JPH0451372Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is designed to quickly discharge lightning surge current to the ground when a lightning surge current flows through a power transmission line due to a lightning strike, thereby suppressing the rise in the lightning surge potential of the power transmission line. This invention relates to a lightning arrester that prevents power outages caused by flash faults and ground faults caused by lightning surges and enables power transmission.

(Prior Art) Conventionally, as a suspended insulator-type earth arresting insulator that has both a wire support function and a lightning protection function, the applicant of the present application has housed a current limiting element with non-linear voltage-current characteristics in the cap of the insulator body. I am proposing something. As shown in FIG. 5, this lightning arrester is similar to the conventional insulator tube type lightning arrester for substations, and has a mounting tube portion 5d integrally formed with the cap portion 5a.
A current limiting element 9 is housed inside, and an upper electrode 32 and a lower electrode 33 made of flat metal are fitted and fixed to both upper and lower ends of the mounting cylinder 5d via a gasket 31, and the upper electrode 32 and A pressure relief hole 34 was provided in the center of the lower electrode 33, this pressure relief hole 34 was shielded by a torn plate 35, and both members were hermetically sealed by welding 36. When the current limiting element 9 becomes conductive due to the lightning surge current and the inside of the mounting tube 5d becomes high pressure due to the high temperature arc, the rupture disc 35 melts and the pressure is released.

Furthermore, as a conventional suspension insulator, a cap-shaped upper electrode 37 and a lower electrode 38 are fitted and fixed to the upper and lower ends of a mounting tube 5d as shown in FIG. 6.

(Problem to be Solved by the Invention) However, in the former suspension insulator, the metal upper electrode 32 and lower electrode 33 are fitted and fixed to the mounting cylinder portion 5d via the gasket 31, so the gasket 31 may deteriorate after long-term use. Deterioration makes it difficult to maintain airtightness inside the mounting tube 5d, and if the airtightness deteriorates, the electrical insulation of the current limiting element 9 will be impaired, and conduction will occur due to deterioration due to operating voltage or insulation drop during lightning strikes. Therefore, there was a problem in that it was not possible to interrupt the discharge of lightning surges or the follow-up current due to the operating voltage, resulting in ground faults.

Furthermore, since the latter suspension insulator is of an integrally sealed type, there is a risk of damage to the entire container and damage to the entire insulator when the pressure is released.

(Means for Solving the Problem) In order to solve the above-mentioned problem, the present invention accommodates a current limiting element with non-linear voltage-current characteristics inside the mounting tube, and The parts are hermetically sealed by an upper lid member and a lower lid member made of electrically insulating ceramic, one part is electrically connected to the current limiting element, and the other part is fixed to a conductive part on the support side and the power source side. A conductive member is penetrated and fixed to the upper and lower lid members, respectively, and a thin wall portion that ruptures earlier than other parts due to a high-temperature and high-pressure arc is surrounded by the penetrated and fixed portion of the conductive member. It is formed to be flexible.

(Function) In other words, the ceramic that constitutes the upper and lower lid members has excellent weather resistance, impact resistance, and heat resistance under normal use environments, so the airtight structure within the mounting cylinder is ensured for a long time. .

Moreover, since the ceramic has electrical insulation properties, the surface leakage insulation distance of the insulator body is ensured to be correspondingly longer.

If the current limiting element becomes conductive due to an excessive lightning surge current and a high-temperature, high-pressure arc occurs inside the mounting cylinder, the thin wall part of the lid member will be affected by internal pressure and rapid heating in the early stages of the occurrence. Stress concentration occurs and cracks occur. Then, since ceramic is not malleable like metal, the crack expands all at once, the thin wall portion ruptures, and the pressure inside the mounting tube is quickly released to the outside.

Furthermore, since the lid member is attached to a conductive member fixed to the conductive parts on the support body side and the power supply side, even after the thin-walled part ruptures, the lid member is suspended and supported by the conductive member, and is carried downward from the ground, etc. There is no risk of falling.

(Example) Hereinafter, an example in which the present invention is embodied in a suspended lightning arrester insulator will be described with reference to FIGS. 1 to 4.

As shown in FIG. 4, a large number of suspension insulator-type lightning arresters 3 are connected and suspended in series from a support arm 1 provided on a steel tower (not shown) via hanging fittings 2.
A power transmission line L is supported at the lowest end of the lightning arrester 3 via a hanging metal fitting 4.

As shown in FIG. 3, the insulator body 5 constituting the lightning arrester 3 includes a shade portion 5a and a plurality of folds 5 formed annularly and concentrically on the inner surface of the shade portion 5a.
b, and a capped cylindrical head 5c integrally formed at the upper center of the cap 5a. A cap fitting 7 is fixed to the outer periphery of the head 5c with cement 6, and a fitting recess 7a is formed in the cap fitting 7 so that it can engage the pin fitting 8 of the lightning arrester 3 directly above it. I have to. The upper part of the pin fitting 8 is fixed inside the head 5c with cement 6, and the lower end is engaged with the fitting recess 7a of the cap fitting 7 of the lightning arrester 3 directly below. In this way, a plurality of lightning arresters 3 are connected in series.

As shown in FIGS. 1 and 2, the cap portion 5a has a plurality of cylindrical mounting portions 5d (four in this embodiment) arranged at equal intervals and parallel to the pin fittings 8. It is integrally formed so as to penetrate the cap 5a. The inner circumferential surface of each mounting cylinder 5d, that is, the through hole 5e, is provided with a plurality of cylindrical columns (such as cylindrical resin) made of zinc oxide (ZnO) as a main material and having non-linear voltage-current characteristics and excellent follow-on current blocking characteristics. In the embodiment, three current limiting elements 9 are inserted in series. Although there is a gap between the inner circumferential surface of the through hole 5e and the outer circumferential surface of the current limiting element 9, an elastic insulating material such as silicone rubber (not shown) may be interposed and bonded thereto.

Thick disk-shaped upper and lower lid members 11 and 12 made of electrically insulating ceramic are fitted into the inner circumferential surfaces of both upper and lower ends of the mounting cylinder 5d, and their outer circumferential surfaces are made of glass, glass solder, or The inorganic bonding material 13 such as metal is airtightly bonded and fixed to the inner circumferential surface of the mounting tube 5d. We are trying to prevent deterioration. The upper lid member 11 and the lower lid member 1
2, arcuate notches 14 are formed in four locations in an annular shape as a whole, and each notch 14
When a lightning surge enters the current limiting element 9 and becomes conductive, the thin part 15 formed by the
Due to high-pressure arc, the mounting tube 5d ruptures prematurely.
The internal gap and the outside are communicated with each other to release pressure, thereby preventing pressure breakdown in the mounting cylinder portion 5d.

Further, a planar donut plate-shaped electrically conductive disc spring 19 is interposed between the current limiting element 9 and the upper lid member 11 to mechanically hold the current limiting element 9 in a fixed position. There is.

Through holes 11a and 12a are respectively formed in the center portions of the upper lid member 11 and the lower lid member 12 so as to be surrounded by the annular cut 14, and leads as conductive members are formed in the through holes 11a and 12a. One end of each of the wires 18 and 19 is inserted. Each lead wire 18, 19 is fixed to the corresponding lid member 11, 12 via glass solder 17 (or a metal bonding material such as silver solder) filled in the through holes 11a, 12a. The upper lead wire 18 is electrically connected to the current limiting element 9 via the disc spring 16, and the lower lead wire 19 is directly connected to the current limiting element 9. The other end of the upper lead wire 18 is connected to a terminal portion 7b integrally formed with the cap metal fitting 7, and the other end of the lower lead wire 19 is connected to a terminal portion 8a integrally formed with the pin metal fitting 8. There is.

Next, the operation of the lightning arrester constructed as described above will be explained.

When an excessive voltage due to a lightning surge is applied to the power transmission line L, the current flows through the hanging fitting 4 to the pin fitting 8 of the lowest lightning arrester 3, and the lead wire 19→
The current is transmitted from the current limiting element 9 to the disc spring 16 to the lead wire 18 to the cap fitting 7. Thereafter, the light is transmitted from the cap fitting 7 to the pin fitting 8 of the lightning arrester 3 directly above it. Similarly, multiple lightning arresters 3 connected in series
It is transmitted to the ground from the cap metal fitting 7 of the lightning arrester 3 at the top end, through the hanging metal fitting 2, and the support arm 1.

At this time, the current limiting element 9 built into the insulator body 5
Due to its characteristics, it quickly reduces its resistance value and discharges the large current caused by lightning surges. Further, in response to the operating voltage that continues after the lightning surge, the current limiting element 9 immediately restores its resistance value and restores insulation, so no follow-on discharge is formed and the electrical line returns to normal.

Now, in the embodiment of the present invention, the mounting cylinder portion 5d
The upper and lower lid members are made of ceramic, which has excellent weather resistance under normal usage conditions, and has excellent impact resistance and heat resistance against external impact forces and heat. 11 and 12 were inserted and hermetically sealed with the inorganic bonding material 13.
The airtightness within the mounting tube 5d can be ensured over a long period of time, the deterioration of the current limiting element 9 due to moisture can be prevented, the durability of the current limiting element 9 can be increased, and the reliability can be improved. , the structure can be simplified compared to the conventional example shown in FIG.

Further, when the current limiting element 9 becomes conductive due to a lightning surge and the inside of the mounting cylinder 5d becomes abnormally high pressure due to a high temperature and high pressure arc, stress is applied to the thin wall portion 15 before other parts. Concentration occurs and cracks occur. Then, since ceramic is not malleable like metal, the crack expands all at once due to the gas pressure caused by the arc, and the thin section 15 ruptures before the other sections. Therefore, the abnormally high pressure is quickly released to the outside from the ruptured thin wall portion 15. As a result, it is possible to prevent the mounting cylinder part 5d from being destroyed due to abnormal pressure inside the mounting cylinder part 5d, and to prevent the insulator body 5 from being destroyed, thereby eliminating the separation of the lightning arrester insulator. I can do it.

Further, in the embodiment, the upper and lower lid members 11,
Since the ceramic constituting the insulator body 5 has electrical insulation properties, the surface leakage insulation distance of the insulator body 5 is ensured at the lid members 11 and 12 portion. Therefore, the diameter of the shade portion 5a of the insulator body 5 can be reduced accordingly, the weight of the insulator body 5 can be reduced, and the cost of the entire insulator chain can be reduced.

Furthermore, if the lid members 11 and 12 rupture at the thin wall portion 15, there is a risk that they will separate from the inner circumferential surface of the end of the mounting cylinder 5d and fall to the ground, etc., but in this embodiment, the glass solder 17 (or The lead wires 18, 1 are connected via a metal binding material such as silver wax.
9, it is possible to avoid such a fear of falling to the ground, etc., and prevent the occurrence of a public disaster.

It should be noted that the present invention is not limited to the above embodiments, but may be embodied as follows.

(1) In the embodiment described above, one end of the lead wires 18 and 19 is passed through each lid member 11 and 12 to be electrically connected to the current limiting element 9.
Connection terminals (not shown) electrically connected to the current limiting element 9 may be provided on the outer surfaces of the current limiting elements 1 and 12, and one ends of the lead wires 18 and 19 may be fixed to the connection terminals. In this case, a conductive member is formed by the connection terminal passing through each lid member 11, 12 and each lead wire 18, 19.

(2) Although not shown, the thickness of the cut 14 may be made larger or smaller than the illustrated example. Also, the notch 14 should be cut out.

(3) The mounting tube portion 5d may be formed separately or flush with the upper surface of the cap portion 5a.

(4) Cut the notches 14 into the upper and lower lid members 1.
1 and 12 should be formed on the outer surface side.

(5) To be embodied in a cylindrical lightning arrester other than a suspended type lightning arrester.

Effects of the Invention As detailed above, the present invention provides an airtight seal between the upper and lower ends of the mounting cylinder using ceramic upper and lower lid members that have excellent weather resistance, impact resistance, and heat resistance under normal use environments. Despite the simple structure, the airtightness of the current limiting element housing space inside the mounting tube can be ensured over a long period of time, preventing deterioration of the current limiting element due to moisture. The durability and reliability of the lightning arrester can be improved. In addition, since the insulation distance against surface leakage current is ensured in the cover member made of ceramic having electrical insulation properties on the surface of the insulator body, the diameter of the insulator body is reduced and the weight of the insulator body is reduced by that amount, which reduces the overall insulator chain. Cost can be reduced. Furthermore, when the current-limiting element becomes conductive due to lightning surge current and a high-temperature, high-pressure arc is generated, stress concentrates in thin-walled parts before other parts, causing cracks. has no malleability, and the crack expands at once under the pressure of the arc gas, rupturing the thin walled part, and quickly releases high-pressure gas to the outside from this ruptured area, thus preventing the insulator body from rupturing. be able to. In addition, even if the lid member ruptures at the thin wall portion, the lid member has a conductive member fixed to the conductive parts on the support side and the power source side, so that the lid member will not rupture due to the rupture. It is possible to avoid falling to the ground, etc., and prevent the occurrence of public disasters. Moreover, since the thin wall part is formed so as to surround the penetration fixed part of the lid member by the conductive member, after the rupture, the thin wall part The lid member part surrounded by the area is suspended in the air by the conductive member, and this hanging display has the excellent effect that the fact that pressure relief has occurred can be easily recognized from below, such as on the ground. play.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of the main parts of an embodiment of the present invention as a suspension type lightning arrester;
3 is a half-longitudinal sectional view showing the lightning arrester, FIG. 4 is a front view showing the usage state of the lightning arrester, and FIGS. 5 and 6 are parts showing conventional examples. FIG. 3...Lightning arrester, 5...Insulator body, 5a...Kasabe, 5c...Head, 5d...Mounting cylinder part, 5e...
Through hole, 7...cap metal fitting, 8...pin metal fitting,
9...Current limiting element, 11...Upper electrode as upper lid member, 12...Lower electrode as lower lid member,
13... Inorganic binding material, 14... Notch, 15
...Thin wall portion, 16... Belleville spring, 18, 19... Lead wires constituting the conductive member.

Claims (1)

[Claims for Utility Model Registration] 1. A current limiting element 9 with non-linear voltage-current characteristics is accommodated inside the mounting cylinder 5d, and both upper and lower ends of the mounting cylinder 5d are connected to an upper part made of electrically insulating ceramic. Conductive members 18 and 19 are airtightly sealed by the lid member 11 and the lower lid member 12, one of which is electrically connected to the current limiting element 9, and the other of which is fixed to the conductive parts on the support side and the power source side. The conductive member 18 is provided with a thin wall portion 15 that penetrates and is fixed to the upper and lower lid members 11 and 12, respectively, and that ruptures earlier than other parts due to a high temperature and high pressure arc on the upper and lower lid members 11 and 12, respectively. 19
A lightning arrester characterized in that it is formed so as to surround a fixed penetrating portion of the lightning arrester. 2. The lightning arrester is constructed by fixing a cap fitting 7 to a capped cylindrical head 5c formed at the upper center of the shade portion 5a of the insulator body 5, and fitting a pin fitting 8 into the inside of the head 5c. In the suspended insulator 3, a mounting tube portion 5d having a through hole 5e is provided in the cap portion 5a, and a current limiting element 9 is installed in the through hole 5e.
The cap metal fitting 7 and the pin metal fitting 8 are connected to the current limiting element 9 by the lead wires 18 and 19 which are inserted and fixed through the upper and lower lid members 11 and 12, respectively.
The lightning arrester according to claim 1 of the utility model registration, which is electrically connected to the lightning arrester.