JPH04513Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a circuit breaker with an improved arc extinguishing chamber structure.

[Technical background of the invention and its problems]

In recent years, gas circuit breakers that use an insulating gas such as SF ₆ gas as an arc extinguishing medium have become mainstream due to their excellent arc extinguishing performance. in general,
As shown in FIG. 3, the arc extinguishing chamber of a gas circuit breaker has an insulating tube 1 disposed inside a container (not shown), and electrical power is turned on and off within this insulating tube 1. That is, fixed electrode support parts 2 are provided at both ends of the insulating cylinder 1, respectively.
and a movable electrode support part 3 are fixed to face each other, and a fixed arc electrode 4 and a fixed current-carrying electrode 5 that protrude toward the movable side are fixed to the fixed electrode support part 2. In addition, the movable electrode supporting portion 3 includes a movable arc electrode 6 and a movable current-carrying electrode 7, which are slidable on both the fixed side electrodes 4 and 5, respectively.
is supported. In this configuration, current is passed between the arc electrodes 4 and 6 and between the current-carrying electrodes 5 and 7.

By the way, as the demand for electric power increases, the amount of current flowing is also increasing. Therefore, when electricity is applied, the electrode generates heat and there is a risk that high-temperature insulating gas stagnates inside the insulating cylinder 1. Therefore, in order to promote cooling of the electrode, a plurality of insulating rods having a circular cross-sectional shape can be used instead of the insulating cylinder 1. However, in this case, problems regarding the electric field design on the surface of the insulating rod remain, which impedes miniaturization of the arc extinguishing chamber and, in turn, the miniaturization of the gas circuit breaker.

[Purpose of invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a gas circuit breaker having a small arc extinguishing chamber that can eliminate the above-mentioned drawbacks, suppress heat generation of electrodes due to energization, and improve dielectric strength.

[Summary of the idea]

In order to achieve the above object, the present invention connects the electrode supporting parts that support the electrodes with a plurality of insulating rods, and the insulating rods have smooth corners and a substantially rectangular cross section. The long side direction of the cross section is arranged in the tangential direction of a concentric circle centered on the electrode, and the dielectric strength in the radial direction is made larger than in the tangential direction of the concentric circle.

[Example of idea]

An embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 shows a cross section of the arc extinguishing chamber of a gas circuit breaker. This arc extinguishing chamber has the following configuration. That is, it is fixed in a container (not shown), and the container is filled with an insulating gas such as SF ₆ gas. Two disc-shaped fixed electrode support parts 11 and a movable electrode support part 12 are arranged facing each other, and four insulating rods 10 are inserted equally on approximately the same circumference between both support parts 11 and 12. There is. And insulation rod 1
Both electrode support parts 11 and 12 are fixed to both ends of the electrode 0 with bolts 13, respectively. Fixed electrode support part 11
A fixed arc electrode 14 that protrudes toward the movable side is fixed approximately at the center of the arc. In addition, this fixed arc electrode 14
A fixed current-carrying electrode 15 is fixed concentrically to the outer side of the electrode. On the other hand, a puffer piston 16 is fixed to the fixed side of the movable electrode support 11, and the puffer piston 16 forms a puffer chamber 18 together with a puffer cylinder 17 that slides on the outer periphery of the puffer pin 16. The puffer cylinder 17 is driven by an insulating rod 19 that passes through the puffer piston 16 and the movable electrode support 12 and is connected to an operating mechanism (not shown). Furthermore, a movable current-carrying electrode 20 that is slidable inside the fixed current-carrying electrode 15 is attached to the outside of the fixed end of the puffer cylinder 17 . A movable arc electrode 21 is fixed to the fixed end face of the puffer cylinder 17 so that the fixed arc electrode 14 can be fitted inside and the movable arc electrode 21 can be moved in and out. This movable arc electrode 21
One end is fixed to the puffer cylinder 17 and the other end extends to the fixed arc electrode 14 side, and an insulating gas flow path 22 is provided between the movable arc contact 21 and the movable arc contact 21 through an outlet 17a provided in the puffer cylinder 17.
An insulating nozzle 23 is arranged to form a.

Here, the structure of the insulating rod 10 will be explained in detail. The insulating rod 10 has a substantially rectangular shape with the long side of the cross section tangential to a concentric circle centered on the electrode, as shown in FIG. It is said that Further, as the material of the insulating rod 10, a substance having directionality in dielectric strength, such as a glass cloth laminate, is used. That is,
Glass laminates have a property that their dielectric strength is stronger in a direction perpendicular to the laminate surface than in a direction parallel to it. By the way, the electric field strength within the arc extinguishing chamber is greater in the radial direction than in the tangential direction of concentric circles centered on the electrodes. Therefore, the glass cloth is an insulating rod of 10
The insulating rods 10 are formed by stacking a plurality of insulating rods in the radial direction of concentric circles centered on the electrodes on which the insulating rods are arranged.

Next, the operation of the configuration of this embodiment will be explained. In FIG. 1, the gas circuit breaker is in the closed state, and the main current is passed between the fixed current-carrying electrode 15 and the movable current-carrying electrode 20. In this case, although both current-carrying electrodes 15 and 20 generate heat when energized, natural convection of the insulating gas is promoted because the fixed electrode support part 11 and the movable electrode support part 12 are connected by four rod-shaped insulating rods 10. Therefore, both current-carrying electrodes 15 and 20 are effectively cooled by the insulating gas. At the time of disconnection, an operation mechanism (not shown) is operated in response to a disconnection command, and the insulating rod 19 moves toward the movable electrode support portion 11. As the insulating rod 19 moves, the movable current-carrying electrode 20 separates from the fixed current-carrying electrode 15, and the current flows entirely between the fixed arc electrode 14 and the movable arc electrode 2.
Flows between 1 and 1. At the same time, as the puffer cylinder 17 moves, the insulating gas within the puffer chamber 18 begins to be compressed. When the insulating rod 19 further moves, the movable arc electrode 21 separates from the fixed arc electrode 14, and both arc electrodes 14, 21
An arc occurs between them. High-pressure insulating gas compressed within the puffer chamber 18 is blown against this arc through the outlet 17a of the puffer cylinder 17 and the flow path 22, and becomes a high-temperature insulating gas that is easily released to the outside of the arc extinguishing chamber. Ru. As a result, the arc is extinguished and the gas circuit breaker is placed in a disconnected state.

In this embodiment, the fixed electrode support part 11 and the movable electrode support part 12 are connected and fixed by four equally arranged insulating rods 10 to form an arc extinguishing chamber. Therefore, although the fixed current-carrying electrode 15, movable current-carrying electrode 20, etc. generate heat when energized, the insulating gas inside and outside the arc-extinguishing chamber can move freely, and the natural convection of the insulating gas inside the arc-extinguishing chamber is not inhibited. Therefore, both current-carrying electrodes 15, 20, etc. are effectively cooled, and the insulating gas, which has become high in temperature and has a reduced dielectric strength, is quickly discharged from between the insulating rods 10 to the outside of the arc extinguishing chamber. Further, at the time of interruption, the insulating gas, which is blown against the arc generated between the fixed arc electrode 14 and the movable arc electrode 21 and has become high in temperature and has a reduced dielectric strength, is similarly promptly discharged to the outside of the arc extinguishing chamber. Therefore, the current carrying capacity of the gas circuit breaker can be increased. At the same time, since the arc extinguishing chamber itself and the space between the arc extinguishing chamber and the container (not shown) can be made small, it is possible to provide a small-sized gas circuit breaker.
Although only the arc extinguishing chamber for a single phase is shown in this embodiment, it is more effective for downsizing if all three phases are housed in a container.

Furthermore, the cross-sectional shape of the insulating rod 10 is approximately rectangular with its long sides tangential to concentric circles centered on the electrodes, and the corners of this rectangle are shaped into smooth arcs. Therefore, an insulating rod 10 for insulatingly supporting the fixed electrode support part 11 and the movable electrode support part 12 is provided.
Mechanical strength is a value that maintains sufficient functionality.
In addition, since the insulating rod 10 is made thinner in the radial direction of the concentric circles centered on the electrode, the distance between the arc extinguishing chamber and the container or between the arc extinguishing chambers can be narrowed, making it possible to manufacture a small gas circuit breaker. I can do it. Moreover, stress concentration and electric field concentration at the corners of the rectangle can be sufficiently alleviated, the insulating rod 10 is mechanically and electrically stable, and the reliability of the gas circuit breaker is improved.

The insulating rod 10 is made of a glass cloth laminate having directional dielectric strength, that is, the electric field strength is strong so that the laminated surface of the glass cloth is almost parallel to the tangential direction of the concentric circle centered on the electrode. Since a plurality of insulating rods are formed by stacking them in the radial direction, the insulation performance of the insulating rod 10 is improved. Furthermore, since the insulating rod 10 is made rectangular when assembling the arc chamber, there is no risk of erroneously oriented the glass cloth. In this example, the electric field on the surface of the insulating rod could be reduced by 20% compared to when an insulating rod with a circular cross section was used.

In this example, only a single-phase arc extinguishing chamber has been described, but it may also be adopted as a three-phase arc extinguishing chamber, and in this case, the distance between the other phases and the container may be narrowed. It is even more effective. In addition, it can be used in a wide range of applications, such as when it does not have a puffer chamber or when it has only one set of fixed and movable electrodes, and provides similar effects. Further, the number of insulating rods 10 can be arbitrarily changed within the guaranteed mechanical and electrical strength range.

[Effect of idea]

As explained above, according to the present invention, the electrode support parts are connected by a plurality of insulating rods, and the insulating rods have a substantially rectangular cross section with smooth corners, and the long side direction of the rectangular cross section is the tangent to the concentric circle. Since the dielectric strength in the radial direction is larger than that in the tangential direction of the concentric circles, the convection of the insulating gas is promoted and the electric field of the insulating rod is relaxed, suppressing the heat generation of the electrode and making it possible to extinguish a small arc. A gas circuit breaker having a chamber can be provided.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of an arc extinguishing chamber of a gas circuit breaker showing an embodiment of the present invention, Fig. 2 is a right-hand sectional view of the - section of Fig. 1 viewed in the direction of the arrow, and Fig. 3 is a conventional FIG. 3 is a cross-sectional view showing the arc extinguishing chamber of the gas circuit breaker. 10...Insulating rod, 11...Fixed electrode support part, 1
2...Movable electrode support part, 13...Bolt, 14...
... Fixed arc electrode, 15 ... Fixed current-carrying electrode, 16
……Puffer piston, 17……Puffer cylinder, 18……Puffer chamber, 19……Insulating rod,
20...Movable current-carrying electrode, 21...Movable arc electrode, 22...Flow path, 23...Insulated nozzle.

Claims (1)

[Claims for Utility Model Registration] (1) A pair of electrode support parts each supporting at least one pair of electrodes that are disposed facing each other in an insulating gas and can be moved into and out of contact with each other, are connected using an insulator. In a gas circuit breaker in which an arc extinguishing chamber is housed in a container, the insulator is arranged outside the electrode and on a substantially concentric circle with the electrode as the center, and the insulation has a directionality in dielectric strength. Consisting of sticks,
This insulating rod has smooth corners and a nearly rectangular cross section, and is arranged so that the long side direction of this rectangular cross section is tangential to the concentric circle, so that the dielectric strength in the radial direction is greater than that in the tangential direction of the concentric circle. A gas circuit breaker characterized by: (2) The gas circuit breaker according to claim (1) of the utility model registration, in which the arc extinguishing chamber is housed in a container for all three phases. (3) The gas circuit breaker according to claim 1, wherein the insulating rod is a glass cloth laminate.