JPS58121520A - Buffer type gas breaker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to a buffer type gas breaker using SFe gas as an arc extinguishing medium.

In general, it goes without saying that in order to improve the short-circuit breaking performance of a circuit breaker, it is important to cool and extinguish the arc that occurs at the time of breaking as quickly as possible, but at the same time, it is important to withstand the re-electromotive voltage that appears after the current zero point. It is well known that it must be a structure. In the case of a buffer-type gas shear breaker with an axially moving electrode, it is relatively easy to prevent flash from occurring near the axis, but it is relatively easy to prevent flash from occurring near the axis, but especially around the outer periphery. The reality is that there is no suitable means for preventing flash faults between the inside wall of the grounding vessel and the grounding vessel, and a solution has been long awaited.

As the conventional type 7 gas circuit breaker, the circuit breaker shown in Figs. A cylindrical fixed 7-shaped contact 2 and a cylindrical movable arc contact 3 coaxially opposed to the cylindrical movable arc contact 3 and arranged so as to be able to slide toward and away from each other.
, an arc-resistant nozzle 4 that surrounds the movable arc contact 3 at a constant interval a around its outer periphery and has an opening on one side into which the fixed arc contact 2 can be inserted; A buffer cylinder 5 concentrically supports the other side of the main contact 3 and the nozzle 4, and the fixed main contact 2.
A cylindrical fixed main contact 6 that is concentrically integrated into the buffer/linder 5 into which the nozzle 4 can fit and maintains a constant distance from the outer periphery of the main contact 6 is connected to and separated from the fixed main contact 6 that is integrated into the buffer/linder 5 The movable main contactor 7 that can be used is configured as a main contact thread.

The buffer cylinder 5 has a front end space of 11+i distance a on its end surface.
The through hole 5a leading to the axial line and the operation I-+7 door 5b integrated on the axis are removed, and the operation iron 5 is removed.
b is axially movably supported by a fixed piston 9K defining a nozzle 7 chamber 8 between it and the bumper cylinder 5, and is connected to a drive device (not shown).

In the contact between the fixed main contact 1-6 and the movable main contact 7, there is no F in the closing operation with respect to the contact and separation between the fixed arc contact 2 and the contact 3. In Kaigo Taisaku, it is structured so that it comes first.

As is well known, the breaker principle of the buffer-type cass breaker in the above ha is that the insulating gas in the buffer chamber 8 is compressed by pulling it in the direction of the arrow P to form a so-called buffer pressure. A gas flow 10 is ejected from the through hole 5a within the interval a and is blown onto the arc 11 generated between the fixed arc contact 2 and the movable arc contact 3 to cool and extinguish it. In the process of reaching the cutoff, the current 7-11 disappears once at the zero point, and after the zero point passes, the current between the contacts 2 and 3 and the 6
, 7 or between the contacts 6, 7 and the inner wall of the container 1, and must be able to withstand the re-electromotive voltage that appears between them and the inner wall of the container 1, thereby preventing flashover.

However, the state inside the breaker immediately after the disappearance of the 7-ring 11 is such that the so-called hot gas 12 exposed to the 7-ring 11 fills around the contacts 2, 3; 6, 7, as shown in FIG. Since a re-electromotive voltage is applied thereto, a flash fault may occur in the paths shown by S, to S4, for example. A flashover in the path SI can be relatively easily prevented by configuring to continue supplying the gas flow 10, which is colder than the inside of the pack and the chamber 8, even after the 7th arc is extinguished. On the other hand, in the case of flash faults on routes S and ~S4, the opening distance between the main contacts at the time of arc extinguishment may be extended, the container 1 may be made larger to increase the distance to the ground, or the flash fault point may be increased. Form of
The only way to alleviate the electric field is to change the 1 state to alleviate the electric field, all of which lead to significant cost increases and major changes, and there are limits to electric field mitigation. This becomes an obstacle to improving the short-circuit breaking performance of
Appropriate improvement measures have been desired for some time. Although the above description has been made for a configuration in which the main contactor is provided separately, the same applies to the case where both the 7-way contacts 2 and 3 have current-carrying lids and the fixed 7-way contact 6 is simply a shield for mitigating the electric field. It is.

In view of the above, this invention provides a buffer 7 that has a simple structure and excellent short-circuit breaking performance without significantly increasing costs or increasing the size.
The purpose is to provide a shaped gas breaker.

According to the present invention, the above-mentioned object is provided with a buffer cylinder that compresses the blown gas in cooperation with a movable contact, and a gap between the movable contact and a fixed contact disposed on the same axis facing the movable contact. In a device that is equipped with a nozzle that sprays compressed gas and sprays the gas on an arc generated in this separated gap, a secondary (5) This is achieved by supplying the gas flow to be blown from the buffer cylinder.

Embodiments of the present invention will be described below based on the drawings.

In FIGS. 4 to 6, parts corresponding to the breaking plan of the conventional breaker shown in FIG.

The difference is that a through hole 5C is provided on the end face of the buffer cylinder 5, which communicates with the buffer chamber 7, and this generates a gas flow different from the cooling gas flow IO of the arc 11, and the outside of the through hole 5a. The holes are uniformly distributed over the entire circumference of the end surface surrounding the through hole 5a, and the total opening area is selected within a range of several percent of the total area of the through hole 5a. This starts the breaking operation and the fixed arc contactor 2
When a 7-ri 11 occurs between the arc contactor 3 and the movable arc contactor 3, a gas flow 10 is blown toward the arc 11, and a gas flow similar to the gas flow 10 is directed from the through hole 5C toward the tip of the fixed main contactor 6. The temperature will be lowered and a fresh gas stream 13 will be ejected. This gas flow 13 causes the through hole 5 to
C and the tip of the fixed main contact 6 are surrounded by a curtain of gas (6) gas flow 13, and its branch flow 13a
Since the gas is blown toward the axis, it is possible to prevent the hot gas 12 that has absorbed the heat from diffusing radially toward the inner wall of the container 1, and also to rapidly cool it and create a fixed arc. It will be pushed towards the rear of contactor 2. This continues even after the current zero point dissipates the wave of the 7-reel 11, and even after the application of the re-electromotive voltage after the current zero point has passed.

Therefore, not only the contacts 2, 3 and 6, 7, but also flashovers between the contacts 6, 7 and the inner wall of the container 1 are prevented. Furthermore, since this can be achieved by dividing the flow by only a few percent with respect to the total opening area of the through hole 5a, the gas flow 10
There is no need to reduce the cooling power of the arc 11 or to increase the opening distance.

7 and 8 are respectively different embodiments of the present invention, and the one shown in FIG. The chamber is partitioned with a distance i5d between the arc cooling buffer chamber 8a and the hot gas cooling chamber 8b, and the one shown in FIG. The nozzle 4 is provided with a through hole 4a for ejecting a gas flow 13 for branching the cooling gas flow 10 from the middle, and is configured to be in series with the through hole 5a. Although detailed description is omitted, in both cases, as in the embodiment shown in FIG. Therefore, it is possible to obtain a 7A type gas circuit breaker that is strong against re-electromotive voltage, that is, has improved short-circuit breaking performance.

The above embodiments are all equipped with an arc contact and a main contact, but as in the conventional example, the arc contact has a current carrying capacity and the main contact is provided with a corresponding shield for mitigating the electric field. It goes without saying that the same effect can be obtained even in a configuration like this, and the same can be said not only for the earthed container type but also for the insulator type.

As explained above, according to the present invention, the short-circuit breaking performance of the breaker can be improved with a relatively simple configuration that only divides the gas flow blown from the buffer chamber to the breaker section into arc cooling and hot gas cooling. What we learned is that it contributes to improving the quality of electricity, and the effect is significant.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIGS. 1 to 3 are each a vertical sectional view of an example of the breaker chamber of a conventional buff 7 type gas breaker, and FIG. 1 is a diagram showing the state when it is closed. 2 and 3 are diagrams showing the shutoff process, and FIGS. 4 to 6 are longitudinal cross-sectional views of an embodiment of the shutoff chamber of the buffer type gas breaker according to the present invention. Figure 5 shows the state when it is closed.
7 and 8 are longitudinal cross-sectional views showing the shutting process of the shutoff chamber of the bag-type gas breaker of different embodiments of the present invention. 2... Fixed contact, 3... Movable contact, 4... Nozzle, 5... Buffer cylinder, 8-output buffer 7 chambers, (
9)

Claims (1)

[Claims] 1) It is equipped with a nozzle cylinder that works together with the movable contact to compress the blown gas, and also supplies compressed gas into the gap between the movable contact and the fixed contact coaxially mounted opposite to the movable contact. In a type that is equipped with a spray nozzle and sprays a spray force onto the arc generated in this separated gap, the gas stream that is sprayed into this gap is surrounded and secondarily sprayed in the axial direction. (7-fur type gas breaker.