KR20230008400A - Gas Insulated Switchgear - Google Patents

Abstract

The present invention relates to a gas insulated switchgear containing a dielectric insulating fluid containing an organofluorine compound. The gas insulated switchgear of the present invention includes an enclosure having an insulating space formed therein and a blocking unit made of a first insulating material and disposed in the insulating space, wherein the insulating space contains an insulating fluid containing an organic fluorine compound. And, the blocking unit is directly exposed to the insulating fluid, and the organofluorine compound is heptafluoro-isobutyronitrile, trifluoromethyl trifluorovinyle ether, ethane ( Ethane), trifluoromethyl methyl ether, penta fluoro, trifluoromethoxy, or mixtures thereof.

Description

Gas insulated switchgear {Gas Insulated Switchgear}

The present invention relates to a gas insulated switchgear, and more particularly to a gas insulated switchgear containing a dielectric insulating fluid containing an organic fluorine compound.

Gas Insulated Switchgear (GIS) is a device that protects the system by safely opening and closing lines in abnormal conditions such as accidents and short circuits as well as opening and closing in normal conditions using gas.

As an important part composing GIS, various insulators are used to support conductors or separate insulating gas compartments. For example, an insulating spacer and an insulating support for supporting conductors inside the enclosure of the GIS are required.

This GIS is stable because the charging part is completely sealed, has low noise, and is not affected by contaminants in the air, so it is highly reliable and easy to repair.

Sulfur hexafluoride (SF6) gas was used as an insulating medium in conventional GIS. This is because SF6 gas has the characteristics of extinguishing the arc generated when the fault current is cut off in the GIS device, as well as the insulating performance and cooling performance as an insulating medium.

However, since SF6 gas is a regulated gas for regulating and preventing global warming, there is an increasing demand to apply eco-friendly gas to GIS devices in the global market.

Recently, eco-friendly fluorine-based gas has been used as an alternative gas to SF6 in GIS devices. Since these fluorine-based gases generally have a high boiling point, CO2 is mixed and used as a diluent gas in order to lower it or lower the Global Warming Potential (GWP).

However, when CO2 dilution gas is used, it is decomposed by arc heat and generates a lot of CO, and the decomposition powder containing a large amount of carbon is attached to the surface of the insulator in GIS, and the insulation performance of the insulator surface rapidly deteriorates due to the increased amount of adhesion. there is.

In order to compensate for this, an example of reducing the amount of CO and carbon component decomposition powder by additionally mixing O2 gas is disclosed.

For example, Patent Publication No. 2018-0125021 discloses the use of an oxidation catalyst comprising noble metal particles coated on or embedded in a carrier for catalytic oxidation of carbon monoxide (CO) to carbon dioxide (CO2) in a high voltage circuit breaker. about it is disclosed.

As another example, Patent Publication No. 2013-0128434 discloses that it is used for insulating electrically active parts in electrical devices such as circuit breakers or transformers, and has a very low GWP and at the same time has a high insulating ability at a relatively low operating temperature and appropriate charging pressure. A dielectric insulating medium having

However, since the dilution gas is added without completely replacing the SF6 gas in the conventional GIS device, there is a limit to solving the enhanced eco-friendly problem, and the oxidation capacity of the metal oxide is reduced over time because the metal oxide is reduced and thus consumed There is a problem that decreases with

In particular, since the insulation between the grounded enclosure and the central conductor in the GIS device is maintained as a solid insulator, a creepage surface exists on the insulator, and carbon generated when metal foreign matter or eco-friendly gas is applied to the insulator creepage surface. When the decomposition powders of the components are continuously accumulated on the surface of the insulating material, the dielectric strength is rapidly lowered and there is a problem in that insulation breakdown occurs between grounds.

Patent Publication No. 2018-0125021 Publication No. 2013-0128434

An object of the present invention is to provide a gas insulated switchgear containing therein a dielectric insulating fluid of an environmentally friendly gas containing an organic fluorine compound.

An object of the present invention is to provide a gas insulated switchgear that reduces or suppresses the degradation of dielectric strength even when CO2 is decomposed by arc heat when CO2 gas is used as a diluent gas in an organofluorine compound insulating fluid and carbon components are attached to the surface of an insulator. there is.

An object of the present invention is to provide a gas insulated switchgear that reduces or prevents degradation of insulation performance by forming a protective layer on the surface of an insulator provided therein.

An object of the present invention is to provide a gas insulated switchgear that can increase use safety and long-term reliability by using an eco-friendly insulating gas.

In the gas insulated switchgear according to the present invention, at least one insulating material formed of a first insulating material is disposed in an insulating space, and a protective layer formed of a second insulating material and having a thickness of at least 50 μm is applied to the surface of the insulating material. , The insulating space contains an insulating fluid containing an organofluorine compound, the insulating material is exposed to the insulating fluid, and the organofluorine compound is heptafluoro-isobutyronitrile, ethane , from the group consisting of trifluoromethyl trifluorovinyle ether, trifluoromethyl methyl ether, penta fluoro, trifluoromethoxy or mixtures thereof is chosen

The first insulating material includes a material selected from the group consisting of ceramics, polymer materials, composite materials, and mixtures thereof or combinations thereof.

The second insulating material comprises or consists of a polymer material selected from the group consisting of epoxy resins, polyolefins, preferably fluorinated polyolefins or hydrogenated polyolefins, more preferably polytetrafluoroethylene, polyurethanes and mixtures thereof. .

The insulating fluid may further include CO2 gas mixed with the selected organic fluorine compound. At this time, the content of CO2 may be 5 to 95% of the insulating fluid.

A gas insulated switchgear according to an embodiment of the present invention has one or more of the following effects.

According to the present invention, it is possible to provide safety in use by using an environmentally friendly insulating gas by containing a dielectric insulating fluid containing an organic fluorine-based compound therein.

According to the present invention, when CO2 gas is used as a diluent gas in an organic fluorine compound insulating fluid, even if the CO2 gas is decomposed by arc heat and the carbon component adheres to the surface of the insulating material, the decrease in dielectric strength at the edge of the insulating material can be reduced or suppressed. .

According to the present invention, by forming a protective layer on the surface of the insulator, it is possible to reduce or prevent degradation of insulation performance.

According to the present invention, it is possible to improve the insulating performance of the surface protective layer of the insulator provided inside the gas insulated switchgear and to increase the life of the protective layer.

1 is a schematic longitudinal section of a gas insulated switchgear according to an embodiment of the present invention.
2 is an enlarged view of a portion of an insulator in the gas insulated switchgear.
3 is an insulation performance test result of an insulator of a gas insulated switchgear according to an embodiment of the present invention.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to completely inform the person who has the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numbers designate like elements throughout the specification.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic longitudinal cross-sectional view of a gas insulated switchgear according to an embodiment of the present invention, and FIG. 2 is a partially enlarged view of an insulator in the gas insulated switchgear.

1 and 2, the gas insulated switchgear 100 according to the present invention may include an enclosure 110 having an insulating space S1 therein.

The enclosure 110 is a body that forms the exterior of the gas insulated switchgear 100, and may be provided so that the insulation space S1 is sealed therein.

The enclosure 110 may be manufactured by being divided into at least two or more parts, each of which is made of a metal material having excellent durability and mechanical strength, and each of the divided parts may be provided to be coupled to each other.

The insulating space S1 may be filled with a dielectric insulating fluid 111 having excellent insulating performance and arc-extinguishing function. The insulating fluid 111 may be, for example, an environmentally friendly insulating gas. In this embodiment, the eco-friendly insulating gas may be used by mixing CO2 as a diluent gas in order to lower the GWP. At this time, CO2 may be mixed in a ratio of 5 to 95%.

A conductive central conductor 130 may be located inside the enclosure 110 . The central conductor 30 may be installed in the longitudinal direction of the enclosure 110 at the center of the insulation space S1.

The central conductor 130 may be formed of a metallic material having excellent conductivity, and thus a high voltage current may flow through the central conductor 130 .

An insulating material may be disposed in the insulating space S1 to support the central conductor 130 in the space so that the central conductor 130 does not touch the enclosure 110 . This insulator is for maintaining insulation between the center conductor 130 through which current flows and the enclosure 110 grounded.

The insulating material may include an insulating spacer 120 capable of dividing the insulating space S1 while supporting the central conductor 130 and an insulating support 140 supporting the central conductor 130 in the space.

The insulation spacer 120 may be formed in a conical or disc shape. Both ends of the insulation spacer 120 are coupled to the inner surface of the enclosure 110, and a through hole through which the central conductor 130 can pass may be formed in the central portion.

The insulation support 140 may support the mechanical unit 160 so that the mechanical unit 160 does not come into contact with the inner surface of the enclosure 110 in the insulating space S1 . The mechanism unit 160 may include, for example, a mechanical operation unit and a resistance assembly.

In this way, insulators such as the insulation spacer 120 and the insulation support 140 as well as the center conductor 130 may be directly exposed to the insulation fluid 111 in the insulation space S1 filled with the insulation fluid 111. .

The insulator may be made of the first insulating material. In this embodiment, the first insulating material may include a material selected from the group consisting of ceramics, polymer materials, composite materials and mixtures thereof, or combinations thereof.

A protective layer 150 made of a second insulating material different from the first insulating material may be applied to the outer surface of the insulating material. Therefore, in the case of an insulating material, the protective layer 150 is directly exposed to the insulating fluid 111 . In this case, the insulating material may be protected from physical or chemical reactions between the insulating fluid and the insulating fluid by the protective layer 150 .

In another embodiment, an intermediate layer (not shown) may be formed between the outer surface of the insulating material and the protective layer 150 .

In this embodiment, the second insulating material of the protective layer 30 is selected from the group consisting of epoxy resin, polyolefin, preferably fluorinated polyolefin or hydrogenated polyolefin, more preferably polytetrafluoroethylene, polyurethane, and mixtures thereof. It may comprise or consist of selected polymeric materials. Preferably, the protective layer 30 may be made of a dielectric material.

In this embodiment, the protective layer 150 prevents the surfaces 10 and 10' of the insulating material from directly contacting the insulating fluid 111, resulting in a physical or chemical reaction between the surface of the insulating material and the insulating fluid 111. It can be shielded from reactions with components that become

Reliability of not only the insulating fluid 111 but also the insulating material surfaces 10 and 10' can be guaranteed by this shielding.

2 shows an enlarged view of a portion of an insulator by way of example. As described above, in this embodiment, the insulating material may be the insulating spacer 120 and/or the insulating support 140 . A protective layer 150 is applied to the surface of the insulator.

The insulating material may be directly exposed to the insulating medium 111 . In this embodiment, the insulating medium may be an organic fluorine compound. Specifically, the organofluorine compound is heptafluoro-isobutyronitrile, trifluoromethyl trifluorovinyle ether, ethane, trifluoromethyl methyl ether ether), penta fluoro, trifluoromethoxy, or a mixture thereof.

In another embodiment, the insulating medium may be used by mixing CO2 as a diluent gas with an organic fluorine compound. Preferably, CO2 gas may be mixed in a ratio of 5 to 95% in the entire insulating medium.

In this case, CO2 gas may be decomposed by arc heat generated by an internal arc to generate a carbon component. If the carbon component continues to adhere to the edge surfaces 10 and 10' of the insulator, dielectric strength may rapidly decrease.

Accordingly, when an insulating fluid is used by mixing the eco-friendly insulating gas with CO2 as a diluent gas, a protective layer 150 having a certain thickness is applied to the surface of the insulating material to prevent a rapid decrease in power yield on the surface of the insulating material.

The protective layer 150 preferably has a thickness of 50 μm or more. When the protective layer 150 is less than 50 μm, gas permeation of organic compounds may occur. In this embodiment, it may be 50 μm to 100 mm.

The protective layer 150 may protect the sliding surface of the insulator and reduce adhesion to the surface of the insulator by repelling the decomposition powder of the carbon component. This makes it possible to suppress the deterioration of the flame resistance of the insulator.

Figure 3 is a graph showing the dielectric strength of the insulating material by the protective layer experimentally in the gas insulated shielding device according to an embodiment of the present invention.

Referring to Figure 3, in the state of applying one of the fluorine-based gases, fluoronitnyl and CO2 mixed gas to the gas insulated shielding device 100 according to the present invention, an experiment evaluating the insulation characteristics for the insulation creepage according to the size of the arc energy This is the result.

Specifically, in the state of placing an insulator surface sample inside the gas insulated shielding device, an insulating medium mixed with 5% fluoronitrile Novec4710 and 95% CO2 is filled at 6.5 bar, and then forcibly blocking a short circuit current of 50 ㎄ As a method, the result of evaluating the insulation performance by increasing the accumulated amount of decomposition powder on the surface of the insulation surface specimen for each number of interruptions is shown.

In FIG. 3, as indicated by the solid line, compared to the rapid drop in dielectric strength at an arc energy of about 2000 kJ in the state where the protective layer is not applied to the surface of the insulating material surface sample, the protective layer is applied as indicated by the dotted lines. In this case, it can be seen that the dielectric strength gradually decreases.

As described above, in the present invention, when organic fluorine-based insulating gas and CO2 are mixed and used in a GIS device, a protective layer is applied to the surface of the insulating material to delay or suppress the decrease in dielectric strength, unlike the sudden drop in dielectric strength due to not applying it. let it be

Although the embodiments of the present invention have been described with reference to the accompanying drawings, the present invention is not limited to the above embodiments and can be manufactured in a variety of different forms, and those skilled in the art in the art to which the present invention belongs A person will understand that the present invention may be embodied in other specific forms without changing the technical spirit or essential features. Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting.

Claims (4)

At least one insulating material formed of a first insulating material is disposed in an insulating space, a protective layer formed of a second insulating material and having a thickness of at least 50 μm is applied to a surface of the insulating material, and the insulating space contains an organic fluorine compound. and the insulating material is exposed to the insulating fluid, and the organic fluorine compound is heptafluoro-isobutyronitrile, ethane, trifluoromethyl trifluorovinyl ether ( Gas insulated switchgear selected from the group consisting of trifluoromethyl trifluorovinyle ether, trifluoromethyl methyl ether, penta fluoro, trifluoromethoxy or mixtures thereof. The gas insulated switchgear of claim 1, wherein the first insulating material includes a material selected from the group consisting of ceramics, polymer materials, composite materials and mixtures thereof, or combinations thereof. The method according to claim 2, wherein the second insulating material is a polymer material selected from the group consisting of epoxy resin, polyolefin, preferably fluorinated polyolefin or hydrogenated polyolefin, more preferably polytetrafluoroethylene, polyurethane, and mixtures thereof. A gas insulated switchgear comprising or consisting of The gas insulated switchgear of claim 1, wherein the insulating fluid further comprises CO2 gas mixed with the organic fluorine compound at a ratio of 5 to 95%.

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