JPH06187880A - Puffer type gas-blast circuit breaker - Google Patents

Abstract

PURPOSE:To provide a miniaturized puffer type gas-blast circuit breaker having a mechanism for preventing lowering of dielectric breakdown voltage that could be caused by an arc-extinguishing hot gas which is heated when an arc generated between fixed and moving arcing contacts is cooled and extinguished. CONSTITUTION:A plurality of vanes 14, each with a certain angle to a plane perpendicular to a contact to rotate a flow of hot gas generated when an arc is cooled, are installed on the upper portion of the fixed contact portion A of a puffer type gas-blast circuit breaker having a puffer chamber wherein an arc-extinguishing gas is compressed by the relative movements of a piston and a cylinder and blown toward an arc generated between a fixed arcing contact 1 and a moving arcing contact 8 to cool and extinguish the arc.

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, and in particular, the arc generated between fixed and movable arc contacts is cooled and extinguished, and dielectric breakdown is caused by the extinguishing gas that has become hot gas. The present invention relates to a puffer type gas circuit breaker that prevents a voltage drop.

[0002]

2. Description of the Related Art In recent years, as the voltage and capacity of power generation systems have increased, the breaking capacity used in substations and switchyards has also increased. In urban areas, substations are being built more and more under the ground due to difficulty in securing a site.Therefore, a gas circuit breaker with high capacity, smaller size, and higher reliability has been developed. Is required.

As a protective switch for a high-voltage power transmission system using SF ₆ gas as an arc extinguishing medium, a puffer type gas circuit breaker with a small number of parts and a simple structure has high reliability and excellent breaking performance. Therefore, it is widely used. The puffer-type gas circuit breaker compresses the arc-extinguishing gas by the relative motion of the cylinder and piston directly connected to the movable contact to create a high-pressure gas flow. It is characterized in that the arc generated between the fixed-side arc contactor and the movable-side arc contactor is sprayed, and this arc is cooled and extinguished. However, during this arc cooling, the arc-extinguishing gas is exposed by the arc and its temperature rises to become so-called hot gas. This hot gas is discharged into the gas space between the breaker and the container at ground potential, which is charged by the gas flow at the time of break. Since the hot gas has a lower density due to an increase in temperature and contains charged particles from the arc, the breakdown voltage drops, so a breakdown may occur in the gas space where the hot gas is released. There is a nature.

Two factors have been considered for the phenomenon of dielectric breakdown voltage reduction due to hot gas. One of them is that the low-density hot gas reaches the site where the electric field strength is high, and the discharge starts there,
The idea is that all roads will be destroyed. The other is the idea that when a high-voltage part and a considerable part of the gas space between the containers are filled with a low-density hot gas, all-way breakdown occurs.

Several proposals have been made as means for suppressing dielectric breakdown due to such factors. One of them will be described with reference to FIG. FIG. 5 shows a puffer type gas circuit breaker having a fixed contact portion A and a movable contact portion B in a container 17 filled with an arc extinguishing gas. The fixed contactor portion A is configured by installing a fixed-side arc contactor 1 and a fixed-side energizing contactor 2 surrounding the arcuate contactor 1 on a contactor support 3. The fixed contactor portion A is supported by the insulating cylinder 7 from the operation mechanism side that drives the connection conductor 4 and the movable contactor portion B. Movable contact part B
Has a movable side arc contactor 8, a nozzle 11 surrounding the movable side arc contactor 8 and a fixed side energizing contactor 9 surrounding the outside of the sizzle 11,
It is installed on the operation mechanism side at 13. In addition, the movable contact part B
A puffer cylinder 10 is installed on the operation rod 13 on the back side of the puffer cylinder, and a puffer chamber 15 is formed together with the puffer piston 5. Further, a gas space having no supporting insulator is formed in a direction opposite to the movable contact portion B of the fixed contact portion A, and the fixed contact portion A is provided in a gas space where hot gas flows out from the fixed contact portion A. A disk-shaped gas flow control plate 20 fixed to the is installed in the axial direction of the contact.

The gas flow control plate 20 is formed in a disk shape, and the flow of the hot gas is opposite to the direction in which the hot gas is blown (the arrow).
(16 directions) once, the velocity component opposite to the velocity component in the contactor axis direction is obtained. As a result, the hot gas mixes with the cold gas in the container and diffuses, so that the breakdown voltage does not drop extremely at the site where the electric field strength is high, and the hot gas directly fills the entire gas space path. You can avoid doing that.

[0007]

In the conventional gas circuit breaker as described above, since the gas flow control plate 20 is installed on the back side of the fixed contact portion A vertically in the axial direction of the contact, The gap length between the control plate 20 and the inner wall of the container 17 where the back surface of the gas flow control plate 20 faces each other is shortened, and even if there is no hot gas when an overvoltage such as surge voltage due to lightning enters Destruction will occur. In order to prevent this, it is necessary to increase the distance in the longitudinal direction of the container 17 to secure the gap length between the gas flow control plate 20 and the fixed contactor A rear surface side, and the entire container 17 of the gas circuit breaker is required. It will be long.

Since the distance between the terminals of the bushing is long when the container is installed in an air-insulated substation,
It is not a factor in determining the size of the whole, but when used in a gas-insulated substation, it is an important factor in determining the size of the substation regardless of the vertical / horizontal arrangement of the gas circuit breakers. As mentioned above, suburban substations are increasingly being constructed in urban areas, and it is currently a big challenge to downsize the equipment installed in such substations and reduce the installation space. There is.

The present invention is provided with a mechanism for preventing the dielectric breakdown voltage by the arc-extinguishing gas which has become a hot gas when the arc generated between the fixed-side arc contactor and the movable-side arc contactor is cooled and extinguished. In addition, it is an object of the present invention to provide a puffer type gas circuit breaker capable of reducing the installation space.

[0010]

According to the present invention, in order to solve the above problems, an arc generated between a movable side arc contactor and a fixed side arc contactor in a container filled with an arc extinguishing gas. Of the fixed contact part of the puffer type gas circuit breaker equipped with a puffer chamber for cooling and extinguishing the arc. It is characterized in that a plurality of blades are provided at the ends of the contactor direction to be generated. Still further, the present invention is characterized in that a reflection plate is provided around the end of the fixed contactor portion opposite to the movable contactor portion, the outer periphery having an opening toward the inner wall of the gas circuit breaker container.

[0011]

As described above, by installing the vanes, which generate a flow in the rotational direction of the hot gas flow generated when the arc is extinguished, at the end of the fixed contact portion in the contact axial direction, the gas circuit breaker in comparison with the prior art. A wide range of cold gas and hot gas in the container can be mixed. Also, by installing a reflection plate having an opening toward the inner wall of the fixed contact portion on the upper part of the blade, mixing and diffusion of hot gas and cold gas can be performed in a wider range. Due to the above, the dielectric breakdown voltage does not drop extremely at the portion where the electric field strength is high, and the entire gas space path is not directly filled with hot gas, so that the dielectric breakdown of the gas circuit breaker can be prevented. Further, unlike the conventional method of installing a gas flow control plate, it is not necessary to take a long distance in the longitudinal direction, so that the length of the container does not become long, and the container of the gas circuit breaker can be downsized. It is possible.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIGS. 1, 2 and 3.

In FIG. 1, the fixed contact portion A is composed of a fixed-side arc contactor 1 and a fixed-side energizing contactor 2 which supports a fixed-side energizing contactor 2. The contact support 3 is electrically connected to the connection conductor 4 supported by an insulator (not shown). The fixed contact portion A is supported by an insulating cylinder 7 from a support flange 6 that supports the puffer piston 5 of the movable contact portion B. The movable contactor portion B includes a movable side arc contactor 8 and a movable side current-carrying contactor 9, a puffer cylinder 10 externally fitted to the puffer piston 5, a nozzle 11 surrounding the movable side arc contactor 8, and a mechanism box 12 of the mechanism box 12. Control rod connected to the drive
It is configured to be fixed at 13. Inside the cylindrical contactor support 3, a plurality of vanes 14 are provided on the radiation. As shown in detail in FIG. 2, the vanes 14 are provided with a plurality of vanes 14 on a radiation in a straight line 15 in a radial direction 22 at an angle with respect to a plane perpendicular to the contactor axis direction.

In the gas circuit breaker configured as described above, when a large current fault current flows and an opening command is issued, the driving device housed in the mechanism box 12 opens the driving force (in the direction of arrow 16). ) Works, and the entire movable contact portion B receives the puffer piston 5
Move in the direction of arrow 16 against. Fixed side energizing contact 2,
When the fixed side arc contactor 1 and the movable side arc contactor 8 are separated after the movable side energization contactor 9, an arc is generated between the fixed side arc contactor 1 and the movable side arc contactor 8 as shown in FIG.
21 occurs. At this time, the puffer cylinder 10 is simultaneously moved by the opening driving force (in the direction of arrow 16), so that the arc-extinguishing gas between the puffer piston 5 and the puffer piston 5 is compressed and high pressure gas is produced. The arc extinguishing gas passes between the nozzle 11 and the movable side arc contactor 8 and is blown onto the arc 21 between the fixed side arc contactor 1 and the movable side arc contactor 8 to cool it. This arc-extinguishing gas is heated when cooling the arc 21, becomes so-called hot gas, and advances straight to the fixed contactor portion A along the contactor axial direction. When this hot gas reaches the blade 14, the blade 14
The direction is changed along the angle of to have a circumferential velocity component. In order to increase the velocity component in the circumferential direction, it is desirable that the angle be smaller than 45 degrees from the axial direction of the contactor. The hot gas that has obtained the velocity component in the circumferential direction travels from the end of the fixed contact portion A to the space between the fixed contact portion A and the container 17 and then spreads due to centrifugal force to form a gas in a wide area. Since the temperature is lowered by being mixed, it is possible to prevent the dielectric breakdown voltage from being significantly lowered. Another embodiment of the present invention will be described below with reference to FIG.

FIG. 4 is a sectional view of the container of the gas circuit breaker in a closed state. A reflection plate 18 having an opening at the outer periphery of the container 17 is provided on the entire circumference or part of the end of the fixed contact portion A. When the hot gas which has obtained the velocity component in the circumferential direction by the blades 14 reaches the reflection plate 18, it further obtains the velocity component opposite to the velocity component in the contactor axis direction. As a result, the temperature of the hot gas can be reduced by advancing to the space between the blocking section 19 and the container 17 and mixing with the gas in this space.

[0016]

As described above, according to the present invention, the fixed contact portion, which receives the hot gas flow generated by cooling the arc on the side opposite to the movable contact portion, is perpendicular to the axial direction of the contact. Radiation is provided with a plurality of blades at an angle to the plane, or the whole or part of the end of the fixed contact part on the side opposite to the movable contact part. By installing the reflection plate having the opening toward the inner wall of the container, the hot gas flow can be mixed with the cold gas and diffused in a wider range. Due to the above, the breakdown voltage does not drop extremely in the region where the electric field strength is high, and the entire gas space is not directly filled with hot gas, which is effective in preventing the breakdown of the gas circuit breaker. . Further, unlike the conventional method of installing the gas flow control plate, it is not necessary to take a long distance in the longitudinal direction, so that the length of the container does not become long and the container of the gas circuit breaker can be downsized. , Economically effective in the construction of underground substations.

[Brief description of drawings]

FIG. 1 is a sectional view of a gas circuit breaker in a closed state according to an embodiment of the present invention.

FIG. 2 is a detailed structural diagram of the blade 14 shown in FIG.

FIG. 3 is a sectional view of a gas circuit breaker according to the present invention in an open state.

FIG. 4 is a sectional view of a gas circuit breaker according to another embodiment of the present invention in a closed state.

FIG. 5 is a sectional view of a conventional gas circuit breaker in an open state.

[Explanation of symbols]

 A ... Fixed contact part B ... Movable contact part 1 ... Fixed side arc contactor 2 ... Fixed side energizing contactor 3 ... Contactor support 4 ... Connection conductor 5 ... Puffer piston 6 ... Support flange 7 ... Insulation cylinder 8 ... Movable Side arc contactor 9 ... Movable side current contactor 10 ... Puffer cylinder 11 ... Nozzle 12 ... Mechanism box 13 ... Operation rod 14 ... Blade 15 ... Puffer chamber 17 ... Vessel 18 ... Reflector 19 ... Breaker 20 ... Gas flow control plate 21 ... Arc 22 ... Radial straight line

Claims (2)

[Claims] 1. A fixed contact portion having a fixed side arc contact, a movable contact portion facing the fixed contact portion, having a movable arc contact and a puffer chamber, and being filled with an arc extinguishing gas, A puffer-type gas circuit breaker comprising a container that houses the fixed contact portion and the movable contact portion, wherein an end of the fixed contact portion in the axial direction of the contact has an angle with a plane perpendicular to the axial direction of the contact. A puffer-type gas circuit breaker comprising a plurality of vanes radially arranged in a radial direction. 2. A reflection plate is provided around the end of the fixed contact portion opposite to the movable contact portion, the outer periphery of which has an opening toward the inner wall of the gas circuit breaker container. 1. The puffer type gas circuit breaker according to 1.