JP2007014070A - Insulating spacer for gas-insulated electrical equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insulating spacer for gas-insulated electrical equipment which enables the downsizing of the insulating spacer and the simplification of the configuration. <P>SOLUTION: A plurality of buried metal fittings 8 are provided on the virtual circumference of the periphery of an insulating spacer 1 which supports a high-voltage conductor by the center conductor 10 buried at the center. This buried metal fitting 8 is open to the side of a circular flange 4, and is shaped like a bottomed non-penetrated recess on opposite side, and an annular groove 7 for storage of a gasket is arranged outside the virtual circumference of arrangement of the buried metal fitting 8, and the insulating spacer 1 and the circular flange 4 are coupled with each other by a bolt 3 which is screwed into the thread part of the bottomed recess from the side of the circular flange 4. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an insulating spacer for gas-insulated electrical equipment that insulates and supports a high-voltage conductor of gas-insulated electrical equipment.

  In a gas insulated switchgear or gas insulated bus known as a gas insulated electrical device, an insulating spacer is used to support a high voltage conductor such as a main circuit conductor in a sealed container filled with an insulating gas. A gas compartment is formed. Conventional insulating spacers have been airtightly connected so that the outer periphery of the insulating spacer is directly sandwiched between the flanges of the sealed container (see, for example, Patent Document 1). As a result, the airtight connection is established by sandwiching the outer periphery of the metal annular flange between the flanges of the sealed container, and an insulating spacer is attached to the inner periphery of the annular flange to insulate the gas-insulated electrical equipment. A spacer is formed (see, for example, Patent Document 2).

  The latter insulating spacer for gas-insulated electrical equipment is provided with a plurality of embedded metal fittings 8 discretely on the virtual circumference of the outer peripheral portion of the insulating spacer 1 in which the central conductor 10 is embedded in the central portion as shown in FIG. An annular groove 7 for accommodating a gasket is formed on the central conductor 10 side of the embedded metal fitting 8. The embedded metal fitting 8 has a cylindrical shape having holes penetrating both surfaces of the insulating spacer 1 existing in the axial direction of the central conductor 10. When such an insulating spacer 1 is incorporated in a gas-insulated electric device and used, an annular flange 4 is sandwiched between the flanges 5a and 5b of the sealed containers 11 and 12, and an airtight connection is made by a bolt (not shown). Inside the sealed containers 11, 12, the left surface of the insulating spacer 1 is brought into contact with the annular flange 4 in a state where the gasket is disposed in the annular groove 7 for accommodating the gasket, and inserted into the inner surface of the embedded metal fitting 8 from the right surface side of the insulating spacer 1. The bolt 3 is screwed into the annular flange 4. By tightening the bolt 3, an airtight connection is made between the annular flange 4 and the insulating spacer 1 by a gasket. Further, an electric field relaxation shield 9 is provided at the head of the bolt 3 so that electric field concentration does not occur, and high voltage conductors 5 and 6 forming main circuits are connected to both sides of the central conductor 10 of the insulating spacer 1, respectively. is doing. In this manner, the insulating spacer 1 supports the high voltage conductors 5 and 6 in a state of being electrically insulated from the sealed containers 11 and 12, and the sealed container 11 side and the sealed container 12 side are separated in terms of gas.

Japanese Utility Model Publication No. 60-62825 JP 2003-153406 A

  However, since the conventional insulating spacer for gas-insulated electrical equipment has holes through which the embedded metal fitting 8 penetrates on both sides of the insulating spacer 1, when forming a gas compartment between the sealed container 11 and the sealed container 12, In order to prevent gas communication through the through hole of the embedded metal fitting 8, an annular groove 7 for accommodating a gasket in which a gasket is arranged on the center conductor 10 side inside the virtual circumference where the embedded metal fitting 8 of the insulating spacer 1 is arranged is provided. Had to form. Further, in order to form a gas seal surface of the gasket disposed in the gasket accommodating annular groove portion 7, the inner diameter side of the annular flange 4 has to be positioned closer to the central conductor 10 side than the gasket accommodating annular groove portion 7. . Therefore, if the predetermined creepage insulation distance between the inner diameter side of the annular flange 4 and the central conductor 10 is reduced and a predetermined creepage insulation distance corresponding to the voltage class is to be secured in the same portion, the insulation having a large outer diameter is performed. It becomes the spacer 1. Moreover, the increase in the outer diameter of the insulating spacer 1 also increases the diameter of the sealed containers 11 and 12, which increases the size and cost of the gas-insulated electrical device.

  An object of the present invention is to provide an insulating spacer for gas-insulated electrical equipment that enables the insulating spacer to be reduced in size and configuration.

  In order to achieve the above object, the present invention provides an insulating spacer having a central conductor provided at substantially the center and connected to the high voltage conductor, and a plurality of embedded fittings embedded on the virtual circumference of the outer periphery. An annular flange disposed on an outer peripheral portion of one side of the insulating spacer in the axial direction of the central conductor, a bolt inserted through the embedded bracket to fix the insulating spacer to the annular flange, the annular flange and the insulating An insulating spacer for gas-insulated electrical equipment, which is provided between a spacer and an annular gasket that is airtightly connected by tightening the bolt, wherein the embedded bracket is open to the surface of the insulating spacer on the annular flange side, and It has a bottomed recess that does not penetrate to the opposite side of the insulating spacer, and the bolt is on the annular flange side. And al inserted screwed into the bottomed recess of the buried metal, the annular gasket characterized in that arranged on the outer peripheral portion of the virtual circumference of the buried metal.

  According to a second aspect of the present invention, in the first aspect of the present invention, the annular flange has an outer peripheral portion disposed between the flanges of adjacent sealed containers that contain the high-voltage conductors, and is airtightly connected. It is characterized by that.

  Furthermore, the present invention described in claim 3 is the one described in claim 1, wherein the annular flange has a three-phase common opening at the center thereof and has a three-phase central conductor in the opening. The three-phase collective insulating spacer is arranged, the embedded metal fitting is provided on the virtual circumference located on the outer periphery of the opening common to the three phases, and the three-phase is further provided on the outer circumference of the virtual circumference of the embedded metal fitting. The above-mentioned common annular gasket is arranged.

  Since the insulating spacer for gas-insulated electrical equipment according to the present invention has a bottomed recess that opens the embedded metal fitting to the annular flange side, the annular groove for accommodating the gasket is arranged outside the virtual circumference of the embedded metal fitting. However, it is possible to form an airtight gas section with a gasket because there is no gas communication through the embedded metal fitting as in the conventional case, and the inner diameter portion located on the center conductor side of the ring-shaped annular flange is embedded. The size can be determined in consideration of the connection with the metal fitting, and there is no need to further reduce the inner diameter by extending the center conductor side of the annular flange for the annular groove for accommodating the gasket as in the prior art. Also, by screwing the bolt from the annular flange side to the threaded portion of the bottomed recess, the electric field concentration on the bolt head side can be reduced with a simple configuration using the annular flange, and the annular flange can be reduced with a small insulating spacer. A sufficient creeping insulation distance can be secured between the inner diameter portion and the central conductor.

  Further, the insulating spacer for gas-insulated electrical equipment according to the second aspect of the present invention has an annular flange disposed between the flanges of the adjacent sealed containers containing the high voltage conductors so as to be airtightly connected. The coupling body with the annular flange can be easily handled as an insulating spacer for gas-insulated electrical equipment.

  Furthermore, the insulating spacer for gas-insulated electrical equipment according to the third aspect of the present invention comprises a three-phase collective insulating spacer having a three-phase central conductor in an opening common to three phases formed in an annular flange, Further, since the annular gasket is disposed on the outer peripheral portion of the opening, the structure of the annular flange and the annular gasket is simplified as a three-phase collective shape, and the annular groove for storing the gasket is disposed outside the virtual circumference of the embedded fitting. It can be arranged to form an airtight gas section, and the inner diameter part located on the center conductor side of the ring-shaped annular flange can be sized in consideration of the connection with the embedded bracket, and it is small overall The structure can be simplified.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing an insulating spacer for gas-insulated electrical equipment according to an embodiment of the present invention.
The insulating spacer 1 includes a central conductor 10 embedded to connect a high-voltage conductor to the central portion thereof, a plurality of embedded metal fittings 8 embedded on a virtual circumference of the outer peripheral portion for use for attachment, and the embedded spacer An annular groove portion 7 for accommodating a gasket is formed in a ring shape in a portion located further on the outer peripheral portion than the virtual circumference of the metal fitting 8. The embedded metal fitting 8 has a bottomed recess that does not have a hole penetrating both surfaces of the insulating spacer 1 existing in the axial direction of the center conductor 10 and is open only to the left side, and a screw portion is formed in the bottomed recess. ing. Therefore, the both sides of the insulating spacer 1 are not communicated in gas by the embedded metal fitting 8. In addition, the embedding metal fitting 8 can adopt various configurations, but here, the right side end portion has an end portion embedded in a smooth curved surface shape for electric field relaxation.

  When such an insulating spacer 1 is incorporated in a gas-insulated electrical device and used, a ring-shaped annular flange 4 is sandwiched between the flanges 11a and 12a of the adjacent sealed containers 11 and 12, and airtightness is achieved by bolts or O-rings (not shown). With the annular gasket placed in the annular groove 7 for accommodating the gasket, the left surface of the insulating spacer 1 is brought into contact with the annular flange 4 located in the sealed container 11, 12 and inserted from the left surface side of the annular flange 4. The bolt 3 is screwed into the threaded portion of the bottomed recess of the embedded metal fitting 8. By tightening the bolt 3 at this time, the annular flange 4 and the insulating spacer 1 are hermetically connected by an annular gasket, and the insulating spacer 1 is fixed to the annular flange 4. High voltage conductors 5 and 6 forming a main circuit are connected to the center conductor 10 on both sides of the insulating spacer 1. In this way, the insulating spacer 1 supports the high voltage conductors 5 and 6 while being electrically insulated from the sealed containers 11 and 12, and the sealed container 11 side and the sealed container 12 side are separated in terms of gas. .

  When the insulating spacer 1 is attached, the embedded metal fitting 8 is at the same potential as the annular flange 4 by contact with the annular flange 4 or by the bolt 3. The annular flange 4 is normally grounded via the sealed containers 11 and 12. Moreover, since the right end portion of the embedded metal fitting 8 has a shape that prevents electric field concentration, it is not necessary to provide a special electric field relaxation shield. However, when the embedded metal fittings 8 are discretely present in a virtual circumferential shape on the outer peripheral portion of the insulating spacer 1 to cause electric field concentration, each embedded metal fitting 8 is arranged in a ring shape arranged on the virtual circumference. Well-known electric field relaxation means can be applied, such as connecting with a metal member for electric field relaxation.

  Further, in the conventional structure, electric field concentration occurs at the head of the bolt 3, but since the head of the bolt 3 is located on the annular flange 4 side, the annular flange 4 is also made of metal. Electric field concentration can be prevented in relation to the overall shape of the left side of the flange 4. If the electric field concentration at the head of the bolt 3 becomes a problem even with this structure, the annular flange 4 at a position corresponding to the head of the bolt 3 is cut as known as electric field relaxation means, and the bolt is added to the cutting portion. It is also possible to prevent electric field concentration by embedding three heads.

  According to such an insulating spacer for gas-insulated electrical equipment, since the embedded metal fitting 8 has the bottomed recess opened to the annular flange 4 side as described above, both side surfaces of the insulating spacer 1 are formed by the embedded metal fitting 8. There is no gas communication. Therefore, by arranging the annular groove 7 for accommodating the gasket outside the imaginary circumference of the embedded metal fitting 8, it is possible to gasify the space between the sealed containers 11 and 12. Moreover, the arrangement of such a gasket allows the inner diameter portion of the ring-shaped annular flange 4 located on the side of the central conductor 10 to have a size that allows for the connection with the embedded metal fitting 8, as in the conventional case. There is no need to further reduce the inner diameter by extending the center conductor 10 side of the annular flange 4 for the gasket accommodating annular groove 7. Therefore, a sufficient creeping insulation distance can be secured between the inner diameter portion of the annular flange 4 and the center conductor 10 without increasing the size of the insulating spacer 1.

  In addition, such an insulating spacer for gas-insulated electrical equipment is an insulating spacer directly interposed between the flanges 11a and 12a of the sealed containers 11 and 12, and the embedded bracket is divided into two in the axial direction, and one embedded bracket is apparently It is not only that the bottomed recess is selected and attached to the annular flange 4. When an insulating spacer is interposed directly between the flanges 11a and 12a of the sealed containers 11 and 12, the embedded metal fitting and the closed containers 11 and 12 are at the same potential due to the connection, so that there is almost no problem with the electric field in the embedded metal fitting. . On the other hand, when an insulating spacer is attached to the inner side of the annular flange 4 and an attempt is made to reduce the size of the insulating spacer, a problem in the electric field of the embedded metal fitting occurs, and this new problem is solved. In addition, if the embedded bracket is divided into two in the axial direction, one embedded bracket is apparently bottomed, but the other embedded bracket is floated in potential, which causes an electric field problem. However, it is possible to solve such a new problem and provide a desirable configuration as the insulating spacer 1 attached to the inner side of the annular flange 4.

  In FIG. 3 showing the conventional structure and FIG. 1 showing the structure according to the present embodiment, the size of the insulating spacer 1 and the size of the imaginary circle of the embedded metal fitting 8 are shown as being the same. With this configuration, a larger creeping insulation distance can be secured between the inner diameter portion of the annular flange 4 and the central conductor 10. However, if the creeping insulation distance between the inner diameter side of the annular flange 4 and the central conductor 10 determined according to the voltage specifications is the same, the outer diameter of the insulating spacer 1 shown in FIG. 1 can be made smaller. This makes it possible to reduce the size of gas-insulated electrical equipment.

  Further, as described above, since the embedded metal fitting 8 is configured to have the bottomed recess opened to the annular flange 4 side, the bolt 3 can be screwed from the annular flange 4 side to the threaded portion of the bottomed recess. . Therefore, the annular flange 4 with reduced electric field concentration is positioned on the head side of the bolt 3 and the electric field concentration at the head of the bolt 3 can be reduced. There is no need to provide a member, and the configuration can be simplified.

  Furthermore, in the insulating spacer for gas-insulated electric equipment described above, the insulating spacer 1 and the annular flange 4 are connected to each other by the bolt 3 so that they can be separated from each other. It can be handled. However, it is also possible to handle only the insulating spacer 1 as an insulating spacer for gas-insulated electric equipment separately from the annular flange 4. According to this latter concept, an insulating spacer for gas-insulated electrical equipment can be configured as follows.

FIG. 2 is a cross-sectional view showing an insulating spacer for gas-insulated electrical equipment according to another embodiment of the present invention, and the same components as those of the previous embodiment are denoted by the same reference numerals and detailed description thereof is omitted.
In this embodiment, the insulating spacer for the gas-insulated electric device is constituted by only the insulating spacer 1, and the annular flange 4 connected to one surface of the insulating spacer 1 is the flange 11a of the sealed container 11 constituting the gas-insulated electric device. It is configured to be used as both. Adjacent sealed containers 11 and 12 are hermetically connected between their flanges 11a and 12a by bolts or O-rings (not shown). The flange 11a of one sealed container 11 has an inner diameter smaller than the diameter of the sealed container 11. Thus, a portion functioning as an annular flange 4 for connecting the insulating spacer 1 is also integrally formed.

  According to such an insulating spacer for gas-insulated electrical equipment, the structure can be simplified by using both the flange 11a and the annular flange 4 of the hermetically sealed container 11, and the embedded metal fitting is the same as in the above-described embodiment. 8 has a bottomed recess that is open on the annular flange 4 side, and therefore, both the side surfaces of the insulating spacer 1 are not communicated with each other by the embedded metal fitting 8, and the annular groove 7 for accommodating the gasket is provided in the embedded metal fitting 8. It is possible to arrange outside the virtual imaginary circumference, and the same effect as in the above-described embodiment can be obtained.

FIG. 3 is a cross-sectional view showing an insulating spacer for gas-insulated electrical equipment according to another embodiment of the present invention, and the same reference numerals are given to the equivalents to the previous embodiment, and detailed description thereof is omitted.
The annular flange 4 determines the outer peripheral shape in accordance with the cross-sectional shape of the sealed containers 11 and 12 shown in FIG. 1, but the inner diameter side of the annular flange 4 is an elliptical shape in a substantially horizontal direction. 4a is formed. A three-phase collective insulating spacer 1 in which three-phase central conductors 10a, 10b, and 10c are embedded in a substantially horizontal direction is disposed in the opening 4a. As in the case of FIG. 1, an embedded fitting 8 having a bottomed recess opened on the annular flange 4 side is embedded in the insulating spacer 1, and the bolt 3 inserted from the annular flange 4 side is screwed into the embedded fitting 8. Then, the insulating spacer 1 is fixed to the annular flange 4. However, the annular groove portion 7 for accommodating the gasket formed on the insulating spacer 1 side and the annular gasket disposed in the same portion are arranged in a three-phase collective manner in the outer peripheral portion rather than the virtual circumference of the three-phase common opening 4a and the embedded fitting 8. Provide as a shape. The shape of the opening 4a common to the three phases can be changed in accordance with the arrangement of the central conductors 10a, 10b, 10c of the respective phases or the high voltage conductors connected thereto.

  According to such a three-phase collective insulating spacer for gas-insulated electrical equipment, a three-phase collective insulating spacer having a three-phase central conductor 10 is provided in the three-phase common opening 4a formed in the annular flange 4. Since the annular gasket is arranged on the outer peripheral portion of the opening 4a, the annular flange 4 and the annular gasket are simplified as a three-phase package, and the gasket is accommodated in the same manner as in the previous embodiment. The gas groove between the two sealed containers 11 and 12 can be formed by arranging the annular groove portion for the outer side of the imaginary circumference of the embedded metal fitting 8. In addition, the inner diameter portion located on the center conductor side of the ring-shaped annular flange ensures a sufficient creeping insulation distance to the high-voltage conductors 5 and 6 even if the size is such that the connection with the embedded metal fitting 8 is considered. As a whole, it is possible to provide a three-phase collective insulating spacer for gas-insulated electrical equipment that is small in size and simple in structure.

  Also, according to such a three-phase collective type insulating spacer for gas insulated electrical equipment, the cross-sectional shape of the sealed containers 11 and 12 and the outer shape of the insulating spacer 1 do not necessarily have to be matched. , 12 can be applied to gas-insulated electrical equipment. That is, when the insulating spacer 1 is directly interposed between the flanges 11 a and 12 a of the sealed containers 11 and 12, the shape of the outer diameter portion of the insulating spacer 1 must be matched with the shape of the flanges 11 a and 12 a. When the insulating spacer 1 is attached to the inner diameter side, for example, the sealed containers 11 and 12 and the flanges 11a and 12a can be formed in a vertically crushed shape in FIG. The sealed containers 11 and 12 and the flanges 11a and 12a can be designed.

  Furthermore, in an insulating spacer for gas-insulated electrical equipment according to another embodiment of the present invention, a plurality of embedded metal fittings 8 are embedded on the virtual circumference of the outer peripheral portion of the insulating spacer 1, and the embedded metal fittings 8 are bottomed on the left end side. The concave portion is opened and embedded on the right side so that it is not exposed on the right side surface of the insulating spacer 1. The concave portion opened on the left end side is bottomed and forms a gas section, and the right end surface takes into account the electric field. If so, the right surface side of the embedded metal fitting 8 may be exposed to the right surface side of the insulating spacer 1.

  The insulating spacer for gas-insulated electrical equipment according to the present invention can be applied not only to the configuration shown in the figure but also to other configurations.

It is sectional drawing which shows the insulation spacer for gas insulated electrical equipment by one embodiment of this invention. It is sectional drawing which shows the insulation spacer for gas insulation electrical equipment by other embodiment of this invention. It is sectional drawing which shows the insulation spacer for gas insulation electric equipment by other embodiment of this invention. It is sectional drawing which shows the insulation spacer for the conventional gas insulation electric equipment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Insulation spacer 2 Embedded metal fitting 3 Bolt 4 Annular flange 6 High voltage conductor 7 Annular groove 11 for storing gasket 11, 12 Airtight container

Claims (3)

  An insulating spacer having a central conductor provided at substantially the center and connected to the high-voltage conductor, and a plurality of embedded brackets embedded on the virtual circumference of the outer periphery, and the insulating spacer in the axial direction of the central conductor An annular flange disposed on the outer peripheral portion of one side of the steel plate, a bolt inserted into the embedded bracket to fix the insulating spacer to the annular flange, and a bolt disposed between the annular flange and the insulating spacer. An insulating spacer for gas-insulated electrical equipment having an annular gasket for airtight connection, wherein the embedded metal fitting is open to a surface on the annular flange side of the insulating spacer and does not penetrate to the opposite side of the insulating spacer. The bolt is inserted from the annular flange side and the embedded metal fitting is Screwed into the bottom recess, the annular gasket gas insulated electric apparatus insulating spacer, characterized in that arranged on the outer peripheral portion of the virtual circumference of the buried metal.   2. The gas-insulated electrical device according to claim 1, wherein the annular flange has an outer peripheral portion disposed between the flanges of the adjacent sealed containers containing the high-voltage conductors and is airtightly connected. Insulating spacer. 3. The annular flange according to claim 1, wherein the annular flange is formed with a three-phase common opening at the center thereof, and the three-phase collective insulating spacer having a three-phase central conductor is disposed in the opening. The embedded metal fitting is provided on a virtual circumference located on the outer circumference of the opening common to the three phases, and the annular gasket common to the three phases is arranged further on the outer circumference of the virtual circumference of the embedded metal fitting. Insulating spacer for gas-insulated electrical equipment.

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