JP2008259262A - Switchgear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a compact gas insulated switchgear in which the occurrence of failure is retarded by simplifying the structure of the switchgear and the failed part can be repaired easily. <P>SOLUTION: In the switchgear, bushings 2, 4 and 7 to be connected, respectively, with a bus 3, a cable head 5 and a switch 11 are attached, respectively, to the wall faces 1a, 1b and 1c of an enclosed tank 1 filled with insulating gas while penetrating the wall faces. The bushings 2, 4 and 7 to be connected, respectively, with the bus 3, the cable head 5 and the switch 11 are connected electrically by first and second connection conductors 9 and 10, and the switch 11 is disposed movably to touch the bushing 7 and to separate therefrom so that the main circuit is disconnected by drawing out the switch 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power switchgear, and more particularly to a switchgear using an insulating gas as an insulating medium.

  In the conventional switchgear, the circuit breaker is configured to be fixed in a sealed tank filled with an insulating gas (see, for example, Patent Document 1).

JP 2004-153953 A (page 4-5, FIG. 1)

In the conventional switchgear, storage main circuit devices such as a circuit breaker / disconnector having a movable part and a ground switch are installed in a sealed tank filled with an insulating gas. In this case, if a device installed in the sealed tank breaks down, the insulating gas in the sealed tank is recovered, then the sealed tank is opened to repair the internal device, and then the insulating gas is put into the sealed tank again. There is a problem that, when the storage device has once failed, a large amount of man-hours are required for collecting and refilling the insulating gas, such as restarting the operation after sealing the container.
There is also a method to reduce the failure frequency of the storage main circuit equipment to reduce the man-hours required for repair. However, to reduce the failure frequency of the storage main circuit equipment, it is necessary to improve the material quality and processing accuracy of the parts. Therefore, there is a problem that the manufacturing cost increases.
Furthermore, since the main circuit device set is built in the closed tank, there is a problem that the size of the closed tank increases and the apparatus becomes larger.

  The present invention has been made in order to solve the above-described problems, and a first object is to simplify the configuration of the switchgear so that the failure hardly occurs and can be easily repaired even if a failure occurs. A switchgear is obtained.

  A second object of the present invention is to obtain an opening / closing device with improved safety.

  In the switchgear according to the present invention, the bushing connecting to the busbar / cable and the switch is respectively attached to each wall surface of the sealed tank filled with the insulating gas, and connected to the busbar / cable and the switch, respectively. The bushings are electrically connected to each other, and the switch is movably disposed so as to be able to contact and separate from the bushings, so that the main circuit is disconnected at the time of dissociation.

In the present invention, the disconnecting device can be omitted because the disconnecting function is provided by disposing the switch so as to be movable outside the sealed tank and to be able to contact and separate from the main circuit in the sealed tank.
In addition, by arranging the switch so that it can be moved out of the closed tank, even if a switch with many moving parts breaks down, it is not necessary to collect and refill the insulating gas in the closed tank. Since the switch can be repaired by pulling it out of the switchgear, a switchgear that can be easily repaired can be obtained.

Embodiment 1 FIG.
1 and 2 show a switchgear according to Embodiment 1 for carrying out the present invention. FIG. 1 shows a disconnection state of a branch main circuit, and FIG. 2 shows a connection state of the branch main circuit. Is. 1 shows a side sectional view of a one-branch circuit, and a plurality of the opening / closing devices are juxtaposed in the paper plane direction of FIG. 1 to constitute a set of opening / closing devices.
In FIG. 1, a bus bar connecting bushing 2 is attached through an upper wall 1 a (first wall surface) of a sealed tank 1 filled with an insulating gas. The horizontal bus 3 includes an insulating bus 3a extending in the horizontal direction (perpendicular to the paper surface) (a bus that covers the outer periphery of the bus conductor with an insulator), and a connector portion 3b provided at a branch location for each branch circuit. The connector part 3b is connected to the horizontal busbar connection bushing 2 to electrically connect the branch main circuits.
A cable connecting bushing 4 is attached through the rear wall 1b (second wall surface) of the sealed tank 1 in an airtight manner, and a cable head 5 attached to an end of a cable (not shown) is connected. An annular current transformer 6 is mounted on the outer periphery of the cable connecting bushing 4 between the cable head 5 and the rear wall 1b.

A switch connecting bushing 4 is attached airtightly through the front wall 1c (third wall surface) of the sealed tank 1, and a connecting portion 8 is provided at the tip of the switch connecting bushing 7.
In FIG. 1, the upper and lower sets of switch connecting bushings 7 are, for convenience of description, the first switch connecting bushing 7a on the upper side and the second switch connecting bushing 7b on the lower side.
The bushings 2, 4, and 7 are provided with flange portions (not shown) that are molded around the through conductors with an insulator such as epoxy and can be attached to the through portions of the walls 1a, 1b, and 1c.
In the sealed tank 1, the first connecting conductor 9 electrically connects the end of the bus connection bushing 2 and the upper switch connection bushing 4 with the end of the cable connection bushing 4. The ends of the lower switch connection bushing 4 are electrically connected by the second connection conductor 10. In FIG. 1, the switch connecting bushing 4 mounted in two upper and lower stages is divided into two parts by dividing the connection conductor composed of the first connection conductor 9 and the second connection conductor 10 when viewed from the entire branch main circuit. It is in a state.
The bus tank 2 for connecting the bus, the bushing 4 for connecting the cable, the bushing 7 for connecting the switch, the first connecting conductor 9 and the second connecting conductor constituting the main circuit for branching in the closed tank 1 and the closed tank 1. A unit consisting of 10 is called a branch unit 14. The branch unit 14 is so called because it is connected to the bus in a branch shape. Functionally, the branch unit 14 is connected to an external power source (not shown) to supply power to the bus 3, and a load (see FIG. (Not shown) to supply power from the bus 3 to the load.

In FIG. 1, a switch 11 having wheels 11a is arranged on the right side of the connecting portion 8 so as to be movable in the front-rear direction of the switchgear (left-right direction in FIG. 1). In FIG. 1, since the switch 11 is moved rightward, the contact 11 b of the switch 11 is disengaged from the connection portion 8. As a result, the bus connection bushing 2 to the cable connection The branch main circuit between the bushings 4 is in a disconnected state.

In addition, the switch 11 is surrounded by a switch storage box 12 to prevent the main circuit around the switch 11 from being contaminated, and to prevent the maintenance staff from touching the main circuit. Is secured. When the switch 11 is inspected or when the switch 11 breaks down, the door 13 provided on the front surface of the switch storage box 12 is opened to check the switch 11, or to the outside of the switch device. 11 Take out and repair.
FIG. 2 shows a state in which the switch 11 shown in FIG. 1 is moved leftward to connect the connecting portion and the contact 11b. In FIG. 2, the branch main circuit between the bus connection bushing 2 and the cable connection bushing 4 is in a connected state.

  In the first embodiment, the bus line is arranged outside the sealed tank 1 and connected to the main circuit in the sealed tank 1 via the bus bar connection bushing 2. However, the second wall surface of the branch unit 14 is described. A cable connecting bushing 4 is attached to 1b, a first switch connecting bushing 7a and a second switch connecting bushing 7b are attached to the third wall surface 1c, and a plurality of branch units 14 juxtaposed in the lateral direction communicate with each other. The bus 11 is arranged inside the branch unit 14, the bus 11 is connected to the first switch connection bushing 7a, and the cable connection bushing 4 is connected to the second switch connection bushing 7b. , A switch 11 that is detachably disposed at the connection portion 8 at each end of the first and second switch connection bushings 7a, 7b. It may be.

In the first embodiment, the main circuit for branching has been described in a single-phase form. However, in a normal switchgear, main circuits for three phases for three phases are juxtaposed in the depth direction of the drawing.
In the first embodiment, the switch having a switching function has been described as a generic switch. However, in a normal switching device, a circuit breaker such as a vacuum circuit breaker, a gas circuit breaker, or an air circuit breaker is used. The However, a normal switch having no blocking function, for example, a load switch, a disconnect switch, a contactor, or the like may be used.
Furthermore, in the description of the first embodiment, the insulating medium in the sealed tank 1 is an insulating gas, but this insulating gas may be carbon dioxide gas, argon gas, nitrogen gas, dry air, etc. in addition to SF ₆ gas. Applicable.

In the first embodiment as described above, the switch 11 can have a disconnect function by disposing the switch 11 so as to be movable outside the sealed tank 1 and to be able to contact and separate from the main circuit in the sealed tank 1. I can do it. As a result, it is possible to omit a disconnector that has a large number of movable parts and is likely to cause a failure, thereby simplifying the configuration of the switchgear. Moreover, since the space volume in the sealed tank 1 necessary for equipment storage can be reduced by eliminating the need for a disconnector, the sealed tank 1 can be made smaller, the manufacturing cost can be reduced, or the switchgear can be made compact. Can be made.
Further, by disposing the switch 11 having many movable parts that are likely to fail, outside the sealed container 1, even if the switch 11 fails, the work of collecting and refilling the insulating gas in the sealed tank 1 is performed. It is possible to repair the switch 11 by pulling it out of the switchgear without performing the maintenance, and the maintenance work becomes extremely easy.

Embodiment 2. FIG.
3 and 4 show the switchgear according to Embodiment 2 for carrying out the present invention. FIG. 3 shows a disconnection state of the branch main circuit, and FIG. 4 shows a connection state of the branch main circuit. Is. 3 shows a side sectional view of a one-branch circuit, and a plurality of the opening / closing devices are juxtaposed in the paper plane direction of FIG. 1 to constitute a set of opening / closing devices.
3 and FIG. 4, the same reference numerals as those in FIG. 1 and FIG. 2 are the same as or equivalent to those in FIG. 1 and FIG.
In the first embodiment, the tip of the switch connection bushing 7 protrudes toward the switch storage box 12, but the switch connection bushing 15 of FIG. 3 is made of an insulator such as epoxy. The connection part 8 connected to the connection conductors 9 and 10 in the sealed tank 1 is provided at the bottom of the basket. In FIG. 3, for convenience of explanation, the upper and lower sets of switch connection bushings 15 are the first switch connection bushing 15U on the upper side and the second switch connection bushing 15L on the lower side.

FIG. 5 shows an enlarged side sectional view of the switch connecting bushing 15 shown in FIG. The switch connecting bushing 15 formed in a bowl shape has a bowl recess 15a inserted into the sealed tank 1 from the opening of the front wall 1c, and the front wall 1c by a flange 15b formed around the opening of the bowl. Although not shown in the figure, the fastening part such as a bolt is fixed again. A seal groove is formed on the contact surface of the front wall 1c of the flange 15b, and an O-ring or a viscous seal member is attached.

  A shutter 16 that can be moved up and down is disposed on the front side of the opening of the switch connecting bushing 15. In the disconnection state in which the switch 11 shown in FIG. 3 is pulled out, the switch moves to the front side of the opening of the switch connection bushing 15 and closes the opening of the switch connection bushing 15. In addition, when the switch 11 is moved to the left and the switch 11 is connected as shown in FIG. 4, the shutter 16 moves upward and downward in conjunction with the movement of the switch 11 to the left. The front side of the opening of the connection bushing 15 is opened, and the contact 11 b of the switch 11 is inserted into the recess 15 a of the switch connection bushing 15 and connected to the connection 8.

By adopting a configuration in which the switch connecting bushing 15 is inserted in the closed tank 1 in the shape of a bowl, there is no protrusion of the switch connecting bushing 7 toward the switch storage box 12, and therefore the switch storage box 12 The depth dimension L can be reduced.
Further, since the recess 15a of the switch connection bushing 15 is disposed in the sealed tank 1 and the front side of the opening is shielded by the shutter 16 that can move up and down, the depth dimension L of the switch storage box 12 Therefore, a safe switchgear that does not allow the maintenance staff to approach the charging unit can be obtained.

Embodiment 3
FIG. 6 shows a connection state of the switchgear according to Embodiment 3 for carrying out the present invention, and shows a switchgear in which the switches 11 are stacked in two stages. In FIG. 6, the same reference numerals as those in FIGS. 3 and 4 are the same as or equivalent to those in FIGS.
In FIG. 6, the bus bar 3 extending in the horizontal direction is accommodated in the intermediate sealed tank 1 d, and the bus bar 11 and the switch connection bushing 15 are electrically connected by the first connection conductor 9. . Two sets of switch connection bushings 15 are arranged on the front wall 1c of the intermediate sealed tank 1d in a vertically separated manner.
An upper closed tank 1e is arranged on the upper side of the intermediate closed tank, a switch connecting bushing 15 is mounted on the front wall 1c, and the cable connecting bushing 4 is mounted on the rear wall 1b. The bushing 4 and the switch connection bushing 15 are electrically connected by a second connection conductor. This unit is referred to as an upper branch unit 14a.
A lower sealed tank 1f is disposed below the intermediate sealed tank, and a switch connection bushing 15 is mounted on the front wall 1c in the same manner as the upper branch unit 14a, and the cable connection bushing 4 is mounted on the rear wall 1b. , And the cable connecting bushing 4 and the switch connecting bushing 15 are electrically connected by a second connecting conductor. This unit is referred to as a lower branch unit 14a.

The upper switch 11 is disposed so as to be able to contact and separate across the switch connecting bushing 15 of the upper sealed tank 1d and the switch connecting bushing 15 of the intermediate sealed tank 1d. Further, the lower switch 11 is disposed so as to be able to contact and separate across the switch connecting bushing 15 of the lower sealed tank 1f and the switch connecting bushing 15 of the intermediate sealed tank 1d.
As described above, the installation area of the entire switchgear can be reduced by stacking the switches in two stages. Furthermore, by connecting / disconnecting the branch main circuit by connecting / disconnecting the switch 11 across the branch units 14a, 14b, it penetrates between the sealed tanks 1 of the branch units 14a, 14b. Since it is not necessary to connect the main circuit, the configuration is simplified and the manufacture is facilitated.
Further, the switch 11 is arranged so that it can be pulled out. When the switch 11 is pulled out, the connecting portion 8 and the contact 11b are dissociated, and the branch main circuit is disconnected. Moreover, in this disconnection state, the shutter 16 moves to the closing position of the front opening of the switch bushing, thereby preventing maintenance personnel from approaching the charging unit.

  In the third embodiment, the bus 3 has the three-phase buses arranged in the vertical direction, so that the depth dimension of the sealed tank 1 can be reduced.

Embodiment 4
FIG. 7 shows a connection state of the switchgear according to Embodiment 4 for carrying out the present invention. 7 having the same reference numerals as those in FIG. 6 are the same as or equivalent to those in FIG. In FIG. 7, the bus 3 has the three-phase buses arranged in the front-rear direction so that the height of the sealed tank 1 can be reduced.

It is a sectional side view which shows the disconnection state of the switchgear which shows Embodiment 1 of this invention. It is a sectional side view which shows the connection state of the switchgear which shows Embodiment 1 of this invention. It is a sectional side view which shows the disconnection state of the switchgear which shows Embodiment 2 of this invention. It is a sectional side view which shows the connection state of the switchgear which shows Embodiment 2 of this invention. It is a sectional side view of the switch connection bushing of Embodiment 2 of this invention. It is a sectional side view which shows the connection state of the switchgear which shows Embodiment 3 of this invention. It is a sectional side view which shows the connection state of the switchgear which shows Embodiment 4 of this invention.

Explanation of symbols

1 Sealed tank 1a Upper wall (first wall)
1b Rear wall (second wall surface)
1c Front wall (third wall surface)
1d Middle closed tank 1e Upper closed tank 1f Lower closed tank 2 Bus connection bushing 3 Bus 4 Cable connection bushing 5 Cable head 7 Switch connection bushing 7a First switch connection bushing 7b Second switch connection Bushing 8 Connection portion 9 First connection conductor 10 Second connection conductor 11 Switch 11b Contactor 12 Switch housing box 14 Branch unit 15 Switch connection bushing 15a Recess 15b Flange 15U First switch connection bushing 15L Second switch connection bushing 16 Shutter

Claims (8)

A bus bar extending in the horizontal direction, a cable connected to a power source or a load, and an internal connection conductor that encloses an insulating gas inside the sealed tank and electrically connects the bus bar and the cable, respectively. A plurality of branch units juxtaposed in the horizontal direction, and a switch connected to the divided portion of the connection conductor divided in at least two in the extending direction to interrupt the circuit, The division unit is led out of the closed tank via a bushing to form a connection part, and the switch is arranged to be connected to and separated from the connection part of the bushing. The switchgear according to claim 1, wherein the switch is a circuit breaker. The bushing has a hook shape made of an insulating material, has a connecting portion disposed in the concave portion of the hook shape, and has a mounting flange around the opening, and the concave portion is inserted into the sealed tank. The switchgear according to claim 1, wherein the switchgear is mounted on a wall surface of the sealed tank. 4. The switchgear according to claim 3, further comprising a shutter that shields a front surface of the opening of the bushing when the switch is in a position disengaged from the connection part of the bushing. Install a bushing for busbar connection on the first wall surface, a bushing for cable connection on the second wall surface, a bushing for switch connection on the third wall surface of the branch unit, and connect the busbar from the outside of the branch unit to the busbar connection bushing. 2. The switchgear according to claim 1, wherein a cable head is connected to the cable connection bushing, and a switch is connected to the switch connection bushing so as to be able to contact and separate. The branch unit has a cable connection bushing on the second wall surface, and first and second switch connection bushings on the third wall surface. The branch unit is connected to a plurality of branch units juxtaposed in the horizontal direction. And connecting the busbar to the first switch connection bushing, connecting the cable connection bushing to the second switch connection bushing, and connecting the first and second switch connections. 2. The switchgear according to claim 1, wherein the switch is connected to the bushing so as to be able to contact and separate. An intermediate sealed tank that has a busbar inside and is electrically connected to the busbar. The intermediate sealed tank is installed on the side wall, and the switch is connected to one side wall above and below the intermediate sealed tank. An upper sealed tank and a lower sealed tank having a bushing and a cable connecting bushing electrically connected to the switch connecting bushing on the other side wall, the switch connecting bushing of the upper sealed tank and the intermediate The upper switch placed so as to be able to contact / separate across the bushing for connecting the switch of the closed tank, the switch connecting bushing of the lower closed tank, and the switch connecting bushing of the intermediate sealed tank can be connected / separated The switchgear according to claim 1, further comprising a lower switch disposed. Insulating gas, SF ₆ gas, carbon dioxide gas, argon gas, nitrogen gas, switchgear according to any one of claims 1 to 7, characterized in that it is dry air.

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