JPH05314843A - Suspension type lightning protection insulator device for transmission line - Google Patents

Abstract

PURPOSE:To prevent permanent ground fault after an accident, by keeping gaps among individual arc horns even when a resistance element is made uncontinued due to dynamic current electric current with thunderbolt surge current intruded in a condition where the resistant element is deteriorated by the long time use of a lightning protection insulator. CONSTITUTION:Plural suspension type lightning protection insulators 5 are linkedly suspended in series with a supporting arm 1 of an iron tower, and also plural suspension insulators 6 are linkedly suspended in series to the lowermost end lightning protection insulator 5, to support a transmission line L with the lower end parts of the insulators 6. Intermediate arc horns, doubling as arc guids 27 and an earthing side discharge electrode, are fitted to a cap fitting 22 of the uppermost part suspension insulator 6, and also a lower part arc horn 12, doubling as a charging side discharge electrode, is supported with the lower part of the lowermost end suspension insulator 6, to form a given aerial discharge gap G between both the horns 30 and 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension type lightning arrester device for power transmission lines.

[0002]

2. Description of the Related Art As a conventional suspension type lightning arrester device for a transmission line, the applicant of the present invention has proposed a device disclosed in Japanese Patent Laid-Open No. 62423/1993. This lightning arrester device suspends multiple suspension type lightning insulators connected in series to a support arm of a steel tower, and suspends multiple lightning insulators that do not have a lightning protection function in series at the lower end of the lightning insulator. However, the power transmission line is supported on the suspension insulator at the lowermost end through suspension metal fittings. Further, the grounding-side and charging-side discharge electrodes are supported by the lightning arrester at the lowermost end and the lower suspension metal fitting so that a predetermined air discharge gap is formed between both discharge electrodes. Further, the cap portion of the lightning protection insulator accommodates a resistance element having a non-linear voltage-current characteristic, and the element is sealed by upper and lower cap electrodes. When the element has no lightning protection function due to deterioration and is continually broken by a follow-up current based on the operating voltage following the lightning surge current, the arc is guided to the outside of the lightning protection insulator to form the lightning protection insulator surface. An arc guide is attached to prevent burnout of the.

In the lightning arrester device thus constructed, even if the resistance element is deteriorated or the resistance element becomes conductive due to an unexpected lightning strike, the lightning protection insulator at the lowermost end and the lower suspension metal fitting are connected to each other. Since there is an air discharge gap between the two, it is possible to prevent a permanent ground fault.

[0004]

However, in the above-mentioned conventional lightning arrester device, since the discharge electrode is supported by the lower cap electrode of the lightning arrester located at the lowermost end, the cap is prevented when the resistance element becomes conductive. When the electrode separates from the insulator body, the discharge electrode also falls in synchronism therewith, so that the horn gap between the lightning arrestors and the horn gap between the suspended insulators cannot be maintained, and thus it is not possible to prevent the surface flashover of the lightning arrestor string. Furthermore, a new problem has arisen that the permanent ground fault cannot be prevented.

The object of the present invention is to solve the above-mentioned problems of the prior art and to prevent the discharge electrode from dropping even when the resistance element cannot process the lightning surge current due to deterioration or the like and the conduction current is broken due to the continuous current. Another object of the present invention is to provide a lightning arrester device for a power transmission line, which is capable of preventing the above and preventing a permanent ground fault.

Further, in addition to the above objects, another object of the present invention is to easily attach the arc guide and the discharge electrode to the cap fitting without processing the cap fitting of the suspension insulator having no lightning protection function. Another object of the present invention is to provide a lightning protection device for a power transmission line.

[0007]

In order to achieve the above-mentioned object, the invention of claim 1 connects the suspension type lightning arresters in series, and the resistance elements of each of the suspension type lightning arrestors are connected to each other via a lead wire. Alternatively, it is electrically connected without any interposition, and a suspension insulator having no lightning protection function is connected in series to the lightning protection insulator series,
In the suspension type lightning arrester device for a transmission line in which a discharge side discharge electrode and a ground side discharge electrode are attached to both ends of this suspension insulator series, and an air discharge gap is provided between both discharge electrodes The arc guide is attached to the cap metal fitting of the suspension insulator close to the above, and the discharge electrode is attached to the arc guide.

According to a second aspect of the present invention, in the first aspect, the arc guide and the discharge electrode are attached to a plurality of divided mounting rings, and the mounting rings are brought into contact with the cap fittings of the suspension insulator to tighten them. A means of fixing with an attachment member is adopted.

[0009]

According to the first aspect of the present invention, when the lightning surge current enters and becomes conductive due to the follow current when the resistance element housed in the lightning protection insulator is deteriorated, the arc caused by the current is an arc. It is guided to the outside by the guide and is captured by the discharge electrodes, and flashover occurs between the discharge electrodes on the charging side and the ground side. At this time, even if the cap electrode that seals the resistance element of the lightning arrestor breaks and separates, the arc guide and the discharge electrode remain supported by the cap metal member of the suspension insulator, and it is possible to re-transmit power after an accident. A ground fault can be prevented.

Further, according to the invention of claim 2, the arc guide and the discharge electrode are detachably tightened and fixed to the cap fitting of the suspension insulator via the plurality of mounting rings, so that a special member for mounting both members is provided. It is possible to easily perform the work of attaching the arc guide and the discharge electrode without preparing a suspension insulator.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment embodying the present invention will be described below with reference to FIGS. As shown in FIG. 1, a suspension metal fitting 2 is connected to a support arm 1 of a steel tower, an upper horn mounting metal fitting 3 and a ball clevis 4 are connected in series to the suspension metal fitting 2, and an upper horn mounting metal fitting 3 is further connected. A plurality of suspension type lightning protection insulators 5 which will be described in detail later are connected and suspended in series at the lowermost end of the.

A plurality of normal suspension insulators 6 having no lightning protection function are suspended in series at the bottommost suspension type lightning arrestor 5, and a lower horn is attached to the bottommost suspension insulator 6 via a socket clevis 7. The mounting member 8 is connected, and the mounting member 8 supports an electric wire clamp 10 that supports the power transmission line L via a connecting link 9.

The upper horn mounting bracket 3 and the lower horn mounting bracket 8 are equipped with an upper arc horn 11 for preventing a creeping flashover of a suspension of insulators and a lower arc horn 12 which also serves as a discharge electrode on the charging side. Has been done.

Next, the structure of the suspended lightning arrester 5 will be described with reference to FIG. A cap metal fitting 22 is fitted and fixed to the head of the insulator main body 21 by cement, and a pin metal fitting 23 is fitted and fixed to the inside of the head by cement. A resistor element 24 made of, for example, a material whose main characteristic is zinc oxide and whose voltage-current characteristic is non-linear is housed inside a plurality of mounting cylinder portions 21a formed integrally with the cap portion of the insulator main body 21. It is fitted and fixed by the upper cap electrode 25 and the lower cap electrode 26 via an electrode plate or a biasing spring.

If the resistance element 24 of the suspension type lightning protection insulator 5 is unable to interrupt the follow current and is in a conducting state on the outer periphery of the cap metal fitting 22, the arc is guided to the outside and the insulator main body 21. Arc guide 2 to prevent the destruction of the
7 is fixed horizontally. The upper cap electrode 25
The arc guide 27 is electrically connected by a lead wire 28, and the lower cap electrode 26 and the pin metal fitting 23 are electrically connected by a lead wire 29.

Next, the arc guide 27, which is the main part of the present invention, and the intermediate arc horn 3 as the discharge electrode on the ground side.
The mounting structure of 0 will be described. As shown in FIG. 3, connecting pieces 31a and 32a are integrally bent and formed at respective ends of the pair of mounting rings 31 and 32, and bolt insertion holes 31b and 32b are formed in the connecting pieces 31a and 32a. As shown in FIG. 4, the bolts 33 and the nuts 34 are fixed to the cap fitting 22 of the suspension insulator 6. Then, the attachment rings 31, 32
Engagement grooves 31c and 32c are formed on the inner peripheral surface of the annular projection 22 formed on the outer periphery of the lower side of the cap fitting 22.
a (see FIG. 1). Both mounting rings 31,
A bracket 35 is welded and fixed to the central portion of the outer periphery of 32 so as to be directed outward, and a mounting plate 36 connected to the base end portion of the intermediate arc horn 30 is tightened and fixed to the bracket 35 by a bolt 37. .. Further, an arc guide 27 is welded and fixed to the upper surface of the bracket 35 so as to face the lower cap electrode 26 of the lowermost lightning arrester 5 with a predetermined gap in the mounted state.

Next, the operation of the lightning arrester device constructed as described above will be described. Now, when a lightning surge current enters the power transmission line L in FIG. 1, this current is connected to the connecting link 9, the lower horn mounting bracket 8 and the lower arc horn 12.
Flow through the air discharge gap G to flow into the intermediate arc horn 30. Then, the cap fitting 22 of the suspension insulator 6, the pin fitting 23 of the lightning protection insulator 5 at the lowermost end, the lead wire 29, the lower cap electrode 26, the resistance element 24, the upper cap electrode 25, the lead wire 28, the cap fitting 22 from the horn. Flow to the resistance element 24 of the suspended lightning arrester 5 located at the upper part, and after passing through this in sequence, pass through the ball clevis 4, the upper horn mounting bracket 3, and the hanging bracket 2 to the support arm 1 of the steel tower, and reach the ground. Is discharged.

On the other hand, the continuous current following the lightning surge current is suppressed and blocked by the air discharge gap G between the intermediate arc horn 30 and the lower arc horn 12 and the restoration of the resistance value of each resistance element 24. Trouble is prevented.

If the resistance element 24 housed in the cap portion of the lightning protection insulator 5 is deteriorated due to long-term use and a lightning surge current intrudes into the resistance element 24 and the subsequent current flowing therethrough cannot be suppressed and cut off, the resistance is reduced. The element 24 is conductively broken, the cap electrodes 25 and 26 thereof are separated from the mounting cylinder portion 21a by the high-temperature and high-pressure gas, and an arc is ejected. The arc is generated by the arc guide 27 on the outside of each lightning protection insulator 5. After being guided in one direction, a flashover is finally made between the upper arc horn 11 and the intermediate arc horn 30, and the creeping flashover of the lightning protection insulator series is prevented.

Further, since the intermediate arc horn 30 is securely supported at the predetermined position, the discharge gap G is secured even for the re-power transmission after the accident, so that the permanent ground fault can be prevented.

In the first embodiment, the arc guide 27 and the intermediate arc horn 30 are attached to both mounting rings 31,
Since it is detachably attached to the cap metal fitting 22 of the suspension insulator 6 by 32, it is not necessary to use, as the suspension insulator 6, a different kind of suspension insulator having a cap metal fitting having a pedestal for mounting the arc guide 27. The conventional suspension insulator can be used, the manufacturing cost can be suppressed, and the arc guide 27 can be used.
Also, the intermediate arc horn 30 can be easily attached.

Next, a second embodiment of the present invention will be described with reference to FIG. In this second embodiment, the arc guide 2
The intermediate arc horn 30 is fixed to the lower surface of 7 by welding or bolts. Then, the arc guide 27 is attached to the cap metal fitting 22 of the suspension insulator 6 for the mounting base 22.
b is formed, and the lower surface of the base end of the arc guide 27 is fastened and fixed to the mounting pedestal 22b with bolts 39.

Therefore, in the second embodiment, the first
Similar to the embodiment, since the discharge gap G is surely secured at the time of the lightning protection function and the conduction breakdown of the resistance element 24, the power can be retransmitted after the accident, and the arc guide 27 and the intermediate arc horn 30 can be mounted. It can be simplified.

The present invention is not limited to the above embodiment, but can be embodied as follows. (1) As shown in FIG. 6, the lightning protection insulator 5 located at the top
The upper arc horn 11 should be fastened and fixed to the arc guide 27 of FIG. In this embodiment, the horn mounting member 3 can be omitted and the insulator connecting length can be shortened.

(2) In the above embodiment, the resistance elements 2 are provided at two locations.
Although the lightning protection insulator 5 accommodating 4 is used, this resistance element 2
Use a type of lightning arrester that contains one or more than three. In this case, the number of arc guides 27 is adjusted according to the number of resistance elements 24.

[0026]

As described above in detail, according to the invention described in claim 1, when the lightning surge current intrudes in the state where the resistance element is deteriorated by the long-term use of the lightning protection insulator and the resistance element is conductively destroyed by the continuous current. Also in the above, since the gaps between the arc horns are maintained, it is possible to prevent a permanent ground fault after the accident.

In addition to the effect of the invention described in claim 1, the invention described in claim 2 facilitates the arc guide and the discharge electrode without processing the cap metal fitting of the suspension insulator having no lightning protection function. Moreover, there is an effect that it can be attached to the cap fitting.

[Brief description of drawings]

FIG. 1 is a front view showing a first embodiment of a lightning arrester insulator device of the present invention.

FIG. 2 is a semi-longitudinal sectional view showing only a lightning protection insulator.

FIG. 3 is a perspective view showing a mounting structure of an arc guide and an intermediate arc horn.

FIG. 4 is a plan sectional view showing a mounting structure of an arc guide and an intermediate arc horn.

FIG. 5 is a front view showing a second embodiment of the present invention.

FIG. 6 is a front view showing another embodiment of the present invention.

[Explanation of symbols]

5 suspension type lightning arrester, 6 suspension insulator, 11 upper arc horn, 12 lower arc horn which also serves as discharge electrode on the charging side, 21 insulator body, 21a mounting cylinder part, 22 cap fitting, 22b mounting base, 23 pin fitting, 24
Resistance element, 25 upper cap electrode, 26 lower cap electrode, 27 arc guide, 28, 29 lead wire,
30 Intermediate arc horn that also serves as the ground side discharge electrode, 3
1, 32 mounting ring, 33 bolts as tightening members, 34 nuts, 35 brackets, G air discharge gap, L power transmission line.

Claims (2)

[Claims] 1. A suspension type lightning arrester is connected in series, and the resistance elements of each suspension type lightning arrester are electrically connected to each other via lead wires or not, and a lightning protection function is provided to the lightning arrestor series. A transmission line in which a suspension insulator is connected in series, and a discharge side discharge electrode and a ground side discharge electrode are attached to both ends of this suspension insulator series, and an air discharge gap is provided between both discharge electrodes. A suspension type lightning arrester device for a transmission line, wherein an arc guide is attached to a cap fitting of the suspension insulator closest to the lightning arrestor, and the discharge electrode is attached to the arc guide. 2. The arc guide and discharge electrode according to claim 1, wherein the arc guide and the discharge electrode are attached to a plurality of attachment rings, and the attachment rings are in contact with a cap fitting of a suspension insulator and fixed by a fastening member. Suspension type lightning arrester device for power lines.