JPS6047315A - 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 [Field of Application of the Invention] The present invention relates to an improvement in an insulating nozzle for a gas circuit breaker, particularly a pumper type gas circuit breaker.

[Background of the invention]

As electric power systems become more voltage-intensive, the voltage applied to gas circuit breakers is on the rise. High voltage of gas circuit breaker is 1aM
This has been addressed by increasing the voltage per unit, but in this case, the duty of interrupting small currents due to the application of very high voltage over a short contact distance becomes extremely severe, and it is desired to improve its performance. .

Recently, attempts have been made to provide a continuous protrusion having a reverse taper in the diverging part of the nozzle as a method of improving its performance. Figure 1 shows its structure. Reference numeral 1 denotes a one-inch dynamic insulating nozzle that also serves as a guide for blowing compressed gas generated by the buffer cylinder 4 and fixed piston 5 during the breaking operation onto the arc generated between the movable arc contact 6 and the fixed arc contact 2. 3 is a movable electron collector, and 7 is a fixed collector.

The insulating nozzle IK is the lower IC1111 on the downstream side of the throat part.
A protruding portion 8 having a reverse tapered portion C-D at a widened portion B-E of 1.
are formed continuously in the circumferential direction 2. Unlike short-circuit current interruption, in advanced small current interruption, the interruption current is small, so gas ionization hardly occurs, and performance is influenced by dielectric strength in a cold gas state.

Since the dielectric strength of gas depends on gas pressure, advanced small current interrupting performance is closely related to gas pressure. The above-mentioned protrusion 8 is formed for the purpose of preventing pressure drop within the insulating nozzle. However, there is a drawback that simply providing the protrusion 8 may not prevent a pressure drop.

The purpose of the present invention has been made in view of the above points,
It is an object of the present invention to provide a structure in which the effect of the protrusion is always effectively exhibited.

Recent research has revealed that there is a special relationship with the cross-sectional area of the gas flow path in order to effectively exhibit the effect of the protrusion. Figure 2 shows this situation.

The shaded width is the pressure variation.

So is the cross-sectional area of the gas flow path at the throat portion A-B, SI is the area of the gas flow path quadrupled by the end of the protrusion 8 and the stator 2, and the horizontal axis is shown as S+/So. The vertical axis is stator 2
Gas pressure P at the tip of the stator when the tip is in the area B-C-D between the nozzle throat outlet and the tip of the protrusion
It is expressed as the ratio of the charging pressure P+ of the gas circuit breaker and the charging pressure P+ of the gas circuit breaker.

Since the dielectric strength tends to be low in the vicinity where the stator 2 exits the throat of the nozzle 1, the gas pressure P at the tip of the stator is compared as the value at that position. S1/So
When ≧1.5, P / P L (1, and gas pressure P decreases by filling pressure P+,,l:p.S+/So is 3
As the value decreases from 1.5 to 1.5, P/P t steadily decreases, and at Sr/So = 1.5, P/P L
becomes extremely small. Furthermore, as Sr/So becomes smaller, P/
P L increases rapidly, and when 8+/So≦1, P /
P L≧1, and the gas pressure P does not decrease. Therefore, if a protruding portion having an inverted taper is provided so that S1/So≦1.5, the inverted tapered portion effectively compresses the debris and effectively prevents a drop in the pressure at the tip of the stator.

An embodiment of the present invention will now be described with reference to FIG. A reverse tapered portion CD is provided at the diverging portion A-E on the downstream side of the throw A-B of the nozzle 1.

The protruding portion 8 is formed by the reverse tapered portion CD and the widened portion DE. The cross-sectional area of the four passages formed by the narrowest part of the protrusion 8 and the stator 2 is equal to the cross-sectional area of the throat A-B of the nozzle 1. The protrusion 8 is an annular continuous body that is continuous in the circumferential direction.

According to this example, the following effects are achieved.

+11 Since the gas pressure at the tip of the stator, where the k field is strong, does not decrease, the dielectric strength increases during the electrode opening operation, and the small current performance improves.

(2) Channel cross-sectional area of the throat section and channel cross-sectional area of the protruding section (
When the stator is located upstream of the narrowest part of the protrusion), the gas flow is the same as when there is no protrusion, and this does not affect the opening speed and time of the circuit breaker. I won't give it.

(3) For the same reason as (2) above, the amount of gas sprayed does not adversely affect the large current interrupting characteristics, where the amount is a major factor.

In addition, although Fig. 3 shows the case of SI/5o=1, S1/5o=1
If So≦1.5, the same effect is achieved although there is some change in performance.

As explained below, according to the present invention, since the gas compression action by the protrusion having the inverted tapered portion is effectively exerted, an insulating nozzle with a small drop in gas pressure can be obtained, and the performance of the circuit breaker can be improved. Significant improvements can be achieved.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a prior gas circuit breaker, FIG. 2 is a characteristic diagram which is the basis of the present invention, and FIG. 3 is a sectional view of a gas circuit breaker according to an obvious embodiment of the present invention. 1... Insulated nozzle, 2... Fixed arc contactor, 3-
1. Movable current collector, 4...Buffer cylinder, 5...
Fixed piston, 6... Movable arc contactor, 7... Fixed output electron, 7th [I(] Figure 2'J/2.j Figure 3 -6)

Claims (1)

[Claims] 1. In a gas circuit breaker that blows arc-extinguishing gas through an insulated nozzle to extinguish the arc that occurs between the fixed contact and the movable contact in the arc-extinguishing chamber when the arc is interrupted, the downstream side of the throat part of the insulated nozzle A protrusion continuous in the circumferential direction having a reverse tapered part is provided at the wide end of the spacer, and the minimum cross-sectional area of the space surrounded by the protrusion and the fixed contact is 1.5 of the cross-sectional area of the space of the throat part.
A gas circuit breaker whose % characteristic is that it is smaller than twice the size.