JP2012038928A - Lightning arrester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightning arrester capable of applying test voltage without doing removal work and performing gas processing even in a withstand voltage test.SOLUTION: The lightning arrester used in a gas insulation opening/closing device comprises: a cylindrical metal container in which gas is filled; a pillar zinc oxide element laminated along the central axis of the metal container; a pillar auxiliary zinc oxide element which is connected through the zinc oxide element and a lead wire along the central axis and laminated on the low pressure side than the zinc oxide element; a low pressure side conductor connected to the low pressure side end of the auxiliary zinc oxide element; and a switch for connecting the low pressure side conductor and the high pressure side end of the auxiliary zinc oxide element.

Description

Embodiments described herein relate generally to a lightning arrester.

In substations or switch stations, high-performance gas-insulated switchgear using an insulating medium having excellent insulation properties and arc extinguishing properties such as SF6 gas is often used.

A line arrester for a general gas-insulated switchgear is provided with a lightning arrester for protecting the switchgear and the transformer from abnormal voltage such as lightning. When installing a gas-insulated switchgear having such a configuration in a substation or the like, a withstand voltage test is conducted on site to confirm its electrical insulation performance before starting actual operation. Yes. In recent years, the insulation emphasis has been reviewed to reduce the lightning impulse level of the lightning arrester element, thereby improving the economic efficiency of the gas insulated switchgear as a whole.

However, as a result of reducing the lightning impulse level of the lightning arrester element, it becomes impossible to apply the AC voltage applied in the conventional withstand voltage test, and it is necessary to disconnect the lightning arrester from the gas switchgear so that no voltage is applied to the lightning arrester part. . In this method, gas processing such as evacuation and gas filling has to be performed, which not only requires a lot of time, but also requires remounting work, so the work process is complicated.

JP-A-4-123781

The problem to be solved by the present invention is to provide a lightning arrester capable of applying a test voltage without performing removal work and gas treatment even during a withstand voltage test.

In order to achieve the above object, a lightning arrester according to an embodiment is a lightning arrester used in a gas-insulated switchgear, and a cylindrical metal container filled with gas and a cylinder stacked along the central axis of the metal container. A zinc oxide element having a shape, a columnar auxiliary zinc oxide element connected to the zinc oxide element via a lead wire along the central axis, and laminated on a lower pressure side than the zinc oxide element, and the auxiliary The low-voltage side conductor connected to the low-voltage side end of the zinc oxide element, and a switch that connects the high-voltage side end of the auxiliary zinc oxide element and the low-voltage side conductor.

The simplified sectional view showing the composition of the lightning arrester by a 1st embodiment. The simplified sectional view showing the composition of the lightning arrester by a 2nd embodiment. The simplified sectional view showing the installation composition of the lightning arrester by a 3rd embodiment.

Hereinafter, embodiments for carrying out the invention will be described.

(First embodiment)
The lightning arrester of 1st Embodiment is demonstrated with reference to FIG. FIG. 1 is a cross-sectional view showing a lightning arrester according to the first embodiment.

The lightning arrester 1 includes a metal container 2, a zinc oxide element 3, a high voltage side conductor 4, an insulating spacer 5, a lead wire 6, an auxiliary zinc oxide element 7, a low voltage side conductor 8, and a switch 9.

The metal container 2 is a cylindrical housing and is filled with SF6 gas. The volume of the metal container 2 is appropriately designed according to the rated voltage. The material of the metal container 2 is mainly iron.

The zinc oxide element 3 is stacked along the central axis of the metal container 2. The zinc oxide element 3 is, for example, a cylindrical shape having a diameter of 20 to 150 mm and a thickness of 1 to 50 mm, and the number of stacked layers varies depending on the rated voltage. The side surface of the zinc oxide element 3 is coated with an insulating material, which is mainly composed of zinc oxide and is a material containing bismuth (Bi), antimony (Sb), manganese (Mn), cobalt (Co), and nickel (Ni). It is.

The high-voltage side upper end of the zinc oxide element 3 is in contact with the high-voltage side conductor 4, the high-voltage side conductor 4 is fixed by an insulating spacer 5, and the insulating spacer 5 is connected to a bus bar 10 such as a gas switching device. Here, the “high voltage side” means the line side. The material of the high voltage side conductor 4 is mainly aluminum.

The auxiliary zinc oxide element 7 is laminated along the central axis of the metal container 2 similarly to the zinc oxide element 3, and is connected to the lower end of the zinc oxide element 3 through the lead wire 6. Here, the “low pressure side” means the grounding side.

The low voltage side lower end of the auxiliary zinc oxide element 7 is connected to the low voltage side conductor 8, and the low voltage side conductor 8 is grounded outside the lightning arrester 1.

The lead wire 6 and the low voltage side conductor 8 are connected to the switch 9. The auxiliary zinc oxide element 7 is used during a local withstand voltage test. In the local withstand voltage test, the withstand voltage test voltage can be applied by closing the switch 9, and the withstand voltage test can be performed without disconnecting the lightning arrester from the circuit. As a result, the construction period can be greatly shortened by omitting steps such as gas treatment. Further, as the auxiliary zinc oxide element 7, an element having an electric field of about 600 V / mm when a current of 1 mA is passed can be used, and the number of stacked elements at the same rated voltage can be reduced. As a result, the overall length of the lightning arrester 1 is reduced, contributing to downsizing and space saving.

(Second Embodiment)
A second embodiment will be described with reference to FIG. The difference of the second embodiment from the first embodiment is the metal plate 11 and the voltmeter 12, and the other parts are the same as those of the first embodiment. Detailed description is omitted.

  The auxiliary zinc oxide element 7 can manage the voltage by inserting the metal plate 11 into the high voltage side end and the low voltage side end, and connecting the voltmeter 12 to the metal plate 11 via the lead wire. With such a configuration, the auxiliary zinc oxide element 7 can be used as an instrument transformer when it is not during the withstand voltage test.

(Third embodiment)
A third embodiment will be described with reference to FIG. The same parts as those in the first embodiment are denoted by the same reference numerals.

The lightning arrester 1 includes a zinc oxide element 3, a high-voltage side conductor 4, and an insulating container 13, is connected to an external switch 15 through a cable 14, and is further connected to a bushing 17 and a transformer 18 through a lead wire 16. .

The insulating container 13 is a container having a casing made of an insulator such as insulator, polymer, and silicon, and has a zinc oxide element 3 on the central axis. The zinc oxide element 3 is stored in the insulating container 13 by, for example, a mold manufacturing method.

The external switch 15 is connected to the high-voltage side conductor 4 of the lightning arrester 1 via the cable 14. The external switch 15 is connected to the lead wire 16. The lead wire 16 branches into two, one is connected to an overhead wire, a gas switchgear or the like (not shown), and the other is connected to a bushing 17 and a transformer 18.

The bushing 17 is a soot tube, and is installed to insulate the electric wire drawn into the equipment from the outer box. Further, the transformer 18 is a transformer device and is installed to change the voltage. In addition, the lightning arrester 1 may be installed in the upper part of the transformer 18 like FIG.

By having the above configuration, the withstand voltage test can be performed without disconnecting from the overhead wire or the lead wire 16 connected to the gas switchgear. In other words, by installing the lightning arrester 1 and the external switch 15 connected thereto on the upper part of the transformer 18, a withstand voltage test can be performed without disconnecting the lightning arrester 1.

In addition, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the intent of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 Lightning arrester 2 Metal container 3 Zinc oxide element 4 High voltage side conductor 5 Insulation spacer 6 Lead wire 7 Auxiliary zinc oxide element 8 Low voltage side conductor 9 Switch 10 Bus 11 Metal plate 12 Voltmeter 13 Insulation container 14 Cable 15 External switch 16 Lead wire 17 Bushing 18 Transformer

Claims (5)

In a lightning arrester used in a gas insulated switchgear,
A cylindrical metal container filled with gas;
A cylindrical zinc oxide element laminated along the central axis of the metal container;
A cylindrical auxiliary zinc oxide element that is connected to the zinc oxide element via a lead wire along the central axis and is laminated on the low-pressure side than the zinc oxide element,
A low voltage side conductor connected to the low voltage side end of the auxiliary zinc oxide element;
A switch connecting the high-voltage side end of the auxiliary zinc oxide element and the low-voltage side conductor;
A lightning arrester characterized by comprising: 2. The lightning arrester according to claim 1, wherein the auxiliary zinc oxide element includes metal plates at a high-pressure side end and a low-pressure side end. The lightning arrester according to claim 1 or 2, wherein a diameter of the auxiliary zinc oxide element is smaller than a diameter of the zinc oxide element. 4. The lightning arrester according to claim 1, wherein the zinc oxide element or the auxiliary zinc oxide element has an electric field of 600 V / mm or more when a current of 1 mA flows. An insulating container;
A zinc oxide element laminated substantially along the central axis of the insulating container;
A high voltage side conductor connected to the high voltage side end of the zinc oxide element;
Comprising
The high-voltage side conductor is connected to an external switch via a cable,
This external switch is connected to the lead wire on the high voltage side,
This lead wire branches into two, one is connected in the order of a bushing and a transformer, and one is connected to at least one of an overhead wire or a gas insulated switchgear.

Images