JP2509741B2 - Lightning arrester device for power lines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is capable of promptly discharging a lightning surge current to the ground when a lightning surge current enters a transmission line, and generating a continuous current of a commercial frequency generated thereafter. The present invention relates to a lightning arrester device for a transmission line, which can prevent and prevent a ground fault by blocking and blocking.

[Conventional technology]

Conventionally, when configuring a lightning protection insulator for a power transmission line, a lightning protection insulator formed separately from an insulating support insulator that supports a power transmission line is supported on a support arm of a steel tower via a mounting adapter, and a section of the insulation support insulator is provided. There is a method in which discharge electrodes are mounted between the electric side suspension metal fittings and the tip of the lightning protection insulator to form an air discharge gap between the discharge electrodes. If this separate method is applied to an existing steel tower, it is difficult to secure an insulation clearance between the lightning protection insulator and the steel tower, and problems such as reinforcement of the support arm occur.

In order to solve this problem, there has been proposed a dual-purpose lightning protection insulator device which is devised so that it can be easily applied to an existing steel tower by giving a lightning protection function to a conventional insulator having electric insulation and wire load supporting functions. As this lightning protection insulator device,
There is something like the one shown in the figure. This device suspends a suspension type lightning arrester insulator 5 in which a large number of suspension type lightning arresters 4 incorporating a current limiting element are connected in series to a support arm 1 via a ground side suspension metal unit 3, and When the current limiting element of each lightning protection insulator 4 is connected in series by a lead wire and a lightning surge current enters the power transmission line 15, the current is discharged to the supporting arm 1 by the current limiting element and the subsequent current flow thereafter. The current is controlled by the current limiting element to prevent a ground fault.

[Problems to be Solved by the Invention]

However, in the above-mentioned lightning protection insulator device, when operated by an excessive lightning surge that exceeds the design, the current limiting element may be damaged and become an electrically defective insulation body, resulting in a permanent ground fault. There was a drawback that the operation could not be restarted when the system was restored from this ground fault accident.

On the other hand, there is a lightning protection device shown in FIG. This device can secure a sufficient horizontal horizontal insulation clearance between the suspension type lightning arrestor series 5 and the tower body, but the connection length L for connecting the lightning arrester series 5 supporting the transmission line 15 and the normal suspension insulator series 11 Is very long, about 20-40%, compared with the case where the conventional normal suspension suspension is connected, and as a result, the vertical insulation clearance between the transmission line 15 and the support arm 1 located in the lower phase is increased. C becomes small, and the clearance with the tower main body when the electric wire sways becomes small, and when applied to the existing power transmission line support insulator device, it will be difficult to achieve insulation coordination with the grounding object and other phases. The problem occurs.

In order to solve the above problem, it has been proposed to provide a discharge gap between each of the current limiting elements of each suspension type lightning protection insulator 4, but the total dielectric strength of the discharge gaps cannot be so large. Therefore, there is a problem that the number of suspension type lightning arrestor 4 must be increased to further increase the length of the lightning arrestor insulator.

The object of the present invention is to deteriorate the current limiting element of the lightning protection insulator,
When the current limiting element becomes conductive due to an unexpected lightning strike, it is possible to prevent a permanent ground fault that hinders the system from returning and shorten the vertical length of the lightning protection insulator and the insulator. Another object of the present invention is to provide a transmission line lightning arrester device that can be easily applied to an existing transmission line support insulator device.

[Means for solving the problem]

In order to achieve the above-mentioned object, the present invention connects and suspends a lightning arrester provided with a current limiting element having a non-linear voltage-current characteristic to a steel tower through a grounding side hanging metal fitting unit, and the lower end of the lightning insulator is connected. The grounding side ends of the pair of left and right insulators oriented in the line direction are connected to the section through the first connecting metal unit, and the second connecting metal unit and the second connecting metal unit are respectively connected to the power applying side ends of the two insulators. The power transmission line is connected through the wire retention fittings, and the wire retention fittings are connected by jumper wires,
Further, a means for providing a ground side discharge electrode on the side of the first connecting fitting unit and a charging side discharge electrode on the side of the second connecting fitting unit to form a predetermined air discharge gap between both discharge electrodes are provided. I am taking it.

[Work]

In this invention, when a lightning surge current enters the transmission line, the surge current flashes from the discharge electrode of the lightning side to the discharge electrode of the lightning side of the lightning protection insulator, then flows into the current limiting element of the lightning protection insulator, and further flows into the steel tower. Be discharged to the ground. afterwards,
By restoring the resistance value of the air discharge gap and the current limiting element of the lightning arrester, the follow current that follows the surge current is suppressed and cut off, so that a ground fault is prevented.

In addition, against a lightning surge current exceeding the design, the current limiting element of the lightning arrestor is damaged and becomes conductive, resulting in a ground fault due to a follow current.However, due to the operation of the circuit breaker in the system, the above-mentioned air discharge Since the gap is restored to insulation, it does not prevent restarting the system due to reclosing the circuit breaker.

Further, according to the present invention, since a pair of left and right insulators are connected to the lower end portion of the lightning arrester via the first connecting unit, the vertical direction of the entire insulator insulator is compared to the case where the lightning insulator and the insulator are vertically connected and suspended. Since the length in the direction is shortened, the insulation clearance between the jumper wire and the steel tower support arm located in the lower phase can be secured, and the application to the existing transmission line support insulator device becomes easy.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

As shown in FIG. 1, a suspension type lightning arrestor in which suspension type lightning arresters 4 are connected in series to a support arm 1 of a steel tower via a ground side hanging metal fitting unit 3 having a ground side arc horn 2 The lightning protection insulator 5 is connected and suspended. At the lower end of the suspension type lightning arrester series 5, a charging side arc horn 6 is provided.
And a connecting yoke 8 is connected to a lower end portion of the hanging metal fitting unit 7.
Further, the grounding side ends of a suspension insulator series 11 as an insulator formed by connecting ordinary suspension insulators 10 in series through grounding side connecting metal fitting units 9 are connected to the left and right ends of the connecting yoke 8, respectively. There is.

In this embodiment, the power-supply-side hanging fitting unit 7, the connecting yoke 8 and the ground-side connecting fitting unit 9 constitute a first connecting fitting unit J. Further, an electric power transmission line 15 is connected and gripped at the end of the suspension insulator string 11 on the side of the voltage applied via a second connecting metal fitting unit 13 having an arc horn 12 on the electric power applying side and a wire retaining metal fitting 14. In addition, the both wire retention fittings 14
Both ends of the jumper wire 6 are connected between them. next,
The structure of the suspension type lightning arrester 4 will be described with reference to FIG.

A cap metal fitting 22 is fitted and fixed to the head of the insulator body 21 by cement, and a pin metal fitting 23 is fitted and fixed to the inside of the head by cement. Inside the plurality of mounting cylinders 21a formed integrally with the cap portion of the insulator main body 21, for example, a current limiting element 24 mainly made of zinc oxide and having a voltage-current characteristic made of a non-linear material is housed, It is fitted and fixed by an upper cap electrode 25 and a lower cap electrode 26 via an electrode plate or a biasing spring (not shown).

If the current limiting element 24 is damaged by a lightning surge current exceeding the design and becomes conductive by a ground fault current after that, the arc main body 21 is guided by an arc toward the outside. The arc deflection plate 27 for preventing the destruction of is horizontally fixed, the upper cap electrode 25 and the arc deflection plate 27 are electrically connected by a lead wire 28,
The lower cap electrode 26 and the pin fitting 23 are electrically connected by a lead wire 29.

Next, the operation of the transmission line lightning arrester device configured as described above will be described.

Now, when a lightning surge current enters the power transmission line 15 in FIG. 1, this current flashes over the air discharge gap G from the discharge electrode 12 on the power application side via the wire retention metal fitting 14 and the second connecting metal fitting unit 13. Flow to the discharge electrode 6 on the ground side and then to the suspension type lightning protection insulator 5 via the first connecting fitting unit J. At this time, in the suspension type lightning protection insulator 4 shown in FIG. 2, the surge current of the pin metal fitting 23, the lead wire 29, the lower cap electrode 26, the current limiting element 24, the upper cap electrode 25, the lead wire 28 and the cap metal fitting 22 is increased. It flows in order, then flows to the suspension type lightning protection insulator 4 located on the upper side one by one, further flows from the grounding side hanging metal fitting unit 3 to the support arm 1 of the steel tower, and is discharged to the ground.

On the other hand, the follow-up current following the lightning surge current is suppressed and interrupted by restoring the resistance value of the air discharge gap G and the current limiting element 24 of each suspension type lightning arrestor 4, thereby preventing a ground fault.

In the embodiment of the present invention, the normal suspension insulator series 1 is arranged at the lower end of the suspension type lightning protection insulator series 5 so as to be directed to the left and right sides.
Since 1 and 11 are connected, compared with the case where the suspension type lightning arrestor series 5 and the normal suspension insulator series 11 are connected in series in the vertical direction,
It is possible to shorten the distance from the lower end of the suspension type lightning arrester string 5 to the jumper wire 16, and as a result, the jumper wire 16
It is possible to secure a sufficient insulation clearance between the lower-phase support arm 1 and the lower-phase support arm 1, and it is possible to easily apply it to an existing transmission line support insulator device.

The present invention is not limited to the above embodiment, and for example, as shown in FIG. 3, the jumper wire 16 may be arranged in the horizontal direction opposite to the support arm 1 of the suspension insulator series 11, 11. it can. In this case, jumper wire 16
It is possible to further increase the insulation clearance between the support arm 1 and the support arm 1 located in the lower phase, which is advantageous in application to an existing steel tower.

〔The invention's effect〕

As described above in detail, the present invention can be easily applied to the existing transmission line support insulator device by shortening the vertical lengths of the lightning protection insulator and the insulator, and at the There is an effect that a permanent ground fault accident can be prevented when the current limiting element of the lightning protection insulator is conducted by the flowing current.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a transmission line lightning arrester device embodying the present invention, FIG. 2 is a semi-longitudinal sectional view of a suspension type lightning arrester, and FIG. 3 shows another example of the present invention. Plan views, FIG. 4 and FIG. 5 are front views showing a conventional example of a suspension type lightning arrester device. 1 ... Support arm, 3 ... Grounding side hanging bracket unit, 4
...... Suspension type lightning arrester, 5 ...... Suspension type lightning insulator series as lightning arrester, 6 ...... Ground side discharge electrode, 8 ...... Connection yoke,
10: Suspended insulator, 11: Suspended insulator series as an insulator
13 …… Second connection fitting unit, 14 …… Wire retention fitting, 16
…… Jumper wire, 21 …… Insulator body, 24 …… Current limiting element,
25,26 …… Cap electrode, G …… Air gap, J ……
First connecting bracket unit.

Claims (1)

(57) [Claims] 1. A suspension fitting unit (3) on the ground side of a steel tower
A lightning arrester (5) provided with a current limiting element (24) having a non-linear voltage-current characteristic is connected and hung through the
The ground side ends of the pair of left and right insulators (11, 11) oriented in the line direction are connected to the lower end of the first connecting metal fitting unit (J), and both insulators (11, 11) are connected. The power transmission line (15) is connected to the power-applying side end of each of the power transmission side metal fittings (14) via the second connecting metal fitting unit (13) and the electric wire retaining metal fitting (14), respectively, and the jumper wire ( 16), the grounding side discharge electrode (6) is provided on the side of the first connecting fitting unit (J), and the charging side discharge electrode (12) is provided on the side of the second connecting fitting unit (13). A lightning arrester device for a transmission line, characterized in that a predetermined air discharge gap (G) is formed between both discharge electrodes (6, 12).