JPH04242023A - Lighting insulator device for power-transmission line - Google Patents

Abstract

PURPOSE:To provide a gapless lightning insulator device which is compact in the suspending direction, not causing permanent grounding even in the case of lightning insulator breakage, and attachable to an existing steel tower. CONSTITUTION:A suspending insulator 4 is suspended by a support arm 1 of a steel tower. To a lowermost end part of the suspending insulator 4, a stretchedly arranged lightning insulator 11 fitted with lightning insulators 10 oriented in one direction of a line and a stretchedly arranged lightning insulator 18 oriented in the other direction of the line are connected. Therefore, this device becomes short in the vertical length in comparison to a device wherein the suspending insulator 4 and the lightning insulator 10 are suspended in series. A breaker 26 is connected between a grounding side and an electric application side of the suspending insulator 4, and in the case where an unexpectedly large lightning surge current is applied, the breaker 26 is broken and parted to electrically separate the lightning insulator 10 from the system.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightning arrester device for a power transmission line that promptly discharges lightning surge current to the ground when it enters the power transmission line.

0002

[Prior art] Lightning arrester 1 in which a lightning arrester element is enclosed within the insulator
As a lightning arrester device in which a lightning arrester 0 is mounted on a steel tower, the one shown in FIG. 11 is known. In this device, a plurality of lightning arresters 10 each having a built-in lightning arrester element are connected in series and suspended from a support arm 1 of a steel tower, and the lightning arrester elements in each lightning arrester 10 are electrically connected in series. If lightning surge current enters the power transmission line 22, the current is discharged to the support arm 1 side by the lightning arrester, and the subsequent flow of operating voltage is limited by the lightning arrester, thereby preventing a ground fault. It is designed to prevent

0003

However, in this lightning arrester device, if the lightning arrester element is damaged, the lightning arrester element becomes a defective insulator and a ground fault occurs. At this time, the circuit breaker operated, but there was a technical problem in that the circuit breaker could not be turned on again. Furthermore, even if such technical issues were solved, the length of the lightning arrester device would not only make it necessary to increase the size of the steel tower, but it would also be necessary to increase the size of the existing steel tower, which has a predetermined gap between the support arms of each phase. There were technical issues that made it impossible to apply.

An object of the present invention is to provide a lightning arrester device for a power transmission line that is compact in the hanging direction and does not cause a permanent ground fault even if the lightning arrester is damaged. .

[0005]

[Means for Solving the Problems] In order to achieve the above object, in this invention, a hanging insulator is suspended from a support arm of a steel tower, and at the lower end of the hanging insulator, at least Stretched insulators with a lightning arrester attached to one side are connected, a power transmission line is stretched across the energized side end of each stranded insulator, and a jumper wire is used to connect the energized side of both stranded insulators. A disconnector is connected between the ground side and the energized side of the hanging insulator, which is activated and electrically disconnected by a faulty ground fault current or an abnormal current exceeding the lightning surge withstand capacity of the lightning arrester.

[0006]

[Operation] In the lightning arrester device of the present invention, a suspended insulator is suspended from a support arm of a steel tower, and a tension insulator connected to the lower end of the suspended insulator is directed in each direction of the railway line. Since the lightning arrester is attached to the lightning arrester, the lightning arrester device is more compact than a lightning arrester device in which each insulator is hung in series. Therefore, there is no need to increase the gap between the upper and lower support arms.

[0007] Furthermore, since the tensioned insulator is equipped with a lightning arrester on at least one side of the tensioned insulator, lightning surges that enter the power transmission line flow from the disconnector to the steel tower via the lightning arrester and are discharged to the ground. At this time, the lightning arrester allows the lightning surge to flow and limits the subsequent flow of the operating voltage. When a lightning surge current or AC ground fault current that is larger than expected flows, the disconnector is activated and electrically disconnects the ground side and the energized side of the suspended insulator. Therefore, the lightning arresters connected in series are disconnected from the grid and permanent ground faults are prevented.

[0008]

[Embodiment] [Embodiment 1] Embodiment 1 embodying the present invention will be described below with reference to FIGS. 1 to 7. As shown in FIG. 2, a ground side hanging metal fitting 2 is rotatably connected to the support arm 1 of the steel tower, and a plurality of suspended type insulators 3 are connected to the lower part of this ground side hanging metal fitting 2. A suspended insulator 4 is suspended. A power-supplying side hanging fitting 5 is connected to the lower end of this hanging insulator 4, and a connecting yoke 6 is connected to the lower end of this power-supplying side hanging fitting 5.

A horn-shaped grounding side discharge electrode 7 and a charging side discharge electrode 8 are attached to the grounding side hanging fitting 2 and the charging side hanging fitting 5, respectively, so as to protrude toward the line direction. has been established. The right end of the connecting yoke 6 is connected to the ground side end of a tensioned lightning arrester 11, which is a tensioned insulator formed by connecting suspended type lightning arrester insulators 10 in series via a grounding side connecting fitting 9. There is.

As shown in FIG. 3, the lightning arrester 10 includes an insulator body 12 having a cap portion, a cap metal fitting 13 that covers the head of the insulator body 12, and a pin metal fitting 14 fixed to the insulator body 12. It is composed of. Two integrally formed mounting tube portions 15 are formed in the cap portion of the insulator body 12, and a lightning arrester element 16 which is mainly made of zinc oxide and has non-linear voltage-current characteristics is housed inside the mounting tube portions 15. The cap metal fitting 13 and the pin metal fitting 14 are electrically connected via this lightning arrester element 16.

As shown in FIG. 4, the ground-side connecting fitting 9 connected to the left end of the connecting yoke 6 has a tension insulator formed by connecting suspended type insulators 17 in series. The grounding side ends of the insulators 18 are connected. A power transmission line 22 is connected to and held at the end portions of the tensioned lightning arrester 11 and the tensioned insulator 18 on the power supply side via a connecting fitting 20 having a power supply side arc horn 19 and a wire holding fitting 21, respectively. In addition, a jumper wire 23 is connected between the two electric wire holding fittings 21.
both ends are connected.

Further, as shown in FIG. 5, the cap fitting 13 of the insulator 3 disposed at the top of the hanging insulator 4 has an arm-shaped arm that intersects with the power transmission line 22 and extends away from the tower. A ground side mounting bracket 24 is attached so as to protrude. Further, an arm-shaped power-supplying side mounting bracket 25 is attached to the power-supplying side hanging bracket 5 so as to protrude substantially parallel to the grounding-side mounting bracket 24 . Both ends of the disconnector 26 are connected to the pin 2 between the tip of the ground side mounting bracket 24 and the tip of the power supply side mounting bracket 25
7 and 28 are connected and fixed. Power supply side mounting bracket 2
A stopper part 25a is formed at the tip of the cutter 5 to prevent the cut-off lower part 26a from hanging down vertically when the separator 26 is cut off as described later. (See Figures 5 and 6). Therefore, it is possible to maintain a sufficient gap between the separated lower part 26a and the jumper wire 23 located below.

As shown in FIG. 6, the disconnector 26 includes a connecting conductor 30 having a mounting portion 29 connected to the ground side mounting bracket 24, and a disconnector connected to the other end of the connecting conductor 30. A main body 31 and a mounting portion 32 connected to the power supply side of the disconnector main body 31.
It is formed from a connecting conductive wire 33 with a. A pleated portion 35 is integrally formed on the outer peripheral surface of the cylinder 34 that constitutes the separator main body 31, and openings at both upper and lower ends of the cylinder 34 are connected to a lid 36.
sealed by. Flange fittings 37 are fixed to the outer peripheral surfaces of both upper and lower ends of the cylinder body 34 with cement 38,
The lid body 36 is fastened to the flange fitting 37 with bolts 39 . Note that a packing 40 is interposed between the flange fitting 37 and the lid body 36.

A cutout portion 41 is formed in the inner peripheral surface of the cylinder 34 in the shape of an annular groove over the entire circumference. A separation element 42 is bonded and fixed in the vicinity of this separation part 41 with a fixing material 43,
A spring holder 44 and a spring 45 are interposed between the separation element 42 and the lid 36, and each spring holder 44 is connected through a conductive member 46. Further, the fixing material 43 is made of, for example, inorganic glass, which has a larger coefficient of thermal expansion than the porcelain forming the cylinder 34, and when heated, stress is applied to the cylinder 34 due to the difference in thermal expansion with the cylinder 34. ing. Further, the disconnection element 42 is mainly composed of zinc oxide and has a voltage of -
Its current characteristics exhibit non-linearity, and it has the property of being destroyed by thermal shock due to lightning surge current exceeding the design value. The disconnection element 42 is connected to the lightning arrester 10.
The maximum discharge withstand capacity is about 5% smaller than the maximum discharge withstand capacity of the lightning arrester element 16.

Now, to explain the relationship between the lightning arrester 16 and the disconnection element 42, FIG. 7(a) illustrates the relationship between the lightning surge current flowing through the lightning arrester 16 or the disconnection element 42 and the destruction rate. It is a graph. As shown in FIG. 7(a), the lightning arrester element 16 and the separation element 42 have a property that the destruction rate increases with a predetermined width. Therefore, if the maximum discharge withstand capacity of the disconnection element 42 is set to be approximately 5% smaller than the maximum discharge withstand capacity of the lightning arrester element 16, the surge current I in FIG.
In case a, the disconnection element 42 of the disconnector 26 is almost certainly activated and destroyed by the lightning arrester element 16 of the lightning arrester 10. Therefore, when a large lightning surge that damages the lightning arrester 16 occurs, the disconnector 26 is activated before the lightning arrester 10 is activated, and the disconnector main body 31 is destroyed and separated from the disconnection part 41. ing.

Next, the operation of the lightning arrester device for power transmission lines constructed as described above will be explained. Now, when a lightning surge enters the power transmission line 22 on the right side in Figures 2 and 3,
This current flows from the wire holding fitting 21, the connecting fitting 20, the lightning arrester 11, the connecting yoke 6, the disconnector 26, and the ground side hanging fitting 2 to the support arm 1 of the steel tower, and is discharged to the ground.

On the other hand, the follow-on current of the operating voltage following the lightning surge current is limited and suppressed by restoring the resistance value of the lightning arrester element 16 built into each lightning arrester 10, thereby preventing a ground fault. In addition, in FIGS. 2 and 3, when a lightning surge current enters the power transmission line 22 on the left side, it bypasses the jumper wire 23 and flows from the connecting fitting 20 on the right side to the tensioned lightning arrester 11. In addition, in the event that an unexpectedly large-scale lightning surge enters the power transmission line 22, the disconnection element 42 will be damaged and the upper and lower parts 26a will be damaged near the disconnection part 41 of the cylindrical body 34. It is destroyed and divided into parts. The upper part is suspended from the ground side mounting bracket 24, and
, as shown by the chain line in FIG. 6, the connecting wire 33 supporting the lower portion 26a is tilted in a direction away from the tower about the pin 28, and is tilted in a substantially horizontal direction by the stopper portion 25a.

After that, since it functions as a lightning arrester device with an air discharge gap G formed between the grounding side discharge electrode 7 and the energized side discharge electrode 8, the circuit breaker must be reactivated to restart the system. This makes it possible to prevent permanent ground faults. In this first embodiment, the maximum discharge withstand capacity of the disconnection element 42 is made 5% smaller than that of the lightning arrester 16, so that the disconnector 26 does not operate even though the lightning arrester 16 has a margin. It can be done.

In addition, in this embodiment 1, since the tensioned lightning arrester 11 and the tensioned insulator 18 are connected to the lower end of the suspended insulator 4 so as to be oriented to both left and right sides, the suspended insulator 4 Compared to the case where the lightning arrester 11 is vertically connected in series to the lower end of the lightning arrester device, the distance from the lower end of the hanging insulator 4 to the jumper wire 16 is shorter, resulting in a compact lightning arrester device. Therefore, it can be easily applied to existing steel towers.

[Embodiment 2] Next, the invention of embodiment 2 will be explained. In this second embodiment, as shown in FIG. 7(b), the maximum discharge withstand capacity of the disconnection element 42 is set to be approximately 5% larger than the surge withstand capacity of the lightning arrester element 16, and the other configurations are the same as in the first embodiment. . Therefore, when a lightning surge current that exceeds expectations occurs, the lightning arrester element 16 is damaged. When the lightning arrester element 16 is damaged and is no longer able to limit and cut off the follow-on current after a lightning surge, the disconnection element 42 is destroyed due to the follow-on current.
The disconnector 26 is configured to operate. Therefore, the lightning arrester 10 is disconnected from the system, making it possible to close the circuit breaker again in order to restart the system, thereby preventing permanent ground faults.

Furthermore, since the lightning arrester element 16 is damaged when the disconnector 26 is activated, it can also function as a failure indicator for the lightning arrester 10. Note that this invention is not limited to the first or second embodiment, but can also be embodied as follows. (1) In Examples 1 and 2, an example was shown in which the tensioned lightning arrester 11 and the tensioned insulator 18 were connected as a tensioned insulator on the lower side of the suspended insulator 4, but instead of the tensioned insulator 18. To connect a lightning arrester insulator having almost the same configuration as the extended lightning arrester 11.

According to this configuration, the jumper wire 23 can be protected against lightning surges that attack from any direction on the power transmission line 22.
It can be quickly guided to the lightning arrester 10 without passing through it, and lightning surges can be handled more reliably. (2) In Embodiments 1 and 2, the grounding side mounting fitting 24 for attaching the disconnector 26 is attached to the cap fitting 13 of the insulator 3 disposed at the top of the hanging insulator 4, and Although an example is shown in which the mounting bracket 25 is attached to the power-supplying side hanging bracket 5,
The disconnector 26 only needs to be installed between the ground side and the energized side of the hanging insulator 4.

For example, as shown in FIG. 8, the ground-side discharge electrode 7 may be mounted using a mounting hole formed in the ground-side hanging fitting 2. Further, as shown in FIG. 9, a grounding side mounting bracket 24 may be attached in place of the left side grounding side discharge electrode 7, and a charging side mounting bracket 25 may be attached in place of the left side energizing side discharge electrode 8. . When the configuration shown in FIG. 9 is adopted, the connecting conductor 33 is moved in the direction away from the tower with the pin 28 as the supporting axis (
It is desirable to have a configuration that tilts toward the front of the page. (3) Connect the disconnector body 31 of the disconnector 26 to the ground side mounting bracket 2
4 and the power supply side mounting bracket 25 may be provided at two locations, upper and lower.

With this configuration, when the disconnector 26 is activated, the intermediate portions of both disconnector bodies 31 are scattered, and air is created between the grounding side mounting bracket 24 and the energizing side mounting bracket 25. A discharge gap is formed. In particular, in this configuration, the jumper wire 23 is connected to the lower side of the tensioned lightning arrester 11 and the tensioned insulator 18.
This is effective when constructing the structure by extending it in the lateral direction as shown in FIG. 10 without stretching the structure. (4) In Examples 1 and 2, the disconnector 2 has a built-in disconnection element 42 made of a zinc oxide element with nonlinear voltage-current characteristics.
6 is shown, however, for example, a disconnector using a fuse using a fusible metal, a current limiting fuse, or the like may be used. (5) In Examples 1 and 2, an example was shown in which a plurality of suspended insulators 3 were connected as the hanging insulators 4, but this may also be a long-stem insulator.

[0025]

Effects of the Invention As detailed above, in this invention, a hanging insulator is suspended from the support arm of a steel tower, and a lightning arrester is attached to the lower end of the hanging insulator at least on one side facing each direction of the railway line. The installed tensioned insulators are connected, and a power transmission line is stretched to the energized side end of each tensioned insulator, and a jumper wire is used to connect the energized side of both tensioned insulators. A disconnector that is electrically disconnected when activated by a faulty ground fault current or an abnormal current that exceeds the lightning surge withstand capacity of the lightning protection insulator is connected between the grounding side and the power supply side, making it compact in the hanging direction. It can be easily installed on existing steel towers, and even if the lightning arrester is damaged, permanent ground faults can be prevented from occurring.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing Example 1.

FIG. 2 is a front view showing the central part of FIG. 1;

FIG. 3 is a front view showing the right side of FIG. 1;

FIG. 4 is a front view showing the left part of FIG. 1;

FIG. 5 is a left side view showing the upper part of FIG. 1;

FIG. 6 is an enlarged sectional view of the separator.

FIGS. 7(a) and 7(b) are graphs showing the relationship between surge current and destruction rate for a lightning arrester element and a disconnection element, respectively.

FIG. 8 is a side view showing another example.

FIG. 9 is a front view showing another example.

FIG. 10 is a plan view showing another example.

FIG. 11 is a front view showing a conventional example.

[Explanation of symbols]

1 Support arm, 4 Hanging insulator, 11 Clamped lightning arrester, 18 Clamped insulator, 22 Power transmission line, 2
3 jumper wire, 26 disconnector

Claims (1)

[Claims] Claim 1: A hanging insulator (4) is suspended from a support arm (1) of a steel tower, and a lightning arrester (4) is provided at the lower end of the hanging insulator (4) on at least one side oriented in each direction of the railway line. The tensioned insulators (11, 18) equipped with Insulator (1)
1, 18) are connected by a jumper wire (23), and a fault ground fault current or a ) A lightning arrester device for a power transmission line, characterized in that a disconnector (26) is connected to the disconnector (26) which is activated and electrically disconnected by an abnormal current exceeding the lightning surge resistance of (26).