JPH01163925A - Lightening insulator - Google Patents

Abstract

PURPOSE:To reduce the thickness of an insulator tube and to make a lightening insulator in a compact size by transferring the arc to pressure release holes while selecting a low strength of porous organic insulator, when a current limit element is made in a conductive condition and an arc is generated. CONSTITUTION:In an enclosed space of a pressure-resisting insulator tube 1, a current limit element 6 with the nonstraightness of voltage-current property is accommodated with a specific interval to the inner periphery surface. And at the adequate positions of the insulator tube 1, plural pressure release holes 1a are penetrated. And to a clearance between the insulator tube 1 and the element 6, a rubber is poured as an insulating filler 14. Moreover, to the clearance between the insulator tube 1 and the element 6, a porous organic insulating material 15 with the strength lower than the filler 14 is accommodated responding to the pressure release holes 1a in the longitudinal direction of the insulator tube 1. Consequently, even when a high temperature and high voltage arc is generated, it is transferred to the pressure release holes 1a while selecting the insulator 15 whose strength is lower than the filler 14, and the high voltage arc is released rapidly from the pressure release holes 1a to the outside. The thickness of the insulator tube 1 can be reduced accordingly.

Description

[Detailed Description of the Invention] Purpose of the Invention (Field of Industrial Application) The present invention promptly discharges lightning surge current to the ground when it flows through a power transmission line or distribution line, and also discharges the subsequent commercial frequency continuation. This invention relates to a lightning arrester that can suppress and interrupt current flow.

(Problems to be Solved by the Prior Art and the Invention) As a conventional lightning arrester, as shown in FIG.
An annular current-limiting element 32 is fitted into the rod, cap fittings 33 and 34 are provided at both ends of the tension-resistant insulating rod 31, and an elastic body 35 is inserted between the cap fittings 33 and 34. There is a structure in which the current limiting element 32 is held under pressure and the outer periphery of the current limiting element 32 is molded with an organic insulator 36 to seal and encapsulate the current limiting element 32.

However, the above-mentioned lightning arrester has a problem in that when the short circuit current increases during pressure release, the current limiting element 32 and the organic insulator 36 are likely to be damaged and scattered due to the high pressure gas and heat generated during pressure release. Therefore, to solve this problem, organic insulator 3
It was necessary to install a rupture disc in 6. However, this rupture disc has been very problematic in terms of manufacturing, installation, and airtight reliability.

In order to solve this problem, the applicant proposed a lightning arrester shown in FIG. In this lightning arrester, cap metal fittings 38 and 39 are fitted and fixed to the openings at both ends of a cylindrical voltage-resistant insulating tube 37, and a current-limiting element 32 is accommodated in the voltage-resistant insulating tube 37. 38 and 39, at least one or more pressure relief holes 37a are provided in the voltage-resistant insulating cylinder 37 so as to correspond to both ends of the current limiting element 32, and the cap fittings 38 and 39 are electrically connected to the cap fittings 38 and 39. Arc inviting members 40 are provided so as to correspond to the outsides of the pressure relief holes 37a, and the outer periphery of the voltage-resistant insulating cylinder 37 and the gap between the voltage-resistant insulating cylinder 37 and the current-limiting element 32 are provided with an organic insulating material 41 made of rubber.
We offer lightning protection insulators molded with

However, in this lightning arrester, the gap g between the voltage-resistant insulating cylinder 37 and the current limiting element 32 is filled with a rubber organic insulating material 41, so in the unlikely event that the current limiting element 32 becomes conductive for some reason. In this case, the pressure-resistant insulating tube must withstand the pressure generated by the arc, so the thickness must be within that range, resulting in an increase in size.

An object of the present invention is to solve the problems existing in the above-mentioned conventional technology, and to prevent the current limiting element from becoming conductive in the unlikely event that an unexpected surge current enters the lightning arrester or for other reasons. In such cases, the high-temperature, high-pressure arc can be easily propagated to the pressure relief hole provided in the voltage-resistant insulating cylinder, and the pressure can be released quickly and reliably. The purpose is to provide lightning protection insulators.

Structure of the Invention (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a structure in which electrode fittings on the grounding side and on the energizing side are fitted and fixed to both ends of a voltage-resistant insulating cylinder having a pressure relief hole. A current-limiting element with non-linear voltage-current characteristics is housed inside the voltage-proof insulating cylinder with a predetermined gap between it and the inner peripheral surface thereof, and the electrode fitting and both upper and lower ends of the current-limiting element are electrically connected. and an insulating jacket is coated on the outer periphery of the voltage-resistant insulating cylinder,
In a lightning arrester in which an insulating filler such as rubber is accommodated in the gap, the insulating filler is placed in the gap so as to correspond to the pressure release hole and to extend in the longitudinal direction of the voltage-resistant insulating tube. The method is to provide a porous organic insulating material whose strength is lower than that of the material.

(Function) By adopting the above-mentioned means, the present invention functions as follows.

In the gap between the pressure-resistant insulation cylinder and the current limiting element, which corresponds to the pressure relief hole,
Since the porous organic insulator is arranged to correspond to the pressure relief hole, in the unlikely event that an unexpected lightning surge current flows through the current-limiting element, or due to other causes, the current-limiting element becomes conductive. When this happens, a high-temperature, high-pressure arc occurs. This arc passes through the porous organic insulator selectively having a lower mechanical and thermal strength than the insulating filler,
Since it propagates to the pressure relief hole, it becomes easy to release the pressure to the outside.

As a result, the pressure applied to the voltage-resistant insulating tube is also reduced, and the wall thickness can be reduced by this amount, making it possible to downsize the lightning arrester.

(Example) Hereinafter, an example embodying the present invention will be described based on FIGS. 1 to 5.

A ground side electrode fitting 3 is fitted and fixed to the upper end outer circumference of a cylindrical pressure-resistant insulating cylinder 1 made of reinforced resin (for example, FRP) with an adhesive 2, and a steel tower (not shown) is attached to the outer circumferential surface of the electrode fitting 3. A flange portion 3a is integrally formed to be attached to a mounting adapter attached to the support arm. Further, a bottomed cylindrical electrode fitting 4 on the power supply side is hermetically fitted and fixed to the outer peripheral surface of the lower end of the voltage-resistant insulating cylinder 1 with an adhesive 2, and on the lower surface of the electrode fitting 4, although not shown, A platen 4a is integrally formed for attaching a power-supplying side arcing horn attached to the power transmission line side and a grounding side arcing horn opposing with a predetermined air discharge gap.

A fitting cylindrical portion 4b is formed on the inner bottom surface of the electrode fitting 4 in the energizing example, and the lower end portion of the conductive fitting 5 on the energizing side is fitted and fixed to this. On the upper surface of the conductive metal fitting 5, a current limiting element 6 whose main material is zinc oxide whose voltage-current characteristics are non-linear is disposed.
are stacked in series, and a ground-side conductive metal fitting 7 having a cylindrical shape with a bottom and also serving as a spring support is supported on the upper end surface of the current-limiting element 6.

On the other hand, a tightening ring 8 is screwed into a threaded portion 3b formed on the inner peripheral surface of the electrode fitting 3 on the ground side, and between the intermediate conductor 9 fitted in the ring 8 and the conductor fitting 7. A coiled spring 11 having a shunt 10 for energization is interposed. This spring 11 presses and fixes the current limiting element 6 between the conductive metal fitting 5 on the power supply side and the conductive metal fitting 7 on the grounding side.

Further, as shown in FIG. 2, a plurality of circular or elongated pressure relief holes 1a are transparently provided at appropriate locations in the voltage-resistant insulating tube 1. Furthermore, an insulating jacket 12 made of, for example, rubber and having a large number of insulating pleats 12a is hermetically molded on the outer peripheral surface of the voltage-resistant insulating cylinder 1. This insulating jacket 1
2 extends to the outer circumferential surface of the electrode fittings 3 and 4 to improve airtightness with the electrode fittings 3 and 4. Further, this outer mantle 12 also enters into the pressure relief hole 1a.

Furthermore, at the same time as the insulating jacket 12 is molded, an insulating sealing body 13 seals the opening of the electrode fitting 3 on the ground side.
is molded. When molding the insulating sealing body 13, the rubber passage 8a formed on the outer periphery of the insulating ring 8 is passed through the inner circumferential surface of the voltage-resistant insulating tube 1 and the current limiting element 6.
Rubber is injected as an insulating filler 14 into the gap g between the outer peripheral surface and the outer circumferential surface.

As shown in FIGS. 1 to 3, in the gap g between the voltage-resistant insulating cylinder 1 and the current limiting element 6, there is a mechanically and thermally A porous organic insulator 15 having low physical strength is accommodated over the entire length of the current limiting element 6 in the longitudinal direction.

The porous organic insulator 15 is made of, for example, silicone rubber, E
It is made of a material such as PDM rubber and is housed in the gap g before the insulating filler 14 is injected, but since the insulating filler 14 is injected under low pressure, there is almost no effect on the insulator 15.

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

Now, when a lightning surge current flows through a power transmission line with a lightning arrester attached to a steel tower, the current flows from the arc horn (path shown) on the power transmission line side to the arc horn at the lower end of the lightning arrester (
The electrode fitting 4 on the charging side is flooded over to the illustrated path),
conductive metal fitting 5, current limiting element 6, conductive metal fitting 7, shunt 10,
It flows through the intermediate conductor 9 and the tightening ring 8 to the electrode fitting 3 on the ground side, further flows to the steel tower via a mounting adapter (not shown), and is discharged to the ground.

Furthermore, subsequent currents that occur thereafter are suppressed and blocked by both arc horns and the current limiting element 6.

Now, in the present invention, a porous organic material having lower strength than the insulating filler 14 is formed in the longitudinal direction of the V11 edge cylinder 1, corresponding to the pressure relief hole 1a, for the gap between the voltage-resistant insulation cylinder 1 and the current limiting element 6. Since the insulating material 15 is included, in the unlikely event that a lightning surge current larger than expected is applied to the current-limiting element 6, the current-limiting element 6 becomes conductive, and a high-temperature, high-pressure arc occurs. Even in the case where the porous organic insulator 15 with weak strength is selected before the insulating filler 14, it is propagated to the pressure release hole 1a,
As a result, the high-voltage arc quickly melts a part of the insulating jacket 12 from the pressure relief hole 1a and is discharged to the outside, so that the pressure rise inside the voltage-resistant insulating tube 1 can be reduced, and the pressure-resistant insulating tube 1 can be It becomes possible to make the wall thinner, and the lightning arrester can be made smaller.

Note that the present invention can also be embodied in the following manner.

In the embodiment described above, the porous organic insulator 15 was provided over the entire length of the current limiting element 6 in the longitudinal direction, but it may be formed only in the vertical direction of the pressure release hole 1a.

Effects of the Invention As detailed above, this invention can prevent the current limiting element from becoming conductive due to unexpected lightning strikes or other causes.
When a high-temperature, high-pressure arc occurs, the arc can be quickly moved to the pressure relief hole by selecting the porous organic JA edge, so the pressure is quickly released and the pressure rise in the pressure-resistant insulation cylinder is reduced. This has the effect of making the voltage-resistant insulating tube thinner.

[Brief explanation of the drawing]

Fig. 1 is a half-box sectional view showing an embodiment of the lightning arrester of the present invention, Fig. 2 is a partial perspective view of a voltage-resistant insulating tube, Fig. 3 is a sectional view taken along line A-A in Fig. 1, and Fig. 4. 1 is a sectional view taken along the line B--B in FIG. 1, FIG. 5 is a sectional view taken along the line C--C in FIG. 1, and FIGS. 6 and 7 are longitudinal sectional views showing the conventional example. DESCRIPTION OF SYMBOLS 1... Voltage-proof insulating cylinder, 1a... Pressure relief hole, 3... Electrode fitting on the grounding side, 4... Electrode fitting on the power supply side, 5... Conductive fitting, 6... Current limiting Element, 7... Conductor fitting, 8...
・Tightening ring, 9... Intermediate conductor, 10... Shunt, 11... Spring, 12.13... Insulating sealing body, 14
... Insulating filler, 15... Porous organic insulator.

Claims (2)

[Claims] 1. Electrode fittings on the grounding side and on the power supply side are fitted and fixed to both ends of a voltage-resistant insulating cylinder having a pressure relief hole, and the voltage-current characteristics are maintained within the voltage-resistant insulating cylinder with a predetermined gap between the inner peripheral surface and the inside. A linear current-limiting element is housed, the upper and lower ends of the current-limiting element are electrically connected to the electrode fitting, the outer periphery of the voltage-proof insulating cylinder is covered with an insulating jacket, and the gap is covered with rubber or the like. In a lightning arrester containing an insulating filler, a porous hole having a lower strength than the insulating filler is provided in the gap so as to correspond to the pressure relief hole and extend in the longitudinal direction of the voltage-resistant insulating tube. A lightning arrester characterized by being provided with a synthetic organic insulating material. 2. The lightning arrester according to claim 1, wherein the porous organic insulating material is formed over the entire length of the current limiting element in the longitudinal direction.