JPH0475215A - Lightning insulator device for transmission line - Google Patents

Abstract

PURPOSE:To shorten length in the vertical direction of a lightning insulator and an insulation insulator by connecting a lightning insulator provided with a current limiting element to a steel tower for being suspended and connecting a pair of insulation insulators pointing to the line direction while interposing a separator. CONSTITUTION:A suspension type lightning insulator group 5 consisting of in-series connecting suspension type lightning insulators 4 provided with non- linear current limiting elements 24 is connected to a supporting arm 1 of a steel tower for being suspended through a grounding side suspension metal fixture unit 3 having grounding side arc horns 2. A charging side suspension metal fixture unit 7 provided with arc horns 6 to a lower end part of the suspension type lightning insulator group 5, a connection yoke 8 is connected to a lower end part of the suspension metal fixture unit 7, further, a grounding side end part of the suspension insulator group 11 as the insulation insulators, in which ordinary insulators are in-series connected through the grounding side connection metal fitting units, are connected to both right and left end parts of said connection yoke 8 respectively. Further, a separator 17 is interposed between the connection yoke 8 and a jumped line 16.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention is capable of quickly discharging a lightning surge to the ground when it enters a power transmission line, and suppressing and interrupting the subsequent follow-on current. The present invention relates to a lightning arrester device for power transmission lines that can prevent ground faults.

[Conventional technology]

Conventionally, when configuring a lightning arrester device for a power transmission line, a lightning arrester formed separately from an insulating support insulator that supports the power transmission line is supported on a support arm of a steel tower via a mounting adapter, and the lightning arrester is There is a method in which a discharge electrode is installed between the power side hanging metal fitting and the tip of the lightning arrester, respectively, to form an air discharge gap between the two power electrodes.

When this separate system is applied to an existing steel tower, there are problems such as difficulty in securing insulation clearance between the lightning arrester and the steel tower, and the need to reinforce the support arm.

In order to solve this problem, a dual-purpose lightning arrester device has been proposed in which the insulating support insulator itself has a lightning protection function and can be easily applied to existing steel towers. As this lightning arrester device, there is one shown in FIG. 6.

This device suspends a suspension type lightning arrester chain 5, which is formed by connecting a number of suspended type lightning arrester insulators 4 having built-in current limiting elements in series, from a support arm 1 via a ground side suspension fitting unit 3. The current limiting elements of each lightning arrester 4 are connected in series by lead wires, and when a lightning surge enters the power transmission line 15, only that current is discharged to the support arm l by the current limiting element, and the operation continues thereafter. The follow-on current of the voltage is limited, and there is virtually no follow-on current to prevent ground faults.

[Problem to be solved by the invention]

However, in the case of the above-mentioned lightning arrester device, if it absorbs a lightning surge that exceeds its design value, the current limiting element of the lightning arrester will be damaged, making it impossible to suppress the follow-on current of the operating voltage, resulting in a ground fault, and the system will be damaged. circuit breaker will be activated. At this time, the current limiting element receives a ground fault or short circuit current and becomes a defective insulator, so unlike conventional arced insulators, it is difficult to successfully re-close the circuit breaker to restart the system. It becomes difficult.

In addition, as shown in FIG.
When the disconnection device 55 is installed in parallel, the circuit breaker can be successfully reclosed by the operation of the disconnection device 55, but compared to the conventional insulator device, the insulator connection length is 40 to 100 mm. % longer, power line 15
The vertical insulation clearance between the insulator and the support arm l located in the lower phase becomes small, and when applied to an existing power transmission line support insulator device, a problem arises in that it becomes difficult to achieve insulation coordination with other phases. .

A first object of the present invention is to provide a lightning arrester device for a power transmission line that can be easily applied to an existing power transmission line support insulator device by shortening the vertical length of the lightning arrester and insulator. be.

In addition to the first object, the second object of the present invention is to operate the disconnector before the lightning arrester is destroyed by conduction when an unexpected lightning surge enters the lightning arrester. It can cut off follow-on current and prevent ground faults.
It is an object of the present invention to provide a lightning arrester device for a power transmission line that can easily determine whether or not a lightning arrester is in a deteriorated state.

Furthermore, in addition to the first object, a third object of the present invention is to operate a disconnector with an alternating current ground fault current to disconnect the lightning arrester after the lightning arrester fails due to a lightning surge. Air gaps can prevent permanent ground faults,
It is an object of the present invention to provide a lightning arrester device for a power transmission line that can easily determine the failure state of a lightning arrester.

[Means to solve the problem]

In order to achieve the above-mentioned first object, the invention according to claim 1 connects and suspends a lightning arrester equipped with a current limiting element with non-linear voltage-current characteristics to a steel tower via a ground side suspension fitting unit. The ground side ends of a pair of left and right insulators oriented toward the line are connected to the lower end of the lightning arrester through a first connecting fitting unit, and the energized side ends of both assembled insulators are connected to the lower end of the lightning arrester. A power transmission line is connected to each through a second connecting fitting unit and a wire holding fitting, and a jumper wire is used to connect the electric wire holding fittings, and the first connecting fitting unit and a jumper wire or a second connecting fitting are connected to each other. A measure is taken to install a disconnector that is destroyed to form an air discharge gap when a lightning surge or switching surge of a predetermined value or more flows between the unit and the unit.

Further, in order to achieve the second object, the invention according to claim 2 takes the step of setting the surge withstand capacity of the disconnector to be smaller than the surge withstand capacity of the lightning arrester in the invention according to claim 1. ing.

Furthermore, in order to achieve the third object, the invention according to claim 3 provides the invention according to claim 1, in which the surge withstand capacity of the disconnector is made larger than the surge withstand capacity of the lightning arrester, and the disconnector A measure is taken to set the withstand capacity against alternating current of the lightning arrester to be smaller than the same withstand capacity of the lightning arrester.

[For production]

According to the first aspect of the invention, when a lightning surge enters a power transmission line, it flows through a disconnector to a lightning arrester, and then flows to a steel tower and is discharged to the ground. At this time, the current limiting element of the lightning arrester allows the lightning surge to flow and limits the subsequent follow-on current, thereby preventing ground faults.

Further, in the invention as claimed in claim 1, since the pair of left and right insulators are connected to the lower end of the lightning arrester through the first connecting fitting unit, compared to the case where the lightning arrester and the insulator are connected and suspended vertically, The vertical connection length of the entire insulator chain is shortened, making it possible to secure insulation clearance between the jumper wire and the tower support arm located at the lower phase, making it easy to apply to existing power transmission line support insulator devices. becomes.

Further, in the invention according to claim 2, when a current of a predetermined value or more flows through the disconnector per unit time, the disconnector is operated before the lightning arrester is broken due to conduction, and the air discharge gap is closed. is formed, and since the lightning arrester is sound, the following current flowing there as an arc current is current-limited and extinguished and cut off in cooperation with the insulation strength of the air discharge gap. Thereafter, it functions as a lightning arrester device equipped with an air discharge gap.

On the other hand, depending on whether or not the disconnector is operating, it can be determined whether or not a lightning surge of an abnormal level that causes the disconnector to operate has entered in a state where the lightning arrester is not in failure.

Furthermore, in the invention as claimed in claim 3, when the lightning arrester is deteriorated and cannot cut off the follow-on current, and the lightning arrester is broken due to continuity, the disconnector is activated by the alternating current ground fault current. hand,
Since an air discharge gap is formed, a permanent ground fault is prevented, and it is possible to determine whether or not the lightning arrester is malfunctioning from whether or not the disconnector is operating.

〔Example〕

An embodiment embodying the invention according to claims 1 and 2 will be described below with reference to FIGS. 1 to 4.

As shown in FIG. 1, a suspension type lightning arrester chain 5 is formed by connecting suspended type lightning arrester insulators 4 in series to a support arm 1 of the steel tower via a ground side hanging bracket unit 3 having a ground side arc horn 2. are connected and suspended. This suspended type lightning insulator series 5
A power-supplying-side hanging fitting unit 7 equipped with a ground-side arcing horn 6 that also serves as a charging-side arcing horn is connected to the lower end of the unit, and a connecting yoke 8 is connected to the lower end of the hanging fitting unit 7. Furthermore, the ground side ends of a suspension insulator chain 11, which is an insulator formed by connecting ordinary suspension insulators 10 in series, are connected to both left and right ends of the connection yoke 8 via a ground side connection fitting unit 9. ing. In this embodiment, the power-supplying side hanging fitting unit 7, the connecting yoke 8, and the grounding side connecting fitting unit 9 constitute a first connecting fitting unit J. Furthermore, a power transmission line 15 is connected and held at the end of the suspension insulator chain 11 on the power supply side via a second connecting fitting unit 13 having a power supply side arc horn 12 and a wire holding fitting 14. Further, both ends of a jumper wire 16 are connected between the two electric wire holding fittings 14.

Furthermore, a disconnector 17 is interposed between the connection yoke 8 and the jumper wire 16, and in this embodiment, as will be described in detail later, the surge withstand capacity of the disconnector 17 is The surge resistance is set to be lower than the surge resistance of the insulator 5.

Next, the structure of the suspension type lightning arrester 4 will be explained based on FIG. 3.

A cap fitting 22 is fitted and fixed to the head of the insulator body 21 with cement, and a pin fitting 23 is fitted and fixed inside the head with cement. The insulator body 21
A current-limiting element 24 made of a material with non-linear voltage-current characteristics, such as zinc oxide as a main material, is housed inside the plurality of mounting cylinder parts 21a integrally formed in the cylinder part, and an electrode plate (not shown) Alternatively, the upper cap electrode 25 may be
and is fitted and fixed by a lower cap electrode 26.

In case the current limiting element 24 is located on the outer periphery of the cap fitting 22,
An arc deflection plate 27 is fixed horizontally to guide the arc outward and prevent destruction of the insulator body 21 when the insulator body 21 is damaged after a lightning surge or by a ground fault follow-on current, and becomes conductive. The upper cap electrode 25 and the arc deflection plate 27 are electrically connected by a lead wire 28, and the lower cap electrode 26 and the pin fitting 23 are electrically connected by a lead wire 29.

Furthermore, the configuration of the separator 17 will be explained based on FIG. 4.

A pleated portion 36a is integrally formed on the outer peripheral surface of a cylinder 36 constituting the separator main body 35, and openings at both upper and lower ends of the cylinder 36 are sealed by a lid 37.

Flange metal fittings 41 are fixed to the outer circumferential surfaces of both upper and lower ends of the cylinder body 36 with cement 42, and the lid body 37 is fastened and fixed to the flange metal fittings 41 with bolts 43.

Note that 44 is a gasket interposed between the flange metal fitting 41 and the lid body 37.

The lower end of the upper connecting conductor 38 is connected to the center of the upper lid 37, and the upper end of the connecting conductor 38 is fixed to the connecting yoke 8 with bolts or the like.

Further, the upper end of a lower connecting conductor 39 is connected to the center of the lower surface of the lower lid 37, and the lower end of the connecting conductor 39 is connected to the jumper wire 16 by a gripping fitting 50.

A cutout portion 40 is formed in the inner peripheral surface of the cylindrical body 36 in the shape of an annular groove over the entire circumference. A current limiting element 45 is bonded and fixed in the vicinity of this separation part 40 with a fixing material 46, and a spring receiving metal fitting 47 and a spring 4 are provided between the current limiting element 45 and the lid body 37.
8 is interposed, and each of the spring receiving metal fittings 47 is connected to the conductive material 4.
9 is connected.

The fixing material 46 is made of, for example, inorganic glass, which has a larger coefficient of thermal expansion than the porcelain forming the cylinder 36, and when heated, stress is applied to the cylinder 36 due to the difference in thermal expansion with the cylinder 36. There is. The current limiting element 45 is mainly composed of zinc oxide whose voltage-current characteristics are non-linear, and has a predetermined value for each lightning surge, switching surge, or alternating current per unit time. It has the property of replacing excess electrical energy with joule energy and destroying it with thermal shock. That is, in this case, when 5 to 5 b of the lightning surge or switching surge withstand capacity of the current limiting element 24 of the lightning arrester main body, that is, the suspended type lightning arrester chain 5, flows into the current limiting element 45, the current limiting element 45 is damaged. , the disconnector 17 is destroyed, and an air discharge gap G is formed between the jumper wire 16 and the connection yoke 8 as shown in FIG. If a surge smaller than the surge withstand capacity of the current limiting element 24 of the suspended lightning arrester chain 5 enters,
Although the current limiting element 24 deteriorates, it retains its lightning protection function, so the discharge gap G is maintained by the current limiting element 24 and the air discharge gap G.
The follow-on arc current flowing through the terminal is cut off by current limiting and extinguished to prevent ground faults. Also, this separator 17
is operated before the current limiting element 24 of the suspended type lightning insulator chain 5 is destroyed, and the suspended type lightning insulator chain 5 is protected, and thereafter functions as a lightning arrester device equipped with an air discharge gap G. I'm trying to do what I can.

Here, according to the graph of FIG. 5(a), the suspension type lightning insulator 4
The relationship between the surge flowing through the current-limiting element 24 and the current-limiting element 45 of the isolator 17 and the destruction rate of the current-limiting element 24 and 45 will be explained. The current limiting element 24°45 becomes 1 due to a specific surge.
Rather than being destroyed 00%, it has a property that the destruction rate increases in a surge region of a predetermined width. Therefore, as mentioned above, the difference in withstand capacity between the two current limiting elements 24 and 45 is 5 to 1.
If it is 0%, for example, in the case of surge Ia in FIG. 5(a), if the current limiting element 45 of the isolator 17 is destroyed, there remains a probability that the current limiting element 24 of the suspended lightning arrester 4 will also be destroyed. ing.

Next, the operation of the lightning arrester device for power transmission lines constructed as described above will be explained.

Now, in FIG. 1, when a lightning surge enters the power transmission line 15, this current flows to the suspended lightning arrester 4 via the wire retaining fitting 14, the jumper wire 16, the disconnector 17, and the connecting fitting unit J. At this time, in the suspended type lightning arrester 4 shown in FIG. After that, it flows sequentially to the suspended lightning arrester 4 located on the upper side, and further flows to the support arm 1 of the steel tower through the ground side suspension fitting unit 3, and is discharged to the ground.

On the other hand, the follow-on current following the lightning surge is transmitted through the current limiting element 45 built into the main body 35 of the disconnector 17 and each suspended lightning insulator 4.
By restoring the resistance value of the current limiting element 24 built in, the current is limited and a ground fault is prevented.

Furthermore, in the event that an unexpectedly large-scale lightning surge enters the isolator 17, the electrical energy flowing through the current limiting element 45 per unit time exceeds a predetermined amount, and the current limiting element 45 The cylindrical body 36 is destroyed near the separated portion 1o of the cylindrical body 36 due to the Joule heat, and an air discharge gap G is formed between the jumper wire 16 and the connecting yoke 8 as shown in FIG. Ru. As a result, the following current is interrupted by the air insulation gap G before the suspension type lightning arrester 4 is broken due to conduction, and a ground fault is prevented. Thereafter, it becomes possible to handle lightning surges as a lightning arrester device equipped with an air discharge gap G. Therefore, as long as it is operated in a region where the surge resistance of the suspension type lightning arrester 4 is not exceeded, it can be used as an abnormality notice (deterioration) indicator for the suspension type lightning arrester 4. Of course, in a region exceeding the surge resistance of the suspended lightning arrester 4, the lightning arresting function itself is lost, and it goes without saying that it functions as an auxiliary failure indicator.

Now, in the above embodiment, a normal suspension insulator chain 11.
1 is connected, a conventional example in which a suspended type lightning arrester chain 5 and a normal suspended insulator chain 11 are connected in series in the vertical direction (Fig. 7)
Compared to the above, the distance from the lower end of the suspended lightning arrester chain 5 to the jumper wire 16 can be shortened, and as a result, sufficient insulation clearance between the jumper wire 16 and the lower phase support arm 1 can be secured. This makes it possible to easily apply it to existing power transmission line support insulator devices.

In other words, in the case of the conventional example (Fig. 7), when the lightning arrester is damaged by an excessive lightning surge and the disconnector is activated, the insulator 11 performs the insulation function, which is a natural feature for boat fishing. However, it is necessary to design insulation due to contamination due to salt damage, etc.
Therefore, the number of connected insulators must be the same as the number of connected insulators.

Therefore, to put it simply, the insulator connection length will be twice as long as the whole.

On the other hand, in the embodiment described above, since the insulator 11 is arranged horizontally, the vertical extension distance can be suppressed to a minimum.

Next, the invention of claim 3 will be explained.

In this invention, as shown in FIG. 5(b), the separator 1
The surge withstand capacity of the current limiting element 45 of No. 7 is set to be larger than the surge withstand capacity of the current limiting element 24 of the suspended type lightning arrester chain 5, and the withstand capacity of the current limiting element 45 with respect to alternating current is set smaller than the withstand capacity of the current limiting element 24. There is.

In the invention of claim 3, the disconnector 17 operates after the current limiting element 24 has deteriorated and the current limiting element 24 of the suspended lightning insulator chain 5 is broken due to conduction due to a follow-on current after a lightning surge. As a result, an air discharge gap G is formed between the jumper wire 16 and the connection yoke 8, thereby preventing a ground fault and making it possible to determine that the lightning arrester chain 5 is out of order.

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

(1) A disconnector 17 provided between the jumper wire 16 and the connection yoke 8 is provided, for example, between the wire holding fitting 14 and the connection fitting unit J, and the jumper wire 16 is normally connected to the insulator chain 11 as shown in the figure. Placed below or usually insulator series 1
Place it on the side of 1.

(2) The main body 35 of the separator 17 is provided at three locations, upper and lower, so that when the separator 17 is operated, the intermediate portion of the side main body 35 is blown away.

〔Effect of the invention〕

As described in detail above, the invention of claim 1 has the effect of shortening the vertical distance between the lightning arrester and the jumper wire, and can be easily applied to an existing power transmission line support insulator device.

In addition, the invention of claim 2 has the effect of the invention of claim 1,
When a lightning surge exceeds expectations, the disconnector is activated,
It is possible to prevent ground faults, and it can be used as a lightning arrester device with an air discharge gap after the disconnector operates, and the operating status of the disconnector can be visually determined. The state of deterioration can be easily determined.

Furthermore, in addition to the effect of the invention of claim 1, the invention of claim 3 operates the disconnector when the lightning arrester deteriorates and is broken due to continuity current, thereby preventing a permanent ground fault from occurring. In addition to being able to prevent this, the failure state of the lightning arrester can be determined based on the presence or absence of operation of the disconnector.

[Brief explanation of drawings]

Fig. 1 is a front view showing an embodiment of a lightning arrester device for power transmission lines embodying the present invention, Fig. 2 is a front view showing a state in which the disconnector is in operation, and Fig. 3 is a front view showing an embodiment of a suspension type lightning arrester insulator. Half-longitudinal section,
Figure 4 is an enlarged sectional view of the separator, Figures 5 (a) and (b).
) is a graph showing the relationship between the surge current and the breakdown rate of the current limiting element, and FIGS. 6 and 7 are front views showing the conventional example. DESCRIPTION OF SYMBOLS 1... Support arm, 3... Ground side hanging bracket unit, 4... Suspended type lightning arrester insulator, 5... Suspended type lightning arrester series, 8... Connection yoke, lO... Suspended insulator , 11...
・Suspension insulator chain as an insulator, 13...Second connecting fitting uni, soto, 14...Electric wire holding fitting, 16...Jumper wire, 17...Disconnector, 21...Insulator body ,
24... Current limiting element, 25.26... Cap electrode,
35... Main body, 36... Cylindrical body, 37... Lid body, 3
8.39... Connecting conductor, 40... Separation part, 45...
・Current limiting element, 46...Fixing material, 48...Spring, G・
...Air discharge gap, J...First connecting fitting unit. Patent applicant Nippon Insulator Co., Ltd. Agent Patent attorney On 1) Hironobu (and 1 other person) 5aiii Air Surge current AC current

Claims (1)

[Claims] 1. A lightning arrester (4) equipped with a current-limiting element (24) with nonlinear voltage-current characteristics is connected and suspended from a steel tower via a ground-side hanging fitting unit (3). The ground side ends of a pair of left and right insulators (11, 11) oriented toward the railway line are connected to the lower end of the lightning arrester (4) via a first connecting fitting unit (J), and A second connecting fitting unit (13) is installed at the end of the power supply side of both insulators (11, 11).
and a power transmission line (15) via a wire clamping fitting (14), connecting the electric wire clamping fittings (14, 14) with a jumper wire (16), and further connecting the first connecting fitting unit (J). and the jumper wire (16) or the second connecting fitting unit (13), the disconnector is broken to form an air discharge gap (G) when a current of a predetermined value or more flows for a predetermined time. A lightning arrester device for a power transmission line, characterized in that it is equipped with (17). 2. The lightning arrester device for a power transmission line according to claim 1, wherein the surge withstand capacity of the disconnector (17) is set to be smaller than the surge withstand capacity of the lightning arrester. 3. The surge withstand capacity of the disconnector (17) is set to be larger than the surge withstand capacity of the lightning arrester, and the withstand capacity against alternating current is set smaller than the same withstand capacity of the lightning arrester. Lightning arrester device for power transmission lines.