JP2004222390A - Enclosed type switchgear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an enclosed type switchgear in which the cost can be reduced by decreasing the number of components while enhancing the insulation performance. <P>SOLUTION: The enclosed type switchgear comprises a disconnector 5 and a vacuum valve 3 for each phase juxtaposed to each other, an enclosed container 1 containing the disconnector 5 and the vacuum valve 3 and encapsulated with insulating gas, and insulating tubular container 2 having a substantially tubular body 2a made of an insulating material and standing on a specified supporting surface 1a in the enclosed container 1 while containing the vacuum valve 3 in the body 2a and supporting the disconnector 5 at the outside part of the body 2a, and an intermediate conductor 4 provided at the opening end part 2c on the side of the body 2a of the insulating tubular container 2 opposite to the supporting surface 1a and securing the vacuum valve 3 in the insulating tubular container 2 while being connected electrically with the first terminal conductor 3a thereof wherein the insulating tubular container 2 has a first insulating barrier part 2d formed integrally with the body 2a and standing at the opening end part 2c to surround the intermediate conductor 4 at least partially. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a closed-type switching device in which a disconnector and a vacuum valve for each phase are housed in a sealed container connected to an insulating bus of an electric power system and filled with an insulating gas, for example.
[0002]
[Prior art]
Improving insulation performance (breakdown voltage characteristics) in a hermetically sealed switchgear with three sets of disconnectors and vacuum valves for each phase of a three-phase AC circuit in a sealed container filled with insulating gas For this purpose, it has been conventionally proposed to dispose an insulating barrier at a predetermined position. Regarding this insulating barrier, an inter-phase insulating barrier disposed between the disconnectors of adjacent phases and between the vacuum valves of adjacent phases, and between the disconnectors and vacuum valves of each phase and the ground potential portion. There is an insulation barrier to ground.
[0003]
Generally, between the high-voltage charging part and the ground potential part in the closed-type switchgear, and between different phases of the high-voltage charging part must be electrically insulated. Such insulation between the ground and the phases is usually provided by an insulating gas inside the sealed container. However, if the insulation distance cannot be increased due to design reasons, an insulation barrier may be provided at a predetermined position (for example, see Patent Document 1).
[0004]
[Patent Document 1]
JP-A-2001-352624
[Problems to be solved by the invention]
However, in the conventional closed-type switchgear having such a configuration, the structure inside the device becomes complicated due to the additionally provided insulating barrier, the number of parts increases, and the cost increases, and the assembly is difficult to assemble. This was a problem because it took more time.
[0006]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a sealed switchgear that can improve insulation performance, reduce the number of components, and reduce costs.
[0007]
[Means for Solving the Problems]
The closed-type switchgear according to the present invention is made of an insulating material and a disconnecting container and a vacuum valve for each phase which are arranged in parallel to each other, a disconnecting container and a vacuum valve that house the disconnecting device and the vacuum valve, and in which an insulating gas is sealed. An insulating tubular container having a substantially cylindrical main body, standing upright on a predetermined support surface in a sealed container, accommodating a vacuum valve inside the main body, and supporting a disconnector on an outer portion of the main body; An intermediate conductor provided at an open end opposite to the support surface of the main body of the container, electrically connected to the first terminal conductor of the vacuum valve, and fixing the vacuum valve in the insulating cylindrical container. The insulating tubular container has a first insulating barrier portion erected at an open end so as to surround at least a part of the periphery of the intermediate conductor and formed integrally with the main body.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a cross-sectional view of a main part of a closed type switchgear according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view showing the entire closed-type switchgear according to Embodiment 1 of the present invention. FIG. 3 is a perspective view of the insulating tubular container of the first embodiment. FIG. 4 is a view of the insulating tubular container of FIG. 3 as viewed from the opening end side. FIG. 5 is a perspective view showing a state in which three-phase insulating cylindrical containers are juxtaposed.
[0009]
1 and 2, an insulating cylindrical container 2 is fixed in a sealed container 1 in which an insulating gas is sealed. The insulating cylindrical container 2 is made of an insulating material such as an epoxy resin, has a substantially cylindrical main body 2a, and has a flange 2b formed at one end of the main body 2a. A support plate 1a vertically arranged on the front side in the sealed container 1 is provided. The support plate 1 a is provided as a positioning reference surface and a support surface of each component in the sealed container 1. The insulating cylindrical container 2 has a flange portion 2b fastened to the support plate 1a with bolts, and is erected in the horizontal direction. As shown in FIG. 5, the insulating tubular containers 2 are provided for each phase of a three-phase AC power supply. In FIG. 1, three insulating cylindrical containers are arranged in a direction perpendicular to the plane of the drawing.
[0010]
Returning to FIGS. 1 and 2, a vacuum valve 3 is housed in the main body 2 a of each insulating tubular container 2. An intermediate conductor 4 is fixed to an opening end 2c of the main body 2a opposite to the flange 2b. The intermediate conductor 4 is made of a conductive material, has a substantially rectangular plate shape, and has a grip portion protruding toward the inner space side of the main body 2a. The grip portion serves as a first terminal conductor of the vacuum valve 3 as a fixed terminal. By gripping the end on the 3a side, the vacuum valve 3 is fixed to the open end 2c inside the main body 2a. The intermediate conductor 4 is electrically connected to the fixed terminal 3a of the vacuum valve 3 at the center. The intermediate conductor 4 is fixed to the four female screw holes 2f shown in FIGS. 3 and 4 by tightening with bolts (not shown).
[0011]
Returning to FIGS. 1 and 2, a disconnector 5 is supported on the outer side of the insulating tubular container 2. The disconnector 5 includes a fulcrum 5a, a closing stator 5b, a blade 5c, and a grounding stator 5d (FIG. 2). A blade 5c is pivotally supported by a fulcrum 5a provided on the outer side of the insulating cylindrical container 2. The blade 5c rotates around the fulcrum part 5a as a fulcrum so that the tip ends are separated from and contacted with the closing stator 5b and the grounding stator 5d. As shown in FIG. 2, the disconnector 5 is operated by an operating mechanism 10 connected as a link mechanism, and is in an open position indicated by a solid line in FIG. It is stopped at any one of three positions, a ground position and a ground position in contact with the ground-side stator 5d.
[0012]
A side opening 2 e is formed in a side surface of the insulating cylindrical container 2. A flexible conductor 6 as a connection conductor for electrically connecting the movable terminal 3b as the second terminal conductor of the vacuum valve 3 and the fulcrum 5a of the disconnector 5 is connected to both via a side opening 2e. Have been. The flexible conductor 6 is made of a conductive material having flexibility, and is flexibly deformed as the vacuum valve 3 opens and closes. Inside the insulating cylindrical container 2, an insulating rod 7 for transmitting electric power for opening and closing the contacts of the vacuum valve 3 from the outside and simultaneously electrically insulating both ends is installed.
[0013]
As shown in FIGS. 3 and 4, the opening end 2 c of the insulating tubular container 2 on the side where the intermediate conductor 4 is arranged is formed so as to surround the intermediate conductor 4 in three directions. An insulating barrier portion 2d is provided. The first insulating barrier portion 2d extends outward from the opening end 2c of the main body 2a and is formed integrally with the main body 2a. The intermediate conductor 4 protrudes from the opening end 2c of the main body 2a by a predetermined length. The intermediate conductor 4 is surrounded in three directions by a first insulating barrier portion 2d protruding more than the protruding length. A first insulating barrier unit 2d, juxtaposed with horizontal barrier portion 2d ₁ for raising the breakdown voltage between the respective layers of the insulating tubular container 2, the vertical barrier portion 2d provided on the disconnector 5 side _{And 2} . Incidentally, on the side facing the vertical barrier portion 2d _2, to bus bar 11 to be described later is connected to an intermediate conductor 4 is provided, the barrier portion is not provided.
[0014]
Returning to Figure 1, extending length with respect to the main surface of the intermediate conductor 4 of the first insulating barrier portion 2d, i.e., when a substantial barrier height and A ₁ (wherein, the body of the first insulation barrier portion 2d extending length from 2a is a _{a 2), preferably,} a 1> 0 mm, more _preferably a a 1> 40 mm. This will be described later.
[0015]
Proceeding to FIG. 2, the intermediate conductor 4 is electrically connected to the lower bushing 12 by a bus bar 11. The closing stator 5b of the disconnector 5 is electrically connected by a bus bar 13 to upper bushings 14, 15, 16 provided on the upper surface of the sealed container 1. In addition, a grounding switch terminal 18 that is electrically connected to the grounding-side stator 5d is provided on a front wall surface of the support plate 1a.
[0016]
FIG. 6 is an enlarged view of the vicinity of the side opening 2 e of the insulating tubular container 2. In FIG. 6, the flexible conductor 6 is shown in cross section. The distance B between the flexible conductor 6 and the side opening 2e is preferably in the range of B = 15 to 30 mm, and more preferably B = 23 mm. This will be described later.
[0017]
The gas sealed in the sealed container 1 is air, dehydrated dry air, gas mixed with dry air, pure nitrogen gas, mixed gas of nitrogen and oxygen, mixed gas of nitrogen, oxygen and helium. , Pure sulfur hexafluoride gas, or a mixed gas of sulfur hexafluoride gas and nitrogen gas.
[0018]
In the hermetically closed switchgear having such a structure, the sealed container 1 is slightly deformed by the pressure of the sealed insulating gas, but the insulating cylindrical container 2 is erected on the support plate 1a serving as a positioning reference surface. Since the vacuum valve 3 and the disconnector 5 are fixed to the insulating cylindrical container 2, the positional relationship between the vacuum valve 3 and the disconnector 5 is accurately maintained. Further, since the vacuum valve 3 and the disconnector 5 are fixed by one insulating tubular container 2 formed of an insulating material, both are fixed in a state of excellent insulation and the number of parts is reduced. Cost can be reduced. Furthermore, since the insulating cylindrical container 2 is made of an insulating material such as an epoxy resin, for example, a cylindrical shape having high strength as in the present embodiment can be easily formed. . Therefore, the vacuum valve 3 and the disconnector 5 to which a large operation force is applied can be firmly supported.
[0019]
Since the insulating tubular container 2 has the first insulating barrier portion 2d which is erected at the open end 2c so as to surround at least a part of the periphery of the intermediate conductor and is formed integrally with the main body 2a, the insulating tubular container 2 A part of the container 2 performs the function of an insulating barrier, and there is no need to provide an insulating barrier as a separate member. This simplifies the internal structure of the switchgear, reduces the number of parts, and reduces costs. The breakdown voltage characteristic (insulation performance) around the intermediate conductor 4 can be further improved. Incidentally, the horizontal barrier portion 2d ₁ improves the breakdown voltage between the phases and between ground (heterophase between tracks adjacent) (between the sealed container 1 wall and path is the ground potential), whereas the vertical barrier portion 2d ₂ Is the dielectric breakdown voltage between the intermediate conductor 4 and the closing stator 5b (when the voltage is applied between the poles of the disconnector 5 when the blade 5c of the disconnector 5 is open and the vacuum valve 3 is closed). Breakdown voltage).
[0020]
For barrier height A ₁ described above will be described. An experiment was conducted on the relationship between barrier height and breakdown voltage using the simulated electrode shown in FIG. FIG. 7 shows the result. In FIG. 8, the simulation electrode has two bases 51 and 52 made of an insulating material. The two bases 51 and 52 are arranged side by side. Insulating barrier portions 51a and 52a are provided upright at the ends of the two opposing bases 51 and 52, and the two insulating barrier portions 51a and 52a are opposed to each other so as to be parallel to each other. The high-voltage electrode 53 is fixed on the base 51, and the ground electrode 54 is fixed on the base 52. The simulated electrode was placed in a sealed container, and the breakdown voltage was measured while changing the barrier height A ₁ (the height from the main surface of the high-voltage electrode 53) and the barrier height A ₂ . The gas to be sealed in the sealed container was obtained by pressurizing the atmosphere or pressurizing air from which water had been removed, and the gas pressure range was 0.1 to 0.2 MPa (absolute pressure). In this experiment, the high-voltage electrode 53 corresponds to the intermediate conductor 4, the ground electrode 54 corresponds to the adjacent intermediate conductor 4, and the insulating barrier portions 51 a and 52 a correspond to the horizontal barrier portions of the adjacent insulating cylindrical containers 2. corresponds to the 2d _1. It is known from other experiments that the measured breakdown voltage does not depend on the distance between the opposing insulating barrier portions 51a and 52a.
[0021]
6, the insulating barrier portion 51a, when the height of the 52a is higher than the height of the test electrodes 53 and 54, that is, when substantially the barrier height _{A 1} is _A 1> 0 mm, if the barrier is not _(A 1 = 0 mm), the breakdown voltage increases at any gas pressure. Even when A ₁ = 0 mm, the breakdown voltage of 0.15 MPa ₁ is higher than that of A ₁ = 0 mm, but does not increase at other gas pressures. From this result, it can be seen that even when the insulating barrier portions 51a, 52a are lower than the heights of the test electrodes 53, 54, the insulating barrier portions 51a, 52a have a discharge progress inhibiting ability and have a breakdown voltage increasing effect. However, it can be understood from FIG. 6 that when A ₁ = 0 mm, a significant breakdown voltage increasing effect is not always obtained. Thus, if A ₁ > 0 mm, the breakdown voltage between the intermediate conductor 4 and the ground of the wall surface of the sealed container 1, between different phases of the intermediate conductor 4, and between the intermediate conductor 4 and the closing-side stator 5 b. Can be assuredly increased. This is the reason that A ₁ > 0 mm is preferable.
[0022]
Further from Figure 6, the increase in breakdown voltage _is seen to exhibit a 0 <A 1 <40Mmmadewajoshosuruga,A _1> 40 mm in saturation tendency. This indicates that increasing the height of the insulating barrier more than necessary does not contribute to an increase in breakdown voltage. In other words, if A ₁ > 40 mm, the maximum breakdown voltage increasing effect can be effectively obtained. This is the reason that it is more preferable if A ₁ > 40 mm.
[0023]
Next, the distance B between the above-described flexible conductor 6 and the insulating cylindrical container 2 (side opening 2e) will be described. The experiment was conducted by placing the simulated electrodes shown in FIGS. 10 and 11 in a sealed container. The result is shown in FIG. When the breakdown voltage between phases was evaluated, the simulation electrode of FIG. 10 was used, and when the breakdown voltage between grounds was evaluated, the simulation electrode of FIG. 11 was used. In FIG. 10, the high-voltage electrode 62 corresponds to the flexible conductor 6, the ground electrode 63 corresponds to the adjacent flexible conductor 6, and the intermediate insulating plate 61 sandwiched between the two insulating cylindrical containers. 2 and the space between them. Here, as two adjacent insulating cylindrical containers 2 and a space between them, two conductors are arranged so as to be closer to the real thing, and one conductor 61 is arranged like this simulated electrode. Other experiments have shown that they are functionally and operationally the same. The gas sealed in the sealed container was obtained by pressurizing the atmosphere or pressurizing air from which water had been removed, and the gas pressure was 0.15 MPa.
[0024]
FIG. 9 shows that when the distance B is increased or decreased within a predetermined range, the breakdown voltage has a peak in this range, and the maximum breakdown voltage is obtained at about B = 23 mm. Compared with the case where the distance B is 0 mm, the effect of increasing the breakdown voltage is clearly observed between the ground and the ground in the range of B = 15 to 30 mm. Although the ascending effect is observed in a slightly wider range between phases, the range observed both between the phases and the ground may be approximately B = 15 to 30 mm. For this reason, setting the distance B to 15 to 30 mm is a preferable distance for effectively increasing the breakdown voltage between the flexible conductor 6 and the ground of the wall surface of the sealed container 1 and between different phases of the flexible conductor 6. It turns out that. Further, it can be said that setting the distance B to 23 mm is more preferable in that the breakdown voltage can be increased most greatly.
[0025]
Here, the reason why a peak appears in the breakdown voltage in the above-described experiment can be considered as follows. FIG. 12 is a model of the insulation barrier effect. In the figure, a case where a positive voltage is applied to the high voltage electrode side and the low voltage side is the wall surface of the sealed container 1 is taken as an example. When a voltage is applied to the high-voltage electrode, corona discharge starts from the tip of the high-voltage electrode, and corona discharge charges are accumulated in the space up to the insulating barrier. However, due to the presence of the insulating barrier, the progress of discharge toward the ground electrode is suppressed, and the charge generated by the corona discharge spreads and accumulates on the barrier surface around the rod electrode axis. The charge density on the barrier surface will be somewhat uniform if the distance between the barrier and the high voltage electrode is appropriate. As a result, the barrier itself has a role as one plate electrode, and approaches a quasi-equivalent electric field barrier between the barrier and the plate electrode. Even if the gap length is the same, the breakdown voltage of the unequal electric field gap and the quasi-equal electric field gap increases, so that the insertion of the insulating barrier increases the breakdown voltage.
[0026]
However, if the barrier is too close to the high voltage electrode, the corona discharge charge cannot spread with a uniform charge density on the barrier surface, and the inequality of the electric field is not sufficiently reduced. As a result, it is considered that the rise of the breakdown voltage was small, and the characteristic as shown in FIG. 9 was obtained.
[0027]
As described above, in the present embodiment, the substantial barrier height A ₁ of the insulating barrier around the intermediate conductor 4 is preferably A ₁ > 0 mm, more preferably A ₁ > 40 mm, and the flexible conductor 6 and the insulating cylinder The distance B to the wall of the container 2 is preferably B = 15 to 30 mm, and more preferably B = 23 mm, so that a gas-insulated switchgear having a high ground-to-ground and phase-to-phase breakdown voltage, particularly a new insulating barrier and its support It can be realized without using any material. Here, the type of gas sealed in the sealed container 1 is air, dehydrated dry air, gas mixed with dry air in the atmosphere, pure nitrogen gas, mixed gas of nitrogen and oxygen, and mixed gas of nitrogen, oxygen and helium. Gas, pure sulfur hexafluoride gas, or a mixed gas of sulfur hexafluoride gas and nitrogen gas. These gases have been confirmed to have an insulating barrier effect, and an increase in the breakdown voltage due to the grounding of the insulating barrier in the present embodiment can be expected.
[0028]
Embodiment 2 FIG.
FIG. 13 is a perspective view of an insulated cylindrical container of the closed type switchgear according to Embodiment 2 of the present invention. FIG. 14 shows a cross-sectional view of the insulating tubular container at a position where a side opening is provided, with a flexible conductor added. In the present embodiment, the insulating cylindrical container 22 is provided on the edge of the side opening 2e so as to surround at least a part of the periphery of the flexible conductor 6, and is formed integrally with the main body 2a. It has a barrier portion 2h.
[0029]
When the disconnecting switch 5 is installed outside the insulating tubular container 2, a second insulating barrier section 2h surrounding the connection conductor 6 for electrically connecting the vacuum valve 3 and the disconnecting switch 5 is provided. Thereby, the breakdown voltage characteristics around the connection conductor 6 can be improved.
[0030]
As shown in Figure 14, the second insulating barrier portion 2h, a height as viewed from the inside of the insulating tubular container 2 is D _2. In particular, when the difference in height between the flexible conductor 6 and _{D 1,} it is preferable that the D 1> 0 mm. More preferably, D ₁ > 40 mm. At the same time, in the present embodiment, the shortest distance B between the flexible conductor 6 and the second insulating barrier portion 2h is preferably in the range of B = 15 to 30 mm, and more preferably B = 23 mm.
[0031]
The effect of the structure of the second embodiment is that an insulating barrier effect is also provided around the flexible conductor 6. The experimental study results of the insulation barrier effect are as described in FIG. This is the reason, substantially the height _{D 1} of the second insulation barrier unit _2h, D 1> 0 mm are preferred, more preferably a _D 1> 40 mm. As a result, the breakdown voltage of the insulation between the ground and the insulation between the phases generated from the flexible conductor 6 as a starting point can be increased.
[0032]
Further, as described with reference to FIG. 9, the breakdown voltage changes so as to have a peak around the flexible conductor 6 with respect to the change in the distance B. For this reason, B is preferably in the range of 15 to 30 mm, and more preferably B = 23 mm. Substantial height D ₁ on set as described above, by optimizing the distance B, the breakdown voltage of the department by the synergistic effect is dramatically increased.
[0033]
【The invention's effect】
The closed-type switchgear according to the present invention is made of an insulating material and a disconnecting container and a vacuum valve for each phase which are arranged in parallel to each other, a disconnecting container and a vacuum valve that house the disconnecting device and the vacuum valve, and in which an insulating gas is sealed. An insulating tubular container having a substantially cylindrical main body, standing upright on a predetermined support surface in a sealed container, accommodating a vacuum valve inside the main body, and supporting a disconnector on an outer portion of the main body; An intermediate conductor provided at an open end opposite to the support surface of the main body of the container, electrically connected to the first terminal conductor of the vacuum valve, and fixing the vacuum valve in the insulating cylindrical container. The insulating tubular container has a first insulating barrier portion erected at an open end so as to surround at least a part of the periphery of the intermediate conductor and formed integrally with the main body. For this reason, it is possible to improve the insulation performance and at the same time reduce the number of components, thereby achieving cost reduction.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part of a closed-type switching device according to Embodiment 1 of the present invention.
FIG. 2 is a cross-sectional view showing the entire closed-type opening / closing device according to Embodiment 1 of the present invention;
FIG. 3 is a perspective view of the insulating tubular container according to the first embodiment of the present invention.
FIG. 4 is a view of the insulating cylindrical container of FIG. 3 as viewed from an open end side.
FIG. 5 is a perspective view showing a state in which the three-phase insulating cylindrical containers of the first embodiment are juxtaposed.
FIG. 6 is an enlarged view of the vicinity of a side opening of the insulating tubular container of the first embodiment.
FIG. 7 is a correlation diagram showing a relationship between a substantial barrier height and a breakdown voltage.
FIG. 8 is an explanatory diagram showing a simulation electrode used to obtain the result of FIG. 7;
FIG. 9 is a correlation diagram showing a relationship between a distance between a flexible conductor and an insulating cylindrical container and a breakdown voltage.
FIG. 10 is an explanatory view showing a simulated electrode used for obtaining a result regarding a breakdown voltage between phases in FIG. 9;
FIG. 11 is an explanatory view showing a simulation electrode used for obtaining a result regarding a breakdown voltage between the ground and the ground in FIG. 9;
FIG. 12 is a diagram showing a model of an insulating barrier effect.
FIG. 13 is a perspective view of an insulated tubular container of the hermetically closed switchgear according to Embodiment 2 of the present invention.
FIG. 14 is a diagram showing a cross-sectional view of the insulating tubular container according to Embodiment 2 of the present invention at a position where a side opening is provided, with a flexible conductor added.
[Explanation of symbols]
Reference Signs List 1 sealed container, 1a support plate (support surface), 2 insulating tubular container, 2a main body, 2b flange portion, 2c open end portion, 2d first insulating barrier portion, 2d ₁ horizontal barrier portion, 2d ₂ vertical barrier Part, 2e side opening, 2f female screw hole, 2h second insulating barrier part, 3 vacuum valve, 3a fixed terminal (first terminal conductor), 3b movable terminal (second terminal conductor), 4 intermediate conductor, 5 disconnection Vessel, 5a fulcrum, 5b closing-side stator, 5c blade, 5d grounding-side stator, 6 flexible conductor (connection conductor), 7 insulating rod, 11 busbar, 12 lower bushing, 13 busbar, 14, 15, 16 Upper bushing, 18 ground switch terminal, 22 insulated cylindrical container.

Claims (5)

Disconnectors and vacuum valves for each phase, which are arranged in parallel with each other,
The disconnector and the vacuum valve are housed, a sealed container filled with an insulating gas, a substantially cylindrical body made of an insulating material, and is erected on a predetermined support surface in the sealed container. An insulating tubular container that accommodates the vacuum valve inside the main body and supports the disconnector on the outside of the main body,
The insulating tubular container is provided at an open end of the main body opposite to the support surface, is electrically connected to a first terminal conductor of the vacuum valve, and connects the vacuum valve to the insulating cylindrical container. With an intermediate conductor fixed inside,
The hermetically sealed tubular container has a first insulating barrier portion erected at the opening end so as to surround at least a part of the periphery of the intermediate conductor and integrally formed with the main body. Type switchgear. The insulating tubular container has, on the side surface of the main body, a side opening through which a connection conductor that electrically connects the second terminal conductor of the vacuum valve and the disconnector is formed,
The insulating tubular container has a second insulating barrier portion which is erected on an edge of the side opening so as to surround at least a part of a periphery of the connection conductor and is formed integrally with the main body. The closed-type opening / closing device according to claim 1. 3. The hermetic switchgear according to claim 1, wherein a length of the first insulating barrier extending from the opening end is longer than a length of the intermediate conductor projecting from the opening end. . The hermetically closed switchgear according to claim 2, wherein a distance between the connection conductor and the side opening edge is 15 mm to 30 mm. The insulating gas sealed in the sealed container is air, dehydrated dry air, a gas in which dry air is mixed with the atmosphere, pure nitrogen gas, a mixed gas of nitrogen and oxygen, a mixed gas of nitrogen, oxygen, and helium, 5. The closed-type switchgear according to claim 1, wherein the device is one of pure sulfur hexafluoride gas and a mixed gas of sulfur hexafluoride gas and nitrogen gas.

Images