JPH08129936A - Gas-blast circuit-breaker for electric power - Google Patents

Abstract

PURPOSE: To easily cope with increase of the current-carrying capacity in a gas-blast circuit-breaker for electric power which has its breaking part sealedby structured by restraining the temperature rise of an current-carrying part in supplying electric current. CONSTITUTION: A breaking part composed of fixed contacts 2, 3 and movable contacts 6, 7 is sealed by sealing structural bodies 1, 4, 11, so as to constitute a part of a sealing sturctural body, and a plurality of vent holes 14 are provided on the side surface of a lower conductive cylinder 11 arranged under the breaking part. In carrying current to a gas breaker, gas heated by generated heat of a current-carrying part is convected with gas on the periphery inside the sealing structural body. When the gas is convected in the lower conductive cylinder, the fresh and low-temperature gas outside the cylinder is taken into the lower conductive cylinder through the vent holes. The gas is mixed with the convecting gas, so as to cool the heated gas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric power gas circuit breaker, and more particularly to an electric power gas circuit breaker having a closed structure in its breaking portion.

[0002]

PRIOR ART Three-phase batch type GIS (gas insulated switchgear)
When a three-phase breaker pole is arranged in the GIS tank like a gas breaker for use in the gas tank, the hot gas generated when the current is cut off is discharged into the GIS tank so that the gas breaker passes through the hot gas. There was a possibility of causing an accident in which an interphase flashover occurred.

In order to prevent this, the shutoff portion is covered with an insulating cylinder or the like to form a closed structure.

[0004]

In the above-described power gas circuit breaker having a closed structure of the breaker, the insulating gas in the breaker is also sealed in the sealed structure. For this reason,
Since the gas warmed by the temperature rise of the interruption part at the time of energizing current only circulates in the closed structure, it is not cooled effectively.

In general, a gas breaker for electric power is required to suppress a temperature rise when a current is applied and to have a duty to interrupt the current. In particular, as the demand for electric power has increased in recent years, it has been required to increase the energizing capacity of the gas circuit breaker for electric power. However, in the above-described power gas circuit breaker having a closed structure of the breaking portion, it is difficult to suppress the temperature rise of the conducting portion, and thus it is difficult to cope with the increase of the conducting capacity.

According to the present invention, in a power gas circuit breaker having a closed shut-off portion, it is possible to suppress an increase in temperature of the current-carrying portion at the time of passing current, and to easily cope with an increase in current-carrying capacity. The purpose is.

[0007]

In order to achieve the above object, the present invention forms a part of a hermetically sealed structure by hermetically sealing a shutoff portion composed of a fixed contact and a movable contact. A plurality of ventilation holes are provided on the side surface of the lower conductive cylinder arranged below the blocking portion.

[0008]

When the gas circuit breaker is energized, the gas heated by the heat generation of the energizing section starts convection inside the sealed structure together with the surrounding gas. When the gas is convected in the lower conductive cylinder, fresh low temperature gas outside is taken into the lower conductive cylinder through the ventilation hole. It then mixes with the convective gas and cools the warmed gas.

This prevents heat from being trapped in the shut-off portion in the closed structure. Therefore, there is a margin to increase the current carrying capacity, and the performance of the power gas circuit breaker can be improved.

[0010]

EXAMPLE An example in which the gas circuit breaker of the present invention is applied to a puffer type gas circuit breaker will be described with reference to the drawings. FIG.
FIG. 4 is a cross-sectional view of a puffer type gas circuit breaker. The space between the upper conductive cylinder 1 and the lower conductive cylinder 11 of the blocking portion is surrounded by the inter-electrode insulating cylinder 4, and a sealed structure that houses the blocking portion together with the insulating support cylinder 13 is formed. A plurality of vent holes 14 are provided on the side surface of the lower conductive cylinder 11 so that gases inside and outside the lower conductive cylinder 11 can pass through each other.

A fixed arc contact 2 and a fixed main contact 3 are attached to the lower part of the upper conductive cylinder 1. An insulating operating rod 12 is connected to an operating mechanism (not shown) and is driven upward when the gas circuit breaker is turned on and downward when the gas circuit breaker is turned on. The movable conductive rod 15 is attached to the tip of the insulating operation rod 12, and the movable main contactor 6 and the movable arc contactor 7 are provided on the tip side thereof. Reference numeral 5 denotes a nozzle fixed to the tip of the movable main contactor 6.

A papper cylinder 9 is formed below the movable main contact 6. The outer circumference of the fixed piston 10 fixed to the lower conductive cylinder 11 side is joined to the inside of the papa cylinder 9. Moreover, the sliding contact 8 comes into contact with the movable conductive rod 15,
The movable main contact 6 and the movable arc contact 7 are connected to the lower conductive tube 1.
1 to be electrically connected. The current cutoff operation in the puffer type gas circuit breaker is well known in the related art, and therefore the description thereof is omitted here.

At the time of energization as shown in the figure, the movable main contact 6 comes into contact with the fixed main contact 3, and the current flows through the upper conductive cylinder 14-fixed main contact 3-movable main contact 6-movable conductive rod 15-sliding. It flows through the path of the contactor 8-the lower conductive tube 11. By passing this current, heat is generated by the contact resistance at the contact portion of each contactor, and the gas around it is warmed. The warmed gas rises inside the enclosed structure with the surrounding gas. As a result, the gas in the sealed structure including the upper conductive cylinder 1, the inter-electrode insulating cylinder 4, and the lower conductive cylinder 11 starts convection.

During the convection of the gas, a part of the heat of the gas is released to the outside of the hermetically sealed structure by the heat conduction between the upper conductive cylinder 1 and the inter-electrode insulating cylinder 4, and the gas is cooled. Further, in the lower conductive cylinder 11, fresh low temperature gas outside is taken in from the vent hole 14 formed in the side surface by the convection of gas, and the low temperature gas is mixed with the warm gas inside the closed structure,
Cool the gas.

As described above, the vent hole 14 provided in the lower conductive cylinder 11 prevents heat from being trapped in the blocking portion in the closed structure. Therefore, there is a margin to increase the current carrying capacity, and the performance of the power gas circuit breaker can be improved. Since the lower conductive cylinder 11 is provided with the ventilation hole 14, the hot gas generated by the arc when the current is cut off is discharged from the ventilation hole 14 to the outside. However, since the distance from the blocking portion to the vent hole 14 can be set large, the hot gas is sufficiently cooled before being discharged to the outside, and the dielectric strength is restored. Therefore, interphase flashover due to hot gas does not occur.

[0016]

According to the present invention, in the power gas circuit breaker having the closed structure of the breaking portion, it is possible to suppress the temperature rise of the conducting portion at the time of energizing the current and easily cope with the increase of the conducting capacity. be able to.

[Brief description of drawings]

FIG. 1 is a side sectional view of an embodiment of a power gas circuit breaker of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Upper conductive cylinder 2 ... Fixed arc contactor 3 ... Fixed main contactor 4 ... Inter-electrode insulating cylinder 5 ... Nozzle 6 ... Movable main contactor 7 ... Movable arc contactor 8 ... Sliding contactor 9 ... Puppa cylinder 10 ... Fixed piston 11 ... Lower conductive tube 12 ... Insulation operating rod 13 ... Insulating support tube 14 ... Vent hole 15 ... Movable conductive rod

Claims (1)

[Claims] 1. A blocking unit composed of a fixed contact and a movable contact, a sealing structure for sealing the blocking unit, and a part of the sealing structure, which is disposed below the blocking unit and has a side surface. And a lower conductive cylinder provided with a plurality of ventilation holes in the electric power gas circuit breaker.