JPH04129426U - lightning insulator - Google Patents

Abstract

(57) [Summary] [Purpose] To improve the durability and reliability of lightning arrester insulators, to simplify the structure, to prevent rupture of the insulator body due to lightning surge current, and to prevent public disasters caused by falling objects caused by rupture of thin walled parts. The purpose is prevention. [Structure] A current limiting element with non-linear voltage-current characteristics is housed inside the mounting tube provided on the lightning arrester.
The upper and lower ends of the mounting tube are hermetically sealed with an upper lid member and a lower lid member made of conductive ceramic with excellent weather resistance, impact resistance, etc. At the ends of the upper lid member, the lower lid member, or the inner wall of the mounting tube, there are formed thin-walled portions that undergo stress concentration earlier than other portions due to high-temperature, high-pressure arcs and rupture. Further, a lead wire is attached to the lid member to prevent the lid member from falling when the lid member ruptures.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

For example, when a lightning surge current flows through a power transmission line due to a lightning strike, this invention can quickly suppress the surge current. By discharging to the ground and suppressing the increase in lightning surge potential on power transmission lines, lightning surges can be suppressed. Regarding lightning arrester insulators that enable power transmission by preventing power outages caused by flash faults and ground faults. It is something to do.

0002

[Conventional technology]

Traditionally, this type of lightning arrester has been used as a suspension insulator that has both wire support and lightning protection functions. The applicant has developed a device in which a current limiting element with non-linear voltage-current characteristics is housed in the cap of the insulator body. We are proposing the following. This lightning arrester is a conventional insulator type lightning arrester for substations, as shown in Figure 7. Similarly, the current limiting element 9 is accommodated in the mounting cylinder part 5d integrally formed with the cap part 5a, and A flat metal upper portion is provided at both upper and lower ends of the mounting cylinder portion 5d with a gasket 31 interposed therebetween. The electrode 32 and the lower electrode 33 are fitted and fixed, and then the upper electrode 32 and the lower electrode 33 are fitted and fixed. A pressure relief hole 34 is provided in the center, and this pressure relief hole 34 is shielded by a rupture disk 35, and both parts are The materials were hermetically sealed by welding 36. Then, due to lightning surge current, the current limiting element When the child 9 becomes conductive and the inside of the mounting tube 5d becomes high pressure due to the high temperature arc, the rupture disc 35 was melted and the pressure was released.

0003 Moreover, as shown in FIG. 8, as a conventional suspension insulator, gold is attached to both the upper and lower ends of the mounting tube 5d. A cap-shaped upper electrode 37 and a lower electrode 38 made of metal are also proposed. It is.

0004

[Problem that the idea aims to solve]

However, in the former suspension insulator, the metal upper electrode 32 and lower electrode 33 are attached to a mounting tube. Since it is fitted and fixed to the part 5d through the gasket 31, the gasket may deteriorate after long-term use. 31 deteriorates, making it difficult to maintain the airtightness inside the mounting tube 5d, and the airtightness may deteriorate. If this happens, the electrical insulation of the current limiting element 9 will be impaired, resulting in deterioration due to operating voltage or during lightning strikes. Due to insulation deterioration, conduction occurs, resulting in lightning surge discharge or follow-on current due to operating voltage. There was a problem in that it was not possible to shut off the power supply, resulting in a ground fault.

[0005] In addition, since the latter suspension insulator is an integrally sealed type, the entire container may be damaged when the pressure is released. There was a risk that this would lead to damage to the entire insulator.

[0006]

[Means to solve the problem]

In order to solve the above problem, the present invention has a non-linear voltage-current characteristic inside the mounting tube. The linear current-limiting element is accommodated, and both the upper and lower ends of the mounting tube are made of conductive ceramic. The upper lid member and the lower lid member are airtightly sealed, and the upper lid member, the lower lid member, or The end of the inner wall of the mounting cylinder is damaged earlier than other parts due to high temperature and high pressure arc. A thin wall portion is formed to split the lid member, and a lead wire is attached to the lid member. I'm picking it up.

[0007] In addition, the lightning arrester has a cap on the head of a covered tube formed in the upper center of the cap of the insulator body. A suspension system in which the top metal fitting is fixed on the crown and a pin metal fitting is inserted and fixed on the inside of the head. The insulator is provided with a mounting cylinder part having a through hole in the cap part, and a current limiting part is provided in the through hole. Insert the element and connect the upper lid member and cap metal fitting, which also serves as the upper electrode, with lead wires. Similarly, the lower lid member and pin metal fittings, which also serve as lower electrodes, are connected to each other using lead wires. It may also be connected mechanically.

[0008]

[Effect]

In other words, the ceramics that make up the upper and lower lid members will not work under normal usage conditions. It also has excellent weather resistance, impact resistance, and heat resistance, so the airtight structure inside the mounting tube will last for a long time. Secured throughout. Moreover, since the ceramic is electrically conductive, the upper part It is designed to serve as both the electrode and lower electrode as well as the upper and lower lid members. And the passing The current limiting element becomes conductive due to the large lightning surge current, causing high temperature and high pressure inside the mounting tube. If an arc occurs, the thickness of the cover member or the inner wall of the mounting cylinder should be Cracks occur in the flesh due to stress concentration due to internal pressure and rapid heating. Then, Lamic is not malleable like metal, so the cracks expand all at once and become thinner. The flesh part is destroyed and the pressure inside the mounting tube is quickly released to the outside. Also, the lid Since the member is attached to the lead wire, even after the thin-walled part ruptures, it will still be able to reach the ground below. There is no risk of it falling.

[0009]

【Example】

An example in which the present invention is embodied in a suspended lightning arrester is shown below according to Figs. 1 to 4. explain.

0010 As shown in Figure 4, a hanging metal fitting is attached to a support arm 1 provided on a steel tower (not shown). A large number of suspended insulator type lightning arresters 3 are connected and suspended in series through the lightning arrester 2. A power transmission line L is supported at the lowest end via a hanging metal fitting 4.

[0011] As shown in FIG. a plurality of folds 5b formed annularly and concentrically on the inner surface of a; It is integrally formed with a capped cylindrical head 5c integrally formed at the upper center of the cap 5a. It is molded. In addition, a cap fitting 7 is covered with cement 6 on the outer periphery of the head 5c. The crown is fixed, and a fitting recess 7a is formed in the metal fitting 7, and the pin metal of the lightning arrester 3 directly above is formed. The tool 8 can be engaged therewith. The upper part of the pin fitting 8 is inside the head 5c. It is fixed with cement 6, and the lower end is fitted with the cap fitting 7 of the lightning arrester 3 directly below. It is engaged with the mating recess 7a. In this way, multiple lightning arresters 3 are connected in series. It is.

0012 As shown in FIGS. 1 and 2, the cap 5a has a plurality of cylindrical shapes (in this embodiment, The mounting cylinder portions 5d (4 locations) pass through the cap portion 5a at equal intervals and parallel to the pin fittings 8. It is integrally formed so that it can pass through. The inner circumferential surface of each mounting cylinder portion 5d, that is, the penetration The hole 5e is made of zinc oxide (ZnO) with excellent voltage-current characteristics and has excellent follow-on current blocking properties. A plurality (three in this embodiment) of current limiting elements 9 having a non-linear cylindrical shape are connected in series. It is inserted. 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. However, an elastic insulating material such as silicone rubber (not shown) may be interposed and bonded.

[0013] The inner circumferential surfaces of both upper and lower ends of the mounting cylinder portion 5d are made of a ceramic material having a conductive thickness. Upper electrode 11 as a meat disc-shaped upper lid member and lower electrode 1 as a lower lid member 2 is inserted, and their outer peripheral surface is made of glass, glass solder, or inorganic material such as metal. It is airtightly bonded and fixed to the inner circumferential surface of the mounting cylinder part 5d by the bonding material 13, and this inorganic crystal is The composite material 13 ensures airtightness within the mounting cylinder 5d, and prevents moisture from forming in the current limiting element 9. We are trying to prevent deterioration.

[0014] There are four arcuate cuts 14 on the inner surfaces of the upper electrode 11 and the lower electrode 12. A thin wall portion 1 formed in an annular shape as a whole at a location and formed by each cut 14 5, an excessive lightning surge current exceeding the design value entered the current limiting element 9, resulting in a conductive state. In this case, the high-temperature, high-pressure arc may cause an early rupture, causing the inner gap and outer space of the mounting tube 5d to become damaged. The pressure is released by communicating with the mounting cylinder part 5d to prevent pressure breakdown of the mounting cylinder part 5d.

[0015] Further, between the current limiting element 9 and the upper electrode 11, there is a conductive plate shaped like a flat donut plate. A disc spring 16 having In addition to making the respective electrical connections, the current limiting element 9 is mechanically held in place. I try to do that.

[0016] A metal bond such as silver wax is formed on the upper surface of the upper electrode 11 and the lower surface of the lower electrode 12, respectively. One end of the lead wires 18 and 19 is adhesively fixed by a composite material 17 or pressure welding, and the upper The other end of the lead wire 18 is connected to the terminal portion 7b integrally formed on the cap fitting 7. The other end of the lower lead wire 18 is connected to a terminal portion 8a integrally formed with the pin fitting 8. It is connected.

[0017] Next, the operation of the lightning arrester constructed as described above will be explained. When excessive voltage due to lightning surge is applied to the power transmission line L, the current at this time is It flows to the pin fitting 8 of the lowest lightning arrester 3 through the lead wire 19 → lower electrode 12 → Current limiting element 9→disc spring 16→upper electrode 11→lead wire 18→cap metal fitting 7 be reached. Thereafter, the transmission is transmitted from the cap fitting 7 to the pin fitting 8 of the lightning arrester 3 directly above. be reached. Similarly, from the cap fitting 7 of the lightning arrester 3 connected in series, It is grounded to the earth via the fixture 2 and the support arm 1.

[0018] At this time, the current limiting element 9 built into the insulator body 5 quickly resists due to its characteristics. Reduce the value to discharge large currents caused by lightning surges. Also, the luck that continues with the lightning surge The current limiting element 9 immediately recovers its resistance value and restores insulation in response to the following current of the rotating voltage. , no follow-on discharge is formed and the electrical line returns to normal.

[0019] Now, in this embodiment, the inner peripheral surface of the upper and lower ends of the mounting cylinder portion 5d is It has excellent weather resistance under the usage environment and is resistant to external impact force and heat. Upper electrode 11 and lower electrode 12 made of ceramic with excellent impact resistance and heat resistance are fitted. Since it is sealed with the inorganic bonding material 13, the airtightness inside the mounting tube 5d can be maintained for a long time. The current limiting element 9 is prevented from deteriorating due to moisture and the current limiting element 9 is maintained for a long period of time. The durability of the element 9 can be increased and reliability can be improved.

[0020] Moreover, the upper and lower lid members are made of conductive ceramic, and both of them are made of conductive ceramic. Since the lid member and the upper and lower electrodes 11 and 12 are also used as members, the structure shown in FIG. The structure can be simplified compared to the conventional example.

[0021] In addition, the current limiting element 9 becomes conductive due to lightning surge, and the inside of the mounting cylinder 5d becomes high temperature. If abnormally high pressure occurs due to a high-pressure arc, the thin-walled area should be Stress concentration occurs at portion 15 and cracks occur. Then, the ceramic has gold Since it is not malleable like metal, cracks are caused by the gas pressure caused by the arc generation. The thin portion 15 expands all at once, and the thin portion 15 ruptures before the other portions. follow Therefore, the abnormally high pressure is quickly released to the outside from the ruptured thin wall portion 15. Ru. As a result, the mounting cylinder 5d may be destroyed due to abnormally high pressure inside the mounting cylinder 5d. By eliminating this, it is possible to prevent the insulator body 5 from being destroyed, and the lightning protection Child separation can be avoided.

[0022] Furthermore, the upper and lower electrodes 11 and 12 do not rupture at the thin wall portion 15. If this happens, there is a risk that it will separate from the inner peripheral surface of the end of the mounting tube 5d and fall to the ground, etc. In this embodiment, it is fixed to the lead wires 18 and 19 via a metal bonding material 17 such as silver wax. This prevents the risk of falling onto the ground, etc., and prevents public disasters. This can be prevented from occurring.

[0023] It should be noted that the present invention is not limited to the configuration of the above-mentioned embodiments, but can be specifically modified as follows. may be converted into (1) As shown in Figures 5 and 6, there are notches 14 and and a thin wall portion 15 is provided. The notch 14 is inserted into the cap metal fitting as shown in FIG. A cap metal fitting is provided on the 7 side to prevent high-temperature and high-pressure arcs from being injected to the 7 side. do not have. The operation of this other example is also almost the same as that of the above embodiment. (2) Although not shown, the thickness of the notch 14 is made larger or smaller than the illustrated example. thing. Also, the notch 14 should be cut out. (3) The mounting cylinder portion 5d may be formed separately or flush with the top surface of the cap portion 5a. To do something. (4) Cut the notch 14 on both the upper and lower electrodes 11, 12 or on the outer surface side of the mounting tube 5d. To form. (5) To be embodied in a cylindrical lightning arrester other than a suspended type lightning arrester.

[0024]

[Effect of the idea]

As detailed above, the present invention allows both the upper and lower ends of the mounting tube to be used under normal usage conditions. Upper and lower lid members made of ceramic with excellent weather resistance, impact resistance, and heat resistance. Since it is airtightly sealed, the airtightness of the current limiting element housing space inside the mounting tube is maintained It can be maintained for a long period of time, prevents deterioration of the current limiting element due to moisture, and increases the durability of the lightning arrester. performance and reliability can be improved. Moreover, the upper part is made of conductive ceramic. and a lower lid member, so that the upper and lower lid members and the upper and lower electrodes are connected to each other. can also be used as a component, simplifying the structure and reducing costs. Ru. Furthermore, the current limiting element becomes conductive due to lightning surge current, causing high temperature and high voltage arcs. When a crack occurs, stress is concentrated in the thin wall part before other parts, causing the crack. Furthermore, ceramics do not have malleability like metals, and the cracks can cause arcing. Due to the pressure of the gas, it expands at once and ruptures the thin part, and from this ruptured part High-pressure gas is quickly released to the outside, preventing the insulator from bursting. I can do it. In addition, even if the lid member ruptures at the thin wall portion, the lid member will not be damaged. Since the lead wire is attached, there is a risk that the lid member will fall to the ground etc. due to the rupture. This has the excellent effect of being able to avoid accidents and prevent public disasters from occurring. play.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of essential parts of an embodiment of the present invention in a suspended lightning arrester.

FIG. 2 is a sectional view taken along line AA in FIG. 1.

FIG. 3 is a half-longitudinal cross-sectional view showing a lightning arrester.

FIG. 4 is a front view showing the usage state of the lightning arrester.

FIG. 5 is a sectional view of main parts showing another example of the present invention.

6 is a sectional view taken along line BB in FIG. 5. FIG.

FIG. 7 is a partial cross-sectional view showing one of the conventional examples.

FIG. 8 is a partial sectional view showing another conventional example.

[Explanation of symbols]

3 lightning arrester, 5 insulator body, 5a cap, 5c head, 5d mounting tube, 5e through hole, 7 cap metal fitting,
8 pin fitting, 9 current limiting element, 11 upper electrode as upper lid member, 12 lower electrode as lower lid member, 14
Notch, 15 Thin wall part, 18, 19 Lead wire.

Claims (2)

[Scope of utility model registration request] Claim 1: A current limiting element with non-linear voltage-current characteristics is housed inside a mounting tube, and both upper and lower ends of the mounting tube are airtight with an upper cover member and a lower cover member made of conductive ceramic. A thin wall portion is formed on the upper lid member, the lower lid member, or the inner wall of the mounting cylinder portion to form a thin portion that ruptures earlier than other portions due to a high-temperature, high-pressure arc; is a lightning arrester characterized by having a lead wire attached to it. [Claim 2] The lightning arrester has a cap (5) of the insulator body (5).
A cap metal fitting (7) is fixed to the capped cylindrical head (5c) formed at the center upper part of a), and a pin metal fitting (8) is fitted and fixed inside the head (5c). The suspension insulator (3) has a through hole (5e) in the cap (5a).
A current limiting element (9) is fitted into the through hole (5e), and a lead wire ( 18)
The lower lid member (12) also serves as the lower electrode.
The lightning arrester according to claim 1, wherein the and pin fittings (8) are electrically connected by lead wires (19).