JPH11122730A - Gas insulated switch device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a small size and low cost gas insulated switch device which can prevent excessive stress due to thermal expansion and compression. SOLUTION: An upper connecting portion 7a of a left circuit breaker 7 is connected in straight with a first branching circuit 31, and a second branching circuit 32 is located at the lower side of the first branching circuit 31 to connect in straight with the lower connecting portion 7a of a right circuit breaker 7. A vertical circuit breaker 7 is fixed so that the circuit breakers 35, 36 may be moved in the right and left direction. Those which are opposed with each other among respective two disconnecting devices 35 and 36 are connected with a flexible joint 40. When the disconnecting devices 35 and 36 opposed to each other are relatively moved in the right and left directions, the flexible joint 40 deforms to prevent excessive stress. Propelling force by the pressure of insulation gas working on both disconnecting devices 35, 36 opposed to each other is canceled with a time rod 42. A contact device can be completed without using a expansive and large size expanding and compressing device such as pressure balancing bellows or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a gas insulated switchgear.

[0002]

2. Description of the Related Art FIG. 7 is a side view of a conventional gas insulated switchgear disclosed, for example, in Japanese Utility Model Laid-Open No. 5-4710. In the figure, 1 is a first main bus, 1A, 1B, 1C
Are the A-phase, B-phase, and C-phase buses of the first main bus 1, 2 are the second main buses, 2A, 2B, and 2C are the A-phases and B of the second main bus 2.
Phase, C phase bus. These extend parallel to each other and horizontally in a direction perpendicular to the plane of the drawing.

The first and second main buses 1 and 2 are separated from the first and second main buses 2 by a first main bus 1 and a second main bus 2, respectively. And a second branch bus. In FIG. 7,
Each A-phase bus 3A, 4A of the first and second branch buses 3, 4
Is visible. 5 is a first disconnector connected to the first branch bus 3, and 6 is a second disconnect bus 4 and the first disconnector 5
7 is a circuit breaker connected to the second disconnector 6, and 8 is a third circuit breaker connected to the circuit breaker 7.
It is a disconnector. The two circuit breakers 7 on both sides of the branch buses 3, 4 are firmly fixed to the foundation.

[0004] 9 is a cable head tank, 10 is a first current transformer provided between the second disconnector 6 and the circuit breaker 7, 1
1 is a second current transformer provided between the right circuit breaker 7 and the third disconnector 8 in the figure, and 12 is provided between the left circuit breaker 7 and the cable head tank 9. A third current transformer. 13 is a cable head, 14 is a cable. 1
5 is a lightning arrester and 17 is a bushing, which is connected to a transmission line 18.

[0005] By the way, in a gas insulated switchgear for high voltage, the device itself becomes large. In addition, it has a large current carrying capacity and must withstand high temperatures. For this reason,
The amount of thermal expansion and contraction of the container constituting the device increases, and it cannot be dealt with only by the deformation in the elastic region of the container, and an excessive force is generated in the plastic deformation region. As a measure against this, for example, FIG.
It is necessary to provide a telescopic absorption device between the first branch bus 3 and the right first disconnector 5 and between the second branch bus 4 and the right second disconnector 6, respectively. Occurs.

The first branch bus 3 and the left and right first disconnectors 5, and the second branch bus 4 and the left and right second disconnectors 6,
The left and right circuit breakers 7 are fixed at fixed points, and expand and contract in the left-right direction in FIG.

For example, Japanese Patent Application Laid-Open No.
There is a pressure balanced type described in JP-A-6-10016. FIG. 8 is a partial cross-sectional view of this pressure-balanced expansion-contraction absorber. In the figure, the expansion / contraction device 20 is configured as follows. The main bellows 21 is provided between the left and right busbar tanks 22. An auxiliary bellows mounting flange 23 is fixed to the right busbar tank 22. A rod fixing flange 24 is fixed to the left busbar tank 22. One end of an auxiliary bellows 25 is attached to the right surface of the auxiliary bellows mounting flange 23.

The right end of the auxiliary bellows 25 has a flange 26
Is provided. The auxiliary bellows 25 has a cylindrical shape, and two auxiliary bellows 25 are provided, one each above and below the bus bar tank 22 as shown in the figure. The sum of the sectional areas of the two auxiliary bellows 25 is set to be substantially equal to the sectional area of the bus bar tank 22. The rod 27 is a rod fixing flange 24.
And the flange 26. The inside of the main bellows 21 and the inside of the auxiliary bellows 25 are communicated by a communication pipe 28.

The expansion / contraction device 20 is constructed as described above, and is provided between the first branch bus 3 and the right first disconnector 5 and the second branch bus 4 and the right first disconnector 5 in FIG. Each is inserted between the two disconnectors 6. In this case, for example, the left bus tank 22 is connected to the first branch bus 3, and the right bus tank 22 is connected to the first disconnector 5 on the right.

The expansion and contraction of the main bellows 21 and the auxiliary bellows 25 are absorbed by the expansion and contraction accompanying the temperature change due to the fluctuation of the outside air temperature, the solar radiation, the energization and the like. Since the circuit breakers 7 on the left and right sides are fixed to the foundation, the bus bar tank 22 moves when the temperature rises, and the facing distance between the rod fixing flange 24 and the auxiliary bellows mounting flange 23 is reduced. This is absorbed by the main bellows 21 contracting and the auxiliary bellows 25 expanding.

At this time, the main bellows 21 and the auxiliary bellows 25 are communicated with each other by the communication pipe 28, and the cross-sectional area of the main bellows 21 is substantially equal to the total cross-sectional area of the two auxiliary bellows 25. Therefore, the leftward force that the left busbar container 22 on the left side of the drawing receives from the branch busbar 3 due to the pressure of the insulating gas sealed in the container is applied to the fixing flange 24.
To the flange 26 via the rod 27, and balances with the rightward force generated in the flange 26 by the gas pressure in the bellows 25. On the other hand, the rightward force that the right busbar container 22 receives from the first disconnector 5 is balanced with the leftward force generated in the flange 23 by the gas pressure in the bellows 25. Therefore, a large force is not applied to the first disconnector 5 and the first branch bus 3, and it is not necessary to make a support structure or the like firmly. Second disconnector 6 or second branch bus 4
The same applies to

Incidentally, if a simple bellows which is not a pressure balanced type is used, a large thrust is applied to the containers on both sides of the bellows due to the gas pressure in the container. For example, when the diameter of the container is 700 mm and the internal pressure is 0.5 MPa, a thrust of about 19 t is applied to the containers on both sides of the container, and a sturdy container, a strong base and a foundation for supporting the container are required.

[0013]

However, in the conventional gas insulated switchgear, since the above-mentioned pressure-balanced expansion / contraction absorber is used, there are the following problems.・ Because the main bellows 21 and the auxiliary bellows 25 must be provided, the expansion and contraction absorption device becomes longer, the horizontal direction in FIG. 7 of the entire gas insulated switchgear becomes longer, and it cannot sufficiently meet the demand for downsizing the device. . The configuration of the expansion / contraction device is complicated, such as requiring at least two types, namely the main bellows 21 and the auxiliary bellows 25.・ This results in higher prices.

An object of the present invention is to solve the above problems and to obtain a small and inexpensive gas-insulated switchgear.

[0015]

In order to achieve the above object, in a gas insulated switchgear of the present invention, a first branch bus and a pair of first branch buses branched in a direction intersecting a first main bus are provided. A first branch circuit in which one of the pair of first disconnectors, the first branch bus, and the other of the pair of first disconnectors are linearly connected, and an insulating gas is sealed therein. A second branch bus bar and a pair of second disconnectors which are branched from the second main bus bar and extend substantially in parallel with the first branch bus bar at a predetermined interval. One of the second branch bus and the other of the pair of second disconnectors are connected linearly, and one of the second disconnectors and the other of the first disconnectors face each other and A second branch circuit in which the other of the two disconnectors and one of the first disconnectors are arranged so as to face each other and the insulating gas is filled therein. And a pair of first disconnectors and a pair of second disconnectors opposing each other in such a manner that the thrusts in opposite directions generated by the insulating gas sealed in the respective disconnectors are cancelled and airtight. In addition, a pair of flexible connecting devices are provided which are connected so as to be relatively movable in the length direction of the first branch bus bar with a force equal to or less than a predetermined value.

With this configuration, when the linear first and second branch circuits expand and contract due to a temperature change, the first disconnector and the second disconnector facing each other are arranged in the length direction of the branch bus. Move relative to. This relative movement is absorbed by the flexible connection device. The flexible coupling device allows opposing disconnectors to move with a force equal to or less than a predetermined value, so that excessive stress does not occur due to thermal expansion and contraction. Since it is not necessary to provide the first and second branch circuits with a pressure-balanced bellows or the like that absorbs the thermal expansion and contraction, the length of the branch circuit is shortened and the configuration is simplified.

The flexible coupling device includes a bellows and a plurality of tie rods provided outside the bellows, and the bellows hermetically connect the disconnectors facing each other, and the disconnectors facing each other by the tie rods. Are connected so that opposing disconnectors can relatively move in a direction substantially parallel to the first branch bus with a force equal to or less than a predetermined value. . With this configuration, when the opposing first and second disconnectors relatively move in the length direction of the branch bus bar, the bellows follow the axis while deforming and maintain airtightness. Also, the tilting of the tie rod allows the opposing disconnectors to relatively move with a force equal to or less than a predetermined value. This flexible coupling device with bellows and tie rods is short in length, simple in construction, and inexpensive.

Furthermore, first and second circuit breakers each having a connection portion are provided, and a first branch circuit is provided at a connection portion of the first circuit breaker, and one of the first disconnectors is a first circuit breaker. Side and linearly connected so that the first breaker can be moved linearly with the fixed point as a fixed point, and a second branch circuit is connected to a connection portion of the second breaker with a second disconnector. One is located on the side of the second circuit breaker and connected linearly so that it can move linearly with the second circuit breaker as a fixed point.
In general, a breaker is connected to the branch circuit,
It is advantageous that the circuit breaker is fixed so as to suppress vibration during its operation, and each branch circuit is configured to expand and contract with the circuit breaker as a fixed point.

The first branch bus and the second branch bus extend substantially horizontally and are arranged so as to overlap with each other vertically. Is a vertical one. By stacking the first and second branch buses vertically and making each circuit breaker vertical, floor space can be saved.

The first and second main buses extend substantially horizontally, and the first branch bus and the second branch bus are defined by the first main bus and the second main bus. They are arranged so that at least one of them is sandwiched between them. When the first and second branch buses are vertically stacked, and the first and second main buses are arranged therebetween, the length of the flexible coupling device is suitable for absorbing relative movement between disconnecting switches facing each other. And the whole is balanced and compact.

Further, the first branch bus and the second branch bus extend substantially horizontally and are arranged so as to be at the same height from a predetermined reference plane.
The first and second circuit breakers are horizontal. If the first and second branch buses are arranged at the same height from the reference plane and each circuit breaker is horizontal, the height of the device is reduced.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1 1 and 2 show an embodiment of the present invention. FIG. 1 is a side view of a gas insulated switchgear,
FIG. 2 is a plan view thereof. In these figures, 1-1
8 is similar to the conventional gas insulated switchgear of FIG. The A-phase bus 1A and the B-phase bus 1B of the first main bus 1 are at the same height from the base plane, that is, at predetermined intervals parallel to each other in a direction perpendicular to the plane of FIG. And extend. The C-phase bus 1C of the first main bus 1 is disposed so as to overlap with the A-phase bus 1A at a predetermined interval in the vertical direction of FIG. I have.

The C-phase bus 2C of the second main bus 2 is on the same horizontal plane as the C-phase bus 1C of the first main bus, and extends so as to vertically overlap the B-phase bus 1B. I have. The B-phase bus 2B of the second main bus 2 is arranged so as to vertically overlap the C-phase bus 1C and the A-phase bus 1A of the first main bus 1, and the A-phase bus 2A is the same as the B-phase bus 2B. It is arranged on the horizontal plane so as to vertically overlap with the C-phase bus 2C.

Each phase bus 1A, 1B, 1 of the first main bus 1
Each phase bus 3A, 3B, 3C of the first branch bus 3 is branched from C (FIG. 2). From each phase bus 2A, 2B, 2C of the second main bus 2, each phase bus 4A, 4B, 4C of the second branch bus 4 is branched. However, in FIG. 1, only the phase buses 3A and 4A of the first and second branch buses 3 and 4 are visible.

Each phase bus 3A, 3B of the first branch bus 3
As shown in FIG. 1, 3C is a direction perpendicular to the plane of FIG. 1 on a first horizontal plane H1 at a height E from the ground, and at a predetermined interval D as shown in FIG. They are arranged so as to be parallel to each other and orthogonal to the first and second main buses 1 and 2. Each phase bus 4A, 4B, 4C of the second branch bus 4
Is a distance D on a second horizontal plane H2 at a height G from the ground.
At each phase bus 3A, 3B, 3C of the first branch bus 3
And are arranged so as to completely overlap in the vertical direction.

As shown in FIG. 1, first and second horizontal planes H
1 and H2 are parallel to each other and have an interval of F, and the height of the second horizontal plane H2 from the ground is G. In a 550 kV class gas insulated switchgear, for example, the diameter of the first and second branch buses 3 and 4 is 0.7 m, the interval D is 1.5 m, and the dimensions F and G are about 1.8 m.

The first branch bus 3 (each phase bus 3A, 3B,
3C), first disconnectors 35 are provided at both left and right ends in FIG. 1, respectively, and the first branch bus 31 and the first disconnectors 35 on both sides which are connected linearly form a first branch circuit 31. Is composed. The left disconnector 35 in FIG. 1 is connected in a straight line to a connection portion 7a above a vertical circuit breaker 7 which is placed vertically as shown in the figure, and is further connected to a cable head tank 9 and a cable head. 13 is connected to a cable 14.

The second branch bus 4 (each phase bus 4A, 4B,
4C), a second disconnecting circuit 36 is connected to each of the left and right ends, and the second branch circuit 32 is connected to the second branch bus bar 4 connected linearly and the second disconnecting switches 36 on both sides. Make up. The second disconnecting switch 36 on the right is connected to the lower connecting portion 7a of the circuit breaker 7 arranged vertically on the right so as to form a straight line. The left and right circuit breakers 7 are firmly fixed to the foundation to suppress vibration at the time of opening and closing.

The right circuit breaker 7 further includes a third disconnector 8
Are connected to the bushing 17 and the power transmission line 18 via the. The lightning arrester 15 also serves as a support base for the bushings 17, and each bushing 17 is firmly fixed on the lightning arrester 15 so as to sufficiently withstand an earthquake or the like.

In the example shown in FIG. 2, the bushings 17 of the A-phase and the C-phase are arranged so that the positions of the phases on both sides thereof are extended outward by the third branch busbar 16, and the interval J is 550 kV.
Is about 8 m. Bushing 17
The reason why the distance J between them is larger than D is to increase the air insulation distance between the bushings 17, and when a bushing is used, it generally has such a shape in many cases. The middle phase bushing 17 has no branch bus 16 and is fixed on the lightning arrester 15 via the third disconnector 8.

In order to measure the current, the first current transformer 10 is connected between the first disconnector 35 and the circuit breaker 7 on the left, and the second disconnector 36 and the circuit breaker 7 on the right. , The second current transformer 11 is provided between the right circuit breaker 7 and the third disconnector 8, and the third current transformer 12 is provided between the left circuit breaker 7 And the cable head tank 9.

The first branch circuit 31 (the first branch bus 3 and the pair of first circuit breakers 35) is free to move in its axial direction (left-right direction in FIG. 1) and It is supported so that it does not move left and right. Therefore, the circuit breaker 7 expands and contracts in the left-right direction in FIG.

Similarly, the second branch circuit 32 (the second branch bus 4 and the pair of second disconnectors 36) can freely move in the longitudinal direction (axial direction), It is supported not to move in the direction. Accordingly, the right circuit breaker 7 is moved to the left in the figure with the right circuit breaker 7 as a fixed point as the temperature rises.

The connection 7a above the left circuit breaker 7, the first branch circuit 31, the connection 7a above the right circuit breaker 7,
The third disconnectors 8 are arranged in parallel on the above-described first horizontal plane H1 so as to have a predetermined interval D for each phase as shown in FIG. That is, for each phase,
The arrangement is such that each phase is on a straight line when viewed from the vertical direction.

The connection 7a below the right circuit breaker 7, the second branch circuit 32, the connection 7a below the left circuit breaker 7,
The cable head tank 9 is disposed on the above-mentioned second horizontal plane H2 and is arranged in parallel so as to have a predetermined interval D for each phase as shown in FIG. That is, each of the phases is arranged so as to be on a straight line for each phase when viewed from the vertical direction.

The flexible coupling 40, which is a flexible coupling device,
As a result, the right and left opposing first disconnectors 35 and second disconnectors 36 are connected as shown in FIG. next,
The detailed configuration of the flexible joint 40 will be described with reference to the cross-sectional view of FIG. The bellows 41 with a flange is a cylindrical bellows part 41.
a, and a circular flange portion 41b welded to both sides of the bellows portion 41a. The tie rod 42 is
2a, a spherical seat nut 42b, a lock nut 42c, and a temporary fixing nut 42d.

The shaft 42a of the tie rod 42 has both ends penetrating through the flange portion 41b, and is screwed to both ends of the shaft 42a so that the spherical seat side of the spherical seat nut 42b is in contact with the flange portion 41b. The lock nut 42c
As a result, the nut 42b with the spherical seat is prevented from rotating.

The temporary fixing nut 42d is for temporarily fixing the distance between the two opposed flange portions 41b of the flanged bellows 41 at the time of assembly or the like. After the attachment of the flexible joint 40 is completed, it is moved inward as shown in FIG. 3 so that the opposed flanges 41b can move in the radial direction with respect to each other. At this time, the two flange portions 41b can move freely in the axial direction, but in fact, the tie rod 42 acts so as to cancel the thrust generated by the insulating gas sealed in each disconnector via the two flange portions 41b. Hardly moves in the axial direction.

The upper flange portion 41 in the drawing of the flexible joint 40
FIG. 3B shows a state in which the insulating spacer 44 supporting the connection conductor 43 connected to the conductor (not shown) of the first disconnector 35 is sandwiched between the bolts 45 and the flange portion of the first disconnector 35 as shown in FIG.
It is fixed as follows. In addition, in order to secure the inside airtightness, between the flange portion 41b and the insulating spacer 44,
An O-ring 46 is interposed between the insulating spacer 44 and the flange of the first disconnector 35.

The lower flange portion 41b of the flexible joint 40 in the figure is bolted by a bolt 45 with an insulating spacer 44 supporting a connecting conductor 47 connected to a conductor (not shown) of the second disconnector 36 interposed therebetween. Is fixed to the flange portion of the disconnector 36. An O-ring 46 is similarly inserted between the insulating spacer 44 and the flange portion 41b and the flange portion of the second disconnector 36 as shown in the figure to maintain airtightness.

The connecting conductor 43 and the connecting conductor 47 are provided with an intermediate conductor 48 and electrically connected by a spring contact 49 so that their axes can be shifted or inclined. The spring contact 49 is formed by arranging a large number of plate-shaped conductors 49a so as to form a cylindrical shape.
9b, the connection conductors 43 and 47 and the intermediate conductor 48 are tightened in the radial direction.

Since the bellows 41 with a flange are used, a thrust upward in FIG. 3 is generated in the first disconnector 35 by the pressure of the insulating gas sealed therein, and the second disconnector 36 is applied to the second disconnector 36. A downward thrust is generated and transmitted to both flanges 41b via bolts 45, respectively. The thrusts in the opposite directions are applied to both flanges 41b by a plurality of tie rods 42.
Offset by pulling.

The flexible joint 40 configured as described above operates as follows, and the first disconnector 35 and the second disconnector 3
The tie rods 42 apply the vertically opposite forces acting on
The first disconnector 35 and the second disconnector 36
Are allowed to move in the left-right direction of the figure due to a temperature change or the like.

That is, in FIG. 3, for example, when the second disconnector 36 is to be shifted rightward with respect to the first disconnector 35, the tie rod 42 presses the spherical surface side of the spherical seat nut 42b against the flange 41b. Thus, the thrusts in opposite directions due to the internal pressure are offset, so that the upper and lower two flanges 41b are shifted with a relatively small force in the radial direction. At this time, the connection conductors 43 and 47 also
Since it tends to shift in the radial direction, this shift is
Absorb by the elastic deformation of b.

In the gas insulated switchgear configured as described above, even when each device has a high temperature and the amount of thermal expansion and contraction increases, the disconnector 3 farthest from the fixed circuit breaker 7
Since there is a flexible joint 40 in the part 5, 36, thermal expansion and contraction is handled in this part, and no excessive stress is generated in the device.

The thermal expansion and contraction between the circuit breaker 7 and the lightning arrestor 15 under the bushing 17 causes a small deformation of the container such as the circuit breaker 7 and the disconnector 8 when the length is short as in the middle phase of FIG. Accordingly, it is possible to cope with this without generating excessive stress. In addition, when there is a branch bus 16 as in the end phase of FIG. 2, the disconnector 8 is movable in the horizontal direction, and the current transformer 11, the disconnector 8, and the branch bus 16 are bent. Excessive stress due to deformation can be prevented, and thermal expansion and contraction can be dealt with.

As described above, in this gas insulated switchgear, the connection port 7a above the left circuit breaker 7 and the first branch circuit 31 (the first disconnector 35, the first branch bus 3, One disconnector 35) is connected in a straight line, and a predetermined interval F
And the connection port 7a below the right circuit breaker 7 and the second branch circuit 32 (the second disconnector 36, the second branch bus 4, the second disconnector 36) are linearly connected. And the first and second disconnectors 35 and 36 facing each other with a pair of flexible joints 40.
Are connected. With this configuration, it is not necessary to use a pressure-balanced bellows that absorbs expansion and contraction in the left-right direction in FIG. 1 as in the related art, so that the size can be reduced accordingly.

When the dimension F (FIG. 1) is selected so that the first or second main buses 1 and 2 are located between the first and second branch buses 3 and 4, the flexible joint 40 The axial length is a length that can sufficiently absorb the expansion and contraction. Thus, by using the flexible joint 40, as is clear from FIGS. 1 and 2, the left and right circuit breakers 7, the first and second disconnectors 3
5, 36, the first and second branch buses 3, 4, and the first and second main buses 1, 2 can be arranged very compactly.

In this embodiment, since the radial displacement between the two flange portions 41b is not so large, a normal nut can be used instead of the spherical seat nut 42b.

Embodiment 2 FIG. 4 is a side view of a gas insulated switchgear showing another embodiment of the present invention. FIG.
In FIGS. 1 and 2, the same reference numerals as in FIGS.
It is similar to that shown in FIG. In FIG. 4, the phase buses 1A, 1B, 1C of the first main bus 1 are provided in parallel on the same horizontal plane. Each phase bus 2 of the second main bus 2
A, 2B, and 2C are also arranged on a horizontal plane different from the first main bus 1. The first and second main buses 1 and 2 extend in a direction perpendicular to the plane of FIG. The disconnector 8 is of a horizontal type which is placed horizontally. With this configuration,
The height of the tip of the bushing 17 can be reduced. Although not shown in the plan view, it is the same as that shown in the plan view of FIG. 2 except that the disconnector 8 is horizontal.

Also in this case, the first and second branch circuits 31,
32, relative to the relative movement of the opposing first and second disconnectors 35 and 36 due to thermal expansion and contraction at 32.
The flexible joint 40 can deal with the problem without any problem.
Also in the case of this embodiment, since the circuit breaker 7 and the bushing 17 in FIG. 2 are fixed, the disconnector 8 and the branch bus 1
6 can be dealt with without generating excessive stress due to the bending deformation of the bent portion.

Embodiment 3 FIG. 5 and 6 show still another embodiment of the present invention. FIG. 5 is a side view of a gas insulated switchgear, and FIG. 6 is a plan view thereof. FIG.
FIG. 6 is a plan view of an A-phase, which is a foremost phase in FIG. 5. In these drawings, since each device constituting the gas insulated switchgear is the same as that shown in FIG. 4, corresponding components are denoted by the same reference numerals and description thereof is omitted.

In this embodiment, the first and second branch circuits 31, 32 are arranged in parallel at the same height from the ground. Further, each phase bus 1A, 1B, 1C of the first main bus 1 is arranged on one plane, and each phase bus 2A, 2B, 2C of the second main bus 2 is arranged on another plane. The first and second branch buses 3 and 4 are arranged between the first and second main buses 1 and 2 as shown in the drawing so as to be orthogonal to the main buses. The distance between the first branch bus 3 and the second branch bus 4 is F (FIG. 6). The first and second branch circuits 31 and 32, that is, the first and second branch buses 3 and 4, and the first and second disconnectors 35 and 36 connected to the branch buses 3 and 4, respectively, are left and right cutoffs. FIG. 6 shows the connection port 7a of the container 7
Are connected linearly as shown in FIG.

That is, the first branch circuit 31 is connected to the horizontal circuit breaker 7 by rotating the first branch circuit 31 by 90 degrees around the second branch circuit 32 in FIG. is there. The disconnector 8 is of a horizontal type, and the height up to the upper part of the bushing 17 is reduced similarly to the one shown in FIG. Although the main body of the circuit breaker 7 is the same as that of the vertical type in FIGS. 1 and 4, the operation mechanism 7 b of the circuit breakers 7 on both sides as shown in FIG. They are located opposite each other. Of course, as in the case of FIG. 4, the circuit breaker 7 is a fixed point, and the first and second branch circuits 31, 32 are changed according to the temperature change as shown in FIG.
Although it expands and contracts in the left-right direction in FIG. 6, the flexible joint 40 absorbs the influence.

As described above, the first and second branch circuits 31,
The height of the gas insulated switchgear can be reduced by arranging the 32 at the same height and connecting them linearly with the two related circuit breakers 7 and the like. In the embodiment of FIG. 5, the height G of the first and second branch circuits 31, 32 from the ground is 550 kV.
It is about 1.8 m in the class, and that of FIG. 1 (G + E = 3.6
m). By greatly reducing the height in this way, when the gas insulated switchgear is blinded by planting or the like for environmental harmony, this can be easily performed.

As shown in FIG. 6, the first and second branch circuits 31,
By arranging 32 on the same horizontal plane, the installation area is increased as compared with that of FIG. But bushing 1
In the case where the bushings 17 are connected to the overhead line (the transmission line 18) via the cable 7, the space between the bushings 17 (J in FIG. 2) is large, so that an increase in the installation area does not matter much. Note that the branch bus 16 is shortened. Therefore, the one shown in FIG. 1 or FIG. 6 can be used properly according to the installation condition of the gas insulated switchgear.

When the bushing 17 shown in FIGS. 5 and 6 is installed in another unobtrusive place far away from the circuit breaker 7, or when the cable is drawn out instead of the bushing, as shown in FIG. By arranging the first and second branch circuits 31 and 32 on the same horizontal plane, the height of the device can be reduced, and environmental harmony can be more easily achieved.

The first and second disconnectors 35, 36 are not limited to those that open in the length direction of the first or second branch buses 3, 4, but open in a direction perpendicular to the length direction. It may be extreme.

[0059]

Since the present invention is configured as described above, it has the following effects. A first branch bus bar that is branched in a direction intersecting with the first main bus bar and a pair of first disconnectors; one of the pair of first disconnectors, the first branch bus bar, and the pair of first A first branch circuit linearly connected to the other of the disconnectors and filled with an insulating gas, a first branch circuit branched from the second main bus and extending substantially in parallel with the first branch bus at a predetermined interval. One having two branch buses and a pair of second disconnectors, and one of the pair of second disconnectors, the second branch bus, and the other of the pair of second disconnectors are linearly connected. It is arranged so that one of the second disconnectors and the other of the first disconnectors face each other and the other of the second disconnectors and one of the first disconnectors face each other, and the insulating gas is filled therein. Of the second branch circuit and the pair of first disconnectors and the pair of second disconnectors facing each other are enclosed in the respective disconnectors. A pair of connecting members are connected to each other so as to cancel the thrusts in opposite directions generated by the insulated gas and to be able to relatively move in the length direction of the first branch bus bar in an airtight manner and with a force less than a predetermined value. Since the flexible coupling device is provided, the first disconnector and the second disconnector facing each other when the linear first and second branch circuits expand and contract due to temperature change are opposed to each other in the length direction of the branch bus. Moving. This relative movement is absorbed by the flexible connection device. The flexible coupling device allows opposing disconnectors to move with a force equal to or less than a predetermined value, so that excessive stress does not occur due to thermal expansion and contraction. Since it is not necessary to provide the first and second branch circuits with a pressure-balanced bellows or the like that absorbs the thermal expansion and contraction, the length of the branch circuit is shortened and the configuration is simplified. Therefore, an inexpensive and compact device can be obtained.

The flexible coupling device has a bellows and a plurality of tie rods provided outside the bellows, and the bellows hermetically connect the disconnectors facing each other, and the disconnectors facing each other by the tie rods. Are connected so that opposing disconnectors can relatively move in a direction substantially parallel to the first branch bus with a force equal to or less than a predetermined value. Therefore, when the opposing first and second disconnectors relatively move in the length direction of the branch bus, the bellows keeps airtight by following its axis while deforming. Also, the tilting of the tie rod allows the opposing disconnectors to relatively move with a force equal to or less than a predetermined value. This flexible coupling device with bellows and tie rods is short in length, simple in construction, and inexpensive. Therefore, an inexpensive and compact device can be obtained.

Further, first and second circuit breakers each having a connection portion are provided, and a first branch circuit is provided at a connection portion of the first circuit breaker, and one of the first disconnectors is a first circuit breaker. Side and linearly connected so that the first breaker can be moved linearly with the fixed point as a fixed point, and a second branch circuit is connected to a connection portion of the second breaker with a second disconnector. One is located on the side of the second circuit breaker and connected linearly so that it can move linearly with the second circuit breaker as a fixed point. Generally, it is convenient to fix the circuit breaker to suppress vibration during its operation, and to configure each branch circuit to expand and contract with the circuit breaker as a fixed point. Therefore, a reasonable and compact device can be obtained.

Further, the first branch bus and the second branch bus extend substantially horizontally and are disposed so as to be vertically overlapped with each other. Is of a vertical type, so that the first and second branch buses are vertically stacked and each circuit breaker is of a vertical type, so that floor space can be saved. Therefore, the device is inexpensive and compact, and the installation space can be saved.

The first and second main buses extend substantially horizontally, and the first branch bus and the second branch bus are defined by the first main bus and the second main bus. Since the first and second branch buses are arranged one above the other, and the first and second main buses are disposed therebetween, the lengths of the flexible coupling devices are opposite to each other. It is suitable for absorbing the relative movement between disconnectors
Overall balance and compactness. Therefore, the device can be made more compact.

Further, the first branch bus and the second branch bus extend substantially horizontally and are arranged at the same height from a predetermined reference plane.
Since the first and second circuit breakers are horizontal, the height of the device can be reduced by arranging the first and second branch buses at the same height from the reference plane and making each circuit breaker horizontal. Therefore, when blindfolding by planting or the like for environmental harmony, it can be easily and inexpensively performed.

[Brief description of the drawings]

FIG. 1 is a side view of a gas-insulated switchgear showing one embodiment of the present invention.

FIG. 2 is a plan view of the gas insulated switchgear of FIG.

FIG. 3 is a sectional view showing a flexible joint.

FIG. 4 is a side view of a gas insulated switchgear showing another embodiment of the present invention.

FIG. 5 is a side view of a gas insulated switchgear showing another embodiment of the present invention.

FIG. 6 is a plan view of the gas insulated switchgear of FIG. 5;

FIG. 7 is a side view showing a conventional gas insulated switchgear.

FIG. 8 is a partial cross-sectional view showing a conventional expansion / contraction device.

[Explanation of symbols]

1 First main bus, 1A, 1B, 1C Each phase bus, 2
2nd main bus, 2A, 2B, 2C each phase bus, 3 first branch bus, 4 second branch bus, 7 circuit breaker, 7a
Connection port, 8 third disconnector, 9 cable head tank, 35 first disconnector, 36 second disconnector, 40
Flexible joint, 41 Bellows with flange, 42 Tie rod.

Claims (6)

[Claims] 1. A first main bus extending in a predetermined direction, a second main bus extending substantially parallel to the first main bus, and branched in a direction intersecting the first main bus. It has a first branch bus and a pair of first disconnectors, and one of the pair of first disconnectors, the first branch bus, and the other of the pair of first disconnectors are linearly connected. A first branch circuit filled with an insulating gas, a second branch bus branched from the second main bus and extending substantially in parallel with the first branch bus at a predetermined interval and a pair of second buses And one of the pair of second disconnectors, the second branch bus and the other of the pair of second disconnectors are connected linearly, and the second One of the disconnectors and the other of the first disconnectors face each other, and the other of the second disconnectors and one of the first disconnectors face each other. The second branch circuit in which the insulating gas is filled and the pair of first disconnectors and the pair of second disconnectors facing each other are sealed in the respective disconnectors. And a pair of members connected to each other so as to be able to relatively move in the length direction of the first branch bus bar in a gas-tight manner and with a force of a predetermined value or less so as to cancel thrusts in opposite directions generated by the insulating gas. Gas insulated switchgear provided with a flexible coupling device. 2. The flexible coupling device has a bellows and a plurality of tie rods provided outside the bellows, and the bellows hermetically connects disconnectors facing each other, and the disconnectors face each other by the tie rods. Are connected so that the opposing disconnectors can relatively move in a direction substantially parallel to the first branch bus with a force equal to or less than a predetermined value. The gas insulated switchgear according to claim 1, wherein: 3. A first and a second circuit breaker each having a connection portion, wherein a first branch circuit is provided at a connection portion of the first circuit breaker and one of the first disconnectors is the first circuit breaker. So that it can be moved linearly with the first circuit breaker as a fixed point, and a second branch circuit is connected to the connection of the second circuit breaker. One of the disconnectors is linearly connected to the second circuit breaker side so as to be able to move linearly with the second circuit breaker as a fixed point. The gas insulated switchgear according to claim 1. 4. A first and a second circuit breaker, wherein the first branch bus and the second branch bus extend substantially horizontally and are arranged so as to vertically overlap each other. The gas-insulated switchgear according to claim 3, wherein is a vertical type. 5. The first and second main buses extend substantially horizontally, and the first branch bus and the second branch bus are defined by the first main bus and the second main bus. The gas insulated switchgear according to claim 4, wherein the gas insulated switchgear is arranged so as to sandwich at least one of them. 6. The first branch bus and the second branch bus extend substantially horizontally and are arranged at the same height from a predetermined reference plane. The gas-insulated switchgear according to claim 3, wherein the first and second circuit breakers are of a horizontal type.