JPH0436917A - Gas blast circuit breaker - Google Patents

Abstract

PURPOSE:To make gas heating with arcs in the normal breaking process by furnishing a storage chamber at the periphery of a puffer chamber, putting the storage chamber in communication with the movable side gas flow path, and boosting in advance the gas pressure at the time of circuitry breaking in this storage chamber by means of feeding the exhaust hot gas on the movable side. CONSTITUTION:The gas in a buffer chamber 6 with the gas pressure boosted by breaking motion is blown to the arc 16 generated between a stationary piece 1 and a moving piece 2. Then the gas stream diverges in two ways, i.e. on the stationary piece 1 side and the gas flow path 8 side, to generate so-called double flow. Gas heating due to the arc 16 is applied to the gas stream (a) on the gas flow path 8 side, and the gas pressure in the storage chamber 7 is going to be boosted. Then the tripping motion is ended, and gas blowing from the buffer chamber does not exist any more. However, the gas pressure in the storage chamber 7 has been boosted in the preceding processes, and now a gas stream (b) is generated from the storage chamber 7 to the stationary piece 1 side. Even though arcs are continued due to multiple lightning, a suffi cient blowing for circuitry breaking will be obtained.

Description

Detailed Description of the Invention [Field of Application in Industry-1-] The present invention relates to a puffer type and thermal buffer type combined gas circuit breaker (G CB ), and in particular, the thermal buffer cutoff part is a puffer type cutoff part. The present invention relates to a configuration suitable for performing the shutoff function after the shutoff operation (1'1) and after the shutoff operation is completed.

[Conventional technology]

G CB is a puffer type CB is the mainstream, but
Due to the principle that gas is sprayed by compressing the gas through a shutoff operation, the time for spraying is limited. Therefore, if a short-circuit accident occurs due to a lightning strike, etc., and a fault current flows as shown in Figure 6, for example, the current will be interrupted without any problem at the 0 point, but after the interruption, it will be struck again by multiple lightning strikes. If the fault current that is interrupted at the 0 point is large, the removal of I/gas between the electrodes is insufficient, insulation recovery is delayed, a flash short occurs between the electrodes, and the short circuit current flows again. As is clear from FIG. 6, at the zero point of this short-circuit current, the puffer pressure P has decreased and it becomes impossible to shut off.

As a method to compensate for these drawbacks of the puffer type GCB, there is a method in which a self-blade arc-extinguishing thermal buffer type interrupter is used, which uses the energy of the interrupting current arc to heat the gas and increase the pressure. FIG. 7 shows an example of this, which is presented in Japanese Patent Laid-Open No. 56-3920. In FIG. 7, the puffer chamber 6 has an uncompressed portion (hereinafter referred to as dead volume Vd) 1.7 that maintains a certain volume even when the puffer chamber 6 is in a shut-off state. The gas within this Vd is heated and pressurized by an arc, and is blown onto the arc to extinguish it. Therefore, it has arc extinguishing ability even in the cut-off state.

However, the method shown in FIG. 7 has the following problems. Since the volume of the puffer chamber 6 increases by Vd, the puffer pressure -1-increase (2) shown in FIG. 6 decreases. This reduction particularly affects performance in the small and medium short circuit current range. That is, in the large current range, the effect of arc heat can be expected, but in the medium and small 'ni range, the pressure due to the interrupting operation can only be expected to rise by 1, resulting in poor interrupting performance. Furthermore, even when a large current is interrupted, the increase in puffer pressure is delayed, so the minimum arc time that can be interrupted becomes longer, and the rated interrupting time becomes longer than in the past.

[Problem to be solved by the invention]

-1- Although the conventional technology provides a countermeasure against multiple lightning strikes, there is a problem in that the normal interrupting performance is degraded.

An object of the present invention is to enable a normal shut-off process to be performed using gas heating using an arc.

[Means to solve the problem]

The above purpose is to provide a storage chamber around the outer periphery of the puffer chamber,
The 5' storage chamber communicates with the movable side gas flow path, and during the shutoff operation, the i'ff moving side M1 gas is fed into the storage chamber to make the gas pressure higher. This is achieved by

[Effect]

Due to the configuration described in the above section, the volume for thermal buffering is not added to the puffer chamber during normal shutoff operation, and therefore the normal shutoff performance is seriously degraded.

In addition, by shifting from the gas blowing from the puffer chamber to the gas blowing from the storage chamber from the latter half of the shutoff operation, the gas blowing time can be extended.

〔Example〕

Embodiments of the present invention will now be described with reference to FIGS. 1 to 5.

FIG. 1 shows the charging state. In Figure 1, the current is fixed 7-1.
It flows with the mover 2. The puffer type shutoff part is a puffer cylinder]1. Bis I・N12. The movable member is composed of a 2° hollow nozzle 18 and the like, and the gas passage 8 of the hollow nozzle 18 communicates with a storage chamber 7 attached to the outer periphery of the puffer cylinder 11.

FIG. 2 shows the middle stage of the cutoff operation, and the gas in the puffer chamber 6 whose gas pressure has been increased by the cutoff operation is blown onto the arc 16 generated between the stationary member f-1 and the movable element 2. After the gas flow from the puffer chamber 6 is blown onto the arc 16, it separates into two directions, the stator 1 side and the gas flow path 8 side, resulting in a so-called double flow. Gas flow a on the gas flow path 8 side
Gas heating by the arc 16 is added to this, and the gas pressure in the storage chamber 7 is increased.

FIG. 3 shows the state at the end of the shutoff operation, after the arc has been extinguished by the blowing of gas from the puffer chamber 6.

Since the shutoff operation has been completed, gas is no longer blown from the puffer chamber. However, the gas pressure in the storage chamber 7 has been increased in the previous steps, and now gas flows from the storage chamber 7 to the stator 1 side. At this point, sufficient blow is obtained to interrupt the arc even if multiple lightning strikes continue.

Figure 4 shows the pressure characteristics of this structure. The storage chamber gas pressure increases with a time delay from the increase in the puffer chamber gas pressure, and reaches its maximum when the puffer chamber gas pressure decreases.

Even after the puffer chamber gas pressure reaches the base pressure, the gas pressure in the storage chamber remains higher than the base pressure. Therefore, even if a short circuit current flows again at the 0 point due to multiple lightning strikes, it can be interrupted at the 0 point by blowing gas from the storage chamber.

According to this embodiment, since the blowing of the high pressure gas stored in the storage chamber starts in the latter half of the shutoff operation when the puffer chamber gas pressure decreases, the time for blowing the gas is extended and the possible shutoff time becomes longer. As a result, it is possible to maintain the interrupting performance so that even if multiple lightning strikes occur, the interrupter will not become unable to interrupt. Furthermore, the volume of the storage chamber into which the exhaust gas flows needs to be large enough not to degrade the normal shutoff performance, but by providing it around the outer periphery of the buffer ascillator, there is an advantage that the volume can be set more precisely.

FIG. 5 shows a second embodiment of the present invention, in which the storage chamber 7 is fixed to the support part "-", and the exhaust gas 1113 of the gas flow path 8 is
During the middle period of the shutoff operation, the exhaust 1.
]l Connects with 5. As a result, the gas flow on the gas flow path 8 side is exhausted into the gas space at a certain cutoff position during normal shutoff, thereby increasing the M1 air efficiency on the gas flow 18 side and improving the normal shutoff performance. You can get it.

〔Effect of the invention〕

According to the present invention, since the gas spraying time can be extended, it is possible to construct a shutoff section with excellent multiple lightning shutoff performance. Further, normal interrupting performance can also be maintained.

[Brief explanation of the drawing]

Figures 1 to 3 are cross-sectional views for explaining the operation of one embodiment of the present invention, Figure 4 is a pressure characteristic diagram of the shutoff section according to the present invention, and Figure 5 is a cross-sectional view of the second embodiment of the present invention. 6 and 7 are explanatory diagrams of conventional puffer type gas circuit breakers. "・Stator, 2. Mover, 3. Main contactor, 4 Main mover, 5. Nozzle, 6. Puffer chamber, 7. Storage chamber,
8... Gas flow path, 9 - Drive shirt 1-110 support part, 1] - Puffer cylinder, 12... Screw 1-
13 Exhaust "1.14 cylinder, 15...exhaust l",
16... arc, 17 dead volume, 18 hollow nozzle. =8 Funeral diagram time diagram Figure 6 Ginkaku right ×

Claims (1)

[Claims] 1. In a gas circuit breaker consisting of an insulating nozzle, a stator, a mover, a hollow nozzle provided in the mover, a puffer chamber consisting of a cylinder and a fixed piston, a gas flow path of the hollow nozzle, etc. . A gas circuit breaker, wherein the gas flow path communicates with a storage chamber provided on the outer periphery of the cylinder. 2. The gas circuit breaker according to claim 1, wherein the storage chamber is attached to the cylinder, which is a movable part during the shutoff operation. 3. The gas circuit breaker according to claim 1, wherein the storage chamber is fixed by a support part. 4. The gas circuit breaker according to claim 3, wherein the gas flow path communicates with a gas space within the gas circuit breaker during the middle period of the circuit breaker.