JPS5917106Y2 - Lightning arrester - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a lightning arrester for a gas-insulated hermetic switchgear, and more particularly to a lightning arrester with an improved hermetically insulating cylindrical portion.

As shown in Figure 1, a conventional surge arrester for a closed type switchgear has SF6 gas 3 between an insulating tube 1 and a tank 2, and N gas inside the insulating tube.
2 gas 4 is sealed, and an internal element 5 is housed inside the insulating cylinder 1.

A capacitor 6 is attached around the insulating tube 1 for mitigating the electric field.

Furthermore, airtightness control in the first part of the insulating tube is achieved by using an O-ring 7.
It is carried out in

In other words, airtightness is maintained by holding the insulating cylinder 1, capacitor 6, etc. in part with studs or the like with the metal upper cover 8, and using only one O-ring.

For this reason, it is quite difficult to support the two layers of the capacitor 6 and the insulating cylinder 1 with the lid 8, and also to ensure sufficient airtightness with the O-ring 7, for quality control reasons. 3 mixed into the inner layer N2 gas 4, it may affect the discharge characteristics of the arrester and impair its function as a main body of the arrester.

The purpose of the present invention has been made in consideration of the above points, and is to provide a lightning arrester that is simple, has a stable potential distribution, and has good airtightness.

The present invention will be explained below with reference to the embodiment shown in FIG.

An insulating cylinder A is placed in a tank 11 whose upper part is closed with a closing member (not shown) and whose lower part is provided with a metal bottom 7 and 21 for closing.
At the same time, an SF6 case is enclosed around this insulating cylinder A to form a cover layer 12.

The insulating cylinder A is formed by loading an insulating cylinder part made up of a cast product 13 and a metal fitting 14, and its upper opening is opened by an upper lid 20.
occlusion.

N2 gas is sealed in an internal layer 15 formed within this insulating cylinder A.

The internal element 16 of the lightning arrester is contained in this N2 gas atmosphere.

As shown in detail in FIG. 3, this insulating cylindrical portion utilizes the embedded portions of metal fittings 14 that are partially embedded in both ends of the cylindrical cast product 13 in the axial direction. .

The joint 17 between the metal fitting 14 and the upper lid 20, and the metal fitting 14
Inter-joint part 18 and joint part 19 between metal fitting 14 and lower lid 21
A multi-stage insulating tube is formed by hard brazing such as silver brazing.

As a result, the upper part of the insulating cylinder is closed with the metal upper lid 20, and the lower part is pressed and sealed with the metal lower lid 21 and the blow-off lid 22.

N2 gas is sealed in the inner layer in the insulating cylinder 5 via the filling valve 23 as described above.

The lightning arrester has an explosion-proof structure, and when explosion-proof, the arc breaks through the lightning arrester film 24 located at the lower lid 22 of the blowout, and the
It has a structure that blows out from 5.

Note that the airtightness between the metal lower lid 21 and the blowout lower lid 22, that is, the sealing between the atmosphere and the N2 gas, is performed by an O-ring.

As mentioned above, when forming the insulating cylinder A, by embedding the metal fitting 14 in the cast product 13, a capacitor is formed in the part where the metal fitting 14 is embedded, and the potential distribution between the tanks 11 on the low pressure side, etc. One layer fulfills the roles of the first layer and the condenser layer formed by the conventional insulating tube, and by simplifying this insulating tube, it is easier to control quality. Become.

Also, airtightness between SF6 gas and N2 gas is achieved by brazing, such as silver brazing, instead of using an O-tank.
We are working to further improve airtightness.

By adopting the above configuration, it is possible to realize a simple lightning arrester with stable internal potential distribution and good airtight performance in a gas-insulated sealed type switchgear lightning arrester, and to obtain stable performance over a long period of time.

In addition, FIG. 4 shows another embodiment of the present invention.

In this insulating cylinder configuration, the metal fitting 2 embedded in the cast product 13
8 is used as part of the electrode of the capacitor, and an aluminum foil electrode 27 is embedded to obtain an arbitrary capacitance, and the relaxation of the potential distribution is appropriately adjusted.

In this way, the airtightness of the insulating cylinder part is improved even more by eliminating the use of auging for airtightness control and instead using a cast product with metal fittings embedded in it and sealing it using brazing such as silver brazing. becomes.

In addition, the metal fittings embedded in this cast product also function as capacitor electrodes, which is effective in alleviating the potential distribution between the tanks.

As described above, according to the present invention, it is possible to provide a lightning arrester for a gas-insulated sealed switchgear that can operate stably for a long period of time.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view showing the main parts of a conventional lightning arrester, Fig. 2 is a longitudinal sectional view showing the main parts of the lightning arrester of the present invention, Fig. 3 is an enlarged view of the main parts of Fig. 2, and Fig. 4 is a longitudinal sectional view showing the main parts of a conventional lightning arrester. The figure is a sectional view of a main part showing another embodiment of the present invention. 11... Tank, 12... External layer (SF6 gas),
13... Casting product, 14... Metal fitting, 15... Internal layer (N2 gas), 16... Internal element, 17.19...
Upper lid and lower lid joint, 18... joint between metal fittings, 2
0...Metal upper lid, 21...Metal lower lid, 22...
・Blowout eye lower lid, 23... Enclosure valve, 24... Pressure avoidance membrane, 25... Outlet.

Claims (1)

[Scope of utility model registration request] An insulating cylinder containing a second gas and internal elements is housed in a tank filled with a first insulating gas, and this insulating cylinder is partially located at both ends of the cylindrical cast product in the axial direction. A plurality of insulating cylindrical parts each having a pair of metal fittings embedded therein are stacked together by brazing the metal fittings together to form a capacitor, and the metal fittings embedded in the insulating cylindrical parts form a capacitor. A lightning arrester characterized by being used as an electrode.