JPH0473823A - Lighting protective insulator device for transmission line - Google Patents

Abstract

PURPOSE:To prevent permanent fault accident beforehand, to shorten the length in a vertical direction by linking a pair of right and left insulators which are directed to a railroad with the lower end of a hung lightning protective insulator. CONSTITUTION:A suspension type lightning protective insulator series 5 as a lightning protective insulator for which a suspension type lightning protective insulator 4 is serially linked with each other, through a ground side hung fitting unit 3, is linked and swung on a supporting arm 1 of an iron tower. A charging side swing fitting unit 7 is linked with the lower end of the suspension type lightning protective insulator series 5, while a suspension insulator series 11 as an insulator for which normal suspension insulator 10 is serially linked with each other in such a way that it is directed to the right and left hand sides through a connection yoke 8 as well as a ground side connection fitting unit 9, is linked with the lower end of the unit 7. The vertical length of the lightning protective insulator 5 and of the insulator 11 is shortened thereby, and thus the device can be applied to a ready-installed transmission line supporting insulator device, and permanent fault accident in case a track current limiting device is electrified due to a dynamic current after a thunder surge current, can thus be prevented beforehand.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is capable of quickly discharging lightning surge current to the ground when it enters a power transmission line, and also suppressing the subsequent commercial frequency follow-on current. The present invention relates to a lightning arrester device for power transmission lines that can suppress and interrupt ground faults to prevent them from occurring.

[Conventional technology]

Conventionally, when configuring a lightning arrester device for a power transmission line, a lightning arrester formed separately from an insulating support insulator that supports the power transmission line is supported on a support arm of a steel tower via a mounting adapter, and the lightning arrester is There is a method in which a discharge electrode is installed between the power side hanging metal fitting and the tip of the lightning arrester, respectively, to form an air discharge gap between the two power electrodes. If this separate system is applied to an existing steel tower, it may be difficult to secure insulation clearance between the lightning arrester and the tower.
Problems such as reinforcing the support arm arise.

In order to solve this problem, a dual-purpose lightning arrester device has been proposed that is designed to be easily applied to existing steel towers by adding a lightning protection function to the conventional insulator that has the functions of electrical insulation and wire load support. As this lightning arrester device, there is one shown in FIG. This device suspends a suspension type lightning arrester chain 5, which is formed by connecting a number of suspended type lightning arrester insulators 4 having built-in current limiting elements in series, from a support arm 1 via a ground side suspension fitting unit 3. The current limiting elements of each lightning arrester 4 are connected in series by lead wires, and when a lightning surge current enters the power transmission line 15, the current is discharged to the support arm 1 by the current limiting element, and the subsequent follow-up current is discharged by the current limiting element. Current is limited and suppressed by a current limiting element to prevent ground faults.

[Problem to be solved by the invention]

However, in the above-mentioned lightning arrester device, if it is activated by the ingress of a lightning surge exceeding the design, the current limiting element may be damaged and become electrically insulated, resulting in a permanent ground fault. There was a drawback in that it was impossible to restart the system when the system was restored after this ground fault accident.

On the other hand, there is a lightning arrester shown in FIG. 5 as a technology that enables restart of operation. Although this device can secure sufficient horizontal insulation clearance between the suspension type lightning arrester chain 5 and the tower main body, the connection length for connecting the lightning arrester chain 5 supporting the power transmission line I5 and the normal suspension insulator chain 11 is required. is about 20 to 40% compared to the case of connecting conventional ordinary suspended insulators.
As a result, the vertical insulation clearance C between the power transmission line 15 and the support arm 1 located at the lower phase becomes smaller, and the clearance with the tower body when the wire sways laterally also becomes smaller. When applied to power transmission line support insulator devices, a problem arises in that it becomes difficult to achieve insulation coordination with grounding objects and other phases.

In order to solve the above problem, it has been proposed to provide discharge gaps between the current limiting elements of each of the suspension type lightning arresters 4, but it was not possible to obtain a large dielectric strength as a sum of the discharge gaps. Therefore, there was a problem in that the number of suspended lightning arresters 4 had to be increased to make the lightning arrester device even longer.

The purpose of this invention is to prevent permanent ground faults that prevent system recovery when the current limiting element of a lightning arrester deteriorates or becomes conductive due to an unexpected lightning strike. To provide a lightning arrester device for a power transmission line, which can be easily applied to an existing power transmission line support insulator device by shortening the vertical length of the lightning arrester and the insulator.

[Means to solve the problem]

In order to achieve the above object, the present invention connects and suspends a lightning arrester equipped with a current limiting element with non-linear voltage-current characteristics from a steel tower via a ground side hanging fitting unit, and the lower end of the lightning arrester is The grounding side ends of a pair of left and right insulators oriented toward the track direction are connected to the section via a first connecting fitting unit, and a second connecting fitting unit and a second connecting fitting unit are respectively connected to the energized side ends of both insulators. The power transmission lines are connected through electric wire holding fittings, the electric wire holding fittings are connected by a jumper wire, and a ground side discharge electrode is provided on the first connecting fitting unit side, and electricity is applied to the second connecting fitting unit side. A method is taken in which side discharge electrodes are provided and a predetermined aerial discharge gap is formed between the two electrodes.

[For production]

In this invention, when a lightning surge current enters a power transmission line, the surge current floods over from the discharge electrode on the energized side to the energized side discharge electrode of the lightning arrester, then flows to the current limiting element of the lightning arrester, and then flows to the steel tower. and is discharged to the ground. After that, the follow-on current following the surge current is suppressed and interrupted by the restoration of the resistance value of the air discharge gap and the current limiting element of the lightning arrester.
Ground fault accidents are prevented.

In addition, when lightning surge current exceeds the design, the current limiting element of the lightning arrester is damaged and becomes conductive, resulting in a ground fault due to follow-on current. Since the gap recovers its insulation, it does not prevent the restart of system operation by re-closing the circuit breaker.

Furthermore, in this invention, since the pair of left and right insulators are connected to the lower end of the lightning arrester through the first connecting unit, the entire insulator chain is The vertical length of the jumper wire is shortened, which makes it possible to secure insulation clearance between the jumper wire and the tower support arm located at the lower phase, making it easy to apply it to an existing power transmission line support insulator device.

〔Example〕

An embodiment embodying this invention is shown in FIGS. 1 and 2 below.
This will be explained based on the diagram.

As shown in FIG. 1, a suspension type lightning arrester 4 is connected in series to a support arm 1 of a steel tower via a ground side hanging bracket unit 3 having a ground side arc horn 2. Lightning arrester series 5 are connected and suspended. A power-side suspension fitting unit 7 equipped with a power-side arc horn 6 is connected to the lower end of the suspended lightning arrester chain 5, and a connecting yoke 8 is connected to the lower end of the hanging metal unit 7. Furthermore, the ground side ends of a suspension insulator chain 11, which is an insulator formed by connecting ordinary suspension insulators 10 in series, are connected to both left and right ends of the connection yoke 8 via a ground side connection fitting unit 9. ing.

In this embodiment, the power-supplying side hanging fitting unit 7, the connecting yoke 8, and the grounding side connecting fitting unit 9 constitute a first connecting fitting unit J. Further, a power transmission line 15 is connected and held at the end of the suspension insulator chain 11 on the power supply side via a second connecting fitting unit 13 having a power supply side arc horn 12 and a wire holding fitting 14 . Further, both ends of a jumper wire 16 are connected between the two electric wire holding fittings 14. Next, the structure of the suspension type lightning arrester 4 will be explained based on FIG. 2.

A cap fitting 22 is fitted and fixed to the head of the insulator body 21 with cement, and a pin fitting 23 is fitted and fixed inside the head with cement. The insulator body 21
A current-limiting element 24 made of a material with non-linear voltage-current characteristics, such as zinc oxide as a main material, is housed inside the plurality of mounting cylinder parts 21a integrally formed in the cylinder part, and an electrode plate (not shown) Alternatively, the upper cap electrode 25 may be
and is fitted and fixed by a lower cap electrode 26.

In case the current limiting element 24 is located on the outer periphery of the cap fitting 22,
If the insulator is damaged by a lightning surge current that exceeds the design and becomes conductive due to a subsequent ground fault current, the arc deflector plate 27 is fixed horizontally to guide the arc outward and prevent the insulator body 21 from being destroyed. The upper cap electrode 25 and the arc deflection plate 27 are electrically connected by a lead wire 28, and the lower cap electrode 26 and the pin fitting 23 are electrically connected by a lead wire 29.

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

Now, in FIG. 1, when a lightning surge current enters the power transmission line 15, this current passes through the wire holding fitting 14 and the second connecting fitting unit 13, and floods over the air discharge gap G from the discharge electrode 12 on the energized side. It flows to the discharge electrode 6 on the ground side, passes through the first connecting fitting unit J, and flows to the suspended type lightning arrester chain 5. At this time, in the suspension type lightning arrester 4 shown in FIG. flow in order, then
It sequentially flows to the suspended lightning arrester 4 located on the upper side, and further,
It flows from the ground side hanging fitting unit 3 to the support arm 1 of the steel tower and is discharged to the ground.

On the other hand, the follow-on current following the lightning surge current is suppressed and interrupted by the air discharge gap G and the restoration of the resistance value of the current limiting element 24 of each suspended lightning arrester 4, thereby preventing a ground fault.

Now, in the embodiment of the present invention, a normal suspension insulator chain 11 is provided at the lower end of the suspension type lightning arrester chain 5 so as to be oriented to both left and right sides.
．． 11 are connected, the distance from the lower end of the suspension type lightning arrester chain 5 to the jumper wire 16 is shorter than when the suspended type lightning arrester chain 5 and the normal suspension type insulator chain 11 are connected in series in the vertical direction. As a result, sufficient insulation clearance between the jumper wire 16 and the lower phase support arm l can be ensured, and it can be easily applied to an existing power transmission line support insulator device.

It should be noted that the present invention is not limited to the above-mentioned embodiment. For example, as shown in FIG. can. In the case of this other example, the insulation clearance between the jumper wire 16 and the support arm I located in the lower phase can be further increased, which is advantageous in application to an existing steel tower.

〔Effect of the invention〕

As described in detail above, the present invention shortens the vertical length of the lightning arrester and the insulator, and can be easily applied to an existing power transmission line support insulator device. This has the effect of preventing a permanent ground fault that would occur if the current-limiting element of the lightning arrester becomes conductive due to the flowing current.

[Brief explanation of the drawing]

Fig. 1 is a front view showing an embodiment of a lightning arrester device for a power transmission line embodying the present invention, Fig. 2 is a half-longitudinal cross-sectional view of a suspended type lightning insulator, and Fig. 3 shows another example of the invention. The plan view, FIGS. 4 and 5 are front views showing a conventional example of a suspension type lightning arrester device. ■... Support arm, 3... Ground side hanging bracket unit, 4... Suspended type lightning arrester, 5... Suspended type lightning arrester series as a lightning arrester, 6... Ground side discharge electrode, 8...
Connection yoke, 10... Suspension insulator, 11... Suspension insulator chain as an insulator, 13... Second connection fitting unit, 14... Electric wire holding fitting, 16... Jumper wire,
2I...Insulator body, 24...Current limiting element, 25.26
... Cap electrode, G ... Air discharge gap, J ...
First connecting fitting unit. Patent applicant Nippon Insulator Co., Ltd. Agent Patent attorney On 1) Hironobu (and 1 other person)

Claims (1)

[Claims] 1. A lightning arrester (5) equipped with a current limiting element (24) with non-linear voltage-current characteristics is connected and suspended from the steel tower via a ground side hanging bracket unit (3), and the lightning arrester (5) is 5), the ground side ends of a pair of left and right insulators (11, 11) oriented in the track direction are connected to the lower end of the insulators (11, 11) via the first connecting fitting unit (J). A second connecting fitting unit (13) is installed at the end of the power supply side of 11).
and a power transmission line (15) via a wire clamping fitting (14), connecting the electric wire clamping fittings (14, 14) with a jumper wire (16), and further connecting the first connecting fitting unit (J). A grounding side discharge electrode (6) is provided on the side, a energizing side discharge electrode (12) is provided on the second connecting fitting unit (13) side, and a predetermined aerial discharge gap is created between both the discharge electrodes (6, 12). A lightning arrester device for a power transmission line, characterized by forming (G).