning arrester device for an overhead power transmission line, a power transmission line is suspended from a support arm of a suspension tower by a suspension insulator, and a lightning arrester is suspended from the support arm at a predetermined distance from the suspension insulator. A disconnection mechanism that is ruptured by a faulty ground fault current is provided at the lower part of the lightning arrester, and the lower end of the suspension insulator and the lightning arrester are connected via this disconnection mechanism. That is, the lightning arrester is arranged in a substantially V-shape so as to be inclined toward the suspension insulator with respect to the suspension insulator suspended from the support arm. When the zinc oxide element built into the lightning protection insulator is healthy, it quickly discharges against lightning surge current, and the resistance value is restored due to the nonlinear resistance characteristics of the zinc oxide element against follow-on current. Power can be retransmitted. Furthermore, when the zinc oxide element deteriorates or is damaged and faulty ground fault current flows, the disconnection mechanism is activated to release the connection between the lower end of the suspension insulator and the lightning arrester, and remove the inclined lightning arrester. It is configured to rotate vertically around its upper hanging point due to gravity. Thereby, a predetermined insulation clearance is secured between the overhead power transmission line and the lightning arrester, and power can be retransmitted.

(Problems to solve the problem) However, in this conventional lightning arrester device, for example, for 500KV, the suspended lightning arrester weighs about 1 ton, so it is difficult to handle the shock and vibration when disconnected. There was a strength problem in that the steel tower side had to be reinforced in order to endure.

In addition, since the lightning arrester after being separated is suspended from the support arm with its lower end free, the lightning arrester may swing sideways due to strong winds, etc.
In this case, there was a problem that the required insulation clearance between the power transmission line and the lightning arrester could not be secured.

In other words, in order to install this lightning arrester device on an existing steel tower, it is necessary to change the specifications of the tower, such as reinforcing the tower or lengthening the support arm to ensure insulation clearance. It was difficult to apply lightning arrester devices to steel towers.

The purpose of the present invention is to enable power to be retransmitted even if the zinc oxide element built into the lightning arrester fails, and to support the existing power transmission line even if lightning surge current enters from any direction on the power transmission line. To provide a lightning arrester device that can reliably prevent lightning surge current from being discharged directly from a supporting insulator device to a steel tower.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention connects in series an insulating support insulator and a lightning arrester insulating a zinc oxide element with non-linear voltage-current characteristics,
A conductor that is not disconnected by lightning surge current but is disconnected by follow-on current is installed between both ends of the support insulator, and the support insulator and lightning arrester insulator connected in series are connected to a steel tower that supports an overhead power transmission line, and to the overhead insulator. A short-circuit conductor is installed between the tower and a position spaced apart in the track direction when viewed from the plane of the power transmission line via a connecting fitting, and a short-circuit conductor capable of short-circuiting the overhead power transmission line and the lightning arrester is connected to the overhead power transmission line and the connecting line. It is constructed between the steel tower and the end of the steel tower.

[Effect]

When a lightning surge current flows through a power transmission line, it is discharged from the steel tower to the ground through the conductors attached to both ends of the insulating support insulator and the zinc oxide element built into the lightning arrester. At this time, the lightning surge current is discharged due to the nonlinear resistance characteristics of the zinc oxide element, and after discharge, the resistance value under the zinc oxide element is restored, so that follow-on current is suppressed and ground faults are prevented.

Further, when the zinc oxide element deteriorates or is damaged by an unexpected large-scale lightning strike, the zinc oxide element becomes conductive and a follow-on current flows. This follow-on flow causes the conductor attached to the support insulator to break off. For this reason,
After that, the necessary insulation clearance is secured by the support insulator, and power can be transmitted again.

On the other hand, even if the conductor is disconnected, the lightning arrester device is not mechanically disconnected and remains supported overhead between the tower and the power transmission. Therefore, there is no need to reinforce the steel tower.

In this invention, since the insulating support insulator and the lightning arrester are connected in series, the length of the connection is longer than in the case of only the lightning arrester, but the support insulator and the lightning arrester are separated from the tower when viewed from the top. Since it is installed via a connecting line between the overhead power transmission line at the location and the steel tower, it can be installed on an existing steel tower without changing its specifications.

Furthermore, since the present invention is provided with a short-circuit conductor, the lightning surge current that has entered from the power transmission line on the opposite side of the connection line with respect to the short-circuit conductor can be quickly guided to the lightning arrester side via the short-circuit conductor. Even if the connection line is long, it is possible to reliably prevent lightning surge current from flowing into the support insulator device that supports the power transmission line.

〔Example〕

Hereinafter, an embodiment embodying the present invention will be described based on the drawings. In the drawings, 1 is a steel tower, 2 is a tension-resistant insulator device hung on a support arm 3 of the steel tower, and 4 is the tension-resistant insulator device 2. Overhead power line latched to, 5
is the jumper wire. Reference numeral 6 denotes a lightning arrester unit installed between the steel tower 1 and a connecting line 7 connected to the overhead power transmission line 4.

To explain the structure of the lightning arrester unit 6 with reference to FIG. 4, an insulator 9 is connected to the steel tower 1 via a connecting fitting 8.
One end of a suspension insulator chain 11 is connected to the insulator 9 via a mounting bracket 10 as a support insulator which has an insulation function in the event of an abnormality.
Further, lightning arrester insulators 13 and 13' are connected in series to the other end of the suspension insulator chain 11 via a fitting 12. This lightning arrester 13 includes a cylindrical insulator tube 14, a zinc oxide element 15 having a lightning protection function housed inside the insulator tube 14, end fittings 16 fitted and fixed to both ends of the insulator tube 14, and further A connecting fitting 17 for connecting the zinc oxide element 15 and the end fitting 16
It is composed of.

Further, a lightning arrester 13' similar to the lightning arrester 13 is connected to the lightning arrester 13 via a connecting fitting 18, and a connecting fitting 19 is connected to the lightning arrester 13'.
The connecting line 7 is connected via the connecting line 7.

On the other hand, the mounting brackets 10 and 12 have rupture mechanisms 20 and 2 that do not operate due to lightning surge current but respond to follow-on current.
1 is attached, and a bypass conductor 22 is installed in parallel between the upper ends of both the breaking mechanisms 20 and 21. The rupture mechanisms 20 and 21 are configured, for example, by using a trailing current as a trigger to ignite gunpowder, explode and destroy the container of the rupturing mechanism, and scatter the bypass conductor 22. Breaking mechanism 20, 2
1 and the bypass conductor 22 may be used.

Arching horns 23 and 24 are attached to the mounting fittings 10 and 12, and the breaking mechanisms 20 and 21
When the suspension insulator chain 11 is operated and both ends of the suspension insulator chain 11 are connected by an arc, it is immediately moved away from the suspension insulator chain 11 to prevent damage. End fittings 1 provided at both ends of the lightning arrester 13, 13'
6, 16' have arching horns 25, 26, 2
5' and 26' are installed, and lightning arresters 13 and 13' are installed.
If the surface of the lightning arrester is abnormally contaminated or flashed due to a large-scale lightning strike, the generated arc is immediately moved away from the lightning arrester to prevent damage.

Shield rings 27 and 28 are attached to the mounting bracket 12 and the end bracket 16, which reduce the electric field between the right end of the suspension insulator chain 11 and the ground side of the lightning arrester 13' and divide the voltage of the zinc oxide element 15'. I'm trying to smooth it out.

Next, the mounting bracket 19 and the mounting bracket 19
The expandable and contractible shorting conductor 32 installed between the terminal fitting 31 attached to the overhead power transmission line 4 in a corresponding manner will be explained with reference to FIG.

The shorting conductor 32 is composed of an elongated conductor 33 and an expansion/contraction mechanism 35 attached to both ends of the conductor 33 via compression terminals 34. or,
The expansion/contraction mechanism section 35 has a pin 36 attached to the compression terminal 34.
A connecting fitting 37 rotatably connected via the
A connecting fitting 38 connected to the mounting fitting 19 and a coil spring 39 connecting between both connecting fittings 37 and 38.
, and a flexible conductor 40 connected to both the connecting fittings 37 and 38 with a margin. In this embodiment, for convenience of explanation, the suspension insulator chain 11, lightning arrester insulators 13, 13', etc. are collectively referred to as a lightning arrester unit 6.

Next, the construction work of the lightning arrester unit 6 and the short circuit conductor 32 constructed as described above will be explained.

First, as shown in FIGS. 2 and 3, at a predetermined position of the steel tower 1, that is, corner A of the four corners A to D, the tension insulator device 2 is suspended from the support arm 3 at a point P.
A connecting fitting 8 is attached to a position P2 higher than P1, and an insulator 9 is attached to the fitting 8.

Next, a retaining metal fitting 30 is attached to a predetermined position P3 of the right overhead power transmission line 4, and the connecting wire 7 is hooked to the metal fitting 30. At this time, the lightning arrester unit 6 is arranged so that it has a component in the same direction as the installation direction Y of the overhead power transmission line 4, as shown in FIG. 3, and in the horizontal direction X and vertical direction Z, as shown in FIGS. Build it so that it has a component.

Further, a short-circuit conductor 32 is installed between the mounting fitting 19 and the retaining fitting 31 attached to the power transmission line 4.

On the other hand, as shown in FIG. 3, a lightning arrester unit 6 and a short-circuit conductor 32 are also installed between the corner C of the tower 1 and the overhead power transmission line 4 on the left side in the same manner as in the above-mentioned overhead work.

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

Now, in FIG. 3, when the lightning surge current generated in the power transmission line 4 enters from the direction in which the lightning arrester unit 6 and the connecting line 7 extend, this current is led to the lightning arrester unit 6 through the connecting line 7. And the zinc oxide element 1 built into the lightning arrester 13', 13
5', 15, the mounting bracket 12, the breaking mechanism 21,
The electricity is discharged from the steel tower 1 to the ground via the conductor 22, the breaking mechanism 20, and the mounting bracket 10. At this time, the lightning surge current is discharged due to the non-linear resistance characteristics of the zinc oxide elements 15' and 15, and the resistance value of the zinc oxide elements is restored after discharge, so the rupture mechanisms 20 and 21 do not operate. , follow-on current is suppressed and ground faults are prevented.

Abnormal discharge occurred due to deterioration of the zinc oxide elements 15, 15' built into the lightning arrester 13, 13' or an unexpected large-scale lightning strike, and the side conductor 22 electrically short-circuited the suspension insulator chain 11. When a follow-on current flows, the breaking mechanisms 20 and 21 operate to cut off the side conductor 22 and remove the main body of ground insulation from the lightning arrester 1.
Move from 3,13' to suspension insulator 11. Both ends of the suspended insulator chain 11 are connected by an arc by the operation of the breaking mechanisms 20 and 21, but this arc immediately moves to the arcing horns 23 and 24. Since this condition is a ground fault phenomenon, the substation function senses this and the circuit breaker opens the line. Therefore, the arc is extinguished, and after a certain period of time it is turned on again to continue power transmission. At this time, the suspension insulator chain 11 is broken by the breaking mechanisms 20, 2.
1 operates, disconnecting the bypass conductor 22 and restoring the insulation, so power can be transmitted again.

In FIG. 3, the lightning arrester unit 6 and the connection line 7
If a lightning surge current enters from the direction opposite to the extending direction (S side), if there is no short circuit conductor 32, after reaching the tension insulator device 2, the connecting wire 7 will be connected as shown by the two-dot chain line in the same figure. It will reach the lightning protection unit 6 via the lightning protection unit 6. Furthermore, since the propagation speed of lightning potential is approximately the speed of light, the distance L from the tension insulator device 2 to the lightning arrester unit 6 by bypassing the retaining metal fitting 30 is determined by keeping the potential of the tension insulator device 2 below a certain level. This is an extremely important factor and must be short-circuited as much as possible when trying to suppress this. In the embodiment, a short circuit conductor 32 is provided between the mounting bracket 19 and the overhead power transmission line 4.
Since the lightning surge current that enters from the opposite side to the direction in which the lightning protection unit 6 is installed, the
2 to the lightning arrester unit 6, and suppresses the potential of the tension insulator device 2 below a predetermined level. As a result, even if the direction of infiltration of lightning surge current is opposite to the extending direction of the lightning arrester unit 6 (S side),
The operational reliability of the lightning arrester unit 6 is improved.

Further, in this embodiment, since the shorting conductor 32 is provided with the expansion/contraction mechanism 35, it is possible to absorb variations in the spacing caused by mechanical vibrations between the overhead power transmission line 4 and the lightning arrester unit 6.

In this embodiment, the lightning arrester unit 6 is installed via the connecting wire 7 between the steel tower 1 and the overhead power transmission line 4 located a predetermined distance away from the tower in the direction of the line. can be constructed without changing the specifications of the steel tower 1.

Furthermore, in the above embodiment, as shown in FIG. 3, between the steel tower 1 and the left overhead power transmission line 4,
A lightning arrester unit 6 was installed on the power supply side (upper side in the figure) across the line, and a lightning arrester unit 6 was installed on the load side (lower side in the figure) between the tower 1 and the overhead power transmission line 4 on the right side. Even if horizontal vibration of the overhead power transmission line 4 occurs due to this, sufficient insulation clearance between the lines can be ensured.

Note that the present invention can also be embodied in the following embodiments.

In the above embodiments, the present invention is embodied in a tension steel tower, but it may also be embodied in a suspended steel tower or a V-hanging steel tower.
Further, although the lightning arrester is attached to the tower at the corner of the tower, it goes without saying that the support arm 3 may be used as necessary since there are various structures of the tower.

〔Effect of the invention〕

As described in detail above, the present invention has the advantage that a lightning arrester unit with a long insulator length can be easily installed on a steel tower. In addition, when lightning surge current enters from the direction opposite to the direction in which the lightning protection insulator extends, the potential of the support insulator device of the overhead power transmission line is suppressed to a certain value or less, and the lightning surge current is discharged directly from the support insulator device to the steel tower. This has the effect of reliably preventing this.

[Brief explanation of the drawing]

FIG. 1 is a partially omitted perspective view showing an embodiment of the lightning arrester device for overhead power transmission lines of the present invention, FIG. 2 is a partially enlarged front view, and FIG. 3 is an enlarged plan view.
FIG. 4 is an enlarged front view of the lightning arrester unit, and FIG. 5 is an enlarged plan view of the vicinity of the short-circuit conductor. DESCRIPTION OF SYMBOLS 1... Steel tower, 2... Tensile insulator device, 3... Support arm, 4... Overhead transmission line, 6... Lightning arrester unit, 7... Connecting line, 11... Suspension insulator chain as support insulator, 13 ,13'... Lightning arrester, 15,1
5′...Zinc oxide element, 20, 21... Fracture mechanism,
22... Bypass conductor, 32... Short circuit conductor, P3...
Position, Y...direction of overhead power transmission line, X...horizontal direction, Z...vertical direction.

Claims (1)

[Claims] 1 An insulating support insulator 11 and lightning arrester insulators 13 and 13' containing a built-in zinc oxide element 15 with non-linear voltage-current characteristics are connected in series, and the support insulator 1
A conductor 22 is installed between both ends of the support insulator 11 and lightning arrester insulators 13, 13' which are connected in series.
is installed via a connecting wire 7 between the steel tower 1 supporting the overhead power transmission line 4 and a position P3 spaced apart from the tower 1 when viewed from the plane of the overhead power transmission line 4, and A lightning arrester device for an overhead power transmission line, characterized in that a shorting conductor 32 capable of short-circuiting the lightning arrester 13 and 13' is installed between the overhead power transmission line 4 and the tower side end of the connecting line 7.