JP2591547B2 - Puffer type gas circuit breaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a puffer type gas circuit breaker used in a substation or switchyard of an electric power system, and more particularly to a puffer type gas circuit breaker having an improved configuration of a tip of an arc electrode where an arc is generated. It relates to a gas circuit breaker.

[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 increasing. In particular, in the case of a circuit breaker used in a system having a high voltage, a circuit breaker having a large energizing current or breaking current is required.

Here, as an example of a gas circuit breaker, a conventional example of a puffer type gas circuit breaker is shown in FIG. Gas circuit breaker 1
Is provided with a container 2 filled with an arc-extinguishing gas,
The arc extinguishing chamber 3 is housed in the container 2. This arc-extinguishing chamber 3
Is fixed to the fixed electrode section 4. A movable electrode unit 5 is disposed opposite to the fixed electrode unit 4 so as to move toward the input side and the opening side and move in contact with and separate from the fixed electrode unit 4.

[0004] The fixed electrode section 4 is composed of a fixed finger 6 for supplying a normal current, a rod-shaped fixed arc electrode 7, a shield 8 on the fixed side, and a fixed support 9 for supporting these. A conductor 19 is connected to the fixed support 9.

[0005] The movable electrode section 5 includes a movable electrode 10 for passing a normal current, a movable arc electrode 11, an insulating nozzle 12,
It comprises an operating rod 13 and a buffer cylinder 14. In addition, there is a supporting insulating cylinder 15 and a movable support 16 attached to the container 2 to support the movable portion 5. A puffer piston 17 is provided on the movable support 16, and the puffer piston 17 forms a compression chamber together with the puffer cylinder 14. The conductor 20 is connected to the movable support 16.

Further, the fixed electrode portion 4 is usually provided with a movable support 16.
And the insulating tube 18. The insulating cylinder 18 may be an insulating rod or a capacitor.

In general, when a current value to be energized is large, the gas circuit breaker 1 includes a fixed finger 6 and a movable electrode 10 which are energizing electrodes, a fixed arc electrode 7 and a movable arc electrode 11 which are current interrupting electrodes. And the two types of electrodes.

In FIG. 4, the gas circuit breaker 1 is in a closed state,
That is, the state of current supply is shown. At this time, the current is
After flowing through the conductor 19, the fixed support 9, and the fixed finger 6, it flows to the conductor 20 through the movable electrode 10, the buffer cylinder 14, and the movable support 16.

Next, a description will be given of a case where the gas circuit breaker 1 shifts from the above-described current energized state (closed state) to an open state in which the gas circuit breaker 1 interrupts an accident current or the like, with reference to FIGS.

The operating rod 1 is operated by an operating mechanism (not shown).
3 is pulled in the direction of the arrow shown in FIG. 5 (to the right in the figure), whereby the movable electrode unit 5 moves to the right in the figure. At this time, first, the fixed finger 6 and the movable electrode 10 are separated.
Then, the current flowing to the movable electrode 10 and the buffer cylinder 14 via the fixed support 9 and the fixed finger 6 is
Since the fixed arc electrode 7 and the movable arc electrode 11 are not yet separated from each other, the fixed arc electrode 7
The flow path is changed to the buffer cylinder 14 via the movable arc electrode 11. That is, current commutation occurs.

Further, as shown in FIG. 6, when the movable electrode portion 5 further moves in the direction of the arrow and the fixed arc electrode 7 and the movable arc electrode 11 are separated, the tip of the fixed arc electrode 7 and the movable arc electrode An arc 21 is generated between the tip 21 and the tip end.

At the same time, when the puffer cylinder 14 moves, the arc-extinguishing gas g in the container 2 is compressed in the compression chamber constituted by the puffer cylinder 14 and the puffer piston 17, and this arc-extinguishing gas g is the insulating nozzle 12
Through the arc 21. As a result, the arc extinguishing gas g cools the arc 21 and extinguishes the arc, thereby completing the interruption of the current.

FIG. 7 shows an open state of the circuit breaker in which the interruption of the current is completed.

[0014]

As shown in FIG. 8, the fixed arc electrode 7 is composed of a base 23 and an arc-resistant metal part 22 attached to a tip end thereof. Among them, the arc-resistant metal portion 22 needs to withstand the high-temperature arc 21 and its resistance value cannot be reduced because it is necessary to supply a current during the commutation. Thus, the arc-resistant metal portion 22 is generally made of an alloy of high-temperature-resistant tungsten and copper having high conductivity.

On the other hand, the base metal part 23 where the arc 21 does not occur.
Is usually made of copper in order to reduce the potential difference during current commutation. Further, the connection between the arc-resistant metal part 22 and the base metal part 23 is made by silver brazing because both are different metals.

However, in the silver solder connection, if the silver solder does not completely enter the gap between the arc-resistant metal part 22 and the base part 23, the connection between the arc-resistant metal part 22 and the base part 23 is incomplete. Therefore, the arc-resistant metal part 22 may fall off from the base part 23 during the operation of the gas circuit breaker 1.

In order to prevent such a problem, as shown in FIG. 9, an arc-resistant metal 22 and a base 23 are connected by screws 25 and then connected by silver brazing. ing.

However, also in this case, if the connection of the silver solder is insufficient, most of the short-circuit current flows through the screw 25, so-called screw energization, and the screw melts as the number of energization increases. Eventually, the arc-resistant metal part 22 falls off from the base part 23 during operation, causing an accident.

Since the arc 21 is also generated in the movable arc electrode 11, the same can be said for the fixed arc electrode 7.

The present invention has been proposed to solve such problems of the prior art.
Highly reliable buffer by eliminating the silver-low connection of dissimilar metals between the arc-resistant metal and the base metal by integrally forming the arc-resistant metal part and the base metal part and improving the quality of the arc electrode An object of the present invention is to provide a gas circuit breaker.

[0021]

In order to achieve the above object, a puffer type gas circuit breaker according to the present invention is characterized in that at least one of a fixed arc electrode and a movable arc electrode is attached to a base and a tip thereof. The arc-resistant metal part is made of a graded alloy of a metal having excellent arc resistance and a metal of the base part, and the graded alloy is formed of a metal of the base part toward the base part. Is increased, and the base metal part and the arc-resistant metal part are configured to be integrated at a joint part with the base metal part.

[0022]

In the present invention having the above structure,
The arc-resistant metal part has a two-layer structure of a graded alloy. In this graded alloy, the ratio of the metal of the base part increases toward the base part, and the metal part of the base part is integrated with the base part at the joint part with the base part. Becomes metal. For this reason, there is no fear that manufacturing defects such as silver-row connection occur.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a puffer type gas circuit breaker according to the present invention will be specifically described below with reference to FIGS. FIG. 1 is a side view of a main part of the present embodiment, and FIG. 2 is a graph showing the proportion of metal in the graded alloy of the present embodiment. In FIG. 1, the same members as those in the conventional example are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG.
Is composed of a metal base 23 made of copper and an arc-resistant metal part 24 attached to a tip end thereof, as in the conventional example. The arc-resistant metal part 24 is made of a graded alloy of tungsten having a high melting point and excellent arc resistance, and copper having a good electrical conductivity.

A graded alloy is an alloy in which the proportion of the metal is gradually changed with a certain directionality. As is apparent from the graph of FIG.
The configuration is such that the proportion of copper increases from the distal end side of the fixed arc electrode 70 toward the base metal part 23, and tungsten decreases in inverse proportion thereto.

That is, 100% of tungsten is present at the tip of the fixed arc electrode 70, and for example, the ratio of tungsten and copper is about 80% toward the base metal part 23.
% And about 20%, and about 60% and about 40%,
The percentage of copper gradually increases, and the percentage of copper at the joint with the base metal part 23 becomes 100%.

In the present embodiment as described above, when the gas circuit breaker interrupts the current, the current flowing through the movable electrode 10 and the buffer cylinder 14 via the fixed support 9 and the fixed finger 6 is transferred to the fixed support. 9 to fixed arc electrode 7
0, through the movable arc electrode 11, the puffer cylinder 1
4, commutating the current path.

At this time, the sliding portion of the fixed arc electrode 70 with the movable arc electrode 11 is a portion having a high copper content, which is a graded alloy of copper and tungsten. The ratio of copper and tungsten in the arc metal part 22 may be the same. Therefore, the resistance value between the arc electrodes can be maintained at the same level as in the related art. Therefore,
There is no occurrence of arcing due to a potential difference during commutation. As a result, the degree of damage of the movable electrode 10 does not worsen than before.

Further, since the arc-resistant metal portion is made of a graded alloy, the fixed arc electrode 70 can be made of an integral metal, and there is no fear that manufacturing defects occur such as silver-low connection.

In addition, since the arc-resistant metal portion and the base metal portion are not connected via an extra connecting member such as a silver solder, it is possible to prevent the conductivity of the fixed arc electrode from deteriorating due to the interposition of the connecting member. Can be. Therefore, if the ratio of copper and tungsten in the sliding portion is set to be the same as that of the conventional alloy, the resistance value between the arc electrodes becomes lower than that between the conventional arc electrodes. As a result, the potential difference generated at the time of commutation can be suppressed, and the degree of damage of the movable electrode 10 is reduced as compared with the conventional one, and the durability is improved.

As described above, according to the arc-resistant metal portion 24 of the present embodiment, the gradient alloy has a structure in which the proportion of copper in tungsten increases from the foremost portion of the fixed arc electrode 70 to the base metal portion 23. Therefore, the fixed arc electrode 70 can be formed as an integral metal, and there is no risk of manufacturing defects such as silver-low connection, and the damage due to commutation of the movable electrode 10 can be suppressed. , The reliability of the gas circuit breaker can be improved.

Further, the leading end of the fixed arc electrode 70 where the arc 21 actually occurs can be made of 100% tungsten, so that it can be made smaller than the conventional arc-resistant metal portion made of an alloy of tungsten and copper. The high temperature resistance performance is improved, and the damage of the electrode due to the arc 21 can be suppressed. As a result, the gas circuit breaker can exhibit excellent arc resistance, and the contact life can be reliably extended.

The present invention is not limited to the above embodiment. FIG. 3 shows the ratio of the graded alloy in the arc-resistant metal part of the fixed arc electrode 71 according to another embodiment.

In the embodiment shown in FIG. 3, unlike the above embodiment, the tip of the fixed arc electrode is made of tungsten 10.
It is not 0%, and it is an alloy of a predetermined ratio of tungsten and copper from the tip of the fixed arc electrode to a certain length, from which the ratio of copper increases toward the base metal part, and It is composed of a graded alloy that becomes 100% copper near the joint.

According to such a fixed arc electrode, by setting the tip of the fixed arc electrode to be the same as the ratio of the conventional alloy of tungsten and copper, the amount of expensive tungsten used can be suppressed and economical. Advantageous fixed arc electrodes can be manufactured.

In each of the above two embodiments, a fixed arc electrode has been described. However, since an arc is similarly generated in a movable arc electrode, a gradient alloy is applied in the same manner as in the fixed arc electrode. Can be.

[0037]

As described above, according to the present invention, the arc-resistant metal part of the arc electrode of the gas circuit breaker is made of a graded alloy of a metal excellent in arc resistance and a metal of the base metal part, Further, by integrally configuring the arc-resistant metal part and the base metal part, the silver-low connection of the dissimilar metal between the arc-resistant metal part and the base metal part of the arc electrode is eliminated, and the quality of the arc electrode manufacturing is improved. Further, it is possible to prevent the movable electrode from being damaged during commutation by preventing an increase in the resistance value due to a connection member such as a silver solder, and to suppress damage to the arc electrode due to an arc. As a result, the puffer type gas circuit breaker exhibits excellent arc resistance and extends the contact life, so that the reliability as the circuit breaker can be improved.

[Brief description of the drawings]

FIG. 1 is a main part side view showing a configuration of an embodiment of the present invention.

FIG. 2 is a graph showing the proportion of the metal in the graded alloy of this example.

FIG. 3 is a graph showing the proportions of metals in a graded alloy according to another embodiment of the present invention.

FIG. 4 is a side view showing a closed state of a conventional puffer type gas circuit breaker.

FIG. 5 is a side view showing a state where a conventional puffer type gas circuit breaker shifts from a closed state to an open state.

FIG. 6 is a side view showing a state in which a conventional puffer type gas circuit breaker shifts from a closed state to an open state.

FIG. 7 is a side view showing an open state of a conventional puffer type gas circuit breaker.

FIG. 8 is a side view of a main part of a conventional puffer type gas circuit breaker.

FIG. 9 is a side view showing the structure of a fixed arc electrode of a conventional puffer type gas circuit breaker.

[Explanation of symbols]

 Reference Signs List 4 fixed electrode part 5 movable electrode part 6 fixed finger 7 fixed arc electrode 10 movable electrode 11 movable arc electrode 14 puffer cylinder 17 puffer piston 21 arc 23 base metal part 24 arc-resistant metal part (graded alloy)

Claims (1)

(57) [Claims] Claims: 1. An arc-extinguishing gas contained in a container,
A fixed electrode portion is fixed in the container, and a movable electrode portion is provided opposite to the fixed electrode portion, the movable electrode portion being moved toward the input side and the opening side to be in contact with and separated from the fixed electrode portion. Is equipped with a fixed finger for energization and a fixed arc electrode in the form of a rod, while the movable electrode section has a movable electrode for energization, a hollow cylindrical movable arc electrode, a puffer cylinder, an insulating nozzle, and a hollow cylindrical operating rod. Is provided integrally, and a puffer piston for slidably housing the puffer cylinder is provided, and the movable electrode portion is separated from the fixed electrode portion and provided in a gap between the fixed arc electrode and the movable arc electrode. When an arc is generated, the puffer cylinder is moved into the puffer piston with respect to the arc to compress the arc-extinguishing gas, and thereby, through the insulating nozzle. In the puffer-type gas circuit breaker that extinguishes the arc by causing the gas flow to blow the arc to the arc, at least one of the fixed arc electrode and the movable arc electrode includes a metal base and a tip thereof. The arc-resistant metal part is attached to the part, the arc-resistant metal part is made of a graded alloy of a metal having excellent arc resistance and a metal of the base part, and the graded alloy becomes more toward the base part. A buffer-type gas shut-off, wherein a ratio of a metal of the base metal portion is increased, and the base metal portion and the arc-resistant metal portion are integrated at a joint portion with the base metal portion. vessel.