JP2698445B2 - Suspended lightning insulator for power transmission lines - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a suspended lightning arrester for transmission lines.

[Prior Art] As shown in FIG. 6, a conventional suspension type lightning arrester for transmission lines has been proposed. This device connects a large number of suspended lightning arresters 5 with built-in current limiting elements in series, and connects the current limiting elements of each of the insulators 5 in series with a lead wire, so that a lightning surge current flows through the transmission line L. Then, the current is discharged to the support arm (ground) side of the tower by the current limiting element, and the subsequent current is suppressed and cut off by the current limiting element, thereby preventing a ground fault accident.

[Problems to be Solved by the Invention] However, in the above-mentioned lightning arrester device, when the current limiting element is deteriorated due to long-term use, or when the current limiting element is brought into a conductive state by an unexpected electric shock, the following current flows following the lightning surge current. Could not be cut off, resulting in a ground fault. In order to solve this drawback, each of the suspended lightning arresters 5
However, it has been proposed that a discharge gap is provided between each of the current limiting elements. However, the dielectric strength of the discharge gaps cannot be increased so much. Therefore, the number of suspended lightning arresters 5 is increased. Problems such as lengthening the length of the lightning insulator and requiring a separate disconnecting mechanism occurred.

An object of the present invention is to degrade the current limiting element, or even when the current limiting element becomes conductive due to an unexpected electric shock, it is not necessary to lengthen the insulator continuous length or separately provide a disconnection mechanism. Another object of the present invention is to provide a lightning arrester for a transmission line which can prevent a short circuit due to a transmission voltage by a suspension insulator having no lightning arrester function.

[Means for Solving the Problems] In order to achieve the above object, according to the present invention, a suspension type lightning arrester having a current limiting element sealed in a suspension insulator is connected in series, and the current limiting of each of the suspension type lightning arresters is performed. The elements are electrically connected to each other with or without a lead wire, and a suspension insulator having no lightning arrester is connected in series to the lightning arrester, and both ends of the suspension arrestor are connected to a power supply side. Attach the discharge electrode and the installation side discharge electrode and provide an air discharge gap between both discharge electrodes, while placing the suspension type lightning insulator series on the ground side with respect to the suspension insulator series without lightning protection function, In addition, the diameter of the suspension type lightning insulator series is made larger than the diameter of the suspension insulator without lightning protection function, and it is attached to the support in a suspended state to hold the wires and ensure the insulation of the wires against the support The configuration was adopted.

[Operation] With the above-described configuration, in a normal power transmission state, the suspension insulator having no lightning arrester is connected in series, so that the insulation between the electric wire and a support such as a steel tower is maintained. For example, even if the current limiting element of the suspended lightning arrester is deteriorated or a malfunction occurs due to electric shock, the transmission current is not short-circuited. On the other hand, when an electric shock occurs, the lightning surge current flashes over between the discharge electrodes of the suspension insulator having no lightning protection function, and is discharged to the support through the current limiting element of the suspension lightning insulator.
At that time, by appropriately setting the current limiting element and the gap of the suspended lightning arrester, the following flow is surely cut off. Also,
Large diameter suspension type lightning insulator series is located on the ground side, that is, on the upper side, so that rainwater is less likely to be applied to the suspension type lightning insulator series to shield rainwater, and suspension insulators without lightning protection function are protected from contamination. Is done.

[Embodiment] A first embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 1, a suspending bracket 2 is connected to a support arm 1 of a tower, an upper horn mounting bracket 3 and a clevis link 4 are connected to the hanging bracket 2 in series, and an upper horn mounting bracket is further connected. At the lower end of 3, a plurality of suspended lightning arresters 5, which will be described in detail later, are connected in series.

A plurality of suspension insulators 6 having no lightning arrester are connected in series to the lower end of the suspension lightning insulator 5, and a lower horn mounting bracket 8 is connected to the lowermost suspension insulator 6 via a socket clevis 7. An electric wire clamp 10 that supports the transmission line L via a connecting link 9 is supported by the mounting bracket 8.

The upper horn mounting bracket 3 and the lower horn mounting bracket 8 are provided with an upper arc horn 11 for preventing creepage of the suspension insulator and a lower arc horn which also serves as a discharge electrode on the power application side.
12 are installed.

Next, the structure of the suspended lightning arrester 5 will be described with reference to FIG.

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 to the inside of the head with cement. Inside the plurality of mounting heads 21a integrally formed on the umbrella portion of the insulator body 21, a current limiting element 24 made of a material having a non-linear voltage-current characteristic, for example, mainly composed of zinc oxide, is housed. The cap is fixed by the upper cap electrode 25 and the lower cap electrode 26 via an electrode plate or a biasing spring which is not used. The cap fitting 22
If the current limiting element 24 of the suspension lightning arrester 5 becomes conductive around the outer periphery of the, the arc deflecting plate 27 for guiding the arc outward and preventing the insulator body 21 from breaking is horizontally The upper cap electrode 25 and the arc deflector 27 are fixed and electrically connected by a lead wire 28, and the lower cap electrode 25 is fixed.
26 and the pin fitting 23 are electrically connected by a lead wire 29.

As shown in FIG. 1, the lower electrode 26 of the suspended lightning arrester 5 located at the lowermost end has an arc horn as a ground-side discharge electrode facing the lower arc horn 12 with a predetermined air discharge gap Z. 30 are supported.

Next, regarding the lightning arrester device configured as described above,
The operation will be described.

Now, when a lightning surge current enters the transmission line L in FIG. 1, this current flashes over the air discharge gap Z from the connecting link 9, the lower horn mounting bracket 8, and the lower arc horn 12, and the arc horn 30 From the horn, the lower cap electrode 26, the current limiting element 24, the upper cap electrode
25, the lead wire 28, the cap fitting 22, the pin fitting 23, and the lead wire 29, flow to the current limiting element 24 of the suspended lightning arrester 5 located at the upper part, and after passing through this sequentially, the upper horn mounting fitting 3, It flows through the lower bracket 2 to the support arm 1 of the tower, and is discharged.

On the other hand, the following current following the lightning surge current is suppressed and cut off by restoring the air discharge gap Z and the resistance value of each current limiting element 24, thereby preventing a ground fault accident.

Here, the connection length of the air discharge gap Z of the first embodiment and the suspension insulator 6 having no lightning arrester function is set to Z0, and the surface of the suspension insulator 6 is not flashed as shown in FIG. When the ratio of Z / Z0 at which the downstream flow could be blocked in the air discharge gap Z was measured, it was 75% in the case of the first embodiment.

On the other hand, as shown in FIG. 7, in the case where the discharge gaps Z1, Z2, and Z3 are provided between the current limiting elements 24 of the suspended lightning arresters 5 as in the prior art, Z = Z1 + Z2 + Z3, Z0 = Z01 + Z02 + Z03, and Then, Z / Z0 = 60-70%. As a result, in the conventional type, it is necessary to increase the connection length of the suspension insulator to prevent creeping flashover. On the other hand, as a result of examining the fouling follow-up flow blocking characteristics, it was found that the type of the first embodiment also had better follow-up flow blocking properties as compared with the conventional one.

Next, a second embodiment of the present invention will be described with reference to FIGS.

In the second embodiment, the upper and cap electrodes 25, 26
5, ring-shaped discharge electrodes 31 are attached as shown in FIG. 5, and predetermined air discharge gaps Z1 and Z2 are provided between the discharge electrodes 31 as shown in FIG.

In the second embodiment, in addition to the air discharge gap Z, there are small air discharge gaps Z1 and Z2.
An air discharge gap can be easily formed, and therefore, it can be easily applied to an existing suspended lightning arrester.

In addition, the present invention can be freely modified and implemented without departing from the spirit thereof.

〔The invention's effect〕

"As described in detail above, in the present invention, even if the current limiting element of the suspended lightning arrester deteriorates or a failure occurs due to lightning, the suspension current without lightning arrester is connected in series, so the transmission current is short-circuited. I will not do it.

Further, since a gap is provided between the discharge electrodes of the suspension insulator having no lightning arrester function, by appropriately setting the current limiting element and the gap of the suspension lightning arrestor insulator, it is possible to reliably block the downstream flow. In addition, since it is always insulated from the suspension insulator that does not have a lightning arrester function by a gap, it is not necessary to increase the connection length of the suspension type lightning arrester or to increase the size of the insulator to suppress the wake. Contributes to downsizing of equipment.

Furthermore, since the suspension type lightning insulator series is arranged on the ground side, that is, on the upper side, and the suspension type lightning insulator series has a larger diameter than the suspension insulator without lightning protection function, the insulation performance is greatly affected by pollution. Suspension insulators without lightning protection can be protected.

[Brief description of the drawings]

FIG. 1 is a front view of a lightning arrester device embodying the present invention,
FIG. 2 is a partially broken front view showing a suspended lightning arrester, FIG. 3 is a schematic front view of the first embodiment, FIG. 4 is a front view showing a second embodiment of the present invention, and FIG. Perspective view of a suspended lightning arrester,
FIG. 6 is a front view showing a conventional example, and FIG. 7 is a schematic front view of the conventional example. 5 ... Suspension type lightning arrester, 6 ... Suspension insulator without lightning arrester function, 12 ... Arc horn as discharge electrode on the power distribution side, 21
... Insulator body, 24 ... Current-limiting element, 30 ... Arc horn as ground-side discharge electrode, 31 ... Ring-shaped discharge electrode, Z ...
... Aerial discharge gap, Z0 ... Connection length of insulator.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-232220 (JP, A) JP-A-61-75103 (JP, U)

Claims (1)

(57) [Claims] A suspension type lightning arrester having a current limiting element sealed in a suspension insulator is connected in series, and the current limiting elements of each of the suspension type lightning arresters are electrically connected to each other with or without a lead wire. And a suspension insulator having no lightning arrester function is connected in series to the lightning arrester, and a discharge electrode on the application side and a discharge electrode on the installation side are attached to both ends of the suspension arrestor. While an air discharge gap is provided between the electrodes, the suspension-type lightning arrester is arranged on the ground side with respect to the suspension-type lightning arrester that does not have a lightning arrester, and the diameter of the suspension-type lightning arrester does not have a lightning arrester. A suspension type lightning insulator for a transmission line, wherein the diameter of the suspension insulator is larger than that of the suspension insulator, and the suspension is attached to the support so as to hold the wire and ensure insulation of the wire against the support.