JP2017060209A - Gas insulated equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve both of improvement of insulation performance in a metallic container and compactification of equipment.SOLUTION: Gas insulated equipment 100 according to an embodiment includes: metallic high-voltage conductors 2a, 2b; a metallic contactor 5 which is fitted into the conductors to electrically connect with the conductors; metallic containers 1a, 1b which house the high-voltage conductors 2a, 2b and the contactor 5 and in which insulation gas 3 is sealed; and a support structure member 10 which is fixed to and supported by the metallic containers 1a, 1b to support the contactor 5. The support structure member 10 includes: an embedded electrode 11; an insulation plate 12 to be a transfer path of load between the contactor 5 and the metallic containers 1a, 1b; and electric field relaxation members 13, 14 made by using nonlinear dielectric material whose relative dielectric constant monotonously increases with increase in an electric field. The gas insulated equipment is configured to form triple junction part 18a, 18b, 17a, 17b among the electric field relaxation members 13, 14, the embedded electrode 11 or metallic containers 1a, 1b, and the insulation gas 3.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a gas insulating device.

Gas Insulated Switchgear (GIS) is installed in substations and power plants, and when overvoltages such as lightning surges and switching surges occur in the power system, these systems and equipment are disconnected. To protect against overvoltage. In general, gas insulated switchgear, the insulation performance and arc superior SF ₆ gas-filled metal container as an insulating gas into the arc extinguishing performance, circuit breakers and busbars, disconnecting switch, earth switch, such as a voltage transformer device It has a structure that stores. The circuit breaker arranged in the container has a configuration in which one end is connected to the bus and the other end is connected to an insulating terminal such as a cable head or a bushing.

  FIG. 8 is a cross-sectional view around a bus bar of a conventional general gas insulated switchgear. The bus bars, that is, the high voltage conductors 2a and 2b are accommodated in the grounded metal containers 1a and 1b. An insulating gas 3 is sealed inside the metal containers 1a and 1b. The high voltage conductors 2a and 2b are supported by the metal containers 1a and 1b via the insulating spacer 4. In GIS under high voltage conditions that require gas insulation, it is necessary to ensure sufficient insulation performance, particularly in the support portion of the bus.

  In the portion where the high voltage conductors 2a and 2b are supported, the high voltage conductors 2a and 2b are not continuously connected, but are electrically connected to each other via the contact 5 and the slide contacts 6a and 6b. Has been. The high voltage conductors 2a and 2b are provided with insulating spacers 4 for insulating and supporting them. The insulating spacer 4 is mainly composed of a composite material mainly composed of a thermosetting resin such as an epoxy resin and filled with alumina or silica from the viewpoint of mechanical properties. The support portion 4a of the insulating spacer 4 is formed of an insulating resin, and a buried electrode 4b is integrally cast at the center.

  In the gas insulated switchgear, the boundary surface where the conductor, the solid insulator, and the insulating gas are in contact with each other is called a triple junction, and the electric field concentrates on the corner of the metal conductor due to the difference in relative dielectric constant, A high electric field is generated. As a result, the electric field strength in the insulating container increases, which may cause dielectric breakdown. For this reason, the insulating container has a sufficient insulation dimension so that the required withstand voltage performance can be secured. Further, the insulating spacer 4 has a truncated cone shape as shown in FIG. 8 in order to secure the longest possible creepage length from the necessity of ensuring the insulating performance under a high voltage.

  In recent years, improvement in economy has been demanded, and the gas insulated switchgear is required to be compact. In order to make it compact, it is inevitable to reduce the size of metal containers and insulating spacers, and it becomes difficult to ensure the required insulating dimensions. In particular, in a gas insulated switchgear, a triple junction part (metal container side) 7 formed when the insulating gas 3 comes into contact with the joint part between the metal containers 1a and 1b and the support part 4a, the support part 4a and the embedded electrode part. A high electric field is generated in the triple junction portion (high voltage conductor side) 8 formed when the insulating gas 3 comes into contact with the joint portion with 4b, so that it is difficult to maintain the required withstand voltage performance. Problems arise.

  In the prior art, there is a method of providing an electric field relaxation shield as a method of reducing the electric field concentration in the triple junction (see Patent Document 1). However, the gas insulated switchgear becomes larger due to the installation of the electric field relaxation shield.

  For example, in Patent Document 1, an electric field relaxation shield is provided so as to surround the outer periphery of the high voltage conductor, and an electric field relaxation shield is formed inside the insulating spacer. However, when the electric field relaxation shield is provided around the high-voltage conductor for energization, it is necessary to increase the insulation distance between the metal container and the high-voltage conductor, so the metal container needs to be enlarged. . Further, when the electric field relaxation shield is provided inside the insulating spacer, the support portion becomes large. It is very difficult to reduce the size of the gas insulated switchgear and improve the insulation characteristics.

JP-A-11-285119 JP 2013-176275 A

  As a means to solve the problem of both miniaturization of gas insulated switchgear and improvement of insulation characteristics, a method of relaxing the electric field using a nonlinear dielectric constant material has been proposed, in which the relative permittivity increases as the electric field increases. (See Patent Document 2). However, the technique proposed in Patent Document 2 has a problem that the cost is increased because a large amount of expensive nonlinear dielectric constant material is used, although only a part of the part where the electric field is desired to be lowered is used.

  Then, embodiment of this invention aims at providing the gas insulation apparatus which made the improvement of the insulation performance in a metal container and the compactization of an apparatus compatible.

  In order to achieve the above-described object, the gas insulation apparatus according to the present embodiment includes two metal high-voltage conductors extending along the same axis and having a gap in the axial direction, and the two high-voltage conductors. And metal contacts that are respectively fitted and electrically connected to the two high-voltage conductors, and the two high-voltage conductors and the contacts are housed, and an insulating gas is sealed in the interior. A metal container extending in the axial direction; and a support structure member fixedly supported by the metal container and supporting the contact, wherein the support structure member is made of metal provided on a radially outer side of the contact The cylindrical embedded electrode, the insulating plate provided on the radially outer side of the embedded electrode and serving as a load transmission path between the contact and the metal container, and the relative permittivity increases monotonously as the electric field increases And an electric field relaxation member using a nonlinear dielectric constant material Wherein the electric field relaxation member, and the buried electrode or the metal container, characterized in that it is configured to form a triple junction portion between the insulating gas.

It is sectional drawing which shows the structure of the gas insulation apparatus which concerns on 1st Embodiment. It is the graph which compared the electric field-dielectric constant characteristic of an epoxy material and a nonlinear dielectric constant material. In order to explain the effect of the bus structure according to the first embodiment, it is a conceptual diagram showing an example of a potential distribution when a nonlinear dielectric constant layer is not provided, (a) is a partial central axis in the axial direction The figure which shows one side from (b) is the figure which expanded a part of (a). It is a conceptual diagram which shows the example of electric potential distribution at the time of providing a nonlinear dielectric constant layer in order to demonstrate the effect of the gas insulation apparatus which concerns on 1st Embodiment, (a) is a part central axis of an axial direction The figure which shows one side from (b) is the figure which expanded a part of (a). It is a graph which shows the reduction effect of the creeping electric field of the surface of the support structure member of the gas insulation apparatus which concerns on 1st Embodiment. It is sectional drawing which shows the structure of the gas insulation apparatus which concerns on 2nd Embodiment. It is a graph which shows the creeping electric field of the surface of the support structure member of the gas insulation apparatus which concerns on 2nd Embodiment. It is sectional drawing around the bus-line of the conventional general gas insulated switchgear.

  Hereinafter, a gas insulating apparatus according to an embodiment of the present invention will be described with reference to the drawings. Here, the same or similar parts are denoted by common reference numerals, and redundant description is omitted.

[First Embodiment]
FIG. 1 is a cross-sectional view showing a configuration of a gas insulating device according to the first embodiment. FIG. 1 shows a device that operates under high voltage conditions, such as a gas insulated circuit breaker, that insulates a high voltage conductor from a metal container that houses it.

The gas insulation apparatus 100 includes a high voltage conductor 2a and a high voltage conductor 2b, and metal containers 1a and 1b that house these and are grounded. The high voltage conductor 2a and the high voltage conductor 2b are made of metal such as copper or aluminum, are cylindrical, and extend along the same axial direction. The metal containers 1a and 1b contain the insulating gas 3. As the insulating gas 3, for example, sulfur hexafluoride (SF ₆ ) having high insulation, inertness, and high thermal conductivity is generally used.

  The high voltage conductor 2a and the high voltage conductor 2b are arranged with a gap therebetween in the axial direction. A contact 5 is disposed in the gap. The contact 5 has a substantially cylindrical shape. Slide contacts 6 a and 6 b are respectively provided on the outer circumferences on both sides in the axial direction of the contact 5. The slide contacts 6a and 6b are made of metal, and have elasticity against a compressive load by being wound around the contact 5 in a spiral shape, for example.

  The high voltage conductor 2a is fitted to the outside in the radial direction of the slide contact 6a. Similarly, the high voltage conductor 2b is fitted to the outside in the radial direction of the slide contact 6b. The high voltage conductor 2a, the slide contact 6a, the contact 5, the slide contact 6b, and the high voltage conductor 2b are electrically coupled in series in this order. The contact 5 is fixedly supported by a support structure member 10 fixedly supported by the metal containers 1a and 1b. That is, the support structure member 10 is a load transmission path between the contact 5 and the metal containers 1a and 1b.

  The support structural member 10 has a perforated disk shape as a whole. The support structural member 10 includes an embedded electrode 11, an insulating plate 12, a high-voltage conductor-side nonlinear dielectric material ring 13, and a metal container-side nonlinear dielectric material ring 14. As will be described later, the high-voltage conductor-side nonlinear dielectric material ring 13 and the metal container-side nonlinear dielectric material ring 14 are electric field relaxation members provided for relaxing the electric field. The embedded electrode 11, the insulating plate 12, the high-voltage conductor-side nonlinear dielectric material ring 13, and the metal container-side nonlinear dielectric material ring 14 constituting the support structure member 10 are respectively connected to the contact 5 and the metal container 1 a, It is a load transmission path between 1b.

  The embedded electrode 11, the insulating plate 12, the high-voltage conductor-side nonlinear dielectric material ring 13, and the metal container-side nonlinear dielectric material ring 14 are each annular, concentrically and radially outward of the contact 5. They are arranged in this order from the inside to the outside in the direction.

  The insulating plate 12 is made of an insulating material such as an epoxy resin, for example. The high-voltage conductor-side nonlinear dielectric material ring 13 and the metal container-side nonlinear dielectric material ring 14 as the electric field relaxation member include, for example, an epoxy resin as a main component and strontium titanate, barium titanate, titanic acid as a filler. It is a composite material containing, for example, about 20% to 30% of one or more of calcium or the like. In addition, each of a main component and a filler is not limited to this. Any other composition may be used as long as the dependence of the dielectric constant on the electric field strength has nonlinear characteristics as described later.

  The embedded electrode 11 is a metal cylinder that is open at both ends (left and right of the embedded electrode 11 in FIG. 1) and extends in the axial direction. The high-voltage conductor-side nonlinear dielectric material ring 13 is provided on the radially outer side of the embedded electrode 11. The high-voltage conductor-side nonlinear dielectric material ring 13 is cast integrally with the embedded electrode 11. Specifically, when the material for the high-voltage conductor-side nonlinear dielectric constant material ring 13 is poured into a mold and molded, the embedded electrode 11 is used as the radially inner mold, so that the high-voltage conductor-side nonlinear dielectric The rate material ring 13 and the embedded electrode 11 can be integrally cast.

  Similarly, when the insulating plate 12 is molded by pouring the material for the insulating plate 12 into the mold, the integrated embedded electrode 11 and the high-voltage conductor-side nonlinear dielectric constant material ring 13 are used as a radially inner mold. By using it, it is possible to cast integrally. Further, the metal container-side nonlinear dielectric material ring 14 is similarly integrated with the embedded electrode 11 and the high-voltage conductor side when the material for the metal container-side nonlinear dielectric material ring 14 is poured into a mold and molded. By using the nonlinear dielectric constant material ring 13 and the insulating plate 12 as a radially inner formwork, integral casting can be performed.

  The metal containers 1a and 1b are arranged with a gap from each other in the support portion of the bus bar. A flange 9 extending outward in the radial direction is attached to each of the metal containers 1a and 1b. The metal containers 1a and 1b are connected to each other by bolts and nuts (not shown) at flanges 9 attached thereto. The metal container-side nonlinear dielectric material ring 14 is sandwiched between the metal containers 1a, 1b and the flange 9, and is fixed by the flange 9, bolts and nuts.

  As described above, in the support portion of the bus bar, the support structure member 10 is fixed to the metal containers 1 a and 1 b at the flange 9, and the support structure member 10 supports the contactor 5. As a result, the high voltage conductors 2a and 2b supported by the contact 5 are indirectly supported by the metal containers 1a and 1b.

  In such a configuration, the surface of the boundary portion between the inner surface of the metal container 1a and the metal container-side nonlinear dielectric material ring 14 is the inner surface of the metal container 1a, the metal container-side nonlinear dielectric material ring 14, the insulating gas 3 and the like. The triple junction portion 17a on the metal container side is formed. Similarly, the surface of the boundary portion between the inner surface of the metal container 1b and the metal container-side nonlinear dielectric material ring 14 is the metal container side of the inner surface of the metal container 1b, the metal container-side nonlinear dielectric material ring 14 and the insulating gas 3. The triple junction portion 17b is formed.

  Further, the surface on both sides of the boundary between the outer surface of the embedded electrode 11 and the high-voltage conductor-side nonlinear dielectric material ring 13 is a high voltage of the embedded electrode 11, the high-voltage conductor-side nonlinear dielectric material ring 13 and the insulating gas 3. Conductor-side triple junction portions 18a and 18b are formed.

  FIG. 2 is a graph comparing electric field-dielectric constant characteristics of an epoxy material and a nonlinear dielectric material. The horizontal axis represents the electric field strength [V / m], and the vertical axis represents the relative dielectric constant [1/1], that is, the ratio of the dielectric constant of the substance to the dielectric constant of the vacuum.

  A curve A shows characteristics in the case of an epoxy resin which is a normal insulating material. Curve B shows the characteristics when the nonlinear dielectric material is an epoxy resin filled with barium titanate. In the characteristics of the epoxy resin which is a normal insulating material, as shown by the curve A, although it slightly increases monotonously as the electric field strength increases, the change is small.

As shown by the curve B, the characteristic of the nonlinear dielectric constant material by the epoxy resin filled with barium titanate is a characteristic that monotonously increases with respect to the electric field strength. In the characteristic of this nonlinear dielectric constant material, the electric field strength is slightly larger than the epoxy resin of curve A up to about 1 × 10 ⁷ V / m, but the relative dielectric constant is almost the same. However, as the electric field strength exceeds about 1 × 10 ⁷ V / m, the relative dielectric constant clearly increases.

  When the electric field strength is small, it is desirable that the values of the curves A and B are approximately the same. This is because, under the condition that the potential difference between the high voltage conductors 2a and 2b of a certain voltage and the grounded metal containers 1a and 1b is determined, the relative dielectric constant is obtained when the original electric field strength distribution is relatively flat. This is because if there is a large portion, the electric field strength of that portion will decrease, but the electric field strength of the other portion will increase, which will be an undesirable state.

  FIG. 3 is a conceptual diagram illustrating an example of a potential distribution when a nonlinear dielectric constant layer is not provided in order to explain the effect of the busbar structure according to the first embodiment, and (a) is a part in the axial direction. The figure which shows one side from the center axis | shaft of (b), (b) is the figure which expanded a part of (a). In FIG. 3, a portion of the support structure member 10 excluding the embedded electrode 11 is an insulating plate 12 made of epoxy resin. In this case, the boundary between the buried electrode 11 and the insulating plate 12 shown in FIG. 3 is the triple junction 8 of the buried electrode 11, the insulating plate 12, and the insulating gas, and the electric field strength in the vicinity thereof is maximum. In the vicinity of the triple junction portion 8, the interval between the equipotential lines 31 is narrow, that is, the electric field strength is high.

  FIG. 4 is a conceptual diagram showing an example of a potential distribution when a nonlinear dielectric constant layer is provided in order to explain the effect of the gas insulating device according to the present embodiment. The figure which shows one side from a central axis, (b) is the figure which expanded a part of (a). That is, the creeping electric field on the surface of the support structure member 10 is shown. In FIG. 4, a high-voltage conductor-side nonlinear dielectric constant material ring 13 as an electric field relaxation member is provided between the embedded electrode 11 and the insulating plate 12. That is, the high-voltage conductor-side nonlinear dielectric material ring 13 is provided at a location where the electric field strength is large.

  That is, in the present embodiment, the portions on both sides of the boundary between the embedded electrode 11 and the high voltage conductor side nonlinear dielectric material ring 13 are respectively embedded in the embedded electrode 11, the high voltage conductor side nonlinear dielectric material ring 13 and It becomes the triple junction part 18a, 18b of insulating gas. In the triple junction portions 18a and 18b, the electric field strength is high. For this reason, the relative dielectric constant of the high voltage conductor side nonlinear dielectric constant material ring 13 is sufficiently larger than the relative dielectric constant of the insulating plate 12. . Since the electric field strength is inversely proportional to the relative dielectric constant, as a result, as shown in FIG. 4, the interval between the equipotential lines 32 is increased in the vicinity of the triple junction portions 18a and 18b as compared with the case of FIG. The electric field strength decreases.

  FIG. 5 is a graph showing the effect of reducing the creeping electric field on the surface of the support structure member of the gas insulating device. The horizontal axis shows the case of the normal epoxy resin insulating plate 12 shown in FIG. 3 and the high voltage conductor side nonlinear dielectric as an electric field relaxation member inside the normal epoxy resin insulating plate 12 shown in FIG. Two cases where the rate material ring 13 is provided are shown. The vertical axis represents the relative value of the magnitude of the maximum electric field with reference to the maximum electric field in the conventional example.

  As shown in FIG. 5, in the gas insulating apparatus 100 according to the present embodiment, the maximum electric field can be reduced to about 80% of the conventional electric field strength.

  Further, in the gas insulating device 100 according to the present embodiment, the support portion 4a of the insulating spacer 4 in the conventional gas insulating device is in the shape of a truncated cone in order to make the creeping length as long as possible. Therefore, it is not necessary to take measures to reduce the electrolytic strength by securing the creepage length, and the insulating plate 12 may be disk-shaped or compact.

  As described above, in the present embodiment, it is possible to provide a gas insulating device that achieves both improvement of the insulating performance in the metal containers 1a and 1b and compactness of the device.

[Second Embodiment]
FIG. 6 is a cross-sectional view illustrating a configuration of a gas insulating device according to the second embodiment. This embodiment is a modification of the first embodiment. In the first embodiment, for example, conventionally, a buried electrode, an epoxy resin insulating plate, and an insulating gas boundary portion that is a triple junction portion, a buried electrode, a nonlinear dielectric constant material, The boundary of the insulating gas is a triple junction.

  The support structure member 20 in this embodiment is provided with an insulating plate 22 on the radially outer side of the embedded electrode 11, and the high-voltage conductor-side nonlinear dielectric material film 23 and the metal container-side nonlinear dielectric are formed on part of both end faces in the axial direction. A rate material film 24 is provided.

  This embodiment is the same as the first embodiment in that the boundary portion between the embedded electrode, the nonlinear dielectric constant material, and the insulating gas is a triple junction portion. However, in the first embodiment, the high-voltage conductor-side nonlinear dielectric material ring 13 and the metal container-side nonlinear dielectric material ring 14 are provided on the radially outer side of the embedded electrode 11.

  On the other hand, in the second embodiment, the embedded electrode 11 and the insulating plate on the end faces on both sides in the axial direction are arranged so that the boundary between the embedded electrode 11 and the epoxy resin insulating plate 22 does not become a triple junction. A high-voltage conductor-side nonlinear dielectric material film 23 as an electric field relaxation member is provided so as to cover the 12 boundary portions.

  Similarly, the boundary between the metal containers 1a and 1b and the insulating plate 22 made of epoxy resin is not a triple junction, so that the boundary between the metal container 1a and the insulating plate 22 at both end faces in the axial direction, A metal container-side nonlinear dielectric material film 24 as an electric field relaxation member is provided so as to cover the boundary between the metal container 1 b and the insulating plate 22.

  As a result, on the high voltage side, the embedded electrode 11, the high voltage conductor side nonlinear dielectric constant material film 23, and the portions on both sides of the boundary of the insulating gas 3 become the triple junction portions 28a and 28b, respectively. On the metal container 1a, 1b side, the boundary between the metal container 1a, the metal container-side nonlinear dielectric material film 24, and the insulating gas 3 is a triple junction portion 27a on the metal container side. The boundary between the metal container 1b, the metal container-side nonlinear dielectric material film 24, and the insulating gas 3 is a triple junction portion 27b on the metal container side.

  That is, as in the first embodiment, the embedded electrode 11 or the metal containers 1a and 1b, the insulating plate 12, and the triple junction portion by the insulating gas 3 are not formed, and the embedded electrode 11 or the metal containers 1a and 1b The non-linear dielectric constant material portion and the triple junction portion by the insulating gas 3 are formed.

  FIG. 7 is a graph showing the creeping electric field on the surface of the support structure member of the gas insulating apparatus according to the second embodiment. As shown in FIG. 7, in the gas insulating apparatus 100 according to the second embodiment, the maximum electric field can be reduced to about 90% of the conventional electric field strength.

[Other Embodiments]
As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. For example, in the present embodiment, the concentration of equipotential lines is reduced by using a non-linear dielectric constant material, and thus it is not necessary to ensure the creepage distance. Therefore, a creepage distance may be secured.

  Alternatively, the case where a nonlinear dielectric material is used for both the high voltage conductor side and the metal container side is shown, but if the insulation performance is secured on the one side, the nonlinear dielectric constant is applied only to the remaining severe part. Materials may be used.

  Moreover, you may combine the characteristic of each embodiment. For example, the high voltage conductor side may use a high voltage conductor side nonlinear dielectric material ring, and the metal container side may use a metal container side nonlinear dielectric material film. Or the reverse may be sufficient.

  Furthermore, these embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1a, 1b ... Metal container, 2a, 2b ... High voltage conductor, 3 ... Insulating gas, 4 ... Insulating spacer, 4a ... Support part, 4b ... Embedded electrode, 5 ... Contact, 6a, 6b ... Slide contact, 7 ... Triple Junction part (metal container side), 8 ... Triple junction part (high voltage conductor side), 9 ... Flange, 10 ... Supporting structural member, 11 ... Embedded electrode, 12 ... Insulating plate, 13 ... High voltage conductor side nonlinear dielectric material Ring (electric field relaxation member), 14 ... Metal container side nonlinear dielectric material ring (electric field relaxation member), 17a, 17b ... Triple junction part (metal container side), 18a, 18b ... Triple junction part (high voltage conductor side), DESCRIPTION OF SYMBOLS 20 ... Support structure member, 22 ... Insulating board, 23 ... High voltage conductor side nonlinear dielectric material film (electric field relaxation member), 24 ... Metal container side nonlinear dielectric material film (electric field relaxation) Wood), 27a, 27b ... triple junction portion (metal container side), 28a, 28b ... triple junction section (high voltage conductor side), 31, 32 equipotential lines, 100 ... Gas-insulated equipment

Claims (6)

Two metal high voltage conductors extending along the same axis and having a gap in the axial direction;
A metal contact that fits into the two high-voltage conductors and is electrically connected to the two high-voltage conductors;
A metal container that houses the two high-voltage conductors and the contact, seals an insulating gas inside, and extends in the axial direction;
A support structure member fixedly supported by the metal container and supporting the contact;
With
The support structure member is
A metal-made cylindrical embedded electrode provided outside in the radial direction of the contact;
An insulating plate provided on the radially outer side of the embedded electrode and serving as a load transmission path between the contact and the metal container;
An electric field relaxation member using a nonlinear dielectric constant material whose relative dielectric constant monotonously increases with an increase in electric field;
Have
A gas insulating apparatus configured to form a triple junction portion between the electric field relaxation member, the embedded electrode or the metal container, and the insulating gas.   The gas insulating device according to claim 1, wherein the electric field relaxation member is provided between the embedded electrode and the insulating plate and has a cylindrical shape.   The gas insulation apparatus according to claim 1, wherein the electric field relaxation member is provided on a radially outer side of the insulating plate and is fixed to the metal container.   The gas insulating device according to claim 1, wherein the electric field relaxation member is provided on an end face in an axial direction so as to cover a contact portion between the embedded electrode and the insulating plate.   4. The gas insulating device according to claim 1, wherein the electric field relaxation member is provided on an axial end surface so as to cover a contact portion between the metal container and the insulating plate.   The gas insulating apparatus according to any one of claims 1 to 5, wherein the insulating plate has a disk shape having a circular opening at a center.

Images