JPS6013126Y2 - butsing - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a bushing, and more particularly to a downsized bushing with an arrester.

Conventionally, in substations using air-insulated electrical equipment,
To protect transformers, switches, transformers, etc., arresters are installed near transformers, busbars, track entrances, etc.

Therefore, in order to install the arrester near the protected equipment,
Air insulation distance is required between this equipment and the arrester.

On the other hand, in substations using gas-insulated switchgear, gas-insulated tank arresters are directly connected to line lines, transformer circuits, busbars, etc. to protect the substation equipment.

Furthermore, conventional air-insulated arresters have drawbacks, such as the fact that a disconnector for the arrester is often provided for cleaning the insulator.

The present invention was developed in consideration of the above points, and its purpose is to provide a reduced-sized bushing with a built-in arrester, without requiring a separate arrester and disconnector for the protected equipment. It is.

Hereinafter, the present invention will be described with reference to embodiments shown in the drawings.

In FIG. 1, a gas bushing 1o has an insulating gas 1 such as SF6 gas as an insulating medium inside a synthetic resin insulator tube 11.
The upper part of the center conductor 13 is connected to a circuit terminal 15, and the circuit terminal 15 seals the insulator tube 11 through a backing (not shown), and the other side of the center conductor 13 is connected to an insulating support member. 16, and this insulating support member 16 is airtightly attached via a backing (not shown) to a grounding flange 17 attached to the synthetic resin insulator tube 11, and the other side of the insulating support member 16 is also supported via the backing. A dedicated grounding wire 19 is airtightly attached to the metal case 18 which is grounded by a grounding wire 18a of a device (not shown), and a dedicated grounding wire 19 is attached to the grounding flange 17 by a grounding terminal 19a, which is grounded to a grounding mesh (not shown).
A dedicated grounding of the arrester element is provided.

The synthetic resin insulator 11 is formed by integrally molding the arrester element 21 with a mold resin 26 made of a synthetic resin such as epoxy resin or polyester resin.

The upper part of the arrester element 21 is connected to the circuit terminal 15 and the lower end is connected to the grounding flange 17.

This arrester element 21 is made by stacking a ring-shaped resistor element 25 made of a non-linear resistor mainly composed of a metal oxide such as zinc oxide and having excellent non-linearity. It is integrally formed into a cylindrical shape by resin 26.

As shown in FIG. 3, the arrester element 21 is formed by stacking resistor elements 25 made of non-linear resistors molded into arc shapes, and these are arranged at intervals on a circumference concentric with the center conductor and molded. It may be integrally molded with resin 26.

In the bushing 10 configured as described above, the arrester element 21 integrally molded within the synthetic resin insulator tube 11 is connected between the circuit terminal 15 and the ground flange 17, and the arrester element 21 is connected between the circuit terminal 15 and the ground flange 17, and a ground wire 19 dedicated to the arrester is provided on the ground flange 17. is grounded to a ground mesh (not shown), so that a large current during arrester operation is prevented from flowing into the grounded metal case 18 and this grounding wire 18a, and this large current is grounded by a grounding wire 19 dedicated to the arrester. You can also run it through mesh.

In this way, the arrester element processes lightning energy during a lightning attack, but because a large current on the order of several KA to 100 KA flows during this instantaneous period, or about 0.5 cycles, a dedicated grounding wire for the arrester is required. If it is not provided, even if the grounding resistance value of the metal case is sufficiently low, there will be a considerable potential rise, which may pose a risk of personal injury.However, by providing the aforementioned grounding wire 19, such a potential rise can be suppressed. , disasters can be prevented.

However, if the equipment is not accessible to people such as maintenance personnel, it is not necessary to provide a dedicated grounding wire.

In the above explanation, an example of a gas bushing was explained, but the present invention can also be applied to an oil-filled capacitor type bushing with oil insulation, an oil-immersed paper capacitor type bushing, a resin paper capacitor type bushing, and a solid insulation type bushing made of synthetic resin as an insulating medium. has the same effect.

Further, the shape of the synthetic resin tube may be conical, and therefore the arrester element may also be formed in a conical shape accordingly.

As mentioned above, the bushing of the present invention can add an arrester function to any device equipped with the bushing, eliminates the need for a separate arrester and disconnector, and allows the bushing and arrester to be integrated into one without increasing space. 2 with 1 device
It is economical because it has two functions, and it is safe even when the arrester is operating because the grounding flange is connected to the ground.

As described above, according to the present invention, by integrally molding the arrester element connected between the circuit terminal and the grounding flange in the synthetic resin tube, the arrester element connected between the circuit terminal and the grounding flange is integrally formed. This disconnector is not required and a reduced bushing with a built-in arrester can be provided.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view showing the bushing of the present invention, Fig. 2 is a cross-sectional view taken along the line ■-■ shown in Fig. 1, and Fig. 3 is a cross-sectional view showing the main parts of another embodiment of the present invention. It is. 10... Gas bushing, 11... Synthetic resin insulator tube, 12... Insulating gas, 13...
...Center conductor, 15...Circuit terminal, 16...
... Insulation support member, 17 ... Ground flange, 18 ... Metal case, 19 ... Ground wire, 21 ... Arrester element, 25 ...・・・・・・
Resistor element, 26...Mold resin.

Claims (1)

[Scope of utility model registration request] A bushing in which a central conductor supported by the circuit terminals and the insulating support member is housed together with an insulating medium in a synthetic resin tube sealed with a circuit terminal and an insulating support member, wherein The circuit terminal and the ground flange are provided at both ends of the synthetic resin insulator tube, which is formed by integrally molding an arrester element formed by stacking a plurality of resistance elements made of linear resistors with a molding resin made of synthetic resin, A bushing characterized in that the arrester element is connected between the circuit terminal and the ground flange.