JP2001006468A - Gas insulated breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas insulated breaker capable of preventing the occurrence of wear power due to the operation of the contacts. SOLUTION: Surface layers 2b, 3b are formed on the surfaces of base metals 2a, 3a of movable and fixed contacts 2, 3, and this part is used as a slide face of both contacts 2, 3. The surface layers 2b, 3b are made of alloy of the base metal 2a, 3a and silver and can be manufactured by applying silver minute particles on the base metal 2a, 3a at a high speed by an ion cluster beam method. Since the hardness of the surface layers 2a, 3a is high, wear powder does not occur easily.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas-insulated switchgear used in a power system.

[0002]

2. Description of the Related Art FIG.
FIG. 2 shows an example of a switching contact of a conventional gas insulated switching device described in JP-A-203364, which is a tulip contact of a disconnector. 13 is a tulip contact, 14 is a movable contact,
14a is a plating layer of the movable contact 14, and 15 is a fixed contact piece. A large number of fixed contact pieces 15 constitute a fixed contact. 15a is a plating layer of the fixed contact piece 15;
Is a conductor, 17 is a mounting bracket, 18 is a fixing bolt, 19 is a supporting bracket, and 20 is a garter spring.

Next, the operation will be described. In FIG. 6, a tulip contact 13 disposed in a container (not shown) filled with insulating gas of a disconnector of a gas insulated switchgear.
The sliding contact surfaces of the fixed contact piece 15 and the movable contact 14 are plated with silver plating or silver composite plating.
5a and 14a are provided to reduce the contact resistance. The thickness of the plating layers 15a and 14a subjected to silver plating or silver composite plating is 50 to 200 μm.
m. Fixed contact piece 15 of tulip contact 13
In addition, the sliding of the movable contact 14 causes the plating layers 15a and 14a to slide, and the sliding wear generates silver wear powder having a thickness of or close to the thickness of the above-mentioned plating layer. It accumulates on the inner surface of the container of the switchgear and lowers insulation. In addition, since the silver layers of the plating layers 15a and 14a are mechanically attached to the copper metal of the fixed contact piece 15 and the movable contact piece 14, they are peeled off when a large load is applied, and the silver of several mm in length is peeled off. Debris is created, causing a greater insulation loss of the disconnector.

Further, when the gas-insulated switchgear is a circuit breaker, the sliding speed of the contact is much higher than that of the disconnector, and a large silver piece of about several mm is generated, thereby insulating the circuit breaker of the gas-insulated switchgear. It is easy to cause a drop. This was because the adhesion between the silver plating layer and the copper copper was weak, and the thickness of the silver plating layer was large. Further, in the conventional gas insulated switchgear, it is necessary to clean the silver plating powder worn out after the initial running-in operation, and it is necessary to clean the silver plating powder generated during the operation even during the periodic inspection after the operation for a predetermined period. However, extra work is required and the cost is increased accordingly.

[0005]

Since the conventional gas insulated switchgear has the above-described configuration, abrasion powder is generated from the silver plating layer of the switchgear, thereby deteriorating the insulation performance, and the initial and periodic operation. There were problems such as an increase in inspection costs. In order to make the gas-insulated electrical equipment including the gas-insulated switchgear compact, an insulating gas such as SF6 gas having a high insulation strength is sealed in the insulation space to reduce the insulation size. Therefore, the adverse effects of the above-mentioned abrasion powder become more remarkable than in the case of air insulation having a large insulation size.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a gas insulated switchgear in which abrasion powder is less likely to be generated by opening and closing operations of the opening and closing contacts.

[0007]

According to a first aspect of the present invention, there is provided a gas-insulated switchgear, wherein the base metal of the switching contact is made of copper or a copper alloy, and at least one of the base metal of the switching contact is provided with the base metal. A surface layer made of a silver alloy and having a thickness of 0.5 to 10 μm is formed, and the switching contactor slides on the surface layer. The gas insulated switchgear according to claim 2 is
2. The method according to claim 1, wherein the thickness is 5 to 20 on the surface layer.
A protective layer made of a μm silver plating layer was formed.
The gas insulated switchgear according to claim 3 is the gas insulated switchgear according to claim 1 or 2, wherein the switching speed of the switching contactor is 2 or less.
２０20 m / s. A gas-insulated switchgear according to a fourth aspect is the gas-insulated switchgear according to any one of the first to third aspects, wherein the component of the surface layer is configured such that the ratio of silver increases from the metal side toward the surface. Things.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, an embodiment of the present invention will be described. FIG. 1 is a cross-sectional view of a disconnector that is a gas-insulated switchgear according to the present embodiment,
FIG. 2 is a sectional view of the movable contact. 1 and 2, reference numeral 1 denotes a disconnector, 2 denotes a movable contact, 2a denotes a copper alloy metal of the movable contact 2, 2b denotes a surface layer of the movable contact 2, and a fixed contact (described later). Is formed of a copper-silver alloy layer having a thickness of 0.5 to 10 [mu] m on the sliding surface, i.e., the surface of the movable contact 2. 3 is a fixed contact, 3a is a fixed contact 3
3b is a surface layer of the fixed contact 3,
The sliding surface with the movable contact 2, that is, the surface of the fixed contact 3 is formed of an alloy layer of copper and silver having a thickness of 0.5 to 10 μm. The movable contact 2 and the fixed contact 3 allow the contact
And two open / close contacts. 4 is a finger contact, 5 and 6 are movable and fixed conductors, 7 is an insulating cylinder, 8 and 9 are metal shields, and 10 is an insulating space. An insulating medium such as SF6 gas is sealed in the metal container.

The surface layers 2b and 3b of the movable contact 2 and the fixed contact 3 are formed by electrically dispersing silver fine particles in a high vacuum on the copper alloy of the base metals 2a and 3a by using an ion cluster beam method. It is manufactured by accelerating and applying at high speed to form an alloy layer of the copper alloy and silver on the base metals 2a, 3a.
The hardness of the alloy layers, that is, the surface layers 2b and 3b, is higher than the hardness of the base metal. There is also a method using this ion cluster beam method in which a silver layer is formed on the surface of a base metal.However, in this case, the surface hardness is equal to that of silver, and a high hardness cannot be obtained. It is necessary to manufacture under the conditions to be performed. In addition, in addition to the ion cluster beam method, it can be manufactured by, for example, an ion implantation method, a CVD method, or the like.

Next, the operation will be described. In FIG. 1, the disconnector 1 is in the open state, the movable contact 2 moves rightward, contacts the fixed contact 3, slides on the inner surface of the fixed contact 3, and moves in the predetermined closed state fixed position. Stop. In addition, disconnector 1
The opening operation of is reverse. That is, the movable contact 2
In FIG. 1, the slider moves leftward and slides on the inner surface of the fixed contact 3, and separates from the fixed contact 3 to enter an open state. The outer surface layer 2b of the movable contact 2 and the inner surface layer 3 on the fixed contact 3
b is in contact with it, and since that portion contains silver, the contact resistance is small and it can withstand a temperature rise due to energization. The surface layers 2b, 3b, which are the sliding surfaces, have a high hardness, and the sliding surfaces of the movable contact 2 and the fixed contact 3 are coated with a thin contact grease to prevent seizure due to sliding. In the above example, the bullion 2a, 3a
Was used as the copper alloy, but the same effect can be obtained by forming an alloy layer of copper and silver as the surface layers 2b and 3b even if copper is used instead of the copper alloy. In any case, the silver component ratio of the alloy layers as the surface layers 2b and 3b is 20 to 99%.
And If the silver content is too small, the contact resistance will increase,
Conversely, if it is too large, the hardness becomes small, which is a problem.

In FIGS. 1 and 2, the disconnector 1 has a high sliding surface between the movable contact 2 and the fixed contact 3 even after a large number of operations. The amount of wear powder due to sliding is extremely small. This is because the Vickers hardness of silver is about 26, while the Vickers hardness of an example of the alloy layer of the surface layers 2b and 3b of the movable contact 2 and the fixed contact 3 is as high as about 100. This is also because the hardness is further increased due to the surface hardening phenomenon of the copper alloy when the silver particles are applied to the copper alloy by the ion cluster beam method.

FIG. 3 is a graph showing the relationship between the opening / closing speed of the contact and the amount of wear of the contact. Curve A shows the case of silver plating (50 μm thickness) similar to the conventional case, and curve B shows an example of an alloy of silver and copper. This is a comparison based on the amount of wear per 100 closing operations. The unit of PU on the vertical axis means that the amount of wear at low speed of the former is represented as 1.
As can be seen from FIG. 3, when the sliding speed of the contact exceeds 2 m / s, the wear amount tends to increase significantly in silver plating, and tends not to change much in the alloy of silver and copper. This is because, in the case of silver-plated contacts having a high sliding speed, the silver plating peels off due to the load when the contacts come into contact with each other. On the other hand, in the case of a silver-copper alloy contact having a high sliding speed, peeling and abrasion hardly occur due to the high hardness of the alloy layer and the high adhesion strength to the base metal.

In FIG. 1, the surface layer 2b of the movable contact 2
Is formed by the ion cluster beam method, but it is the most suitable method to form a thin alloy layer on the surface of the processed copper alloy, and the other method forms a silver-copper alloy layer with high surface accuracy It is difficult to do. The formation of an alloy layer of silver and copper with good surface accuracy is a particularly excellent effect of the ion cluster beam method in which silver ionized in a high vacuum is applied to the copper alloy surface at high speed.

FIG. 1 shows an example of a disconnecting switch as a gas-insulated switchgear, but the present invention can also be applied to a circuit breaker. The circuit breaker
A switching speed of 2 to 20 m / s is used, but in the case of a circuit breaker having a much higher switching speed as described above, FIG.
As shown in (1), the generation amount of abrasion powder is greatly reduced as compared with the conventional case, and it is more effective in terms of improving the insulation reliability of the gas insulated switchgear and reducing the maintenance cost. Similar effects can be obtained in other gas-insulated switchgear such as a gas-insulated ground switch.

In FIG. 2, although the thickness of the surface layers 2b, 3b is as thin as 0.5 to 10 μm, the amount of wear is small, so that the base metals 2a, 3a are exposed even after a large number of operations of, for example, thousands or more. Therefore, a low contact resistance due to the silver component can be maintained for a long period of time. Even if the thickness of the surface layers 2b and 3b in FIG. 2 is formed to be slightly thicker, the same effect can be obtained without any trouble. Although the surface layer is formed on both the movable contact 2 and the fixed contact 3 in the one shown in FIG. 1, the same effect equivalent to that of one of them is obtained although the amount of wear is slightly increased in one of them. . Further, the surface layers 2b, 3b may be graded alloy layers so that the components of the surface layers 2b, 3b increase in the ratio of silver from the base metal 2a, 3a side toward the surface.
Thereby, the degree of adhesion between the surface layers 2b, 3b and the base metals 2a, 3a increases.

Embodiment 2 Hereinafter, another embodiment of the present invention will be described. FIG. 4 is a sectional view of a movable contact of a disconnector which is a gas-insulated switchgear according to the present embodiment. In the figure, reference numeral 2c denotes a silver plating layer which is a protective layer formed on the surface layer 2b and has a thickness of 5 to 20 μm. Other configurations are the same as those in the first embodiment, and a description thereof will be omitted.

The method of manufacturing the movable contact 2 shown in FIG.
As in the case of FIG. 2, silver particles are electrically accelerated in a high vacuum and applied at high speed to the surface of the copper alloy base metal 2a by the ion cluster beam method, and the alloy of the base metal 2a and silver is applied to the surface. A layer is formed to a thickness of 0.5 to 10 μm to form a surface layer 2b, and a silver plating layer 2c similar to the conventional silver plating layer 2c is formed on the surface layer 2b.
Is applied as thin as 5 to 20 μm. The surface layer 2b of the alloy of the base metal 2a and silver having a thickness of 10 μm or less is slightly damaged depending on handling, and the base metal 2a is partially exposed on the surface. In the case of long-term storage in the air, copper oxide or copper sulfide may be generated to increase the contact resistance. To prevent this oxidation or sulfidation, a thin silver plating layer 2c for protecting the surface is provided. Have been. This silver plating layer 2c
Compared with the conventional silver plating layer having a thickness of 50 to 200 μm,
Since it is as thin as 20 μm, even if abrasion or peeling occurs due to multiple operations, it becomes fine silver powder of 20 μm or less and does not significantly affect the insulation of the gas insulated switchgear. After the silver plating layer 2c has been worn out, it operates in the same manner as in the first embodiment. Therefore, applying the thin silver plating has an effect in improving the long-term reliability of the gas-insulated electric equipment. The reason why the thickness of the protective layer 2c is set to 5 to 20 μm is that if it is too thick, silver abrasion powder becomes large and adversely affects the insulating performance, and if it is too thin, it cannot function as a protective layer. Although the silver plating layer 2c is formed on the surface layer 2b of the movable contact 2 in the above description, it may be formed on the surface layer of the fixed contact or on both.

Embodiment 3 Hereinafter, still another embodiment of the present invention will be described. FIG. 5 is a cross-sectional view of a movable contact of a disconnector that is a gas-insulated switchgear according to the present embodiment. The surface layer 2b is formed only on the surface of the tip portion of the movable contact 2 and a portion following the tip portion. Other configurations are the same as those in the first embodiment, and a description thereof will be omitted. In the case of the movable contact 2 shown in FIG. 5, the surface layer 2b is partially formed by the ion cluster beam method.
Since the area of “b” is much smaller than that of FIG. 2, the manufacturing cost can be greatly reduced as compared with the movable contact 2 of FIG. 2, and the economy can be improved.

[0019]

As described above, according to the gas insulated switchgear of the first aspect of the present invention, the surface layer made of the alloy of the metal and silver is formed on the surface of the metal of the switching contact. In addition, the hardness of the surface of the switching contact is increased, so that abrasion powder due to sliding of the contact is less likely to be generated, whereby the effect of improving the insulation reliability of the gas insulated switching device and reducing the maintenance cost can be obtained.

Further, according to the gas insulated switchgear according to the second aspect, since the protective layer is formed by silver plating on the surface layer of the switchgear, the surface is protected during storage and oxidation and sulfide of copper are prevented. To prevent. Further, according to the gas insulated switchgear according to the third aspect, since the switchgear is applied to a device having a high switching speed of 2 to 20 m / s, the abrasion amount of the switching contact can be significantly reduced as compared with the conventional device. Further, according to the gas insulated switchgear according to claim 4, since the component of the surface layer is configured such that the ratio of silver increases from the metal side toward the surface, the degree of adhesion between the surface layer and the metal is high. Become.

[Brief description of the drawings]

FIG. 1 is a sectional view of a disconnector according to Embodiment 1 of the present invention.

FIG. 2 is a sectional view of a movable contact of the disconnector of FIG. 1;

FIG. 3 is a graph showing a relationship between an opening / closing speed of a movable contact and a wear amount of the gas insulated switchgear of the present invention.

FIG. 4 is a sectional view of a movable contact of a disconnector according to a second embodiment of the present invention.

FIG. 5 is a sectional view of a movable contact of a disconnector according to a third embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a switching contact of a conventional switching device.

[Explanation of symbols]

2 Movable contact, 2a Metal for movable contact, 2b Surface layer for movable contact, 3 Fixed contact, 3a Metal for fixed contact, 3b Surface layer for fixed contact, 2c Silver plating layer.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5G017 BB21 FF02 FF12 5G050 AA01 AA13 BA06 DA05 DA10 EA09 FA01 5G051 KA09

Claims (4)

[Claims] 1. A gas-insulated switchgear in which two switching contacts that can slide and come apart from each other are mounted inside a metal container and an insulating gas is sealed, wherein the metal of the switching contacts is copper or copper. An alloy made of an alloy and having a thickness of 0.5 made of an alloy of the metal and silver on at least one surface of the metal of the switching contactor.
A gas insulated switchgear, characterized in that a surface layer of 10 to 10 μm is formed, and the switching contactor slides on the surface layer. 2. The gas insulated switchgear according to claim 1, wherein a protective layer made of a silver plating layer having a thickness of 5 to 20 μm is formed on the surface layer. 3. The switching speed of the switching contactor is 2 to 20 m / s.
The gas insulated switchgear according to claim 1 or 2, wherein: 4. The gas insulated switchgear according to claim 1, wherein the component of the surface layer is configured such that the ratio of silver increases from the metal side toward the surface. .