JPH0567416A - Gas-blast circuit breaker - Google Patents

Abstract

PURPOSE:To hardly increase movable part mass and minimize damage of a current-flowing electrode due to an arc generated at the time of current commutation. CONSTITUTION:An operating rod 13 is formed of a titanium alloy. An inclined alloy 30 formed of a titanium alloy at an operating rod side and of a metal having electric conductivity higher than the titanium alloy at the outside is arranged on a contact surface of the operating rod 13 with a movable arc electrode 11, a contact surface of the rod 13 with a buffer cylinder 14 and a peripheral part connecting both the surfaces to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas circuit breaker having an improved operation rod for connecting a movable arc electrode and a puffer cylinder.

[0002]

2. Description of the Related Art In recent years, as the demand for electric power has increased, the capacity of gas circuit breakers used in power plants and substations has been increased. In particular, in the case of a circuit breaker used in a system having a high voltage, there is a demand for a circuit breaker having a large energizing current or breaking current.

FIG. 2 shows an example of a conventional gas circuit breaker. That is, the gas circuit breaker 1
An extinction chamber 3 is housed in a container 2 in which an insulating gas is sealed. The extinction chamber 3 is provided with a fixed portion 4 and a movable portion 5 which are arranged to face each other. The fixed portion 4 is composed of a fixed finger 6 that normally conducts a current, a fixed arc electrode 7, a fixed side shield 8 and a fixed support 9 that supports these. On the other hand, the movable portion 5 is composed of a movable electrode 10 that normally supplies a current, a movable arc electrode 11, an insulating nozzle 12, an operating rod 13, and a puffer cylinder 14.

A puffer piston 17 which constitutes a compression chamber together with a support insulating cylinder 15, a movable support 16 and a puffer cylinder 14 is arranged on the back side of the movable part 5 to support the movable part. ing. The fixed portion 4 is usually connected to the movable support 16 by an insulating cylinder 18. The insulating cylinder 18 may be an insulating rod or a capacitor.

When the value of the current to be applied is large, the gas circuit breaker generally has a fixed finger 6 and a movable electrode 10 which are electrodes for energization, and a fixed arc electrode 7 and a movable arc which are electrodes for current interruption. Two types of electrodes, electrode 11, are provided. Then, as shown in FIG. 2, the gas circuit breaker 1
Is in the closed state (current-carrying state), the current flows from the movable electrode 10, the puffer cylinder 14, and the movable support 16 through the conductor 20 through the conductor 19, the fixed support 9, and the fixed fingers 6. .

On the other hand, when the gas circuit breaker 1 shuts off an accident current or the like, the operating rod 13 is pulled toward the arrow in FIG.
Moves to the right in the figure. Along with this, as shown in FIG. 3, the fixed finger 6 and the movable electrode 10 are first separated from each other. At this time, since the fixed arc electrode 7 and the movable arc electrode 11 are not yet separated from each other, the electric current flowing to the movable electrode 10 and the puffer cylinder 14 via the fixed support 9 and the fixed fingers 6 is from the fixed support 9. After passing through the fixed arc electrode 7 and the movable arc electrode 11, the puffer cylinder 1
Change the flow path to 4, i.e. commutate.

Then, as shown in FIG. 4, when the movable portion 5 further moves to the right in the figure and the fixed arc electrode 7 and the movable arc electrode 11 are separated from each other, the gap between the fixed arc electrode 7 and the movable arc electrode 11 is increased. An arc 21 is generated at. At this time, the puffer cylinder 14 moves to the right side in the figure, so that the gas compressed by the puffer cylinder 14 and the puffer piston 17 passes through the insulating nozzle 12 to generate the arc 2
1, which results in the arc 21 being cooled and extinguished, thus completing the interruption of the current. The open state of the gas circuit breaker 1 in which the current interruption operation has been completed in this manner is shown in FIG.
It was shown to.

[0008]

By the way, in the gas circuit breaker as described above, as one of the methods for improving the current interruption performance, the puffer cylinder is increased by increasing the opening speed of the movable part 5. There is a method of increasing the blowing force of the gas compressed between 14 and the puffer piston 17. That is, when the driving force of the operation mechanism unit is constant, it is effective to reduce the mass of the movable unit 5 in order to increase the opening speed of the movable unit 5, and for this reason, the operation rod 1
It is considered that 3 is made of a tungsten alloy having a smaller specific gravity than iron.

However, since the resistivity of tungsten is higher than that of copper or aluminum by one digit or more, compared with the resistance values of the movable electrode 10 and the puffer cylinder 14 via the fixed support 9 and the fixed finger 6, the fixed support is different. 9 to fixed arc electrode 7, movable arc electrode 11, operating rod 1
After 3, the resistance value up to the puffer cylinder 14 becomes very large.

As a result, at the time of the above-mentioned commutation in the current interruption process, the potential difference due to commutation becomes large, the commutation does not go smoothly, and a small amount of arc is generated when the fixed finger 6 and the movable electrode 10 separate. This arc is extinguished immediately when the current is transferred to the fixed arc electrode 7 and the movable arc electrode 11, but the arc causes the surfaces of the fixed finger 6 and the movable electrode 10 to be roughened, and the heat of the arc causes a part of the arc. However, there is a drawback that the current-carrying performance of the circuit breaker is degraded due to melting of the metal and removal of the plated surface.

The present invention has been proposed in order to solve the above-mentioned drawbacks of the prior art. The purpose of the present invention is to increase the mass of the movable part and to reduce the resistance value so that the energization is reduced. It is an object of the present invention to provide a gas circuit breaker capable of minimizing damage to a current-carrying electrode due to an arc that occurs when a current is commutated from a working electrode to an arc electrode.

[0012]

According to the present invention, a fixed electrode portion and a movable electrode portion are arranged so as to be movable relative to each other in a container filled with an arc extinguishing gas. In a gas circuit breaker that extinguishes arcs by blowing insulating gas to an arc sometimes generated, the movable electrode side has a higher conductivity than the metal forming the operating rod, at the movable electrode side end of the operating rod that drives the movable electrode section. It is characterized in that a gradient alloy made of metal is arranged.

[0013]

In the gas circuit breaker of the present invention, since the movable electrode side is provided with a gradient alloy made of a metal having a higher conductivity than the metal forming the operating rod, the movable electrode side end is fixed. From arc electrode to movable arc electrode,
It is possible to reduce the resistance value of the entire energization path from the operation rod to the puffer cylinder, and the weight of the operation rod hardly increases. Therefore, the resistance difference between the current-carrying electrode and the arc electrode can be reduced, and as a result,
It is possible to suppress as much as possible the generation of an arc that occurs when the current is commutated from the energizing electrode to the arc electrode.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to FIG. The same members as those of the conventional type shown in FIGS. 2 to 5 are designated by the same reference numerals, and the description thereof will be omitted.

In this embodiment, as shown in FIG.
The operating rod 13 is made of a titanium alloy, and the operating surface of the operating rod 13 and the movable arc electrode 11 is in contact with the contact surface of the puffer cylinder 14 and the peripheral portion connecting the two. A gradient alloy 30 made of a metal having a higher conductivity than the titanium alloy is provided.

The gas breaker for electric power of this embodiment having such a structure operates as follows. That is, when the gas circuit breaker interrupts the electric current, the electric current flowing through the fixed support 9 and the fixed fingers 6 to the movable electrode 10 and the puffer cylinder 14 flows from the fixed support 9 to the fixed arc electrode 7 and the movable arc electrode 11. , Through the tilted alloy portion 30 of the operating rod to the puffer cylinder 14.

At this time, the tilted alloy portion 3 of the operating rod 13
Since 0 is configured such that the operating rod side is made of a titanium alloy and the outer side is made of a metal having a higher conductivity than the titanium alloy, the resistance value of the entire alloy portion is determined by the outer side portion having a low resistivity. Compared to the operating rod made by
The resistance value can be lowered. As a result, the resistance difference between the energizing electrode and the arc electrode can be reduced, and the potential difference caused by the commutation of the current is reduced,
It is possible to suppress the generation of an arc that occurs when the current is commutated from the energizing electrode to the arc electrode, and it is possible to reduce damage to the energizing electrode caused by the arc.

It should be noted that the present invention is not limited to the above-mentioned embodiment, and the gradient alloy is composed of a metal having a higher conductivity than the metal constituting the operating rod on the outer side (movable electrode side). If it is good. Further, the metal forming the operating rod is not limited to the above titanium alloy.

[0019]

As described above, according to the present invention, the movable electrode side end portion of the operating rod that drives the movable electrode portion is made of a metal whose conductivity is higher than that of the metal forming the operating rod. By disposing the graded alloy, the mass of the moving part can be hardly increased and the resistance value can be reduced, and damage to the current-carrying electrode due to the arc occurring when the current is commutated from the current-carrying electrode to the arc electrode can be prevented. It becomes possible to provide a gas circuit breaker that can be minimized.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a breaker showing an embodiment of a gas circuit breaker of the present invention.

FIG. 2 is a cross-sectional view showing a closed state of a conventional gas circuit breaker.

FIG. 3 is a cross-sectional view showing a state of a conventional gas circuit breaker during opening of electrodes.

FIG. 4 is a cross-sectional view showing a state of a conventional gas circuit breaker in the middle of opening an electrode.

FIG. 5 is a sectional view showing an open state of a conventional gas circuit breaker.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Gas circuit breaker 3 ... Arc extinguishing chamber 4 ... Fixed part 5 ... Movable part 6 ... Fixed finger 7 ... Fixed arc electrode 9 ... Fixed support 10 ... Movable electrode 11 ... Movable arc electrode 13 ... Operation rod 21 ... Arc 30 ... Tilt Alloy part

Claims (1)

[Claims] 1. A fixed electrode part and a movable electrode part are movably arranged in a container filled with an arc-extinguishing gas, and insulating gas is applied to an arc generated when the electrodes are opened. In a gas circuit breaker for extinguishing by spraying, a gradient alloy made of a metal whose conductivity is higher than that of the metal forming the operating rod is arranged at the movable electrode side end of the operating rod driving the movable electrode. A gas circuit breaker characterized in that