JP2015226436A - Gas-insulated switchgear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas-insulated switchgear capable of maintaining high withstand voltage performance even if decomposition products, produced by arc discharge, adhere to an insulation spacer.SOLUTION: In a gas-insulated switchgear 100, a high voltage conductor 1 is supported while being insulated from a ground tank 2, inserting the high voltage conductor 1 into the insulation gas sealed ground tank 2, connecting a high voltage shield 5 with the high voltage conductor 1, while furthermore connecting a connection conductor 4 with the high voltage shield 5, and then extending an insulation spacer 3 for supporting the connection conductor 4 from the inner surface of the ground tank 2 toward the central axis 1a. A triple contact point 7 of an insulation gas space 6 and connection conductor 4 and insulation spacer 3 occurs, and a protrusion 31 is protruded from the surface of the insulation spacer 3 in the vicinity of the triple contact point 7.

Description

  Embodiments described herein relate generally to a gas-insulated switchgear having a circuit breaker that generates arc discharge in a current interruption process.

  Currently, gas-insulated switchgears are installed in high-voltage power systems such as high-voltage power plants and substations, but they are required to be applied to underground substations in cities and to improve economic efficiency. Equipment innovations are progressing with technological innovations to meet requirements.

  A gas insulated switchgear is a device in which a circuit breaker, a disconnect switch, a ground switch, a voltage transformer, and the like are connected by a high voltage conductor. The circuit breaker is a device that switches between turning on and off the current by contacting and separating the fixed contact and the movable contact. The high voltage conductor is insulated and supported from the ground tank via the high voltage shield and the connection conductor by an insulating spacer extending from the inner surface of the ground tank.

  In order to advance the downsizing of this gas insulated switchgear, the improvement of insulation performance plays an extremely important role. This is because with the progress of downsizing, the insulation distance between the high-voltage conductor inside the device and its container is shortened, and the risk of dielectric breakdown increases. Therefore, many of the devices are configured as gas-insulated switchgear in which an insulating gas is sealed in a ground tank, thereby improving the insulation performance.

  Further, in the gas insulated switchgear, there is a triple contact point on the ground tank side where the space in which the insulating gas is sealed, the insulating spacer and the inner surface of the ground tank are in contact, and this triple contact point is a small gas gap. Therefore, it is known that local power concentration occurs and the insulation performance is likely to deteriorate. Therefore, a configuration in which ring-shaped electrodes are provided on both surfaces of the flange for attaching the insulating spacer to the ground tank has been proposed (see, for example, Patent Document 1). According to this proposal, the withstand voltage performance of the gas insulated switchgear is improved by reducing the electric field at the triple contact point on the ground tank side where the space in which the insulating gas is sealed, the insulating spacer and the inner surface of the ground tank are in contact. It is improving.

JP-A-11-285119

  Here, in the circuit breaker, arc discharge is generated in the process of interrupting current, and powdery decomposition products are generated by the thermal energy of the arc discharge. This decomposition product may diffuse inside the ground tank in which the high voltage conductor is disposed, and reaches the vicinity of the insulating spacer and then accumulates on the inner surface of the ground tank. Further, in a state where the circuit breaker interrupts the current, a DC voltage may remain at the fixed contact or the movable contact included in the circuit breaker. As a result, of the decomposition products, only the decomposition products charged to a polarity opposite to the polarity of the high-voltage conductor are lifted by the electrostatic force and adhere to the surface of the insulating spacer.

  FIG. 7 shows equipotential lines in the ground tank when decomposition products adhere to the surface of the insulating spacer. FIG. 7 shows an example in which a negative DC voltage remains on the high-voltage conductor 1, and an example in which the decomposition product charged to the positive polarity of the opposite polarity floats and adheres to the surface of the insulating spacer 3. , Along with an example that does not adhere. When the decomposition product of (a) in FIG. 7 does not adhere and when the decomposition product of (b) adheres, the equipotential lines when the decomposition product adheres to the insulating spacer 3, as can be seen from the comparison. Will be distributed in the direction of the high-voltage conductor 1.

  Then, the gas-insulated switchgear also has a triple contact point 7 on the high voltage conductor side where the space in which the insulating gas is sealed, the connection conductor, and the insulating spacer 3 are in contact. For this reason, the electric field in the vicinity of the triple contact point 7 on the high voltage conductor 1 side becomes high, and this high electric field generates a discharge 30 at a voltage lower than usual, and along the surface of the insulating spacer 3 to the ground tank 2. There is a risk of progress. That is, when a decomposition product generated by arc discharge adheres to the insulating spacer 3, a discharge 30 along the surface of the insulating spacer 3 is started from the triple contact point 7 on the high voltage conductor 1 side, and gas insulating switching is performed. There is a risk of dielectric breakdown at the rated voltage of the device or lower.

  Embodiments of the present invention have been proposed in order to solve the above problems, and are capable of maintaining a high withstand voltage performance even when decomposition products generated by arc discharge adhere to insulating spacers. The object is to provide an insulated switchgear.

  In order to achieve the above object, a gas insulated switchgear according to an embodiment includes a ground tank filled with an insulating gas, and a high voltage conductor inserted into the ground tank and applied with a high voltage for power transmission. A high-voltage shield connected to the high-voltage conductor, a connection conductor connected to the high-voltage shield, extending from the inner surface of the ground tank toward a central axis, and supporting the connection conductor, An insulating spacer that insulates and supports the high-voltage conductor from the ground tank via the connecting conductor and the high-voltage shield, and an insulating gas space in the ground tank in which the insulating gas is sealed, and the connecting conductor It has a triple contact point with the insulating spacer, and a protrusion is formed in the vicinity of the triple contact point on the surface of the insulating spacer.

  The gas-insulated switchgear according to the embodiment includes a ground tank filled with an insulating gas, a high-voltage conductor inserted into the ground tank and applied with a high voltage for power transmission, and the high-voltage conductor. A high voltage shield to be connected, a connection conductor connected to the high voltage shield, and extending from an inner surface of the ground tank toward a central axis, and supporting the connection conductor, whereby the connection conductor and the high voltage shield An insulating spacer that insulates and supports the high-voltage conductor from the ground tank, and includes an insulating gas space in the ground tank in which the insulating gas is sealed, a triple of the connection conductor and the insulating spacer. It has a contact point, and the triple contact point is covered with a non-linear resistance material.

  The gas-insulated switchgear according to the embodiment includes a ground tank filled with an insulating gas, a high-voltage conductor inserted into the ground tank and applied with a high voltage for power transmission, and the high-voltage conductor. A high voltage shield to be connected, a connection conductor connected to the high voltage shield, and extending from an inner surface of the ground tank toward a central axis, and supporting the connection conductor, whereby the connection conductor and the high voltage shield An insulating spacer that insulates and supports the high-voltage conductor from the ground tank, and includes an insulating gas space in the ground tank in which the insulating gas is sealed, a triple of the connection conductor and the insulating spacer. It has a contact point, and the triple contact point is covered with an insulating material.

It is a lineblock diagram showing a schematic structure of a gas insulated switchgear concerning a 1st embodiment. According to the first embodiment, (a) shows a structure in the ground tank, and (b) is an enlarged view of a triple contact point portion in the vicinity of the high voltage conductor. It is a schematic diagram which shows the mode of deposition to the ground tank concerning a 1st embodiment. It is a schematic diagram which concerns on 1st Embodiment and shows adhesion to the insulating spacer surface of a decomposition product. It is an equipotential diagram in the ground tank according to the first embodiment, (a) in increments of 5%, (b) in increments of 2%, (c) is an enlarged view in the vicinity of the protrusion. (A) shows the structure in the installation tank of the gas insulated switchgear according to the second embodiment, (b) is an enlarged view near the triple contact point on the high voltage conductor side, (c) is a ground tank It is an enlarged view near the triple contact point on the inner surface side. It is an equipotential diagram in the ground tank of the conventional gas insulated switchgear, (a) shows no adhesion of decomposition products, (b) shows the presence of adhesion of decomposition products.

(First embodiment)
(Constitution)
The gas insulated switchgear according to the first embodiment will be specifically described with reference to the drawings. As shown in FIG. 1, the gas-insulated switchgear 100 includes a high-voltage conductor 1 disposed coaxially with the ground tank 2 and includes a circuit breaker 10 connected to the high-voltage conductor 1. In addition, the gas insulated switchgear 100 includes a disconnect switch, a ground switch, a voltage transformer, a cable head, and the like, and these devices are also electrically connected to each other by the high voltage conductor 1.

  The circuit breaker 10 is a device that turns on and off a current by connecting and disconnecting contacts, and includes a fixed contact 11 and a movable contact 12. The fixed contact 11 and the movable contact 12 are each connected to the high voltage conductor 1 and become contacts on the electric circuit. The fixed contact 11 and the movable contact 12 are insulated and supported by the high voltage conductor 1 in the airtight container 13.

The ground tank 2 in which the high-voltage conductor 1 is disposed is a cylindrical metal container, and communicates with the sealed container 13 of the circuit breaker 10 by being fully opened or partially opened. The ground tank 2 is filled with an insulating gas. An insulating gas includes SF ₆ gas. In recent years, SF ₆ gas is a gas with a high global warming potential, and therefore has been designated as an emission control target. Therefore, from the viewpoint of reducing the environmental load, as the insulating gas to be sealed, dry air, carbon dioxide (CO ₂ gas), oxygen (O ₂ gas), nitrogen (N ₂ gas), carbon tetrafluoride gas (CF ₄ gas) ), Or a mixture of two or more of them may be used.

  The high-voltage conductor 1 is a cylindrical body made of a single material such as aluminum or copper that transmits electric power, and extends on the central axis 1 a of the ground tank 2. A high voltage is applied to the high voltage conductor 1 for power transmission. The high voltage conductor 1 is separated from the inner surface of the ground tank 2 for insulation from the ground tank 2, and is supported in a hollow space by the insulating spacer 3 via the connection conductor 4 and the high voltage shield 5.

  The insulating spacer 3 is an insulator having a cone shape. The connection conductor 4 is a conductive cylindrical body, and is formed at the apex portion of the cone shape of the insulating spacer 3. A flange is formed at the base of the insulating spacer 3, and the insulating spacer 3 is sandwiched between the joints between the ground tanks 2, so that the axes of the connection conductor 4 and the ground tank 2 are aligned. Installed in the ground tank 2.

  The high voltage shield 5 is a cylindrical body having both ends opened. The high voltage shield 5 is connected to both end faces of the cylindrical connection conductor 4. The diameter of the opening of the high voltage shield 5 is the same as the diameter of the high voltage conductor 1. The high voltage conductor 1 is disposed opposite to the front and back surfaces of the cone apex portion of the insulating spacer 3, and is inserted into the high voltage shield 5 toward the connection conductor 4. As a result, the opposing high voltage conductors 1 are electrically joined via the connection conductor 4 to form a single electric path as a whole.

  As shown in FIG. 2, the connection conductor 4 is longer than the thickness of the insulating spacer 3 and protrudes from the front and back of the insulating spacer 3. Further, the outer diameter of the high voltage shield 5 is larger than the outer diameter of the connection conductor 4. Since the connecting conductor 4 is longer than the thickness of the insulating spacer 3, there is a triple contact point 7 where the connecting conductor 4, the insulating spacer 3, and the insulating gas space 6 filled with the insulating gas all contact. The insulating spacer 3 has a protrusion 31 with respect to the triple contact point 7. The protrusion 31 extends from the outer surface of the insulating spacer 3 and is positioned in the vicinity of the triple contact point 7.

  The protrusion 31 is formed in a circumferential shape so as to surround the central axis 1 a of the ground tank 2. The rising direction of the protruding portion 31 is parallel to the central axis 1 a of the ground tank 2 or is tapered so that the tip of the protruding portion 31 faces the central axis 1 a side of the grounded tank 2 from the root of the protruding portion 3. Yes. For example, the protruding portion 31 stands in a direction inclined about 30 degrees toward the central axis 1 a side of the ground tank 2. The outermost peripheral portion 31 a that is the outermost diameter of the protruding portion 31 is configured to have a smaller diameter than the outermost outer periphery that is the outermost diameter of the high-voltage shield 5, in other words, a ground tank that is smaller than the outer peripheral surface 5 a of the high-voltage shield 5. 2 near the central axis 1a.

(Function)
When it is necessary to cut off an excessive accident current, a small advance current, a delayed load current such as a reactor cutoff, or an extremely small accident current, an opening command signal is input to the gas insulated switchgear 100, and the breaker 10 has a fixed contact. 11, the movable contact 12 is separated. At this time, an arc discharge is generated between the fixed contact 11 and the movable contact 12. The arc discharge is extinguished through the current zero point by the arc extinguishing action of the insulating gas, and the fixed contact 11 and the movable contact 12 recover the insulation performance and the current is interrupted.

  Here, in the current interruption process, a powdery decomposition product 20 having a positive charge and a negative charge is generated by the thermal energy of the arc discharge, and the decomposition product 20 enters the ground tank 2 as shown in FIG. In some cases, it may accumulate on the inner surface of the ground tank 2. In addition, a DC voltage may remain at the fixed contact 11 or the movable contact 12 due to current interruption. Then, as shown in FIG. 4, the decomposition product 20 having the opposite polarity to the DC voltage remaining on the fixed contact 11 or the movable contact 12 is levitated by electrostatic force and adheres to the surface of the insulating spacer 3.

  FIG. 5 shows equipotential lines in the ground tank 2 when the decomposition product 20 adheres to the insulating spacer 3 in the gas insulated switchgear 100. FIG. 5 illustrates a state in which a negative DC voltage remains on the fixed contact 11 or the movable contact 12, and thus the positive decomposition product 20 adheres to the surface of the insulating spacer 3. As shown in FIG. 5, the equipotential lines are distributed in the direction of the high voltage conductor 1 and the electric field in the vicinity of the triple contact point 7 is increased. However, due to the presence of the protrusion 31, the equipotential line is formed with a bulge of the equipotential line along the surface of the protrusion 31 in the vicinity of the protrusion 31.

  Generally, the discharge 30 develops along the direction of the electric lines of force. The electric lines of force travel while intersecting perpendicularly with the equipotential lines. When the discharge 30 develops along the creeping surface of the insulating spacer 3, the discharge 30 develops in a direction in which the creeping direction component of the insulating spacer 3 exceeds zero among the lines of electric force.

  Then, the discharge 30 generated from the triple contact point 7 where the electric field is increased proceeds along the creeping surface of the insulating spacer 3 toward the inner surface of the ground tank 2. However, in the vicinity of the protrusion 31, the equipotential lines swell so as to follow the surface of the protrusion 31. In other words, the creeping direction component of the insulating spacer 3 along the surface of the protrusion 31 out of the lines of electric force. Not suitable for the direction. Ultimately, of the lines of electric force, the creeping direction component of the insulating spacer 3 is orthogonal to the surface of the protrusion 31. Therefore, when the discharge 30 that has developed from the triple contact point 7 reaches the projection 31, it cannot progress in the direction over the projection 31 along the surface of the projection 31, and only proceeds in a direction that penetrates the projection 31. It becomes possible.

  The dielectric breakdown strength for penetrating the protrusion 31 is at least twice as high as the creepage of the insulating spacer 3. That is, a voltage of about twice or more is required for the discharge 30 to penetrate the protrusion 31 and reach the ground tank 2. Therefore, the decomposition product 20 is generated by the current interruption operation of the circuit breaker 10, diffuses in the ground tank 2, and further develops from the triple contact point 7 even if it adheres to the surface of the insulating spacer 3 by electrostatic force. The discharge 30 stops at the protrusion 31 and becomes difficult to reach the ground tank 2.

(effect)
As described above, the gas-insulated switchgear 100 according to the present embodiment inserts the high-voltage conductor 1 into the ground tank 2 filled with the insulating gas, connects the high-voltage shield 5 to the high-voltage conductor 1, and By connecting the connection conductor 4 to the high voltage shield 5 and extending the insulating spacer 3 supporting the connection conductor 4 from the inner surface of the ground tank 2 toward the central axis 1a, the connection conductor 4 and the high voltage shield 5 are connected to each other. The voltage conductor 1 is insulated and supported from the ground tank 2.

  At this time, a triple contact point 7 of the insulating gas space 6, the connecting conductor 4, and the insulating spacer 3 is born. The protrusion 31 protrudes from the surface of the insulating spacer 3 in the vicinity of the triple contact point 7. . As a result, the discharge 30 that has developed from the triple contact point 7 stops at the protruding portion 31 and becomes difficult to reach the ground tank 2, so that the withstand voltage performance of the gas insulated switchgear 100 can be enhanced.

  The protrusion 31 is formed in a circular shape so as to surround the central axis 1a of the ground tank 2, and the standing direction is parallel to the central axis 1a of the ground tank 2 or the tip is closer to the central axis 1a side of the ground tank than the base. In other words, the outermost peripheral portion 31 a has a smaller diameter than the outer peripheral surface 5 a of the high voltage shield 5. Thereby, it is possible to effectively prevent the discharge 30 from getting over the protruding portion 31a, and the discharge 30 becomes more difficult to reach the ground tank 2, so that the withstand voltage performance of the gas insulated switchgear 100 can be further improved. it can.

For this reason, the insulating gas can be one or more of N ₂ gas, O ₂ gas, CO ₂ gas, CF ₄ gas, or dry air, or a mixed gas. That is, although these insulating gases have insulating performance lower than that of SF _{6, the} withstand voltage performance is increased due to the structure of the gas insulated switchgear 100, so that the gas insulated switchgear 100 having high insulation performance and low environmental load is obtained. be able to.

(Second Embodiment)
(Constitution)
A gas insulated switchgear according to a second embodiment will be specifically described with reference to the drawings. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. In this gas insulated switchgear, a triple contact point 7 is covered with a covering 8 as shown in FIG. The covering 8 is a non-linear resistance material or an insulating material.

  The resistivity of the nonlinear resistance material changes depending on the electric field value. For example, titanium oxide, zinc oxide, barium titanate or strontium titanate particles, or a combination thereof is mixed in the base material. An example of the base material is an epoxy resin. The characteristics of the nonlinear resistance material can be adjusted by adjusting the content of these particles. This nonlinear resistance material is adjusted so that the resistivity decreases as the covering 8 when the electric field at the triple contact point 7 rises to the electric field value at the start of discharge. The insulating material is, for example, an epoxy resin and has a withstand voltage performance.

  In addition to the triple contact point 7 with the insulating spacer 3, the connecting conductor 4, and the insulating gas space 6, the covering body 8 includes the insulating spacer 3 and the inner surface of the ground tank 2 as shown in FIG. And it can also be provided at the triple contact point 9 with the insulating gas space 6.

(Function)
It is assumed that a decomposition product 20 having a polarity opposite to that of the DC voltage remaining on the fixed contact 11 or the movable contact 12 floats due to electrostatic force and adheres to the surface of the insulating spacer 3. In this case, when the electric field at the triple contact point 7 rises to the electric field value at the start of discharge, the resistivity of the covering 8 made of a non-linear resistance material decreases. If it does so, the effect that the electric field around covering 8 will be reduced is acquired. Therefore, the electric field in the vicinity of the triple contact point 7 is less likely to rise above the electric field value at the start of discharge. That is, even if the decomposition product 20 is generated by the current interruption operation by the circuit breaker 10 and the decomposition product 20 diffuses into the ground tank 2 and further adheres to the surface of the insulating spacer 3 by electrostatic force, the triple contact point 7 is difficult to reach the electric field at which discharge starts, and the withstand voltage performance of the gas-insulated switchgear 100 can be improved.

  In addition, when the triple contact point 7 is covered with the covering 8 made of an insulating material, the dielectric breakdown electric field on the surface of the insulating coating generally has an effect of improving the withstand voltage performance of about 1.1 times in the case of a bare electrode. I can expect. That is, a voltage of 1.1 times or more is required for the discharge to progress through the covering 8 made of an insulating material. For this reason, when the covering 8 is made of an insulating material, it becomes difficult to start discharge from the triple contact point 7 and the withstand voltage performance of the gas insulated switchgear 100 can be improved.

  Further, by covering the triple contact point 9 with the covering 8, even if the condition that the electric field becomes high at the triple contact point 9 occurs, the electric field reduction effect by the non-linear resistance material or the dielectric breakdown strength by the insulating material Since the improvement effect is obtained, the withstand voltage performance of the device can be enhanced.

(effect)
As described above, the gas-insulated switchgear 100 according to the present embodiment inserts the high-voltage conductor 1 into the ground tank 2 filled with the insulating gas, connects the high-voltage shield 5 to the high-voltage conductor 1, and By connecting the connection conductor 4 to the high voltage shield 5 and extending the insulating spacer 3 supporting the connection conductor 4 from the inner surface of the ground tank 2 toward the central axis 1a, the connection conductor 4 and the high voltage shield 5 are connected to each other. The voltage conductor 1 is insulated and supported from the ground tank 2.

  At this time, a triple contact point 7 of the insulating gas space 6, the connection conductor 4, and the insulating spacer 3 is born. The triple contact point 7 is covered with a covering 8 made of a non-linear resistance material or an insulating material. . Thereby, according to the covering 8 made of a non-linear resistance material, an electric field reduction effect can be obtained, and according to the covering 8 made of an insulating material, an effect of improving the dielectric breakdown strength can be obtained. Can be increased.

  Further, the triple contact point 9 between the insulating gas space 6, the inner surface of the ground tank 2 and the insulating spacer 3 is also covered with a covering 8 made of a non-linear resistance material or an insulating material. As a result, even if a condition where the electric field is increased at the triple contact point 9 is generated, the electric field reduction effect can be obtained by the covering 8 made of the nonlinear resistance material, and the dielectric breakdown by the covering 8 made of the insulating material. The strength improvement effect is obtained, and the withstand voltage performance of the gas insulated switchgear 100 can be enhanced.

(Other embodiments)
As mentioned above, although several embodiment concerning this invention was described in this specification, these embodiment was shown as an example and is not intending limiting the range of invention. A combination of all or any of the embodiments is also included in the scope of the invention. Each embodiment 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 modifications thereof are included in the invention described in the claims and equivalents thereof as well as included in the scope and gist of the invention.

  For example, the formation of the protrusions 31 and the like has been described by exemplifying the inside of the ground tank 2 that supports the high-voltage conductor 1 that is directly connected to the circuit breaker 10, but the decomposition and generation generated by the arc discharge generated by the circuit breaker 10. If it is a location where the thing 20 may spread | diffuse, the projection part 31 can also be provided in the creeping surface where the discharge 30 progresses in the location. For example, the protrusion 31 can be provided on the surface of the insulating spacer 3 in the installation tank 2 between devices connected by the high voltage conductor 1 such as a disconnect switch, a ground switch, or a voltage transformer.

  In addition, the triple contact point 7 and the triple contact point 9 are covered with a covering 8 made of a non-linear resistance material while the protrusion 31 is provided to make it difficult for the discharge to progress, and the triple contact point 7 and the triple contact are covered. The electric field at the point 9 may be relaxed or may be covered with a covering 8 made of an insulating material to improve the insulating performance. That is, by adopting the protrusion 31, the cover 8 made of a non-linear resistance material, and the cover 8 made of an insulating material in a single or a combination, it becomes possible to prevent dielectric breakdown synergistically from various viewpoints. .

DESCRIPTION OF SYMBOLS 1 High voltage conductor 1a Center axis | shaft 2 Ground tank 3 Insulating spacer 31 Protrusion part 31a Outermost peripheral part 4 Connection conductor 5 High voltage shield 5a Outer peripheral surface 6 Insulating gas space 7 Triple contact point 8 Covering body 9 Triple contact point 10 Breaker DESCRIPTION OF SYMBOLS 11 Fixed contact 12 Movable contact 13 Sealed container 20 Decomposition product 30 Discharge 100 Gas insulated switchgear

Claims (6)

A grounded tank filled with insulating gas;
A high voltage conductor that is inserted into the ground tank and to which a high voltage is applied for power transmission;
A high voltage shield connected to the high voltage conductor;
A connection conductor connected to the high voltage shield;
An insulating spacer that extends from the inner surface of the ground tank toward a central axis and supports the connection conductor, thereby insulating and supporting the high-voltage conductor from the ground tank via the connection conductor and the high-voltage shield;
With
Having a triple contact point between the insulating gas space in the ground tank filled with the insulating gas, the connection conductor and the insulating spacer;
Protrusions are formed in the vicinity of the triple contact point on the surface of the insulating spacer,
A gas insulated switchgear characterized by. The protrusion is
It is formed in a circumferential shape so as to surround the central axis of the ground tank,
The standing direction is parallel to the center axis of the ground tank, or the tip is directed to the center axis side of the ground tank from the base,
The outermost peripheral portion has a smaller diameter than the outermost periphery of the high-voltage shield;
The gas insulated switchgear according to claim 1. A grounded tank filled with insulating gas;
A high voltage conductor that is inserted into the ground tank and to which a high voltage is applied for power transmission;
A high voltage shield connected to the high voltage conductor;
A connection conductor connected to the high voltage shield;
An insulating spacer that extends from the inner surface of the ground tank toward a central axis and supports the connection conductor, thereby insulating and supporting the high-voltage conductor from the ground tank via the connection conductor and the high-voltage shield;
With
Having a triple contact point between the insulating gas space in the ground tank filled with the insulating gas, the connection conductor and the insulating spacer;
The triple contact point is coated with a non-linear resistance material;
A gas insulated switchgear characterized by. A grounded tank filled with insulating gas;
A high voltage conductor that is inserted into the ground tank and to which a high voltage is applied for power transmission;
A high voltage shield connected to the high voltage conductor;
A connection conductor connected to the high voltage shield;
An insulating spacer that extends from the inner surface of the ground tank toward a central axis and supports the connection conductor, thereby insulating and supporting the high-voltage conductor from the ground tank via the connection conductor and the high-voltage shield;
With
Having a triple contact point between the insulating gas space in the ground tank filled with the insulating gas, the connection conductor and the insulating spacer;
The triple contact point is coated with an insulating material;
A gas insulated switchgear characterized by. The insulating gas space in the grounding tank in which the insulating gas is sealed, the inner surface of the grounding tank, and the insulating spacer have a triple contact point, and the triple contact point is covered with a non-linear resistance material or an insulating material. Being
The gas insulated switchgear according to claim 3 or 4, characterized in that. The insulating gas is one or more of SF ₆ gas, N ₂ gas, O ₂ gas, CO ₂ gas, CF ₄ gas or dry air;
The gas insulated switchgear according to any one of claims 1 to 5.