JPH0594744A - Puffer type gas circuit breaker - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the relative dielectric constant and minimize the deterioration of dielectric strength and breaking performance while ensuring excellent arc resistance in the nozzle. [Structure] The nozzle is composed of ethylene tetrafluoride particles 2 in which boron nitride particles 1 are mixed, and has a porous structure having pores 3 continuously inserted into the surrounding space.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a puffer type gas circuit breaker used in a substation or a switching station of a power system,
In particular, the present invention relates to a puffer type gas circuit breaker in which arc resistance of a nozzle that blows an arc extinguishing gas on an arc is improved.

[0002]

2. Description of the Related Art Generally, gas circuit breakers are used in power plants and substations. What is a gas circuit breaker? A fixed electrode part and a movable electrode part that can be contacted and separated from each other are provided in a container filled with an arc-extinguishing gas such as SF6 gas. By separating the movable electrode part from the fixed electrode part This is a shutoff operation.
Further, when the gas circuit breaker performs the current interruption operation, an arc is generated between the fixed electrode portion and the movable electrode. BACKGROUND ART Conventionally, a puffer-type gas circuit breaker has been known that blows an arc-extinguishing gas onto the arc to extinguish the arc and extinguishes the arc.

The puffer type gas circuit breaker is a circuit breaker in which a movable electrode part is provided with a puffer chamber and an insulating nozzle. The puffer chamber is composed of a puffer piston and a puffer cylinder, and compresses the arc extinguishing gas. On the other hand, the nozzle is made of an insulating material such as fluorine resin, and injects the arc-extinguishing gas compressed in the puffer chamber into the arc. Since such a puffer type gas circuit breaker has a large energizing current and a breaking current and can be used in a system having a high voltage, it is easy to increase a high voltage and a large capacity. In recent years, the demand for electric power has increased, and gas circuit breakers are required to have high voltage and large capacity. The puffer type gas circuit breaker is widely used as a circuit breaker that meets this requirement.

However, in a puffer type gas circuit breaker, when the nozzle made of fluororesin is exposed to the arc for a long time, the energy ray emitted from the arc penetrates and is absorbed into the inside of the nozzle. As a result, voids were generated in the nozzle, and the fluororesin forming the nozzle was carbonized. As a result, the insulation performance of the nozzle was significantly reduced. Further, if the nozzle is exposed to the arc for a long time, the abrasion of the fluororesin due to the arc progresses, so that the force of the gas flow of the arc-extinguishing gas blown from the nozzle to the arc is weakened, and the arc extinguishing ability is deteriorated. As a result, the puffer type gas circuit breaker has a problem that the breaking performance is deteriorated.

Therefore, in order to solve the above problems, the arc resistance of the nozzle has been conventionally improved.
For example, Japanese Examined Patent Publication No. 49-17654 proposes a nozzle in which 0.1 to 50% by weight of alumina powder is uniformly dispersed in tetrafluoroethylene resin. In addition, Japanese Patent Publication Sho 53-
No. 28216 proposes a nozzle excellent in arc resistance by a broad expression of a resin composition in which an inorganic filler is mixed in a fluororesin.

In these nozzles, even if the energy ray generated from the arc is incident on the nozzle, the energy ray is shielded by the inorganic material mixed in the fluororesin, so that the energy ray is not locally concentrated. Therefore, cracking and carbonization of the nozzle can be prevented, and wear of the nozzle can be minimized. Therefore, the arc resistance of the nozzle is improved and the nozzle can exhibit high dielectric strength. As a result, the puffer type gas circuit breaker can ensure excellent breaking performance even when the nozzle is exposed to the arc for a long time.

[0007]

By the way, the relative dielectric constant of the inorganic material mixed in the fluororesin is usually larger than that of the fluororesin alone. Therefore, the effective relative permittivity of a nozzle made of a fluororesin mixed with an inorganic material should be higher than the relative permittivity of a nozzle made of a single fluororesin regardless of the material and the amount of the mixture. Is inevitable.

Generally, the effective relative permittivity εe of a mixture obtained by mixing a second material having a relative permittivity of εd with a volume fraction v of a first material having a relative permittivity of εc is as follows. It is given by the equation (1).

[Epsilon] e / [epsilon] c = {2 [epsilon] c + [epsilon] d-2 ([epsilon] c- [epsilon] d) v} / {2 [epsilon] c + [epsilon] d + ([epsilon] c- [epsilon] d) v} ... (1) Here, tetrafluoroethylene resin is used as the fluorine resin, and Japanese Patent Publication No. 57-23377, Japanese Patent Publication No. 62-60
Specific description will be made using titanium oxide described in Japanese Patent No. 783, Japanese Patent Publication No. 1-378222, and the like. Dielectric constant and density of tetrafluoroethylene resin are usually 2.2 and 2.1 g / cm
It is about ³ . On the other hand, the relative permittivity and density of titanium oxide (TiO ₂ ) are about 95 and 4.3 g / cm ³ , respectively. When a mixture of titanium tetrafluoride resin and 10% by weight of titanium oxide is prepared, its effective relative dielectric constant is 2.53 according to the equation (1). The relative permittivity of this mixture is effectively about 15% higher than that of pure tetrafluoroethylene resin.

As described above, the nozzle formed by mixing the fluorocarbon resin with the inorganic material exhibits high arc resistance, but its relative dielectric constant is increased. If the relative permittivity of the nozzle increases, the lines of electric force passing through the inside of the nozzle are relatively reduced and the electric field is concentrated outside the nozzle. As described above, the gas circuit breaker is required to have a high voltage and a large capacity, but the shared voltage per breaking point is increased accordingly. There is a risk that the insulation performance of the nozzle will be significantly reduced if the shared voltage per breaking point increases with the electric field concentrated outside the nozzle due to the increase in the relative dielectric constant.

The present invention has been proposed in order to solve the problems of the above-mentioned prior art, and its purpose is to ensure excellent blocking performance by suppressing a decrease in the dielectric strength of the nozzle to a minimum. In addition, it is another object of the present invention to provide a puffer type gas circuit breaker that reduces the production cost by minimizing the amount of expensive inorganic material used.

[0012]

In order to achieve the above object, a puffer type gas circuit breaker of the present invention is provided with a nozzle for injecting an arc extinguishing gas into an arc in a container in which the arc extinguishing gas is enclosed. The nozzle is characterized in that it is made of a fluorine resin mixed with an inorganic material and has a porous structure having pores continuously inserted into the surrounding space.

[0013]

In the present invention having the above structure,
Even if the energy ray generated from the arc enters the nozzle, the inorganic material shields it. Therefore, cracking and carbonization of the nozzle can be prevented, and wear of the nozzle can be minimized.

Further, since the arc extinguishing gas in the container flows into the holes, the nozzle becomes a three-body mixture of the insulating material, the inorganic material and the arc extinguishing gas. The dielectric constant of arc-extinguishing gas is usually
Lower than that of insulating material. Therefore, the ratio of the arc-extinguishing gas can be adjusted by appropriately setting the volume fraction of the holes in the nozzle. Therefore, even if a desired amount of inorganic material is mixed, the relative permittivity of the entire nozzle can be suppressed to a level that does not adversely affect it.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the puffer type gas circuit breaker according to the present invention will be specifically described below with reference to FIG. The nozzle in the puffer type gas circuit breaker of this embodiment is SF6.
It is provided in a container (not shown) in which gas is sealed, and SF6 gas is injected to the arc generated between the fixed electrode portion and the movable electrode. As shown in FIG. 1, this nozzle is a tetrafluoroethylene particle 2 which is a fluororesin.
Is mixed with boron nitride particles 1 which is an inorganic material. Further, the nozzle has a porous structure in which a hole portion 3 which is continuously inserted into the surrounding space is formed. In addition, the SF enclosed in the container is not enclosed in the space around the nozzle.
6 Gas is present.

In the present embodiment having the above-mentioned structure, even if the energy beam of the arc enters the nozzle, it is shielded by the boron nitride particles 1. Therefore, the nozzle can be prevented from cracking and carbonization, and the nozzle is worn. Can be minimized. Therefore, the arc resistance of the nozzle is improved.

Further, since SF6 gas existing in the surrounding space flows into the void portion 3, the nozzle becomes a three-body mixture of boron nitride particles 1, tetrafluoroethylene particles 2 and SF6 gas. The effective relative permittivity of this three-body mixture, that is, the relative permittivity of the entire nozzle can be determined by repeatedly using the above equation (1).

If the relative permittivity of the entire nozzle is kept below 10% of the relative permittivity of the nozzle made of tetrafluoroethylene resin alone, adverse effects such as deterioration of insulation performance due to electric field concentration outside the nozzle will not occur. Has been done. As described in the conventional example, the relative permittivity of the tetrafluoroethylene resin simple substance is 2.2, so that the relative permittivity of the nozzle of this embodiment needs to be set to 2.4 or less. When the relative permittivity of such a value is to be derived, even if the relative permittivity of the boron nitride particles 1 is high, SF6
Since the relative permittivity of gas is as low as 1.0, the relative permittivity of the entire nozzle can be suppressed low. In addition, the SF6 gas amount can be adjusted by appropriately setting the volume fraction of the voids 3 according to the mixing amount of the boron nitride particles 1, so that the relative permittivity of the entire nozzle always obtains an ideal value. be able to.

As described above, in this embodiment, the arc resistance of the nozzle is improved and the relative permittivity of the nozzle is reduced, so that the electric field concentration outside the nozzle is alleviated. As a result, it is possible to minimize the decrease in the dielectric strength of the nozzle. Therefore, the puffer-type gas circuit breaker of this embodiment can ensure high breaking performance.

Although boron nitride particles were used as the inorganic material in the above examples, aluminum nitride,
Needless to say, even if one or more materials of aluminum oxide and silicon nitride are used as the inorganic material, the same effect as described above can be obtained.

[0021]

As described above, according to the puffer type gas circuit breaker of the present invention, the nozzle made of the fluorine resin mixed with the inorganic material has the porous portion having the void portion continuously connected to the surrounding space. By adopting a quality structure, the arc resistance of the nozzle is improved and the relative dielectric constant of the nozzle is reduced, so it is possible to minimize the decrease in the dielectric strength of the nozzle and ensure a high breaking performance. ..

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating a particle configuration inside a nozzle according to an embodiment of the present invention.

[Explanation of symbols]

 1 Boron Nitride Particles 2 Tetrafluoroethylene Particles 3 Voids

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[Procedure amendment]

[Submission date] December 9, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

However, in a puffer type gas circuit breaker, when the nozzle made of fluororesin is exposed to the arc for a long time, the energy ray emitted from the arc penetrates and is absorbed into the inside of the nozzle. This or voids are generated in the nozzle by, it occurs a phenomenon that the fluorine resin is carbonized constituting the nozzle, to decrease the insulating performance of the resulting nozzle is significantly
There was a possibility that Also, if the nozzle is exposed to the arc for a long time, the abrasion of the fluororesin due to the arc will progress,
Weakens the force of the gas flow arc extinguishing gas sprayed from the nozzle to the arc, extinguishing capability is deteriorated, as a result, if the puffer type gas circuit breaker is further high voltage future possible the interruption performance is reduced There is a nature .

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Iwao Oshima 2-1-1 Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Stock company Toshiba Hamakawasaki Factory

Claims (1)

[Claims] 1. A fixed electrode part and a movable electrode part which can be contacted and separated from each other are provided in a container in which an arc-extinguishing gas is enclosed, and the arc-extinguishing gas is composed of a puffer piston and a puffer cylinder in the movable electrode part. A puffer chamber for compression and an insulating nozzle for injecting the arc-extinguishing gas compressed in the puffer chamber are provided, and the nozzle extinguishes the arc generated between the fixed electrode portion and the movable electrode portion. In a puffer type gas circuit breaker for extinguishing the arc by blowing an arc gas, the nozzle is made of a fluororesin mixed with an inorganic material, and has a hole portion continuously inserted into the surrounding space. A puffer type gas circuit breaker characterized by having a porous structure having.