JPH07114863A - Gas circuit breaker - Google Patents

Abstract

PURPOSE:To reduce damage to a current electrode due to an arc generated at the time of commutating a current from the current electrode to a breaker electrode in a current breaking process, by press coating a slide conductive part of a movable electrode with a low resistance electric conductor plate material. CONSTITUTION:A movable electrode 30, serving as a slide conductive electrode part 30b on a movable electrode base material 30a which is a main constitutional member, is press coated with a low resistance electric conductor plate material of copper or the like by spinning work. In the electrode 30, since the electrode part 30b with a fixed electrode is press coated with the low resistance electric conductor plate material of copper or the like, resistance between the electrode 30 and the fixed electrode is reduced, and even in the case of performing switching action of a high voltage switchgear, such as roughing a surface of the electrode 30 is prevented, to further realize the electrode 30 of low weight. Since the low resistance electric conductor can by surely brought into contact with the fixed electrode, damage to a current electrode due to an arc generated at the time of commutating a current from the current electrode to a breaker electrode in a current breaking process, is reduced, and reliability can be improved.

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, and more particularly to a gas circuit breaker having an improved movable electrode portion.

[0002]

2. Description of the Related Art As the demand for electric power increases, the capacity of gas circuit breakers used in power plants and substations is increasing. In particular, a gas circuit breaker used in a high voltage system is required to have a large energizing current or breaking current.

An example of a conventional gas circuit breaker will be described with reference to FIG. In the figure, a gas circuit breaker 1 is configured by housing an arc extinguishing chamber 3 in a container 2 in which an insulating gas is sealed.
The arc extinguishing chamber 3 is provided with a fixed portion 4 and a movable portion 5 which are arranged opposite to each other. In addition, the fixed part 4 includes a fixed finger 6, a fixed arc electrode 7, a fixed-side shield 8, and a fixed-side shield 8, which normally pass a current.
And a fixed support 9 for supporting them.
On the other hand, the movable part 5 includes a movable electrode 10 that normally supplies a current,
Movable arc electrode 11, insulating nozzle 12, operating rod 1
3, and the puffer cylinder 14.
Further, in order to support the movable portion 5, a support insulating cylinder 15, a movable support 16, and a puffer cylinder 14 and a puffer piston 17 that constitutes a compression chamber are provided. Further, the fixed portion 4 is connected to the movable support 16 via the interelectrode insulating cylinder 18. An insulating rod or a capacitor may be used as the inter-electrode insulating cylinder 18.

In the conventional gas circuit breaker configured as described above, generally, when the value of the current to be applied is large, the fixed finger 6 and the movable electrode 10, which are the electrodes for energization, and the fixed arc electrode, which is the electrode for interrupting the current, are used. 7 and movable arc electrode 11
2 types of electrodes are provided.

FIG. 2 shows a closed state of the gas circuit breaker 1, that is, a state in which an electric current is applied. In this case, the electric current passes through the conductor 19, the fixed support 9, and the fixed finger 6, and then the movable electrode 10 and the puffer cylinder. 14, flowing from the movable support 16 through the conductor 20.

On the other hand, when the gas circuit breaker 1 shuts off an accident current or the like, the operating rod 13 is pulled in the direction of the arrow shown in FIG. 3 (rightward in the figure) by an operating mechanism (not shown), The movable part 5 also moves in the direction of the arrow. Then, as shown in FIG. 3, first, the fixed finger 6 and the movable electrode 10 are separated from each other. As a result, the current flowing through the fixed support 9 and the fixed fingers 6 to the movable electrode 10 and the puffer cylinder 14 is fixed to the fixed arc electrode 7 and the movable arc electrode 11.
Since they are not yet separated, the flow path is changed from the fixed support 9 to the puffer cylinder 14 via the fixed arc electrode 7 and the movable arc electrode 11, and the commutation occurs.

Then, as shown in FIG. 4, the movable portion 5 further moves in the direction of the arrow (rightward in the figure), and an arc 21 is generated between the fixed arc electrode 7 and the movable arc electrode 11. The gas compressed by the puffer cylinder 14 and the puffer piston 17 is blown through the insulating nozzle 12 to the arc 21 generated in this way, and as a result, the arc 21 is cooled and extinguished, and the current is reduced. Shut off. FIG. 5 shows an open state of the circuit breaker 1 in which the interruption of the current is completed.

However, the conventional gas circuit breaker described above has the following drawbacks. That is, the tip of the fixed arc electrode 7 is made of an arc resistant metal 22 that can withstand the high temperature arc 21, as shown in the detailed view of FIG. On the other hand, as shown in FIG. 7, the movable electrode 10 is made of aluminum, which is light in weight and has a low resistivity, as a single material. This is because the current always flows when the circuit breaker is turned on, and the movable part can quickly operate when the circuit breaker is open / closed.

By the way, as described above, during the current interruption process, the current flowing between the fixed finger 6 and the movable electrode 10 is interrupted, and the current path is changed between the fixed arc electrode 7 and the movable arc electrode 11. However, at this time, the fixed finger 6 and the movable electrode 10 are heated by Joule heat due to contact resistance. Further, when the resistance value between the movable arc electrode 11 and the fixed arc electrode 7 is relatively large, commutation is not performed smoothly, and as a result, an arc is generated for a short time between the movable electrode 10 and the fixed finger 6. Sometimes. However, this arc is extinguished immediately when current is transferred between the fixed arc electrode 7 and the movable arc electrode 11.

However, the surface of the movable electrode 10 and the fixed finger 6 is roughened by the generation of the Joule heat and the arc, or a part of the surface is melted, and the plated surface is lost, so that the current-carrying performance of the circuit breaker is deteriorated. However, there is a drawback in that it causes galling during operation, which eventually leads to a reduction in breaking performance.

As a measure for solving the above-mentioned drawbacks, it is conceivable that the material of the movable electrode is a low resistance current-carrying material. Aluminum or copper is usually used as the current-carrying material. Copper has a lower resistance than aluminum and is suitable as a material for the movable electrode, but it is heavy and it is not appropriate to use copper for all the movable electrodes. Therefore, it is conceivable to cover the movable electrode made of aluminum with copper only at the portion in contact with the finger of the fixed electrode.

[0012]

However, as one of the coating methods, copper is sprayed on the finger contact portion of the fixed electrode of the aluminum movable electrode to coat the copper, and the high voltage switchgear is tested. As a result, there was a new problem that the surface of the movable electrode became rough.

The reason for this is that the weldability between aluminum and copper was poor, and the presence of fine voids in the copper portion made it impossible to obtain the expected reduction in resistance.
Moreover, it is presumed that the phenomenon of thermal spraying is inevitable to some extent.

The present invention has been made in order to solve the above-mentioned drawbacks of the prior art, and its purpose is to occur during the commutation of the current from the energizing electrode to the interrupting electrode in the process of interrupting the current. An object of the present invention is to provide a highly reliable gas circuit breaker capable of reducing damage to the energizing electrode due to an arc.

[0015]

In order to achieve the above object, the present invention arranges a fixed electrode portion and a movable electrode portion in a container filled with an arc extinguishing gas so as to face each other, and to open the electrodes. In a gas circuit breaker equipped with a gas blowing mechanism that blows an insulating gas to extinguish an arc that sometimes occurs, a low-resistance electric conductor is attached to a sliding current-carrying portion of a current-carrying movable electrode that constitutes the movable electrode section. It is characterized in that the plate material is covered and pressure-bonded by a spinning process.

[0016]

In the gas circuit breaker of the present invention, the resistance between the movable electrode and the fixed electrode can be reduced by applying the low-resistance electric conductor plate material to the current-carrying contact portion by spin coating so that the resistance between the movable electrode and the fixed electrode can be reduced. Thus, it is possible to reduce the damage to the energizing electrode due to the arc generated when the current is commutated from the energizing electrode to the breaking electrode.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the movable electrode of the high voltage switchgear according to the present invention will be described below with reference to FIG. In FIG. 1, the movable electrode 30 is obtained by coating a low-resistance electric conductor plate material such as copper as a sliding current-carrying electrode portion 30b on a movable electrode base material 30a, which is a main constituent member, by spin-coating. In the movable electrode 30 configured in this manner, the sliding current-carrying electrode portion 30b with the fixed electrode is covered and pressure-bonded with a low-resistance electric conductor plate material such as copper, so that the resistance between the movable electrode and the fixed electrode is reduced, Even when the opening / closing operation of the high-voltage switchgear is performed, the movable electrode having a low weight can be realized without the surface of the movable electrode being roughened.

It may be considered that the step of coating and crimping the low-resistance electric conductor plate material can be performed by pressing, but according to the experiments by the present inventor, the shape of the movable electrode 30 is generally complicated and the movable electrode 30 is movable. Since it is necessary to press-bond the electrode base material 30a and the low-resistance electric conductor plate material, it is appropriate to carry out spinning using a roller. In addition, since the movable electrode generally has a complicated three-dimensional shape that is symmetrical with respect to the axis, when an NC automatic spinning machine driven by an NC is used as the spinning process, a good coating pressure bonding process can be performed because the processing force is large. It can be realized and the processing time is short.

The operation of the gas circuit breaker having the movable electrode according to the present embodiment will be described with reference to FIG. 2 (the explanation of the operation is possible in the conventional example). For example, when the gas circuit breaker interrupts the current, the 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. After that, the flow is changed to the puffer cylinder 14. At this time, the movable electrode 10 and the fixed finger 6
A short arc may occur between the and. But,
Even in such a case, in the present embodiment, the movable electrode base material 30a, which is the main constituent member of the movable electrode 30, is made of aluminum, while the sliding current-carrying electrode portion 30b is used.
However, since the electric conductor plate material such as copper having low resistance and high thermal conductivity is coated and crimped by spinning,
Compared with a conventional movable electrode composed of only aluminum, the generation of Joule heat due to a breaking current can be reduced, and the generated Joule heat can be quickly released to the outside, so that the movable electrode 30 is damaged by the arc. Can be kept small. Furthermore, since the combined shape of the movable electrode base material 30a and the sliding current-carrying electrode portion 30b is configured to be the same as that of the conventional movable electrode, the weight of the movable electrode portion is increased too much. Without
The above effect can be obtained.

As the low resistance electric conductor plate material, the copper material is mainly targeted in the above-mentioned embodiment, but the same effect as in this embodiment can be realized by using silver.

[0021]

As described above, according to the present invention,
The low-resistance electric conductor plate material can be surely brought into contact with the fixed electrode by covering the sliding current-carrying electrode portion of the movable electrode with the spinning process by spinning, so that the current-carrying electrode during the current interruption process. It is possible to provide a highly reliable gas circuit breaker capable of reducing damage to the energizing electrode due to an arc generated when a current is commutated from the electrode to the interrupting electrode.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a movable electrode used in 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.

3 is a cross-sectional view showing a state in which the fixed finger and the movable electrode of FIG. 2 are separated.

FIG. 4 is a cross-sectional view showing a state where the fixed arc electrode and the movable electrode arc of FIG. 2 are separated.

FIG. 5 is a cross-sectional view showing a contact opening completed state of the gas circuit breaker of FIG.

6 is an enlarged cross-sectional view of a main part of FIG.

7 is a sectional view of the movable electrode shown in FIG.

[Explanation of symbols]

1 ... Gas circuit breaker, 2 ... Container, 3 ... Arc extinguishing chamber, 4 ... Fixed part,
5 ... Movable part, 6 ... Fixed finger, 7 ... Fixed arc electrode, 8 ... Fixed side shield, 9 ... Fixed support, 10 ... Movable electrode, 11 ... Movable arc electrode, 12 ... Insulation nozzle, 13
... operation rod, 14 ... puffer cylinder, 15 ... support insulating cylinder, 16 ... movable support, 17 ... puffer piston, 18
... Inter-electrode insulating cylinder, 19 ... Conductor, 20 ... Conductor, 30 movable electrode, 30a ... Movable electrode base material, 30b ... Sliding energizing electrode section.

Claims (1)

[Claims] 1. A gas blower for extinguishing arc by extinguishing an arc generated when the fixed electrode part and the movable electrode part are opposed to each other in a container filled with an arc-extinguishing gas by blowing an insulating gas. In a gas circuit breaker having a mounting mechanism, a low-resistance electric conductor plate material is coated and pressure-bonded to a sliding current-carrying portion of a current-carrying movable electrode constituting the movable electrode section by spinning.