JPH02234376A - Lightning protecting insulator - Google Patents

Abstract

PURPOSE:To secure the insulation strength as a lightning protecting insulator by protruding terminal metals of a current limiting element on the outer periphery of an insulating outer casing so that arc capturing members 15 and 18 on the grounding side and the charging side are faced to each other, and connecting the terminal metals and electrodes with fusible conductors on the outside of the insulating outer casing. CONSTITUTION:Terminal metals 21 and 22 of a current limiting element 3 are protruded on the outer periphery of an insulating outer casing 13 so that arc capturing members 15 and 18 on the grounding side and the charging side, and the terminal metals 21 and 22 and electrodes 4 and 5 are connected by fusible conductors 23 and 25 on the outside of the insulating outer casing 13. The fusible conductors 23 and 25 are melted by the dynamic current after the lightning surge, arc discharges occur across the terminal metals 21 and 22 and the arc capturing members 15 and 18 on the grounding side and the charging side of a lightning protecting insulator, and the internal arc of the lightning protecting insulator is instantly changed to the aerial discharge across the arc capturing members 15 and 18. The insulation as a device including the lightning protecting insulator is improved, and reliability can be increased.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention quickly discharges the high voltage caused by a lightning surge to the ground when it is applied to a power transmission line, and limits the subsequent current. This article relates to lightning arrester insulators used in TR insulators that prevent ground faults from occurring by blocking them with elements. More specifically, when it becomes impossible to break the current following a lightning surge due to deterioration of the current-limiting element due to an unexpected lightning strike, moisture absorption, or other causes, the high-temperature, high-pressure arc that occurs in the current-limiting element is At the initial stage, it quickly migrates into the atmosphere. This article relates to lightning arresters that reduce damage to voltage-resistant insulation sheets. [Prior art] Conventional lightning arresters of this type include a current-limiting element made of zinc oxide (ZnO) with non-linear voltage-current characteristics, and a reinforced synthetic resin with a plurality of pressure relief holes provided on the outer periphery. It is known that the main material is a pressure-resistant insulating cylinder made of (FRP), and arc trapping members such as arcing rings are provided at both the upper and lower ends. In this lightning arrester, the above-mentioned Iil current element usually prevents ground faults even after lightning surge treatment, and deterioration of the current limiting element due to unexpected lightning strikes, moisture absorption, or other causes. Due to this, follow-up 3I after lightning surge! If it becomes impossible to disconnect, in order to minimize damage to the current-limiting element, voltage-resistant insulation sheet, etc., the arc is blown out from the pressure relief hole, and the blown-out arc is used to control the internal arc in the upper and lower directions. It is designed to transition to an air arc between arc capture members. By the way, in this conventional lightning arrester, even under conditions where the following current reaches 20 to 50 KA, it is necessary to increase the thickness of the voltage-resistant insulation strip, provide special reinforcement, or provide pressure relief holes. This can be solved by increasing the number of lightning arresters, but there are problems in that the overall size of the lightning arrester becomes larger, the number of processing steps during manufacturing increases, and the manufacturing price increases. In order to solve these problems, the applicant of the present invention disclosed the previous patent application No. 1N (Japanese Patent Application No. 61-26583).
In No. 1), we proposed the following lightning arrester hook device. That is, in this lightning arrester hook device, the grounding side electrode of the lightning arrester is attached to the support arm of the tower body via the horn mounting bracket and an insulating material, and the grounding arcing horn is attached to the horn mounting bracket in correspondence with the grounding side electrode. On the other hand, the lightning arrester's electrode is connected via an insulating material! Attach the arcing horn of @, connect the ground side electrode of the lightning arrester and the ground side arcing horn with a fusible conductor, *t
rpJtf1 and the arcing horn on the power supply side are connected by a fusible conductor, and the arcing horn on the power supply side and the power transmission line are connected with or without a discharge gap. In this lightning arrester device, when a lightning surge is applied to a power transmission line, the fusible conductor normally exhibits a current carrying function.
Current is discharged through the current limiting element. On the other hand, if it becomes impossible to cut off the follow-on current after a lightning surge, the fusible conductor will be blown off by the follow-on current, and there will be a gap between the grounding side electrode and energized side electrode of the lightning arrester and the arcing horn. Arc discharge occurs. This arc is caused by the current flowing through the arcing horn and the arc discharge 44f! Due to the electromagnetic force between the lightning bolt and the arcing horn, the internal arc of the lightning arrester instantly shifts to the air arc between the arcing horns on the grounding side and the charging side. Therefore, the duration of the current flowing through the lightning arrester is significantly reduced, reducing damage. [Problems to be Solved by the Invention] However, in the configuration of the prior application, the insulating material is located outside the lightning arrester between the ground side electrode of the lightning arrester and the horn mounting bracket, and between the energized side electrode of the lightning arrester. Since they are interposed between the lightning arrester and the arcing horn on the power-supplying side, when attaching the lightning arrester hook to the support arm of the tower body, it is necessary to attach it to the support arm at the site through the horn mounting bracket and insulating material. The grounding side electrode of the lightning arrester must be fixed with multiple bolts, etc., making the installation process extremely troublesome.Moreover, when the lightning arrester is installed, the insulating material is exposed at both the upper and lower ends. The problem was that the overall length of the lightning arrester hook device became long, making it difficult to install it on existing railway lines. This improvement was made by focusing on the problems existing in the conventional technology and the technology of the prior application, as described above, and its purpose is to install the lightning arrester to the support arm of the tower body. In this case, there is no need to separately install an insulator, and the installation work can be performed easily.In addition, the overall length of the lightning arrester device in the installed state is shortened, and it can be easily applied to existing railway lines. In addition, the burden on the lightning arrester itself from follow-on arcs is reduced, and there is no need to increase the thickness of the voltage-resistant insulation sheet or increase the number of pressure relief holes, and the reinforcement structure can be simplified. In addition, even if the lightning arrester fails as mentioned above, the insulation of the jacket body facing the fusible conductor is sound, so it can be manufactured at a certain level as a lightning arrester. The purpose of this project is to provide a lightning arrester with the added fail-safe function of ensuring insulation strength. [Means for Solving the Problems] In order to achieve the above-mentioned goal, in the lightning arrester of the present invention, a current-limiting element with a non-linear voltage-current characteristic is housed inside the voltage-resistant insulation sheet, and the voltage-resistant A grounding side electrode and an energizing side electrode are connected to both ends of the insulating strip, and the outer periphery of the voltage-proof insulating tube is covered with a green jacket, and both electrodes are protected against creeping flash under conditions where the jacket is contaminated. Arc trapping members are installed on the grounding side and on the energized side to minimize damage to the insulating jacket during short-circuiting or pressure release when a lightning surge flows through the current limiting element and the internal pressure of the voltage-resistant insulation sheet increases. In the installed lightning arrester, an insulator is interposed between both ends of the current limiting element and each electrode in the voltage-resistant insulating cylinder, so as to correspond to the arc trapping members on the ground side and the energized side. Terminal fittings on the grounding side and power supply side connected to both ends of the current limiting element are protruded from the outer periphery of the insulating mantle, and each terminal fitting and the electrode are connected by a fusible conductor on the outside of the insulating mantle. It is. [Function] According to the lightning arrester configured as described above, since the insulator is recessed into the voltage-resistant insulation cylinder at both ends of the current limiting element, the lightning arrester is attached to the support arm of the tower body. There is no need to use a separate insulator when installing the insulator, making the installation process easy. Furthermore, since the insulator is not exposed outside the lightning arrester when the lightning arrester is installed, the overall length of the lightning arrester device can be shortened.
In a lightning hook device using this lightning arrester, when a lightning surge is applied to a power transmission line, the fusible conductor normally exhibits a current-carrying function, so the current is discharged through the current-limiting element. On the other hand, if it becomes impossible to cut off the follow-on current after a lightning surge, the fusible conductor will be fused and cut off by the follow-on current.
Arc discharge occurs between the terminal fittings on the grounding side and energized side of the lightning arrester and the arc trapping member. Due to the electromagnetic force between the current flowing through the arc trapping member and the arc discharge electrode, this arc is quickly transferred between the tips of the arc trapping members on the grounding side and the energized side, and the internal arc of the lightning arrester is instantaneously removed. As the arc eventually shifts to an airborne arc between the arc trapping members, the duration of the current flowing through the lightning arrester is significantly reduced, reducing damage. In addition, since the insulation of the outer body facing the fusible conductor is sound, even in the event of a failure, the insulation of the device including the lightning arrester hook can be improved compared to the conventional method, and reliability can be increased. [Example] Hereinafter, an example of a lightning arrester embodying the present invention will be described in detail based on FIGS. 1 to 3. As shown in Figures 1 and 2, the lightning arrester 1 is made of reinforced synthetic resin (PR).
The present invention includes a voltage-resistant insulating cylinder 2 made of P), in which a current-limiting element 3 whose main material is lead oxide (ZnO) with non-linear voltage-current characteristics is housed in a laminated state. Voltage proof insulation simple 2
There is a grounding side voltage f! at both ends. 4 and a charging side electrode 5 are fitted and fixed, and the lightning arrester hook 1 is mounted on a mounting adapter 6 extending from a support arm or the like of a tower (not shown) by means of this grounding side electrode 4.

In the voltage-resistant insulating cylinder 2, conductor fittings 7.8 on the grounding side and on the charging side are connected to both ends of the current limiting element 3, and between the conductor fitting 8 on the charging side and the charging t-side electrode 5. Insulator 9 is interposed. A nut 10 made of an insulating material or metal is screwed and fixed to the ground ll1j electrode 4, and an insulator 11 is connected to the inner end of the nut 10. A coil spring 12 is interposed between the conductive metal fitting 7 on the ground side and the insulator 11, and the current limiting element 3 is fixed and pressed between both the conductive metal fittings 7 and 8 by this coil spring 12. An insulating jacket 13 made of rubber or the like is molded on the outer circumference of the voltage-resistant insulating cylinder 2, and a plurality of insulating folds 1 are formed on the outer circumferential surface of the insulating jacket 13.
3a is provided. When molding this insulating jacket 13, the injection hole 10a provided in the nut 10 is
Rubber or the like is injected as an insulating filler 14 into the gap between the inner circumferential surface of the voltage-resistant insulating cylinder 2 and the outer circumferential surface of the current limiting element 3 through the insulating tube 2 . An arcing ring 15 serving as a grounding-side arc capturing member is mounted on the mounting adapter 6 via a bracket 16 so as to correspond to the grounding-side electrode 4. A mounting bracket 17 is provided protrudingly on the energizing @electrode 5, and an arcing ring 18 serving as an arc capturing member on the energizing side is attached to the mounting bracket 17 via a bracket 19.
Further, the mounting bracket 17 is equipped with a discharge voltage f! for arc discharge. 20
is attached, and is placed opposite to a discharge electrode provided on a support insulator (not shown) that supports a power transmission line, with a predetermined air discharge gap. As shown in FIGS. 1 to 3, the conductor fitting 7 on the ground side
A terminal fitting 21 on the grounding side is screwed and fixed to the terminal fitting 21, passes through the voltage-resistant insulating strip 2, projects to the outer surface of the insulating jacket 13, and corresponds to the arcing ring 15 on the grounding side with a predetermined gap. The conductor metal fitting 8 on the power charging side has a terminal metal fitting 22 on the power charging side.
is screwed and fixed, penetrates the voltage-resistant insulating strip 2 and protrudes from the outer surface of the insulating jacket 13, and an arcing ring 18 on the energized side
A fusible conductor 23 for connecting the two is fixed with a screw 24 between the ground side terminal fitting 21 and the ground side electrode 4, which correspond to each other with a predetermined gap. Furthermore, a fusible conductor 25 is fixed between the terminal fitting 22 on the power supply side and the power supply side electrode 5 with a screw 26 for connecting the two. In this embodiment, both the fusible conductors 23 and 25 are each made of a thin plate made of copper or aluminum with a thickness of 0.2 mm and a width of 10 to 15 mm, and are not blown out by lightning surges and remain continuous. Depending on the flow, it can be fused.

Furthermore, in this example, each fusible conductor 23.25
Insulating pleats 27 are formed on the outer circumferential surface of the insulating jacket 13 in accordance with
are formed respectively, and when the fusible conductors 23 and 25 are fused,
Sufficient insulation 1? is provided between the terminal fitting 21 on the grounding side and the grounding electrode 4, and between the terminal fitting 22 on the charging side and the charging t-side electric fi5. Ii separation is ensured. Next, the operation of the lightning arrester formed as described above will be explained.

Now, if a lightning surge is applied to a power transmission line (not shown),
The surge current is discharged in the air discharge gap between the discharge electrode on the support insulator supporting the power transmission line and the discharge electrode 20 on the lightning arrester 1, and reaches the energized side electrode 5 of the lightning arrester 1. At this time, since both the fusible conductors 23 and 25 have a energizing function for the lightning surge current, the surge @ current flows from the electrode 5 on the section 4a side to the fusible conductor 25, the terminal fitting 22 on the charging side, and The flow passes through the conductor fitting 8 to the current limiting element 3, and further flows through the grounding side conductor fitting 7, the terminal fitting 21, the fusible conductor 23, and the grounding side electrode 4.
It then reaches the mounting adapter 6 via the support arm (not shown) and is grounded via the tower body. Subsequent currents are blocked by the above-mentioned air discharge gap and the current limiting element 3 in the lightning arrester 1. However, if the current limiting element 3 deteriorates or the follow-on current following an abnormally large lightning surge becomes unblockable, the excessive follow-on current may damage the lower and upper fusible conductors 23 of the lightning arrester 1.
25 is fused. At this time, the insulators 11.9 provided at the lower and upper parts of the voltage-resistant insulator 2 of the lightning arrester 1 create a space between the grounding side electrode 4 and the conductor fitting 7, and between the voltage-supplying side electrode 5 and the conductor fitting 8. Since the terminal fitting 21 on the ground side and the arcing ring 15 are insulated from each other,
An arc is simultaneously generated between the terminal fitting 22 on the section T side and the arcing ring 18. Due to magnetic action, the shark arc connects with the arcing ring 15 on the ground side.
It quickly culms between the tips of the arcing ring 18 of a, forming an aerial arc. Therefore, the duration of the arc within the lightning arrester 1 is significantly shortened, and the burden on the voltage-resistant insulating sheet 2 from the heat and pressure of the internal arc is reduced. Therefore, there is no need to provide reinforcement such as increasing the wall thickness of the pressure-resistant green cylinder 2, and the structure of the catching structure can be simplified, and the lightning arrester 1 can be made smaller. In addition, in the lightning arrester 1 of this embodiment, the insulator 9,
11 is an ellipse built into the voltage-proof insulating cylinder 2, facing both the upper and lower ends of the current limiting element 3, so that the insulator 9.
11 is not required to be separately installed, and the installation work can be easily performed. Furthermore, since the insulators 9 and 11 are not exposed outside the lightning arrester 1 when the lightning arrester 1 is installed, the overall length of the lightning arrester device is shortened, and it can be easily applied to existing railway lines. can. Further, in this embodiment, since the insulating pleats 27 are formed on the outer circumferential surface of the insulating jacket 13 in correspondence with the respective fusible conductors 23 and 25, the fusible conductors 23 and 25 due to excessive follow-on current. 25, a sufficient insulation distance is ensured between the grounding side terminal fitting 21 and the grounding side electrode 4, and between the energizing side terminal fitting 22 and the energizing IllI electrode 5. An increase in reliability can be expected as the insulation strength improves. It should be noted that the present invention is not limited to the configuration of the above-mentioned embodiment. For example, as shown in FIGS. 4 and 5, an arcing horn 28 is provided as an arc capturing member on the grounding side, and
The configuration of each part may be arbitrarily changed and embodied without departing from the spirit of the present invention, such as by similarly providing an arcing horn as the arc trapping member on the energizing side.
I directly support the wire! ! It is also possible to apply it as an M T4 child. [Effects of the Invention] Since the lightning arrester of the present invention is configured as explained above, there is no need to separately interpose an insulator when installing the lightning arrester to the support arm of the tower body, and the installation work is simplified. It is easy to carry out, and the overall length of the lightning arrester device in the installed state is shortened, making it possible to easily apply it to existing railway lines, which is an excellent effect. In addition, in the lightning arrester of the present invention, the burden on the lightning arrester itself against follow-on arcs is reduced, so there is no need to thicken the wall thickness of the pressure-resistant B cylinder or increase the number of pressure relief holes.
It also has the effect of simplifying the reinforcing structure and making it possible to manufacture it at low cost with fewer processing steps. In addition, since the insulation of the jacket body facing the fusible conductor is sound, even in the event of a failure, the insulation of the device including the lightning arrester can be improved compared to conventional methods, and reliability can be increased.

[Brief explanation of drawings]

Fig. 1 is a partial sectional view of the grounding side end of an embodiment of a lightning arrester embodying the present invention, Fig. 2 is a partial sectional view of the energized side end of the lightning arrester, and Fig. 3 is a partial sectional view of the energized side end of the lightning arrester. FIG. 4 is a front view of the arcing horn portion showing another embodiment of the present invention, and FIG. 5 is a partial plan view of the arcing horn. 1-... Lightning arrester hook, 2... Voltage-proof insulation tube, 3...
Current-limiting cable, 4... Grounding side electrode, 5... Voltage charging side electrode,
9.11... Insulator, 13... Insulating jacket, 15.
... Arcing ring as an arc capturing member on the grounding side, 18... Arcing ring as an arc capturing member on the charging side, 21... Terminal fitting on the grounding side, 22... Terminal fitting on the charging side, 23.25...Flutable conductor. Patent applicant Nippon Teiko Co., Ltd. Agent Patent attorney Hironobu Onda and 1 other person jI1 Figure 10a IQ M4 Figure mouth big smile ◎

Claims (1)

[Claims] 1. A current-limiting element (3) with non-linear voltage-current characteristics is housed inside a voltage-resistant insulating tube (2), and a grounding side and Connect the electrodes (4, 5) on the power supply side,
The outer periphery of the voltage-resistant insulating tube (2) is covered with an insulating mantle (13), and both the electrodes (4, 5) are covered with the current limiting element during creeping flash under conditions where the insulating mantle (13) is contaminated. (3
) is used to minimize damage to the insulation jacket (13) when the internal pressure of the voltage-resistant insulating tube (2) increases due to lightning surge flowing through
5, 18), an insulator (9, 11) is provided between both ends of the current limiting element (3) and each electrode (4, 5) in the voltage-resistant insulating cylinder (2). interposed, and the arc trapping member (1
5, 18), terminal fittings (21, 22) on the grounding side and on the charging side connected to both ends of the current limiting element (3) are provided protruding from the outer periphery of the insulating jacket (13). , each terminal fitting (21, 22) and electrode (4, 5) are connected to an insulating jacket (13).
) is connected to the outside of the lightning arrester by a fusible conductor (23, 25).