JP2005057944A - Gas-insulated switchgear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a gas-insulated switchgear that can cope with the uneven settlement of a foundation and safely perform installation even if the foundation is connected to a separated existing electric apparatus. <P>SOLUTION: The gas-insulated switchgear comprises a gas-insulated connecting bus bar that is movable in the horizontal direction, has bidirectional horizontal connecting directions, and comprises orthogonally arranged two connecting ports. The electric apparatuses at an existing installation side and an additional installation side are connected to the connecting ports by an expansion joint, and the expansion joint is restrained in movement to the direction where a bellows is extended. By such a constitution, two problems are solved that, (1) when an additional installation-side gas-insulated switchgear that is installed on a newly arranged different foundation is additionally installed to an existing installation-side electric apparatus that is installed on the foundation, the gas-insulated bus bar of an additional installation connecting part is damaged due to the mutual uneven settlements of the foundations, thus causing the risk of an insulation accident; and, (2) when the additional installation-side gas-insulated switchgear and the existing installation-side electric apparatus are connected by the expansion joint that is expandable and composed of the bellows for absorbing relative displacements of the both, the pressure of an insulating gas in a tank acts on the bellows, thus causing the risk that the breakage of the bellows results in gas leakage and insulation breakage. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a gas-insulated switchgear, and more particularly to a gas-insulated switchgear having an improved connection structure when connected to other electrical equipment installed on a different foundation.

In recent years, switchgears used in substations, power plants, etc., store the main circuit in a grounded container due to space reduction, environmental harmony, etc., and fill this grounded container with an insulating gas such as SF6 gas. Insulated so-called gas insulated switchgear has come into use.
However, there are many air-insulated switchgears that have been generally used in existing electrical equipment.

When a new gas-insulated switchgear is to be added and connected to these existing electrical devices, the conventional method of extension is as follows.
In other words, gas insulation bushings and gas insulation buses are installed on the foundation of the existing electrical equipment to connect to the newly installed gas insulated switchgear, and the gas insulated switchgear on the expanded side is installed on the newly installed foundation Like to do.

Therefore, since the foundations on the existing side and the extension side are separated, it is possible that the foundations of each other will sink unevenly due to earthquakes or secular changes.
Conventionally, a structure of a gas insulated switchgear that can cope with the case where there is a risk of uneven settlement on such a separated foundation is employed.

FIG. 8 shows a connection structure between a conventional gas-insulated switchgear adopting a structure for dealing with the unequal settlement and the existing electrical equipment.
In FIG. 8, 1 is a tank of a gas-insulated bus formed on an existing electrical device installed on an existing foundation B1, and 2 is a line L portion separated from the existing electrical device foundation B1. The tank of the gas insulation bus bar of the expansion side gas insulated switchgear provided on the other new foundation B2 so as to face the tank 1 of the existing side electrical equipment, 3 is the gas of the existing side and the expansion side This is a flexible joint that flexibly connects the tanks 1 and 2 of the insulated bus.

The flexible joint 3 includes an intermediate connection tank 4 and two expansion joints 5 and 6 connected to both ends of the connection tank 4 and made of bellows.
The connection tank 4 and the two expansion joints 5 and 6 are respectively formed with flanges 4a, 5a and 6a at both ends, and the flanges 5a and 6a at one end of the expansion joints 5 and 6 are bolted to the flanges 4a at both ends of the connection tank 4. The integral flexible joint 3 is formed by connecting with the nut 7.

  Furthermore, the flange 5a at the other end of the expansion joint 5 is a flange 1a formed at the end of the tank 1 of the existing electrical equipment, and the flange 6a at the other end of the expansion joint 6 is the tank 2 of the expansion side gas insulated switchgear. The flange 2a formed at the end is airtightly connected by a bolt and a nut 8, respectively.

The flanges 5a, 6a connected to the tanks 1, 2 of the expansion joints 5, 6 are formed larger than the diameters of the flanges 1a, 2a of the tanks 1, 2.
A stud 9 connects the flanges 5a and 6a facing the equipment side of the expansion joints 5 and 6 to prevent the entire flexible joint 3 from being bent.

  As shown in FIG. 9, the stud 9 is connected to the flanges 5 a and 6 a of the expansion joints 5 and 6 by forming a through hole 10 larger than the thickness of the stud 9 on the flange 5 a and 6 a side. 9, and further, nuts 12 are screwed into the flanges 5 a and 6 a at intervals with the washers 11 sandwiched between the flanges 5 a and 6 a at both ends of the stud 9.

  Accordingly, a gap G1 is formed between the inner surface of the through hole 10 and the outer peripheral surface of the stud 9, and gaps G2 and G3 are formed between the flanges 5a and 6a and the nut 12 on both sides. (For example, patent document 1).

  With such a configuration, the relative displacement between the tank 1 and the tank 2 along the axial direction X of the flexible joint 3 is absorbed by the expansion and contraction of the expansion joints 5 and 6 within the range allowed by the gap G2 + G3. .

The relative displacement between the tank 1 and the tank 2 along the direction Y perpendicular to the axis of the flexible joint 3 is absorbed within the range allowed by the gap G1.
As a result, the uneven settlement of the foundation between the existing electrical equipment and the expansion side gas insulated switchgear is dealt with.
JP-A-9-215134

  However, with such a configuration, the expansion and contraction of the expansion joints 5 and 6 in the axial direction X is not restricted within the range allowed by the gap G2 + G3. A load is generated to extend the expansion joints 5 and 6 along the axial direction X by the pressure. Conventionally, this load has been supported by a foundation by attaching fixed legs or the like to gas insulated buses connected to both sides of the flexible joint 3. However, if this gas pressure load is also a 550 kVGIS three-phase collective bus, if the gas sealed inside is about 0.4 MPa-g, it will be about 50 t, and a solid foundation is required to support it.

  If such a load is predicted from the beginning in a new property, it was possible to cope with it by designing and producing it to support the load. Such loads are often not assumed for the foundations on the side. For this reason, the bellows of the expansion joints 5 and 6 could not withstand the internal gas pressure, or could be damaged in some cases, and the internal insulating gas leaked out, leading to a serious dielectric breakdown accident.

  An object of the present invention is to solve the above problems and to obtain a gas-insulated switchgear that can cope with uneven settlement of a foundation and can be safely installed even when connected to an existing electrical device with a separated foundation. To do.

  In order to achieve the above-described object, the invention according to claim 1 is installed on an existing electrical device installed on one of at least two separated foundations on the other foundation, via an expansion joint. In the gas-insulated switchgear that is additionally connected to the existing electrical equipment, a gas-insulated connection bus having two connection ports that are movable in the horizontal direction and that are connected at right angles in two horizontal directions is disposed, Connect the existing electrical equipment to one connection port of the gas-insulated connection bus through an expansion joint made of bellows, and connect the gas insulation bus of the gas-insulated switchgear to the other connection port through an expansion joint made of bellows. The expansion joint is restricted from moving in the direction in which the bellows extends.

  According to this invention, even when the foundation of the existing electrical equipment and the foundation of the expansion side gas insulated switchgear sink unevenly, they are absorbed by the displacement of the expansion joint, and the force due to the pressure of the insulating gas in the bellows is expanded and contracted. Since the joint is restrained from moving in the direction in which the bellows extends, it can be suppressed.

  According to the present invention, the gas insulation is installed on the existing electrical equipment installed on one of the separated at least two foundations, and installed on the other foundation and connected to the existing electrical equipment via an expansion joint. In the switchgear, a gas-insulated connection bus having two connection ports which are movable in the horizontal direction and are connected at right angles in two horizontal directions is arranged, and one side of the gas-insulated connection bus is provided on the existing side Electrical equipment is connected through an expansion joint made of bellows, and the gas insulation bus of the gas insulated switchgear is connected to the other connection port through an expansion joint made of bellows, and the expansion joint is moved in the direction in which the bellows extends. Therefore, it is possible to obtain a gas-insulated switchgear that can cope with uneven settlement of the foundation and can be safely installed even when connecting to existing electrical equipment with a separated foundation. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description of the embodiment, the same parts as those of the conventional gas insulated switchgear shown in FIGS. 8 and 9 are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 1 is a plan view showing a first embodiment of the present invention, and FIG. 2 is a front view thereof. 1 and 2, reference numeral 20 denotes an L-shaped gas-insulated connection bus, which has two connection ports 21 and 22 whose connection directions are perpendicular to each other, and flanges 21a and 22a around the connection ports 21 and 22, respectively. Is formed.

  1 is a tank of a gas-insulated bus formed on an existing electrical device installed on an existing foundation B1, and 2 is a new foundation B2 separated from the foundation B1 of the existing electrical device by a line L portion. It is a tank of the gas insulated bus of the expansion side gas insulated switchgear that is installed in the existing side electrical equipment tank 1 and connected via the L-shaped gas insulated connection bus 20.

  The tank 1 and the L-type gas insulated connection bus 20 of the existing side electrical equipment, and the tank 2 and the L-type gas insulated connection bus 20 of the extension side gas insulated switchgear are respectively connected via expansion joints 5 and 6 as in the conventional case. It is connected.

  In the present embodiment, the connection between the stud 9 and the flanges 5a and 6a of the expansion joints 5 and 6 is performed in the direction A in which the bellows of the expansion joints 5 and 6 extend by the nut 23 and the washer 24, as shown in FIG. The flanges 5a and 6a are restrained so as to be prevented from moving.

  Further, a spherical washer 25 is interposed between the washer 24 and the flanges 5a and 6b, and the stud 9 and the flanges 5a and 6b are relatively moved in a direction Y that is perpendicular to the bellows axis and within the range G1 allows. The configuration is possible.

  As shown in FIG. 2, the fixing portion of the L-shaped gas insulated connection bus 20 to the extension side foundation B <b> 2 has a mounting seat 26 and a support 27 at the lower part of the L-shaped gas insulated connection bus 20. The pad 29 and the stainless steel plate 30 are arranged, and the pad 29 is made of a material that can be expanded and contracted in the horizontal direction. With this configuration, the L-shaped gas-insulated connection bus 20 is fixed in the vertical direction but is movable in the horizontal direction.

By setting it as the above structures, it can respond to the displacement to each direction accompanying the uneven settlement of a foundation in a foundation separation part.
That is, the displacement of the expansion joint 5 in FIG. 1 along the axial direction X is the displacement of the expansion joint 6 in the axial direction X, and the displacement of the expansion joint 5 along the direction Y perpendicular to the axial direction X is The displacement of the expansion joint 5 in the Y direction can be absorbed by the displacement of the expansion joints 5 and 6 in the Z direction perpendicular to the axial direction X.

  In addition, the expansion joints 5 and 6 restrain the movement of the bellows in the direction in which the bellows extends in the connecting portion between the flanges 5a and 6a and the stud 9, so that the load on the bellows due to the internal gas pressure load is reduced. This can suppress the damage of the bellows.

  In this way, in the first embodiment, it is possible to cope with unequal settlement of the basic division by absorbing in all directions, but the gas pressure load due to the internal gas is suppressed against the bellows. Can be installed safely.

Next, a second embodiment of the present invention will be described. FIG. 4 is a diagram showing a second embodiment of the invention. In FIG. 4, the two connection ports 21 and 22 of the L-shaped gas insulated connection bus 20 are connected to the expansion joints 5 and 6 and the detachable buses 31 and 32, respectively. Connected to tanks 1 and 2. Inspection windows 33 and 34 are provided on the detachable bus bars 31 and 32, and the inner conductors of the detachable bus bars 31 and 32 can be attached and detached by the inspection windows 33 and 34.
Therefore, the removable bus bars 31 and 32 can be easily removed by removing the internal conductors in the removable bus bars 31 and 32 through the inspection windows 33 and 34 and reducing the expansion joints 5 and 6.

  By adopting such a configuration, in addition to the effects of the first embodiment, by arranging the detachable buses 31 and 32, the expansion joints 5 and 6 are used, and the gas insulated switchgear in this part is used. Separation is possible. That is, it can be divided at the time of an accident or failure, and the restoration can be made quickly. At the time of assembling, it is possible to assemble this part finally after assembling the gas insulated switchgears on both sides. It can also be divided during local withstand voltage tests.

  Next, a third embodiment of the present invention will be described. FIG. 5 is a plan view showing a third embodiment of the present invention, and FIG. 6 is a side view thereof. In the present embodiment, instead of the L-shaped gas insulated connection bus 20, a vertical gas insulated bus 35 is arranged. The vertical gas insulated bus 35 is formed with connection ports 36 and 37 whose upper and lower positions and their connection ports face each other at right angles, and tanks 1 and 2 are connected to the connection ports 36 and 37 via expansion joints 5 and 6. Is connected.

  With such a configuration, in addition to the effects of the first and second embodiments, it is possible to change the height of the gas insulated bus at this portion, and the degree of freedom in the layout of the gas insulated switchgear is increased. Increase. Further, even if one expansion joint is arranged in a vertical portion between the two connection ports 36 and 37 of the vertical gas insulated bus 35, the same effect can be exhibited.

FIG. 7 is a plan view showing an overall configuration in which the gas-insulated switchgear according to the present invention is connected to the existing electrical apparatus.
As shown in FIG. 7, the expansion joint 5, the L-shaped gas insulation connection bus 20, the expansion joint 6, and the connection bus are connected to the gas insulation bus 1 through the connection bushing 36 and the connection bus 37 provided in the existing electrical equipment. 38, a disconnector 39, a circuit breaker 40, and a transformer 41. Further, the foundations B1 and B2 on the existing side and the extension side are separated at the portion of the gas insulated bus 1.

In the description of the above embodiment, the case where the L-type gas insulated connection bus 20 is positioned on the base B2 on the extension side is illustrated. However, the present invention is not limited to this, and the L-type gas insulated You may make it arrange | position the connection bus 20 on the foundation B1 of the existing side positionally.
Furthermore, the present invention can be implemented in either a three-phase collective gas insulated switchgear or a single-phase gas insulated switchgear.

The top view which shows the 1st Embodiment of this invention. The front view which shows the 1st Embodiment of this invention. The principal part enlarged view of FIG. The top view which shows the 2nd Embodiment of this invention. The top view which shows the 3rd Embodiment of this invention. The front view which shows the 3rd Embodiment of this invention. The top view which shows the whole layout of the gas insulated switchgear by this invention. The top view which shows the connection part of the conventional gas insulated switchgear and the existing electrical apparatus. The principal part enlarged view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Gas insulated bus tank of the existing side electric equipment, 2 ... Gas insulated bus tank of the extension side gas insulated switchgear, 3 ... Flexible joint 5, 6 ... Expansion joint, 5a, 6a ... Flange, 9 ... Stud, G1 G2, G3: Gap, 12 ... Bolt, 20 ... L-type gas insulated bus, 21, 22 ... Connection port, 25 ... Spherical washer, 31, 32 ... Detachable bus, 33, 34 ... Inspection window, 35 ... Vertical gas Insulated busbar.

Claims (5)

  In a gas insulated switchgear that is installed on the other side of the existing electrical equipment installed on one of the separated two foundations and connected to the existing electrical equipment via expansion joints in the horizontal direction The gas-insulated connection bus having two connection ports arranged at right angles in two horizontal directions is arranged, and an existing electrical device is formed of a bellows at one connection port of the gas-insulated connection bus. An expansion joint is connected, and the gas-insulated switchgear of the gas-insulated switchgear is connected to the other connection port via an expansion joint made of a bellows, and the expansion joint is restrained from moving in the direction in which the bellows extends. A gas insulated switchgear characterized by the above.   2. The gas insulation according to claim 1, wherein a detachable bus bar that can be separated from the existing electrical equipment or the gas insulated bus bar is provided by shrinking the expansion joint between the connection port of the gas insulated connection bus bar and the expansion joint. Switchgear.   A stud that connects the flanges formed at both ends of the expansion joint is provided, and the movement of the expansion joint in the extending direction is restricted by a nut attached to the flange outer portion of this stud. 2. The gas insulated switchgear according to claim 1, wherein the gas insulated switchgear has a shape.   The gas-insulated switchgear according to claim 1, wherein the two connection ports of the gas-insulated connection bus are arranged at right angles in the horizontal direction and are displaced in the vertical direction. 5. The gas insulated switchgear according to claim 4, wherein one of the expansion joints is disposed in a vertical portion of the gas insulated connection bus.

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