JPH01137583A - Lightning arrester - Google Patents

Abstract

PURPOSE:To make a gas insulated equipment small-sized and improve the protection effect by connecting the zinc oxide elements of element blocks in series so that the direction of the current is made opposite on mating faces and connecting them between a center conductor and a metal container having the ground potential. CONSTITUTION:The zinc oxide elements 1 of the required number of lightning arrester elements are connected with a connection conductor 2, and they are inserted into an insulating tube 3 form a element block 4. The element block 4 is fitted to a gas insulated bus bar 7 arranged with a center conductor 6 in a metal container 5 which is a gas insulated equipment in a ring shape having an opening concentrical with the center conductor 6. The zinc oxide elements 1 of the element blocks 4a and 4b respectively are connected in series between the center conductor 6 and the metal container 5 having the ground potential. The direction of the current I flowing through mating portions above and below is made opposite. The diameter of the element blocks 4 is made smaller as they near the center conductor 6 and made larger as they near the ground potential side. The whole equipment is thereby made small-sized, and the protection effect is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a lightning arrester for protecting power systems, particularly gas-insulated equipment, from abnormal voltages.

(Prior Art) A gas insulated switchgear is used that makes advanced use of the insulation performance and arc extinguishing performance of SF and gas, and has an integrated structure combining a bus bar, a disconnector, a circuit breaker, a lightning arrester, etc. The lightning arrester for this gas-insulated switchgear is constructed by incorporating a lightning arrester element into a metal container, and the metal container of this arrester is branch-connected to a part of the bus metal container in which the bus conductor is arranged, and the lightning arrester element is connected to the bus conductor. This is a structure in which the so-called lightning arrester conductor is externally attached to gas-insulated equipment.

(Problem that the invention attempts to solve) Therefore, the overall configuration of the gas insulator is as follows.

Gas-insulated switchgear, which is larger due to the installation of an external lightning arrester and is intended to reduce the overall configuration, is not only subject to installation restrictions but also increases the size of the entire device. It's undesirable 1.

[Structure of the invention]

(Means for Solving the Problems) The lightning arrester of the present invention has a central conductor disposed in a metal container containing insulating gas, and a required number of zinc oxide elements connected in series along the longitudinal direction of the central conductor. A required number of ring-shaped element blocks are arranged concentrically at intervals, and the zinc oxide elements of each element block are connected in series so that the direction of current is opposite on the opposing surfaces, and the center Connect between the conductor and the metal container at ground potential, and reduce the diameter of the ring-shaped element block on the side connected to the center conductor.

This device is characterized in that the diameter of the ring-shaped element block on the side connected to the metal container is increased.

(Function) In the present invention, since the lightning arrester is installed inside the gas-insulated bus bar, a special installation space is not required, and the entire gas-insulated device can be downsized. Furthermore, it is possible to suppress an increase in mutual inductance within each element block and reduce the influence of the electric field due to the center conductor.

(Embodiments) The present invention will be described below with reference to embodiments shown in FIGS. 1, 2, and 3. In the lightning arrester of the present invention, first, a required number of zinc oxide cords 1 of the arrester 1 backing element are connected with a connecting conductor 2, and this is inserted into, for example, an insulating tube 3 to form an element block 4.

In order to install the element block 4 on a gas insulated bus bar 7 in which a center conductor 6 is disposed in a metal container 5 which is a gas insulated device, the device block 4 is mounted in a ring shape having an opening concentrically with the center conductor 6. The required number of element blocks 4 are arranged and mounted in accordance with the voltage class of the center conductor 6.

The connection relationship between the element block 4, the center conductor 6, and the metal container 5 is as shown in FIG. is connected to one end of the lower element block 4b by a connecting conductor 8b, and the other end of the lower element block 4b is connected to the metal container 5 by a connecting conductor 8c. Thus, the zinc oxide elements 1 of each element block 4a, 4b are connected in series between the center conductor 6 and the metal container 5 at ground potential.

According to this connection of the element blocks 4a and 4b, the directions of the currents I flowing in the vertically opposing portions are opposite, thereby canceling mutual inductance.

This suppresses an increase in mutual inductance between the element blocks 4a and 4b, and is useful for downsizing the overall configuration.

Furthermore, in order to reduce the influence of the electric field due to the center conductor 6, the diameter φ1 of the upper element block 4a near the center conductor 6 is reduced, and the diameter φ2 of the lower element block 4b on the connection potential side is reduced.
It is desirable to increase . That is, the diameter of the element block 4 is made smaller as it approaches the center conductor 6, and becomes larger as it approaches the grounding position.

In the embodiment, the element block 4 is formed into a ring shape by being placed inside the insulating tube 3, but the zinc oxide elements 1 may be arranged in a ring shape and insulated molded. Although the element block 4 in FIG. 1 is a ring with a portion cut out, it may be formed into an integral ring shape, and connection terminals may be led out from the zinc oxide elements at both ends of the element block 4.

〔Effect of the invention〕

As described above, the present invention has a structure in which the lightning arrester element is built into the gas-insulated equipment, suppresses mutual inductance, and improves the potential. This helps in downsizing and reducing the size of the entire equipment, and it The separation distance can be shortened and the protection effect can be improved.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing one embodiment of the lightning arrester of the present invention, and FIG.
The drawings are a sectional view taken along line 1--2 in FIG. 1, and FIG. 3 is a perspective view showing a connected state of the element block of the present invention. 1... Zinc oxide element 2... Connection conductor 3...
Insulating tube 4...Element block 5...Metal container 6...Center conductor 7...Metal container
8...Connecting conductor (8733) Agent Patent attorney Yoshiaki Inomata (and 1 other person) Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] (1) A required number of ring-shaped element blocks are connected concentrically to a central conductor placed in a metal container containing insulating gas, and a required number of zinc oxide elements are connected in series along the longitudinal direction of the central conductor. The zinc oxide elements of each element block are connected in series so that the direction of current is opposite on the opposing surfaces, and this is connected between the center conductor and a metal container at ground potential. Also, a lightning arrester characterized in that the ring-shaped element block on the side connected to the center conductor has a smaller diameter, and the ring-shaped element block on the side connected to the metal container has a larger diameter.