JPS6326523B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tank-type surge arrester incorporating a surge arrester element within the tank.

A tank-type lightning arrester connected to a gas-insulated switchgear is used as shown in FIG. 1 to suppress lightning and switching surges.

The tank type lightning arrester 1 is composed of, for example, a series gap with voltage dividing elements arranged in parallel, or a zinc oxide element that eliminates the need for a series gap, and is used to protect the main equipment of gas insulated switchgear such as gas shields and disconnectors 2. equipment with a reduced level of protection. For this reason, when a voltage is applied from the pushing 3 to perform a withstand voltage test on the gas insulated switchgear, the tank type lightning arrester 1 may not be able to withstand this test voltage.
For example, the AC withstand voltage test for 275KV gas insulated switchgear is 460KVrms, and in the case of a rated voltage 266KV zinc oxide arrester, the charge rate is 100% or more.
The internal zinc oxide elements or voltage dividing elements will burn out and no longer function as a tank-type lightning arrester.

For this reason, pressure tests of gas-insulated switchgear were conducted with the tank-type lightning arrester removed.
The insulating spacer 4, which mainly performs gas separation between the gas-insulated switchgear and the tank-type lightning arrester 1, is built into the tank-type lightning arrester 1. Therefore, for example, the withstand voltage test of the insulating spacer 4 can be performed using the withstand voltage of the gas-insulated switchgear. It was not possible to do it at the same time as the exam. In this way, the lightning arrester must be removed every time a gas insulated switchgear is subjected to a withstand voltage test, and this poses a problem in that the advantages of the integrated wheel transmission structure in particular are lost. One possible method for disconnecting the tank-type lightning arrester during testing of the gas-insulated switchgear is to interpose a disconnector between the two, but this would complicate the structure and increase the size of this part. Furthermore, even if an attempt is made to apply a switching device such as that described in the insulator type arrester in Japanese Patent Application Laid-Open No. 55-32430 to a tank type arrester, the arrester element is placed directly inside the metal tank and one end is closed. Since the other end is grounded on the high voltage side, it was not possible to easily apply an insulator type of completed insulation to the ground side.

SUMMARY OF THE INVENTION An object of the present invention is to provide a tank-type lightning arrester that can be subjected to a pressure test while being incorporated into a gas-insulated switchgear.

In the present invention, when a surge arrester element is arranged in a tank, one end of which is connected to the main circuit conductor and the other end is grounded, and an opening/closing part is provided on the ground side, insulation between the ground side of the surge arrester element and the bottom plate of the tank is provided. A board is interposed between the insulating board and the arrester element, and an insulating support means that can withstand voltage tests is placed between the insulating board and the lightning arrester element with a plate conductor installed above and below to provide insulating support from the ground, and the plate conductor on the insulating board side is installed in the tank. It is grounded via a sealed terminal, and the opening/closing part is provided between the upper and lower plate-shaped conductors so as to be electrically parallel to the insulating support means, so that the ground side and the earth can be disconnected. If a withstand voltage test is performed on a gas-insulated switchgear with the switching section open, the full test voltage will not be applied to the arrester element, so it is possible to perform this withstand voltage test with a tank type arrester installed. can. Furthermore, by closing the opening/closing part after the voltage resistance test, it can be operated using the same electrical circuit as a conventional tank-type lightning arrester.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows a tank-type lightning arrester connected to a gas-insulated switchgear, and there is an insulating spacer 4 between the sheath 5 of the gas-insulated switchgear and the tank-type lightning arrester 1. One end of a lightning arrester element 7 is electrically connected to the main circuit conductor 6 supported by the insulating spacer 4 . An insulating plate 1 is placed on the bottom plate 9 of the tank 8.
0 and a plate-shaped conductor 11 are fixed, and an insulating support means 12 such as an insulating cylinder is further fixed. The lightning arrester element 7 is electrically connected to the upper end of the insulating support means 12 via a plate-shaped conductor 13 and is mechanically fixed. A current collector 14 and a stator 15 are mounted on the plate-shaped conductors 11 and 13 facing each other inside the insulating support means 12.
is installed. Both of these are short-circuited by a movable element 16, and this movable element 16 is opened and closed by an operating device 17 from outside the tank 8. A sealed terminal 18 is provided on the side of the tank 8, and the plate-shaped conductor 11 and the operation alarm 19 are connected by the conductor.

The figure is in operation, with stator 15 and collector 1.
4 are connected by a movable member 16, and the opening/closing portion is in a closed state. Therefore, main circuit conductor 6...surge arrester element 7...plate conductor 13...stator 15...mover 1
6... collector 14... plate-shaped conductor 11... connecting wire sealed terminal 18... operation alarm 19.

When carrying out a pressure test of the gas insulated switchgear prior to this operating state, the movable element 16 is driven downward by the operating device 17, and the stator 15 and the collector 1 are
This is done by electrically separating the two. In this state, a test voltage is applied to the main circuit conductor 6. Thereby, the withstand voltage test of the insulating spacer 4 etc. can be performed at the same time. The axial length etc. of the insulating support means 12 are selected so as to withstand this test voltage.

FIG. 3 shows a different embodiment in which a hand hole 20 is provided in the side of the tank near the insulating support means 12.
is formed. A device for short-circuiting the plate-shaped conductors 11 and 13 is arranged outside the insulating support means 12 and at a position corresponding to the hand hole 20.
That is, stators 21 and 22 are provided at opposing portions of the plate-shaped conductors 11 and 13, respectively, and the stators are connected by a shorting conductor 23 to form an opening/closing section. The lightning arrester element 7 is made of laminated donut-shaped zinc oxide elements, and an insulating rod 24 with one end fixed to the bottom plate 9 is inserted into the hollow part of the center. Spring 2
Supported by 5.

The withstand voltage test of the gas insulated switchgear is performed by removing the shorting conductor 23 from the hand hole 20. Although this embodiment requires work to recover and fill the gas in the tank 8 as the hand hole 20 is opened and closed, the same effects as in the previous embodiment can be achieved.

FIG. 4 shows a tank-type lightning arrester according to yet another embodiment. This tank-type lightning arrester has a plurality of stacks formed by stacking lightning arrester elements 7, and these stacks are electrically connected in series so as not to form inductance.

In such a configuration, since the lightning arrester element 7 is donut-shaped, an insulating rod 24 is provided for each stack, and an insulating support means 12 is also provided for each stack. That is, each insulating rod 24 has one end fixed to a bottom plate or the like, and the donut-shaped insulating plate constituting the insulating support means 12 is also supported by the insulating rod 24. This donut-shaped insulating plate is an insulating plate 2 provided for electrically connecting the lightning arrester elements 7 in series.
The same items as 6 can be stacked and used.

The withstand voltage test of the gas insulated switchgear is performed by removing the shorting conductor 23 from the hand hole 20 and opening the switch section.

The insulating support means 12 in this embodiment may be integrated into a single piece separate from the insulating rod 24, or one end of the insulating rod 24 may be fixed to the plate-shaped conductor 13 or the like.

As explained above, the present invention provides the ground side of the surge arrester element insulated from the ground by the insulating support means, and connects the ground side of the lightning arrester element and the ground in electrical parallel relationship with the insulating support means. Since the opening/closing section is provided, the pressure resistance test of the gas-insulated switchgear can be performed by opening the opening/closing section when the tank-type lightning arrester is connected.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an example of a gas-insulated switchgear, and FIGS. 2 to 4 are longitudinal sectional views of different embodiments of the tank-type lightning arrester of the present invention. 1...Tank type lightning arrester, 4...Insulating spacer,
6... Main circuit conductor, 7... Lightning arrester element, 8... Tank, 9... Bottom plate, 10... Insulating plate, 11, 13
... Plate conductor, 12 ... Insulating support means, 16 ...
Mover, 18... Sealed terminal, 23... Short circuit conductor,
24...Insulating rod.

Claims (1)

[Scope of Claims] 1. A lightning arrester element arranged in a tank, one end of the lightning arrester element connected to a main circuit conductor, the other end grounded, and an opening/closing part provided on the ground side, wherein the lightning arrester element An insulating plate is interposed between the grounding side and the bottom plate of the tank, and an insulating support means that can withstand voltage tests is arranged between the insulating plate and the arrester element with plate-shaped conductors provided above and below to provide insulated support from the ground, The plate-shaped conductor on the insulating plate side is grounded via a sealed terminal provided on the tank, and the opening/closing part is provided between the upper and lower plate-shaped conductors in an electrically parallel relationship with the insulating support means to connect the ground side and the earth. A tank type lightning arrester characterized by being configured to be electrically intermittent. 2. The tank type lightning arrester according to claim 1, wherein an insulating cylinder is used as the insulating support means, and the opening/closing part is configured in an internal space of the insulating cylinder. 3. In claim 1, there is provided a tank-shaped tank, wherein the opening/closing part is formed outside the insulating support means, and a hand hole removably sealed with a lid is formed in the side of the tank corresponding to the opening/closing part. Lightning arrester. 4. In claim 1, the lightning arrester element is constituted by a donut-shaped zinc oxide element, the zinc oxide element is supported by an insulating rod disposed in a hollow part, and the insulating support means is a donut-shaped zinc oxide element. A tank-type lightning arrester comprising an insulating plate supported by the above-mentioned insulating rod.