JP4004681B2 - Switchgear - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention includes a main circuit opening / closing portion that contacts and separates the bus-side conductor and the load-side conductor and a ground opening / closing portion that contacts and separates the load-side conductor and the grounding conductor in a vacuum vessel maintained in a high vacuum. Related to switchgear.
[0002]
[Prior art]
A switchgear (closed switchboard) used to distribute the power received from the busbars to various load devices or other electrical rooms is connected to the busbar side conductors for connection to the busbars, power transmission cables to the load, etc. Connecting conductors such as load-side conductors, main circuit switches that connect and disconnect the bus-side conductors and load-side conductors, earthing switches that ground the load-side conductors, and control devices necessary for monitoring and control, etc. It is arranged in an outer box made of ground metal.
As one of this type of switchgear, Japanese Patent Application Laid-Open No. 7-28488 discloses that a main circuit switch and a ground switch are integrated with a part of a connection conductor and arranged in an outer box, and are connected to a bus and a power transmission cable. There is disclosed a switchgear that is configured to be connected only.
[0003]
FIG. 7 is a side sectional view showing the configuration of the main part of the switchgear.
This switchgear includes a bushing 72a for connecting a power transmission cable that penetrates a part of the peripheral wall of a metal container 71 filled with insulating SF6 gas, and a busbar connection part that penetrates a part of the peripheral wall. A bushing 76a is provided, and the container 71 is provided with first, second, and third switches 73, 74, and 75 and a vacuum valve 79.
[0004]
The bus-side conductor 76 is fixedly supported by an insulating support glass 70 a fixed to a part of the peripheral wall of the container 71 via a switching contact (not shown) formed inside the vacuum valve 79 and a first switch 73. It is connected to the intermediate conductor 70. Each branch path branched in two directions by the intermediate conductor 70 is connected to the load conductor 72 supported by the bushing 72a via the second and third switches 74 and 75, and through this load conductor 72 to the outside Connected to a power transmission cable (not shown).
[0005]
In this switchgear, when an arc short circuit occurs inside the container 71, the SF6 gas enclosed in the container 71 may explode at a high temperature and pressure in a short time due to arc energy. The container 71 needs to be provided with an open valve for releasing pressure, and further, the container 71 is required to have a strength to withstand a high pressure state until the releasing pressure is completed. Therefore, there is a problem that the structure of the container 71 is complicated and the cost of the product is increased.
[0006]
Furthermore, the use of SF6 gas is avoided due to environmental problems. For this reason, the main circuit opening / closing part and the ground opening / closing part are configured to be accommodated in a vacuum vessel by taking advantage of high arc extinction and insulation in a vacuum state. The switchgear shown in FIG. 8 has been developed.
This switchgear is connected to a bus-side conductor 83 having one end connected to a bus and the other end forming a fixed electrode 83a, and a load side connected to an external power transmission line in a vacuum vessel 94 maintained at a high vacuum. The conductor 84, the operation rod 85 that supports the movable electrode 86 via the coupling member 95 so as to face the fixed electrode 83a, the fixed member 87 joined to the middle of the movable electrode 86, and the load side conductor 84 are connected. The flexible conductor 88 is provided.
The bus bar side conductor 83 penetrates one end wall of the vacuum vessel 94 through the bushing 90, and the operation rod 85 is supported by the other end wall of the vacuum vessel 94 through the bellows 92 so as to be movable in the axial length direction. The load-side conductor 84 passes through the peripheral wall of the vacuum vessel 94 through the bushing 91. A fixed contact 81 is fixed to the tip of the fixed electrode 83 a of the bus-side conductor 83, and a movable contact 82 is fixed to the tip of the movable electrode 86. A grounding conductor 89 is supported on the other end wall of the vacuum vessel 94 in parallel with the operation rod 85 via a bellows 93. A movable contact 89a is provided at the tip of the conductor 89 and faces the movable contact 89a. A fixed contact 84 a is provided on the peripheral surface of the load-side conductor 84.
[0007]
The outer end of the operation rod 85 is connected to an operation mechanism (not shown), and the operation rod 85 is moved in the axial length direction according to the operation of the operation mechanism. The grounding conductor 89 is also moved in the axial direction by an operating mechanism (not shown). The movement of the operating rod 85 is transmitted to the movable electrode 86 via the connecting member 95, and the movable contact 82 at the tip of the movable electrode 86 contacts and separates from the fixed contact 81, that is, between the bus-side conductor 83 and the load-side conductor 84, that is, The current is opened and closed between the bus and the power transmission cable to the load.
When the movable contact 82 is separated from the fixed contact 81 and the main circuit current from the bus-side conductor 83 to the load-side conductor 84 is interrupted, the grounding conductor 89 is moved upward in the figure to ensure safety. The movable contact 89 a is brought into contact with the fixed contact 84 a of the load side conductor 84.
[0008]
Since the switchgear of FIG. 8 is used in a vacuum having excellent insulating properties, the required insulation distance between the members can be made smaller than that of the switchgear of FIG. Furthermore, even when an arc short circuit occurs inside the vacuum vessel 94, no gas is present inside the vacuum vessel 94, so there is no risk of the arc short circuit explosion described above.
[0009]
[Problems to be solved by the invention]
The switch gear of FIG. 8 is configured as described above, but the vacuum vessel is grounded to ensure safety, and insulation breakdown occurs between the bus-side conductor 83 or the load-side conductor 84 and the vacuum vessel 94. If this happens, it will lead to a ground fault, so ensuring withstand voltage performance is essential.
Since the bus-side conductor 83 and the load-side conductor 84 are usually made of copper or a copper alloy and have a low dielectric strength with the vacuum vessel 94, a sufficient insulation distance is necessary, and the vacuum vessel 94 is large. Become a thing. Since the flexible conductor 88 is also composed of conductive foil or thin wire, the electric field is easily concentrated, and a sufficient insulation distance is necessary to ensure voltage resistance, and the vacuum vessel 94 becomes large. .
[0010]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a switchgear that is excellent in voltage resistance, secures safety, and can be downsized.
[0011]
[Means for Solving the Problems]
The switchgear according to the first invention supports a bus-side conductor, a load-side conductor, and a movable electrode, each having a fixed electrode provided at the tip thereof, in a metal vacuum vessel, and the movable electrode is used as the fixed electrode. An operation member to be contacted and separated, a fixed member joined to a middle part of the movable electrode, and a flexible conductor that connects the load side conductor, and an end portion of the load side conductor is fitted into the end portion, A first cover made of stainless steel covering a part of the flexible conductor, and a second cover made of stainless steel covering the part of the flexible conductor by fitting the peripheral surface of the fixing member to the end of the first cover. comprising a portion of the first cover is characterized in that are more over the second cover.
The flexible conductor is made of conductive foil or fine wire, so the electric field tends to concentrate. However, in this switchgear, the flexible conductor is covered with a stainless steel cover, so the electric field is relaxed and possible. The withstand voltage between the flexible conductor and the vacuum vessel is improved, and the insulation distance can be shortened.
[0012]
A switchgear according to a second invention is the switchgear according to the first invention, wherein the bus-side conductor and the load-side conductor are covered with a stainless steel cover, and a metal vacuum vessel facing the cover. A part or all of the inner surface of the first cover and the second cover are covered with a material having a lower conductivity than stainless steel , or the first cover and the second cover are made of a metal facing the first cover and the second cover. A part or all of the inner surface of the vacuum vessel is covered with a substance having a lower conductivity than stainless steel.
In this switchgear, the withstand voltage is further improved, so that the insulation distance can be shortened.
[0014]
A switchgear according to a third aspect of the present invention supports a bus-side conductor, a load-side conductor, and a movable electrode, each having a fixed electrode provided at the tip thereof, in a metal vacuum vessel, and the movable electrode is used as the fixed electrode. An operation member to be contacted and separated, and a flexible conductor that connects the movable electrode and the load-side conductor, the busbar-side conductor, the load-side conductor, and a part or all of the peripheral surface of the flexible conductor , And part or all of the inner surface of the vacuum vessel facing the peripheral surface of the bus-side conductor, the load-side conductor, and the flexible conductor is covered with a material having a conductivity lower than that of copper. To do.
In this switchgear, bus side conductor, the load-side conductor, and a part or the whole of the peripheral surface of the flexible conductor, as well as bus side conductor, the load-side conductor, and the peripheral surface opposite to the vacuum vessel flexible conductor Since part or all of the inner surface is directly covered with a substance having low electrical conductivity, the voltage resistance between the flexible conductor or the like and the vacuum vessel is improved, and the insulation distance can be shortened.
[0015]
The switchgear according to a fourth invention is characterized in that, in the second or third invention, the substance having low conductivity is Ti, Cr, Ni, Mo, Ta, W, or a carbide or nitride thereof. To do.
In this switchgear, the voltage resistance is further improved and the insulation distance can be shortened.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof.
1 is a side sectional view showing a configuration of a main part of a switchgear according to Embodiment 1 of the present invention.
This switchgear constitutes a main circuit switch that opens and closes between the bus-side conductor 3 and the load-side conductor 4 inside a stainless steel vacuum vessel 14 maintained at a high vacuum.
The bus-side conductor 3 made of copper or copper alloy penetrates through one end wall of the vacuum vessel 14 via the bushing 10, and the outer end is connected to a bus (not shown). The inner end of the bus-side conductor 3 forms a fixed electrode 3a, and the fixed contact 1 is fixed to the tip of the fixed electrode 3a. The bus-side conductor 3 is covered with a stainless steel cover 18 that extends from the end face of the bushing 10 toward the fixed contact 1. The end portion of the cover 18 is in contact with the end surface of the bushing 10 in a state where the bus-side conductor 3 is passed through a hole provided in the center portion thereof.
The load-side conductor 4 made of copper or copper alloy penetrates the load-side conductor introduction portion 14b provided on the peripheral wall of the vacuum vessel 14 through the bushing 11, and its outer end is connected to a power transmission cable to a load (not shown). Has been. The load-side conductor 4 is also covered with a stainless steel cover 19 extending toward the tip of the load-side conductor 4 with its end abutting against the end surface of the bushing 11, as with the bus-side conductor 3.
[0018]
An operation rod 5 is supported on an operation rod introduction portion 14 a provided on the other end wall of the vacuum vessel 14 so as to be movable in the axial direction via the bellows 12, and the operation rod 5 extending inside the vacuum vessel 14. The movable electrode 6 is coupled to the end of the first electrode through a coupling member 15 with its tip abutted substantially coaxially with the fixed electrode 3a. The movable contact 2 is fixed to the tip of the movable electrode 6, and the inner end of the load-side conductor 4 is connected to the fixed member 7 joined in the middle of the movable electrode 6 through the flexible conductor 8. ing.
[0019]
A grounding conductor introduction part 14c is provided on the peripheral wall of the load-side conductor introduction part 14b in parallel with the operation rod introduction part 14a. The grounding conductor introduction part 14c moves in the axial length direction via the bellows 13. A grounding conductor 9 is supported as possible. A movable contact 9a is fixed to the tip of the grounding conductor 9, and a fixed contact 4a is fixed to the peripheral surface of the load-side conductor 4 so as to face the movable contact 9a. The outer end of the grounding conductor 9 is grounded.
[0020]
The outer end of the operation rod 5 is connected to an operation mechanism (not shown), and the operation rod 5 is moved in the axial length direction according to the operation of the operation mechanism. The grounding conductor 9 is also moved in the axial direction by an operating mechanism (not shown).
[0021]
When the operating rod 5 is moved upward from the state shown in FIG. 1, the movable contact 2 is pressed through the connecting member 15 and the movable electrode 6 to come into contact with the fixed contact 1 to obtain a closed state. . At this time, the fixed contact 4a of the load side conductor 4 and the movable contact 9a of the grounding conductor 9 are separated. A main circuit current from a bus (not shown) flows to the movable electrode 6 via the bus-side conductor 3, the fixed contact 1 and the movable contact 2, and further to a power transmission (not shown) via the fixed member 7, the flexible conductor 8 and the load-side conductor 4. Sent to the cable.
On the other hand, in this closed state, the movable contact 2 is pulled away from the fixed contact 1 by moving the operating rod 5 in the downward direction in the figure, and an open circuit state is obtained, and the main conductor from the bus side conductor 3 to the load side conductor 4 is obtained. Circuit current is interrupted. At this time, by moving the grounding conductor 9 upward in the figure, the movable contact 9 a is brought into contact with the fixed contact 4 a of the load-side conductor 4 to ensure safety.
[0022]
In the switchgear according to the first embodiment, the bus-side conductor 3 and the load-side conductor 4 made of copper or copper alloy are covered with stainless steel covers 18 and 19 having a conductivity lower than that of copper. The withstand voltage between the conductor 3, the load side conductor 4, and the vacuum vessel 14 is improved. Therefore, dielectric breakdown is prevented and the insulation distance can be shortened, so that the vacuum vessel 14 can be reduced in size.
[0023]
Embodiment 2. FIG.
FIG. 2 is a side sectional view showing a configuration of a main part of the switchgear according to the second embodiment of the present invention. In the figure, the same parts as those of the switchgear of FIG.
In this switchgear, the cover 18 is joined to the bus-side conductor 3 by a brazing or the like without a gap, and the cover 19 is joined to the load-side conductor 4 by a brazing or the like without a gap. Accordingly, since the mechanical strength of the bus-side conductor 3 and the load-side conductor 4 is improved, the diameters of these conductors can be reduced, and the vacuum vessel 14 can be further downsized.
[0024]
Embodiment 3 FIG.
FIG. 3 is a side sectional view showing a configuration of a main part of the switchgear according to the third embodiment of the present invention. In the figure, the same parts as those of the switchgear of FIG.
In this switchgear, the end portion of the load-side conductor 4 is fitted into the end portion, and has a predetermined length and a stainless steel cover 16 that covers the flexible conductor 8 and a larger diameter than the cover 16. A stainless steel cover 17 that covers the flexible conductor 8 and a part of the cover 16 by fitting the peripheral surface of the fixing member 7 into the portion is provided. The flexible conductor 8 is composed of a conductive foil or thin wire, so that the electric field tends to concentrate. However, by covering with the covers 16 and 17, the electric field is relaxed and the withstand voltage is improved. Therefore, the insulation distance can be shortened and the vacuum vessel 14 can be miniaturized.
[0025]
Embodiment 4 FIG.
FIG. 4 is a side sectional view showing a configuration of a main part of a switchgear according to a fourth embodiment of the present invention. In the figure, the same parts as those of the switchgear of FIG.
In this switchgear, a high withstand voltage material layer 20 is provided on the outer surface of the cover 18 and the inner surface of the vacuum vessel 14 facing it, and on the outer surface of the cover 19 and the inner surface of the vacuum vessel 14 facing it. . The high withstand voltage material layer 20 is made of Ti, Cr, Ni, Mo, Ta, W, or a carbide or nitride thereof having a lower conductivity than stainless steel on the outer surface of the cover 18 and the inner surface of the vacuum vessel 14. It is obtained by plating or spraying. Compared with the switchgear according to the first embodiment, the voltage resistance between the bus-side conductor 3, the load-side conductor 4 and the vacuum vessel 14 is further improved, so that the insulation distance can be further shortened and the vacuum The container 14 can be reduced in size.
[0026]
Embodiment 5 FIG.
FIG. 5 is a side sectional view showing the configuration of the main part of the fifth embodiment of the switchgear according to the present invention. In the figure, the same parts as those of the switchgear of FIG.
In this switchgear, a high withstand voltage material layer 20 is provided on the outer surfaces of the covers 16 and 17 and the inner surface of the vacuum vessel 14 facing the covers 16 and 17. The high withstand voltage material layer 20 is formed on the outer surfaces of the covers 16 and 17 and the inner surface of the vacuum vessel 14 facing the same, with Ti, Cr, Ni, Mo, Ta, W, or their carbides having lower conductivity than stainless steel. Alternatively, it can be obtained by plating or spraying nitride or the like. Compared with the switchgear according to the third embodiment, the withstand voltage between the flexible conductor 8 and the vacuum vessel 14 is further improved, so that the vacuum vessel 14 can be further downsized.
[0027]
Embodiment 6 FIG.
FIG. 6 is a side sectional view showing the configuration of the main part of the sixth embodiment of the switchgear according to the present invention. In the figure, the same parts as those of the switchgear of FIG.
In this switchgear, is the high withstand voltage material layer 21 provided on the peripheral surfaces of the bus-side conductor 3, the load-side conductor 4 and the flexible conductor 8, and the inner surface of the vacuum vessel 14 facing them? The high withstand voltage material layer 21 is formed by plating or spraying the peripheral surface and the inner surface with Ti, Cr, Ni, Mo, Ta, W, or a carbide or nitride thereof having a lower conductivity than copper. can get. By providing the high withstand voltage material layer 21, the withstand voltage between the bus bar side conductor 3, the load side conductor 4, the flexible conductor 8 and the vacuum vessel 14 is improved, so that the insulation distance can be shortened. The vacuum vessel 14 can be reduced in size.
[0028]
In the fourth, fifth, and sixth embodiments, the case where Ti, Cr, Ni, Mo, Ta, W, or a carbide or nitride thereof is used as the high withstand voltage material is described, but the present invention is not limited thereto. Other materials may be used instead. However, it is preferable to use the above-mentioned substances in view of voltage resistance.
[0029]
【The invention's effect】
As described in detail above, according to the switchgear according to the first aspect of the invention, since the flexible conductor made of conductive foil or fine wire is covered with the stainless steel cover, the electric field is relaxed and the flexible The withstand voltage between the conductor and the vacuum vessel is improved. Therefore, the insulation distance can be shortened and the switch gear can be miniaturized.
[0030]
According to the switchgear according to the second invention, in the first invention, the outer surface of the cover and a part or all of the inner surface of the vacuum vessel facing the cover are covered with a substance having a conductivity lower than that of stainless steel. Further, the voltage resistance is further improved. Therefore, the insulation distance can be further shortened, and the switch gear can be further reduced in size.
[0032]
According to the switchgear according to the third invention, the bus-side conductor, the load-side conductor, and a part or all of the peripheral surface of the flexible conductor , and the bus-bar-side conductor, the load-side conductor, and the peripheral surface of the flexible conductor Since part or all of the inner surface of the opposing vacuum vessel is directly covered with a substance having low conductivity, the voltage resistance is improved. Therefore, the insulation distance can be shortened and the switch gear can be miniaturized.
[0033]
According to the switchgear according to the fourth aspect of the present invention, the material having low conductivity is Ti, Cr, Ni, Mo, Ta, W, or a carbide or nitride thereof, and the voltage resistance is further improved. Therefore, the insulation distance can be further shortened, and the switch gear can be further reduced in size.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing a configuration of a main part of a switchgear according to a first embodiment of the present invention.
FIG. 2 is a side sectional view showing a configuration of a main part of a switchgear according to a second embodiment of the present invention.
FIG. 3 is a side sectional view showing a configuration of a main part of a switchgear according to a third embodiment of the present invention.
FIG. 4 is a side sectional view showing a configuration of a main part of a switchgear according to a fourth embodiment of the present invention.
FIG. 5 is a side sectional view showing a configuration of a main part of a switchgear according to a fifth embodiment of the present invention.
FIG. 6 is a side sectional view showing a configuration of a main part of a switchgear according to a sixth embodiment of the present invention.
FIG. 7 is a side sectional view showing a configuration of a main part of a conventional switch gear.
FIG. 8 is a side sectional view showing a configuration of a main part of a conventional switch gear.
[Explanation of symbols]
3 Busbar side conductor, 4 Load side conductor, 5 Operating rod, 6 Movable electrode, 8 Flexible conductor, 9 Grounding conductor, 14 Vacuum container, 18, 19 Cover, 20, 21 High withstand voltage material layer.

Claims (4)

In a metal vacuum vessel, a bus-side conductor provided with a fixed electrode at the tip, a load-side conductor, an operation member that supports the movable electrode, and contacts and separates the movable electrode from the fixed electrode, and the movable A flexible conductor connecting the fixing member joined to the middle part of the electrode and the load-side conductor, and stainless steel that covers the end of the load-side conductor at the end and covers a part of the flexible conductor A first cover made of steel, and a second cover made of stainless steel that covers a part of the flexible conductor by fitting the peripheral surface of the fixing member at an end thereof;
It said portion of the first cover, the switch gear, characterized in that are more over the second cover. When the bus-side conductor and the load-side conductor are covered with a stainless steel cover, the outer surface of the cover and a part or all of the inner surface of the metal vacuum vessel facing the cover are electrically conductive from stainless steel. It is covered with a low rate material, or with the first cover and the outer surface of the second cover, the inner surface of the metallic vacuum vessel facing the first cover and the second cover and a part or the whole, of stainless steel 2. The switchgear according to claim 1, wherein the switchgear is covered with a substance having lower conductivity. In a metal vacuum vessel, a bus-side conductor provided with a fixed electrode at the tip, a load-side conductor, an operation member that supports the movable electrode, and contacts and separates the movable electrode from the fixed electrode, and the movable A flexible conductor connecting the electrode and the load-side conductor, the bus-side conductor, the load-side conductor, a part or all of the peripheral surface of the flexible conductor , and the bus-side conductor, the load side A switchgear characterized in that a part of or all of the conductor and the inner surface of the vacuum vessel facing the peripheral surface of the flexible conductor are covered with a material having a conductivity lower than that of copper. The switchgear according to claim 2 or 3, wherein the substance having low conductivity is Ti, Cr, Ni, Mo, Ta, W, or a carbide or nitride thereof.

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