JPS6238285Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for preventing deflection of an arc when the shield is cut off in a power shield breaker, particularly in a puffer type gas shield breaker.

In recent years, puffer-type gas shield breakers have become increasingly smaller and larger in capacity, and the influence of electromagnetic force on the arc of the lead-out conductor when the current is interrupted cannot be ignored. There is.
In other words, when the arc breaks, it is biased in a specific direction within the arc extinguishing chamber due to the electromagnetic force of the lead-out conductor, and as a result, the arc reduces the withstand voltage between the individual fixed main contact and the movable main contact. There is a risk of flashover occurring between the main contacts.

The present invention has been devised to deal with this problem, and the present invention will be explained below using examples.

Figure 1 shows the structure of the arc extinguishing chamber of a conventional puffer-type gas shield breaker. and the movable arc contact 4 are engaged with each other, and the movable cylinder 5
The puffer chamber 7 between the base plate and the fixed piston 6 is filled with an insulating gas. Note that 8 is an arc extinguishing nozzle, and 9 is a container.

When the movable contact rod 10 for driving the movable part is pulled down as shown by the arrow, the movable main contact 2 first separates from the fixed main contact 1, and then the movable arc contact 14 moves away from the fixed arc contact. 3, an arc occurs between arc contacts 3.4. in this case,
As schematically shown in FIG. 2a, the fixed-side lead-out conductor 11 and the movable-side lead-out conductor 13 drawn out from the movable contact rod 10 via the sliding contact 12 are usually They are pulled out in the same direction. For this reason, a closed circuit is formed, and the arc 14 generated between the fixed and movable arc contacts 3 and 4 is caused by electromagnetic force to move to the lead-out conductor 1 as shown in the figure.
The main contacts 1 and 13 are driven to the left side, which is opposite to the drawing direction, and there is a risk of flash shorting between the main contacts 1 and 2. In addition, FIG. 2b is a cross-sectional view schematically showing a state in which the arc 14 is biased to the left, and illustrations of fixed and movable main contacts, movable arc contacts, puffer cylinders, etc. are omitted. .

In the present invention, in order to prevent the arc 14 from shifting to the side, one to several small holes 15 are inserted, as shown in FIG. For example, it is provided on the movable main contact 2 on the side, and the compressed insulating gas in the puffer chamber 7 is spouted out in the direction of arrow A during the shearing operation.

At the time of cutting, the compressed fresh insulating gas in the puffer chamber 7 is ejected from the nozzle 8 as shown by the arrow B→C, and the arc 14 generated between the arc contacts 3 and 4 is caused to reach the lead-out conductor 11. , 13, but this is blocked by the insulating gas flow in the direction of arrow A from the small hole 15, and the arc 14 is stretched along the fixed arc contact 3 as shown. It is exposed and finally disappears.
Note that the exhaust gas is discharged outside the arc extinguishing chamber as indicated by arrow D.

In this case, the amount of insulating gas ejected from the small hole 15 is extremely small compared to the insulating gas ejected from the nozzle 8, and the effect on the insulating gas can be ignored. Since it is fresh and has not been subjected to ionization by the arc 14, it is possible to effectively prevent the arc 14 from shifting. In the above embodiment, the case where the small hole 15 was provided in the movable main contact 2 was shown, but the small hole 1
5 can also be provided in the nozzle 8, and one or more can be provided on the side where the arc is biased depending on the situation. In addition, the insulating gas ejected from the small hole 15 was assumed to be supplied from inside the puffer chamber 7, but in addition to this, a separate cylinder and piston or another insulating gas generator may be provided so that the insulating gas ejected from the small hole 15 is supplied from the inside of the puffer chamber 7. It can also be made to squirt.

In other words, the purpose of the present invention is to prevent the arc from being biased due to the electromagnetic force of the closed circuit formed by the lead conductor at the time of a burnout to be prevented by using an insulating fluid such as an insulating gas ejected from a small hole provided at an appropriate location. It is particularly suitable for use in puffer-type gas shields and disconnectors, since the insulating gas compressed in the puffer chamber can be diverted by the shriveling action.
It is also effective when applied to other gas vents and disconnectors, as well as air vents and disconnectors.

As explained above, the present invention prevents the arc from being driven sideways by the electromagnetic force of the lead conductor, and eliminates the risk of flash shorts occurring between the main contacts, which is highly effective. It is.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the arc extinguishing chamber of a conventional puffer-type gas shield breaker, and Figures 2 a and b show the state in which an arc is generated when the shield is disconnected and is driven laterally by the electromagnetic force of the lead-out conductor. FIG. 3 is a cross-sectional view schematically showing an embodiment of the present invention. 11, 13... Output conductor, 14... Arc,
15...Small hole.

Claims (1)

[Scope of utility model registration request] In a puffer-type gas circuit breaker in which the input and output conductors are drawn out in the same direction, the movable main contact or arc extinguishing nozzle has a small A hole is provided, and the small hole is communicated with the puffer chamber of the puffer-type gas circuit breaker, and when shutting off, fresh non-ionized insulating gas is blown out, and the above-mentioned,
A power circuit breaker characterized in that the arrangement of the output side conductor prevents the arc from shifting due to electromagnetic force.