JP2588256B2 - Gas insulation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a gas insulating device installed in a substation or the like.

[Conventional technology]

Recently, in order to reduce the installation space for power equipment and increase safety, breakers, disconnectors, buses, etc. were installed in grounded metal containers, and SF ₆ gas ( Gas-insulated switchgears that achieve ground and interphase insulation with an insulating gas) are widely used.

In this gas insulated switchgear, if an abnormal voltage enters and a ground fault occurs, an arc is generated between the conductor and the grounded metal container, but when the normal voltage is reached, the arc extinguishing action of SF ₆ gas causes The arc is extinguished. That is, by an arc is set appropriately neutral point impedance of the transformer as a ground fault current higher than the self-turn-off current to the arc extinguishing decreases by SF ₆ gas, ground fault current is promptly extinguished.

However, when an out-of-phase ground fault occurs, no current flows through the neutral point impedance, so that even when the voltage returns to a normal voltage, the ground fault self-current does not become smaller than the fault extinction current, and the ground fault fault current is reduced. It remains flowing. as a result,
The arc may increase the pressure in the metal container and cause the metal container to burst, and may cause a part of the metal container to be melted and damaged due to sticking of the arc root.

Therefore, the present applicant has previously proposed a gas insulating device in which the arc is extinguished when the voltage is restored to a normal voltage even if an out-of-phase ground fault occurs (JP-A-62-123906).

The gas insulated apparatus, when hetero-phase ground fault, used to set the inter inner surface an outer surface resistance value of the closed container as fault current flowing through the closed container to a grounded is smaller than the self-turn-off current value due to SF ₆ gas Specifically, the closed container is composed of a resistor and a pair of good conductors attached to the inner and outer surfaces of the resistor.

[Problems to be solved by the invention]

However, in the gas insulating device proposed by the present applicant, it is not clear what kind of material the resistor is made of. That is, regarding the material of the resistor, the aforementioned JP-A-62-12390 describes an epoxy resin to which conductive powder is added or a synthetic resin to which conductivity is added. It is actually very difficult to obtain a resistor that meets the object of the invention by uniformly dispersing the agent in a resin, and it has not been a good idea to obtain a resistor that is stable in quality.

The present invention seeks to solve the problem by selecting a polymer material itself to be a matrix without using such an external additive. That is, an object of the present invention is to set the inner and outer surface resistance values of the sealed container such that the fault current value flowing through the grounded sealed container becomes smaller than the self-extinguishing current value of SF ₆ gas at the time of out-of-phase ground fault. To provide a gas insulating device using a resistor made of a specific material.

[Means for solving the problem]

The gas insulating device according to the present invention comprises a closed container comprising a resistor which is an epichlorohydrin rubber alone or a blend with another rubber, and a pair of good conductors adhered to the inner and outer surfaces of the resistor. is there.

FIG. 1 is a sectional view showing an example of the closed container according to the present invention. In the figure, 1 is the conductor, 2 resistors, 3 and 4 conductor, 13 is an SF ₆ gas.

The epichlorohydrin rubber constituting the resistor 2 is
Homopolymers of epichlorohydrin or other monoepoxides copolymerizable therewith, such as ethylene oxide,
It is a copolymer with propylene oxide, allyl glycidyl ether, glycidyl acetate, glycidyl propionate and the like, and the copolymer contains 20 mol% or more of epichlorohydrin.

Here, when a binary or terpolymer of epichlorohydrin and ethylene oxide and / or allyl glycidyl ether is used, the molar ratio thereof is such that epichlorohydrin: ethylene oxide: allyl glycidyl ether is 20 to 100: 0 to 80: 0. It is appropriate that it is about 10 or so. Ethylene oxide is used to adjust the electrical resistance of the rubber. However, if the molar ratio exceeds the above range, the electrical resistance decreases and it becomes difficult to obtain a desired resistor.
On the other hand, allyl glycidyl ether is used mainly for improving the deterioration stability of rubber, but even if the molar ratio exceeds the above range, the effect is hardly increased.

Various known vulcanizing agents can be used for vulcanizing the epichlorohydrin-based rubber, but it is particularly preferable to use a non-sulfur vulcanizing agent in order to avoid metal contamination of the conductor. Examples of the non-sulfur vulcanizing agent include polyamines, thiourea derivatives, polymercaptans, and the like.

In addition, the vulcanized composition of epichlorohydrin rubber,
If necessary, known additives such as an acid acceptor, a stabilizer, a reinforcing agent, a filler, a plasticizer, an antioxidant and the like can be added.

Other rubbers blended with the epichlorohydrin rubber include, for example, styrene-butadiene rubber,
Acrylonitrile-butadiene rubber, ethylene-propylene-non-conjugated diene rubber, butyl rubber, chlorinated butyl rubber, brominated butyl rubber, chloroprene rubber, chlorinated polyethylene, chlorosulfonated polyethylene, acrylic rubber, ethylene-acrylic rubber, fluorine rubber, etc. it can. The proportion of the blend is preferably 40% by weight or more, more preferably 60% by weight or more, of epichlorohydrin rubber. If the blending amount is less than the above range, the resistance of the resistor becomes too high, so that the thickness of the resistor for obtaining a predetermined resistance becomes too thin, and the sticking operation becomes extremely difficult, which is not preferable.

The electrical resistance of the resistor made of the epichlorohydrin rubber alone or a blend of another rubber in the present invention is about 10 ⁶ to 10 ¹¹ Ω-cm, depending on the size of the device, the thickness of the resistor 2, and the like. It is preferably, a thickness is too thin sticking work of the resistor as described above when the electrical resistance is larger than this range is difficult, whereas a ground fault current is SF ₆ gas when the small consisting this range The self-extinguishing currents of the above are all undesired. Adjustment of the electric resistance is performed by adding various known compounding agents to epichlorohydrin or blending with other rubber.

The rubber composition is formed into a sheet having a thickness of 0.1 to 50 mm, preferably 1 to 10 mm from the viewpoint of work, and is adhered to a closed container (duct), that is, the inner surface of the outer good conductor 4. At this time, in order to improve the adhesive strength with the inner surface of the closed container, the inner surface of the closed container may be treated with a primer or an adhesive may be used. After bonding in this way, 100
It is vulcanized by heating at ~ 200 ° C for 1 minute to 24 hours.

A good conductor 3 on the inner surface side is formed on the inner surface of the obtained resistor 2 by laminating a metal foil or applying a conductive paint. As metal foil, usually 1 to 500
A metal foil having a thickness of about 10 μm, preferably about 10 to 300 μm, such as aluminum, iron, or copper is used. In addition, as the conductive paint, a conventionally known conductive paint can be used as it is, but in order to disperse the current of the resistor by causing the arc generated in the closed vessel to run along the good conductor on the inner surface side and have an electric resistance of 10%. ^It is preferable to use a material having a resistance of ⁴ Ω-cm or less and flexibility from the viewpoint of workability.

[Action]

According to the present invention, since the closed container is composed of a resistor mainly composed of epichlorohydrin-based rubber and a good conductor adhered to the inner and outer surfaces of the resistor, an abnormal voltage is applied to the conductor, and a different-phase ground fault current is generated. Even if it occurs, the arc will quickly disappear when the voltage applied to the conductor returns to the normal voltage.

〔Example〕

Examples 1 and 2: A rectangular cylindrical closed container (total length 1.2 m, side length 165 mm) shown in FIG. 1 was prepared. Outer good conductor 4
Was a 2.3 mm thick iron plate, and a conductive coating film was used for the inner good conductor 3. Conductor 1 inserted in the center has a diameter of 50 mm
Copper bars were used.

As the resistor 2, a 5 mm thick sheet made of the rubber composition shown in Table 1 was attached to the inner surface of the outer good conductor 4 (duct).
It was vulcanized by heating at 0 ° C. for 1 hour. In addition, the inner good conductor 3
Was formed by applying a conductive paint (D-4259 manufactured by Shinto Chemitron Co.).

A sealed container was filled with SF ₆ gas 13 at 0.4 kg / cm ² g, and a fuse 12 having a rated current of 0.1 A was connected between the conductor 1 and the inner good conductor 3 in order to generate an arc.

Then, in the test device shown in FIG.
An arc was generated inside and the arc extinguishing characteristics were examined. In FIG. 2, reference numerals 6 and 6 denote insulating spacers, 7 denotes a short-circuit test generator, 8 denotes a short-circuit transformer, 9 denotes an instrument transformer, and 10 denotes an instrument current transformer. An electromagnetic oscillograph is connected to the instrument transformer 9 and the instrument current transformer 10.

(1) Copolymer of epichlorohydrin: E0 = 40: 60 (mol) (EO = ethylene oxide) As a comparative example, as shown in Table 1, except that a rubber composition mainly composed of polychloroprene was used. Example
A resistor was prepared in the same manner as in steps 1 and 2.

The volume resistivity of each of the resistors obtained in Examples 1 and 2 and Comparative Example was measured based on JIS K 6911. Table 2 shows the results.

Further, each of the sealed containers of Examples 1 and 2 and Comparative Example was attached to the test device shown in FIG. 2, and the arc extinguishing characteristics after arc generation were examined. As a result, in Examples 1 and 2,
As shown in the figure, when 3/3 kV was applied at point 0 to generate an arc, the arc was extinguished at point A. Current i ₂ is the arc current (ground fault current). v ₁ is the fuse both ends electrode,
v ₂ is the arc voltage. Ie fuse after ₁ hour
12 was melted and the arc was extinguished ₂ hours after the occurrence of the arc.

On the other hand, in the comparative example, the arc could not be extinguished, and a through-hole was formed in the sealed container.

Next, the arc quenching characteristics of the resistor having the rubber composition of Example 1 were examined under various conditions. Table 3 shows the results.

From these test results, it can be seen that the sealed container of this example has excellent arc extinguishing characteristics at the time of a ground fault.

〔The invention's effect〕

According to the present invention, since the closed container is composed of a resistor mainly composed of epichlorohydrin-based rubber and a good conductor adhered to the inner and outer surfaces of the resistor, an abnormal voltage is applied to the conductor, and a different-phase ground fault current is generated. Even if it occurs, there is an effect that the arc is quickly extinguished when the voltage applied to the conductor returns to the normal voltage.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing an example of the closed container of the present invention, FIG.
The figure is an explanatory view of the test apparatus, and FIG. 3 is a graph showing the test results. 1 ...... conductor, 2 ...... resistors, 3,4 ...... conductor, 13 ...... SF ₆
gas

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Keio Yamada 1-23-244 Nakajima, Nishiyodogawa-ku, Osaka-shi, Osaka (72) Inventor Yasuo Matoba 2-1-1-208, Shoji 2-chome, Toyonaka-shi, Osaka (56 References JP-A-57-177216 (JP, A) JP-A-62-123906 (JP, A)

Claims (1)

(57) [Claims] 1. A gas insulating device in which a conductor is disposed in a grounded hermetic container and an insulating gas is filled, wherein the hermetic container includes a resistor made of epichlorohydrin rubber alone or a blend with another rubber. A gas insulating device comprising a pair of good conductors attached to an inner surface and an outer surface of a resistor.