JPH0326889B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lightning arrester device for an overhead power transmission line. More specifically, the present invention relates to a lightning arrester device for an overhead power transmission line that has an insulation recovery function and can retransmit power even if a zinc oxide element built into the lightning arrester fails.

[Conventional technology]

Conventionally, the zinc oxide element built into the lightning insulator of the lightning insulator installed between the steel tower and the overhead power transmission line, which has non-linear voltage-current characteristics, has deteriorated and is struck by lightning, or the zinc oxide element becomes normal. However, if the element is damaged by a large-scale lightning strike, the zinc oxide element becomes conductive due to the follow-on current based on the operating voltage following the lightning surge. As a result, current flows from the overhead power transmission line to the tower via the lightning arrester device, causing a ground fault, which is then interrupted by a circuit breaker at the substation. However, even after the circuit breaker was activated, the insulation of the lightning arrester had not recovered.
Retransmission becomes impossible.

A lightning insulator device for overhead power transmission lines for preventing the occurrence of such abnormal conditions is disclosed in Japanese Patent Application Laid-Open No. 138202/1983. In this lightning arrester device for an overhead power transmission line, a power transmission line is suspended from a support arm of a suspension tower by a suspension insulator, and a lightning arrester is suspended from the support arm at a predetermined distance from the suspension insulator. A disconnection mechanism that is ruptured by a faulty ground fault current is provided at the lower part of the lightning arrester, and the lower end of the suspension insulator and the lightning arrester are connected via this disconnection mechanism. That is, the lightning arrester is arranged in a substantially V-shape so as to be inclined toward the suspension insulator with respect to the suspension insulator suspended from the support arm. When the zinc oxide element built into the lightning protection insulator is healthy, it quickly discharges against lightning surge current, and the resistance value is restored due to the nonlinear resistance characteristics of the zinc oxide element against follow-on current. Power can be retransmitted. Furthermore, when the zinc oxide element deteriorates or is damaged and faulty ground fault current flows, the disconnection function is activated to release the connection between the lower end of the suspension insulator and the lightning arrester, and remove the inclined lightning arrester. It is configured to rotate vertically around its upper hanging point due to gravity. Thereby, a predetermined insulation clearance is secured between the overhead power transmission line and the lightning arrester, and power can be retransmitted.

[Problem to be solved by the invention]

However, with this conventional lightning arrester system, for example, for 500KV, the suspended lightning arrester weighs about 1 ton, so in order to withstand the shock and vibration when disconnected, the tower side must be reinforced. There was a problem with the strength.

In addition, since the lightning arrester after being separated is suspended from the support arm with its lower end free, the lightning arrester may swing sideways due to strong winds, etc.
In this case, there was a problem that the required insulation clearance between the power transmission line and the lightning arrester could not be secured.

In other words, in order to install this lightning arrester device on an existing steel tower, it is necessary to change the specifications of the tower, such as reinforcing the tower or lengthening the support arm to ensure insulation clearance. It was difficult to apply lightning protection insulators to steel towers.

The purpose of the present invention is to enable power to be retransmitted even if the zinc oxide element built into the lightning arrester breaks down, to be easy to install on an existing steel tower, and to prevent the lightning arrester located in the upper phase from disconnecting. An object of the present invention is to provide a lightning arrester device for an overhead power transmission line, which can prevent destruction of a lightning arrester located in the lower phase even when the lightning arrester is located in the lower phase.

[Means to solve the problem]

In order to solve the above problems, the present invention connects in series an insulating support insulator and a lightning arrester incorporating a zinc oxide element with non-linear voltage-current characteristics,
A conductor is attached between both ends of the support insulator, which is not disconnected by lightning surge current, but is disconnected by follow-on current, and the support insulator and lightning arrester connected in series are connected to a steel tower;
An upper phase support insulator and a lightning arrester insulator installed on the upper phase overhead power transmission line and installed via a connecting fitting between the tower and a position spaced apart in the track direction when viewed from the plane of the overhead power transmission line; The lower phase support insulator and lightning arrester insulator installed on the lower phase overhead power transmission line are placed on the power supply side and the load side with the steel tower as the boundary.

[Effect]

When a lightning surge current flows through a power transmission line, it is discharged from the steel tower to the ground through the conductors attached to both ends of the insulating support insulator and the zinc oxide element built into the lightning arrester. At this time, with respect to the follow-on current following the lightning surge current, the resistance value is restored due to the non-linear resistance characteristics of the zinc oxide element, so the follow-on current is suppressed and ground faults are prevented.

Further, when the zinc oxide element deteriorates or is damaged by an unexpected large-scale lightning strike, the zinc oxide element becomes conductive and a follow-on current flows. This follow-on flow causes the conductor attached to the support insulator to break off. For this reason,
After that, the necessary insulation clearance is secured by the support insulator, and power can be transmitted again.

On the other hand, even if the conductor is disconnected, the lightning arrester is not mechanically disconnected and remains supported overhead between the tower and the power transmission line. Therefore, there is no need to reinforce the steel tower.

In this invention, since the insulating support insulator and the lightning arrester are connected in series, the length of the connection is longer than when only the lightning arrester is used. Since it is installed between the tower and the overhead power transmission line at a distance from the tower, it can be installed on an existing tower without changing its specifications.

Furthermore, in this invention, support insulators and lightning arrester insulators are installed on the power supply side and the load side with the steel tower as the boundary, which are installed in correspondence with the overhead power transmission lines of the upper and lower phases that are adjacent to each other. Even if the lightning arrester of the second phase is separated, direct damage to the lower phase lightning arrester is prevented.

〔Example〕

An embodiment embodying the present invention is shown in FIGS.
To explain based on Fig. 4, 1 in the drawing is a steel tower,
2 is a tension insulator device installed on the support arm 3 of the steel tower, 4 is an overhead power transmission line hooked to the tension insulator device 2, and 5 is a jumper wire. Reference numeral 6 denotes a lightning arrester unit installed between the steel tower 1 and the overhead power transmission line 4.

To explain the configuration of the lightning arrester unit 6 with reference to FIG. 4, an insulator 9 is connected to the steel tower 1 via a connecting fitting 8, and the insulator 9 has an insulation function in the event of an abnormality via a mounting fitting 10. One end of a suspension insulator chain 11 serving as an insulating support insulator is connected. Further, a lightning arrester 13 is connected in series to the other end of the suspension insulator chain 11 via a mounting bracket 12. This lightning arrester 13 includes a cylindrical insulator tube 14,
A zinc oxide element 15 having a lightning protection function housed inside the insulator tube 14, end fittings 16 fitted and fixed to both ends of the insulator tube 14, and further the zinc oxide element 15 and end fittings 16 are connected. Connection fitting 17
It is composed of.

Further, one end of a lightning arrester 13' similar to the lightning arrester 13 is connected to the lightning arrester 13 via a connecting fitting 18, and the other end of the lightning arrester 13' is connected to a mounting fitting 19 as a connecting fitting. Lines 7 are connected.

On the other hand, the mounting brackets 10 and 12 include a rupture mechanism 20 that does not operate due to lightning surge current but responds to follow-on current.
21 is attached, and a bypass conductor 22 is installed in parallel between the upper ends of both the breaking mechanisms 20 and 21. The breaking mechanisms 20 and 21 are configured, for example, by using the trailing current as a trigger to ignite gunpowder, explode and destroy the container of the breaking mechanism, and scatter the side conductor 22. Breaking mechanism 20, 21 for fusible wire that responds to follow-on current and melts
There is also a configuration in which the bypass conductor 22 is replaced.

Arching horns 23 and 24 are attached to the mounting fittings 10 and 12, and the breaking mechanisms 20 and 21
When the suspension insulator chain 11 is operated and both ends of the suspension insulator chain 11 are connected by an arc, it is immediately moved away from the suspension insulator chain 11 to prevent damage. End fittings 16 provided at both ends of the lightning arrester 13, 13'
1, 16' have arching horns 25, 26,
25' and 26' are installed, and lightning arresters 13 and 1 are installed.
If the surface of the lightning arrester 3' is abnormally contaminated or caused by a large-scale lightning strike, the generated arc is immediately moved away from the lightning arrester to prevent its damage.

Shield rings 27 and 28 are attached to the mounting fitting 12 and the end fitting 16 to alleviate the electric field between the right end of the suspension insulator chain 11 and the ground side of the lightning arrester 13. Further, a shield ring 29 is attached to the end fitting 16' of the lightning arrester 13' to relieve the electric field on the charged side of the lightning arrester 13' and smooth the voltage sharing of the zinc oxide element 15'. .

In this embodiment, for convenience of explanation, the suspension insulator chain 11, the lightning arrester 13, 13', the connecting line 7, etc. are collectively referred to as a lightning arrester unit 6.

Next, the construction work of the lightning arrester unit 6 constructed as described above will be explained.

First, as shown in FIGS. 2 and 3, at a predetermined position of the steel tower 1, that is, corner A of the four corners A to D, the tension insulator device 2 is suspended from the support arm 3 at a point P.
A connecting fitting 8 is attached to a position P2 higher than P1, and an insulator 9 is attached to the fitting 8.

On the other hand, a retaining metal fitting 30 is attached to a predetermined position P3 of the overhead power transmission line 4 on the right side, and the connecting wire 7 is hooked to the metal fitting 30. At this time, the lightning arrester unit 6 is arranged so that it has a component in the same direction as the installation direction Y of the overhead power transmission line 4, as shown in FIG. 3, and in the horizontal direction X and vertical direction Z, as shown in FIGS. Build it so that it has a component.

As shown in FIG. 3, on the overhead power transmission line 4 side of the uppermost phase of the steel tower 1,
The above-mentioned lightning arrester unit 6 is installed between the corner A and the overhead power transmission line 4 and between the corner C and the overhead power transmission line 4, respectively. In addition, as shown in FIG. 5, the smell on the intermediate phase overhead power transmission line 4' side is between the corner B and the right side overhead power transmission line 4' of the four corners A to D of the tower 1, and the corner. A lightning arrester unit 6 is installed between D and the overhead power transmission line 4' on the left side. moreover,
Although not shown on the side of the lowest phase overhead power transmission line 4, it is installed in the same manner as the above-mentioned top phase lightning arrester unit 6. The upper phase lightning arrester unit 6 located on the left side of FIG. 3 is placed on the power supply side (upper side in the figure) with the steel tower 1 as the boundary, and conversely, the lower phase lightning arrester unit 6 located on the left side of FIG. is placed on the load side (lower side in the figure) with the steel tower 1 as the boundary.

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

Now, when the zinc oxide elements 15, 15' built into the lightning arrester 13, 13' are in a normal state, when a lightning surge current enters the lightning arrester 13, 13' from the power transmission line 4 via the connection line 7, the lightning The surge current flows through the zinc oxide elements 15, 15', the breaking mechanism 20,
21 and the bypass conductor 22, etc., from the steel tower 1 to the ground. At this time, with respect to the follow-on current following the lightning surge current, the resistance value is restored due to the non-linear resistance characteristics of the zinc oxide elements 15, 15', so the follow-on current is suppressed and ground faults are prevented.

In addition, abnormal discharge occurs due to deterioration of the zinc oxide elements 15, 15' or an unexpected large-scale electric shock, and the moment a follow-up current flows to the side conductor 22 that electrically short-circuits the suspension insulator chain 11, it breaks. mechanism 20,2
1 operates and disconnects the side conductor 22, and the main body of ground insulation is transferred from the lightning arrester 13, 13' to the suspension insulator chain 11.
Move to. Both ends of the suspended insulator chain 11 are provided with a breaking mechanism 20,
An arc is formed by the action of 21, but this arc immediately moves to arcing horns 23 and 24. And since this condition is a ground fault phenomenon,
The substation function senses this and the circuit breaker opens the line, thus extinguishing the arc, and after a certain period of time, re-energizes and continues power transmission. At this time, the breaking mechanisms 20 and 21 of the suspended insulator chain 11 operate and cut off the side conductor 22, so that insulation is restored and power can be transmitted again.

Now, in the embodiment described above, the lightning arrester unit 6 is installed between the steel tower 1 and the overhead power transmission line 4 separated from the tower in the direction of the line so that it has the same direction component as the installation direction Y of the overhead power transmission line 4. A lightning arrester unit 6 with a long insulator length can be installed without changing the specifications of the steel tower 1.

Further, in the above embodiment, the lightning arrester units 6 located in the adjacent upper phase and lower phase are arranged on the power supply side and the load side so that the lightning arrester units 6 do not correspond to each other in the upper and lower phases. Lightning arrester unit 6
Even if the lightning arrester unit 6 were to break off and cause a pendulum-like vibration, direct damage to the lightning arrester unit 6 located in the lower phase can be prevented.

As mentioned above, the installation positions of the top and bottom phase lightning arrester units 6 correspond to the top and bottom, but this is because the distance between the two phases is large, so in the unlikely event that the top phase lightning arrester unit 6 Even if it breaks off and vibrates in a pendulum-like manner, the possibility of directly hitting the lowest phase lightning arrester unit 6 is extremely small.

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

In the above embodiments, the present invention is embodied in a tension steel tower, but it may also be embodied in a suspended steel tower or a V-hanging steel tower. Furthermore, although the attachment points of the lightning arrester unit 6 to the steel tower are set at the corners A to D of the steel tower, since there are various structures of steel towers, support arms 3 may be attached as necessary.
You can also use it as

〔Effect of the invention〕

As described in detail above, the present invention enables the installation of a lightning arrester without changing the specifications of the steel tower, and even if the upper phase lightning arrester insulator were to break off, the lower phase lightning arrester would be destroyed by a direct hit. This has the effect of preventing secondary disasters.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of a lightning arrester device for overhead power transmission lines embodying the present invention, Fig. 2 is a partially enlarged front view of the same, and Fig. 3 shows the installation structure of the top phase lightning arrester unit. FIG. 4 is an enlarged front view of the lightning arrester unit, and FIG. 5 is a plan view showing the construction structure of the intermediate-phase lightning arrester unit. DESCRIPTION OF SYMBOLS 1... Steel tower, 2... Tension-resistant insulator device, 3... Support arm, 4... Overhead power transmission line, 6, 6'... Lightning arrester unit, 7... Connecting line as a connecting fitting, 11...
...Suspended insulators as support insulators, 13, 13'...
...Lightning insulator, 15,15'...Zinc oxide element, 1
9...Mounting metal fittings as connecting metal fittings, 20, 21...
... Breaking mechanism, 22 ... Side path conductor, position ... P3,
Y...Direction of installation of overhead power transmission lines, X...Horizontal direction,
Z...Vertical direction.

Claims (1)

[Scope of Claims] 1. An insulating support insulator 11 and lightning arrester insulators 13, 13' incorporating a zinc oxide element 15 with non-linear voltage-current characteristics are connected in series, and the support insulator 1
A conductor 22 which is not disconnected by lightning surge current but is disconnected by following current is attached between both ends of the support insulator 11 and lightning arrester insulators 13, 13' connected in series,
The steel tower 1 seen from the plane of the steel tower 1 and the overhead power transmission line 4
The upper phase support insulator 11 and lightning arrester insulator 13, 13' installed on the upper phase overhead power transmission line, and the lower phase Lower phase support insulator 11 and lightning arrester insulators 13, 13' installed on the phase overhead power transmission line
A lightning arrester device for an overhead power transmission line, characterized in that these are arranged on a power source side and a load side with a steel tower 1 as a boundary. 2 The connecting fittings include the mounting fitting 19 and the mounting fitting 19.
A lightning arrester device for an overhead power transmission line according to claim 1, which comprises a connecting wire 7 connected to a lightning insulator device for an overhead power transmission line.