JPH09182224A - Gas-insulated switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To compactify a switch by interconnecting main bus bars which are divided into two, and composing a circuit capable of being connected to either of the main bus bars of the minimum number of equipment. SOLUTION: Main bus bars 1a, 1b and an auxiliary bus bar 1c are disposed so that each other's axes are in parallel and that the end parts overlap each other. Respective bus bar disconnecting switches 4a, 4b are connected to the position where the respective bus bars 1a, 1b overlap each other, and a bus bar sectioning circuit breaker 9a for interconnecting the min bus bars 1a, 1b is connected to the disconnecting switches 4a, 4b. Also, respective disconnecting switches 4c, 4d are disposed in the position where the auxiliary 1c and the respective main bus bars 1a, 1b overlap each other, the main bus bars 1a, 1b and the auxiliary bus bar 1c are connected to each other through the respective disconnecting switches 4c, 4d. Furthermore, an external connection circuit breaker 9b is connected to the auxiliary bus bar 1c.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas-insulated switchgear having a busbar section line for connecting divided main busbars to each other, and more particularly to a gas insulated switchgear having an improved line structure in order to make the device compact. The present invention relates to an insulating switchgear.

[0002]

2. Description of the Related Art Conventionally, there has been known a gas-insulated switchgear in which a high-voltage conductor is insulated with SF6 gas or the like and housed in a pressure vessel. This gas-insulated switchgear has the advantages that it is easy to miniaturize, downsize, and simplify, and that it has excellent safety and maintainability. The gas-insulated switchgear with these advantages can address the issues that have been emphasized in recent years, such as difficulty in obtaining land for construction of power plants and substations due to rising land prices, and environmental harmony with the surroundings. for that reason,
The demand for gas-insulated switchgear tends to increase, and it has come to be applied to most switchgear. As a result, the gas-insulated switchgear is always desired to be more compact in order to make full use of the above advantages.

Here, as an example of the gas-insulated switchgear,
Gas insulated switchgear adopting two sets of single bus system
This will be described with reference to FIG. 6 is a single wire connection diagram of the gas insulated switchgear, FIG. 7 is a plan view showing the arrangement of circuit components based on the single wire connection diagram, and FIG. 8 is a side view taken along line XX of FIG.
9 is a YY side view of FIG. 7, and FIG. 10 is a ZZ side view of FIG.

As shown in FIG. 7, in this gas insulated switchgear, two main buses 101 and 102 are arranged on the same axis, and a bus section line A is connected between these main buses 101 and 102. Has been done. In addition, the main bus 10
A power transmission line B, a transformer line C, a main bus line D, and an external connection line E are connected to 1 and 102, respectively. Among these lines A, B, C, D, E, the busbar section line A is arranged in a direction parallel to the axes of the main buses 101, 102.

Further, all the remaining lines B, C, D, E are arranged at right angles to the axes of the main buses 101, 102, and both directions (vertical direction in FIG. 7) with the bus section line A as the center. ), The transmission line B, the transformer line C, the external connection line E, and the main bus line D are arranged in this order in a symmetrical manner.

Next, FIG. 8 shows an arrangement configuration of the bus section line A. That is, a busbar breaker 90 for connecting the main buses 101 and 102 is provided between the main buses 101 and 102.
Is arranged. This breaker 90 has a main bus 101,
Two branch connection parts 21 and 22 facing 102 are formed on the same axis as the main buses 101 and 102. Current transformers 81 and 8 for measuring instruments are provided in the respective branch connecting portions 21 and 22.
2, work ground switch 61, 62, busbar disconnector 41,
42 are sequentially connected, and the busbar disconnectors 41 and 42 are connected to the main buses 101 and 102, respectively.

Further, the transformer line C and the external connection line E
9 shows the arrangement configuration of the main bus 101 side as an example. That is, the circuit breaker 91 for external connection is arranged adjacent to the main bus 101. In this circuit breaker 91, two branch connecting portions 23, 24 are formed in a direction perpendicular to the axial direction of the main buses 101, 102.

Of the branch connecting portions 23 and 24, the branch connecting portion 23 adjacent to the main bus 101 has a current transformer 8 for measuring instruments.
3, a work ground switch 63, and a busbar disconnector 43 are sequentially connected, and the busbar disconnector 43 is connected to the main busbar 101. On the other hand, the branch connecting portion 24 has a current transformer 8
4 and a busbar grounding switch 50 are connected. Further, the cable head 10 is connected to the busbar grounding switch 50.

The main bus line D has a structure including a bus grounding switch 51 and an instrument transformer 30 (see FIG. 10).

In the gas-insulated switchgear described above, it can be said that the main buses 101 and 102 are connected by the bus section line A. In other words, the bus section line A is separated from the circuit breaker 90 so that either one of the main buses 101 and 102 (more accurately, the switching unit of the switching unit including the lines B, C, D, and E on the main buses 101 and 102). Only one of them) can be stopped.

Therefore, when either one of the main buses 101 and 102 is inspected, when a line expansion work is performed, or when there is a mismatch, only one main bus is stopped and the other main bus is disconnected. Can be used normally.
Therefore, it is not necessary to stop the entire gas-insulated switchgear to stop one main busbar, which is economically advantageous in terms of equipment operation.

[0012]

By the way, the gas-insulated switchgear is a circuit that is required to be constantly operated, such as a starting transformer circuit of a power plant or an in-house circuit of a substation (hereinafter, always-operated here). (Referred to as a circuit) is generally installed. These always operating circuits can normally fulfill their role if they are installed at only one place on the main bus constituting the gas insulated switchgear.

However, in the case of having two sets of main buses as in the above-described gas-insulated switchgear, it is necessary to actually install the above-mentioned constantly operating circuits for both main buses. This means that when only one main bus is stopped, if a constant operation circuit is installed on the main bus side to be stopped, the constant operation circuit will be stopped along with the main bus, and the entire gas-insulated switchgear will It will stop. As a result, only the other main bus cannot be used normally. Therefore, conventionally, a dedicated line for an always operating circuit has usually been installed in each of the two sets of main buses. In the above-mentioned conventional example, the main buses 101, 10
The external connection line E connected to 2 is such a dedicated line.

The conventional gas-insulated switchgear described above has the following problems. That is, since it is necessary to connect a dedicated line for an always operating circuit to both of the two sets of main buses, the device configuration becomes large and complicated. Moreover, even if two dedicated lines are provided corresponding to the main bus, only one of them is used in the normal state, and the other is not used, so there is a strong impression that it is useless. Nowadays, there is a demand for further downsizing of the gas insulated switchgear, and it is expected that the lines that give such a useless impression will be particularly omitted.

As described above, in the gas-insulated switchgear in which the main busbar is divided into two and the main busbars are connected to each other by the circuit breaker, it is necessary to connect a dedicated line for the always operating circuit to each main busbar. Had become larger and more complicated.

The present invention has been proposed in order to solve the problems of the prior art as described above, and it is possible to connect two main busbars that are divided into two and connect both main busbars. The main purpose is to configure the line with a minimum of equipment and to make the device compact.

More specifically, the object of the invention of claim 1 is to connect a main bus bar divided into two parts by a line having a simple structure such as two disconnecting switches and one circuit breaker. An object of the present invention is to provide a gas-insulated switchgear that can be connected to only one of the main buses.

An object of the invention of claim 2 is to provide a gas-insulated switchgear adopting two sets of single busbar systems, wherein an auxiliary busbar for connecting two main busbars is arranged outside the busbar section line via a disconnector. It is an object of the present invention to provide a gas-insulated switchgear capable of stopping only one main bus bar by pulling out a line connecting to the outside and operating and using the other main bus line and auxiliary bus line side.

The object of the invention of claim 3 is the above-mentioned claim 2.
It is an object of the present invention to provide a gas-insulated switchgear capable of reducing the equipment arrangement space by arranging the main buses at positions shifted in parallel with each other.

An object of the present invention is to provide a gas-insulated switchgear in which the equipment arrangement space can be reduced by arranging the main bus line equipment at the connecting portion between the main bus and the auxiliary bus. That is.

It is an object of the present invention to provide a gas-insulated switchgear having a rational arrangement in which the arrangement of the auxiliary bus bar connected to the main bus bar can be appropriately applied to various conditions.

It is an object of the present invention to provide a plurality of disconnecting switches between the bus bar breaker and the external circuit breaker, so that the circuit can be completely disconnected during the field test. A gas-insulated switchgear is provided.

[0023]

In order to achieve the above object, the invention of claim 1 is a main bus bar and a bus bar breaker for dividing the main bus line into two and connecting the main bus lines to each other. A gas insulated switchgear having a circuit breaker for external connection for connecting a circuit breaker to each of the two main buses divided by the circuit breaker for dividing the bus bar, and a circuit for external connection. It is characterized by being connected in between.

According to a second aspect of the present invention, in two sets of single-bus type gas-insulated switchgear having at least two lines, main buses are arranged on the same axis, and auxiliary buses are provided in parallel with the main buses. The main busbars and the auxiliary busbars are connected to each other by connecting disconnectors to the ends of the mainbusses, and connecting busbar section breakers for connecting the two mainbusbars between the disconnectors. Is connected via a disconnector, and an external connection circuit breaker for constructing a line to be connected to the outside is connected to the auxiliary bus bar.

According to a third aspect of the present invention, in two sets of single-bus type gas-insulated switchgears having at least two lines, the main bus lines are arranged such that their axes are parallel and their ends overlap. , A busbar section breaker for connecting two main busbars to each other by connecting a disconnector switch to a position where the main busbars overlap each other, arranging the connecting busbar from the disconnector switch in a direction perpendicular to the main busbar, and connecting the two main busbars to the connecting busbar Connecting the auxiliary busbars in parallel with the main busbars, disposing disconnectors at positions where the auxiliary busbars and the respective main busbars overlap, and the main busbars and the auxiliary busbars through these disconnectors. And a circuit breaker for external connection for connecting to the outside to form a line for connecting to the outside are connected to the auxiliary bus bar.

According to the invention of claim 4, the axes thereof are parallel to each other,
The main busbar and the auxiliary busbar, which are arranged so that their end portions are overlapped with each other, are arranged at a position where the main busbar instrument transformer and the grounding switch are arranged.

The invention of claim 5 is characterized in that the auxiliary bus is arranged between two main buses.

The invention of claim 6 is characterized in that the auxiliary busbars are arranged outside the two main busbars.

According to a seventh aspect of the present invention, between the busbar section breaker and the disconnector on the main busbar, and between the disconnector on the auxiliary busbar and the external connection breaker, respectively. The feature is that a disconnector is arranged.

According to the invention of claim 8, between the busbar section breaker and the disconnector on the main busbar, and between the disconnector on the auxiliary busbar and the external connection breaker, respectively. A disconnecting switch is arranged, and a grounding switch is arranged between the disconnecting switches.

The operation of the present invention having the above structure is as follows. That is, in the invention of claim 1, it is possible to configure a line in which two sets of main buses are respectively connected to a circuit breaker via a disconnector and are connected to the outside via the circuit breaker. Therefore, by selectively operating the disconnector, it is possible to easily connect and disconnect either one of the two main buses.
Further, since the two disconnectors are connected to the two sets of main buses, the inspection work of the disconnectors can be carried out only by stopping the main bus on one side. Further, the inspection work of the line connected to the outside can be performed while the main busbars are operating by disconnecting the two disconnectors.

Further, since the main bus bar on one side can be stopped by selectively operating the disconnector,
When the main bus is stopped, it is not necessary to stop the line itself connected to the outside, and this line can be operated and used as usual. Therefore, the starting transformer circuit of the power plant,
It is very effective as a line that constitutes a constant operation circuit such as a substation circuit.

According to the invention of claim 2, the same operation as that of the invention of claim 1 can be taken in the two sets of single bus type gas-insulated switchgear.

In the invention according to claim 3, the invention according to claim 2
Similar to the invention of (1), two sets of single-bus type gas-insulated switchgear can have the same function as that of the invention of claim 1, and also has the following function. That is, the two main buses in the invention of claim 2 are arranged so as to be shifted in parallel, and the auxiliary bus connecting between the main buses is arranged in parallel with the main bus. Therefore, compared to the invention of claim 2, in the main bus axis direction. The longitudinal dimension can be shortened.

According to the fourth aspect of the invention, since the main bus line equipment is installed at the position where the main bus and the auxiliary bus overlap with each other, the longitudinal dimension in the main bus axial direction can be shortened.

In the fifth and sixth aspects of the invention, the auxiliary busbars are arranged between the two main busbars or outside the two, so that the arrangement of the auxiliary busbars can be appropriately arranged for various conditions. be able to.

In the invention of claim 7, a disconnector is arranged between the breaker for dividing the busbar and the disconnector on the main busbar, and between the disconnector on the auxiliary busbar and the breaker for external connection. As a result, even if one of the main buses continues to operate and the other main bus performs a local withstand voltage test, the circuit can be opened at two points without affecting the circuit on the operating side. In addition, it is possible to safely test the other main bus.

According to the invention of claim 8, in addition to the function of the invention of claim 7, a grounding switch is arranged between the disconnecting switches, so that more excellent safety can be secured.

[0039]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an example of an embodiment of a gas-insulated switchgear according to the present invention will be specifically described with reference to FIGS. The same members as those in the conventional example, such as the power transmission line B, the transformer line C, the in-house line D, and the devices that compose these lines, are denoted by the same reference numerals and the description thereof will be omitted.

[Structure] The present embodiment is a gas-insulated switchgear adopting two sets of single-bus systems.
It includes the inventions of 4, 6, and 8. 1 is a single line connection diagram of the present embodiment, FIG. 2 is a plan view showing the arrangement of circuit components based on this single line connection diagram, FIG. 3 is a side view of OO of FIG. 2, and FIG. 2 is a PP side view, and FIG.
It is a QQ side view of.

The main buses 1a and 1b and the auxiliary bus 1c are
The axes are parallel to each other and are arranged horizontally with respect to the installation surface so that the ends overlap each other. Main bus 1a, 1
A bus section line A, main bus lines D1 and D2, and an external connection line E are connected between b. In addition, main buses 1a, 1
A power transmission line B and a transformer line C are connected to b, respectively.

All of the above lines A, B, C, D and E are arranged at right angles to the axes of the main buses 1a and 1b. Above all, the transmission line B and the transformer line C are different from the conventional example. Similarly, they are symmetrically arranged in both directions (vertical direction in FIG. 2) centering on the bus section line A. The bus bar section line A and the main bus line D1 are connected and arranged in the main bus lines 1a and 1b and the auxiliary bus line 1c at the portions where the three bus lines overlap, and the main bus line D2 is connected to the main bus line 1b and the auxiliary bus line 1c. 1c is connected and arranged in a portion overlapping with 1c. Further, the external connection line E is connected and arranged in a portion where the main bus 1a and the auxiliary bus 1c overlap.

Next, FIG. 3 shows the arrangement of the bus section line A. That is, the first busbar disconnecting switches 4a and 4b and the work grounding switches 6a and 6b are connected to the positions where the ends of the main busbars 1a and 1b overlap each other. Connection buses 2a and 2b are connected to these devices in a direction perpendicular to the axial directions of the main buses 1a and 1b. The second busbar disconnector 7a is connected to the connection busbar 2a on the main busbar 1a side.
Is connected.

The current transformers 8a and 8b for measuring instruments are connected to the ends of the connecting busbars 2a and 2b, and the breaker 9a for dividing the busbars is connected through the current transformers 8a and 8b for measuring instruments. There is. The busbar section circuit breaker 9a is a circuit breaker for connecting the main busbars 1a and 1b, and is arranged outside the auxiliary busbar 1c (right side in FIG. 2). More specifically, the busbar breaker 9a has two branch connection portions 25 and 26 vertically formed in the same direction at right angles to the axial direction of the main busbars 1a and 1b. Part 25
Is connected to the instrument current transformer 8a and the connecting bus bar 2a, and the lower branch connecting portion 26 is connected to the instrument current transformer 8b and the connecting bus bar 2b. Bus line section line A is the first line above
Busbar disconnectors 4a, 4b, work ground switches 6a, 6
b, second busbar disconnector 7a, instrument current transformers 8a, 8b
And a busbar breaker 9a.

By the way, FIG. 3 also shows the arrangement of the main bus line D1. That is, a transformer 3a for measuring instruments for the main bus is branched and connected to an end portion of the main bus 1a, and a grounding switch 5a for the main bus is further connected. The main bus bar 1a is formed by the instrument transformer 3a and the main bus grounding switch 5a.
A main bus line D1 for use is configured.

Next, the arrangement of the main bus line D2 will be described with reference to FIG. That is, the main bus 1b and the auxiliary bus 1
A main busbar grounding switch 5b is connected to the main busbar 1b at a position where the end of c overlaps. Auxiliary bus 1
An instrument transformer 3b for the main bus is arranged on the right side of c, and the instrument transformer 3b is connected to the main bus grounding switch 5b. A main bus line D2 for the main bus 1b is configured by the instrument transformer 3b and the main bus grounding switch 5b. Further, a first main bus line disconnector 4c is connected to an end of the auxiliary bus line 1c.

Finally, the arrangement of the external connection line E will be described with reference to FIG. That is, the first busbar disconnecting switch 4d and the work ground switch 6c are connected to the end of the main busbar 1a. The work ground switch 6c has a second
The busbar disconnecting switch 7b and the work ground switch 6d are connected. A connecting bus 2c is connected to these devices in a direction perpendicular to the axial direction of the main buses 1a and 1b.

An instrument current transformer 8c is provided at the end of the connecting bus bar 2c.
Is connected, and the circuit breaker 9b for external connection is connected via the current transformer 8c for measuring instrument. The circuit breaker 9b for external connection is a circuit breaker for forming a line to be connected to the outside,
It is arranged outside the auxiliary bus bar 1c (right side in FIG. 2). More specifically, the external connection circuit breaker 9b is formed with two branch connection portions 27, 28 in the up-down direction in a direction perpendicular to and opposite to the axial direction of the main buses 1a, 1b. The current transformer 8c and the connecting bus bar 2c are connected to the branch connection portion 27. On the other hand, a current transformer 8d for an instrument and a grounding switch 5e for a busbar are connected to the upper branch connection portion 28. Furthermore, the grounding switch 5c for busbars
A cable head 10 is connected to the. The external connection line E includes the above-mentioned components, that is, the first main bus line disconnector 4d and the first main bus line disconnector 4c shown in FIG.
Working ground switches 6c, 6d, second busbar disconnector 7
b, current transformers 8c and 8d for instruments, circuit breaker 9b for external connection,
It is composed of a busbar grounding switch 5c and a cable head 10.

[Operation and Effect] According to the present embodiment having the above-described structure, the following operation and effect can be obtained. That is, a line that connects two sets of main buses 1a and 1b to the external connection breaker 9b on the auxiliary bus 1c via the first main bus disconnectors 4c and 4d, respectively, and connects the breakers 9b to the outside. Can be configured. for that reason,
It is easy to connect and disconnect one of the two main buses 1a and 1b. Therefore, it is also possible to operate the first main bus and the second main bus in different systems.

Further, since the two disconnectors 4a to 4d are connected to each of the main buses 1a and 1b, the disconnector 4 is connected.
The inspection work of a to 4d can be performed only by stopping the main bus bar on one side. Further, the inspection work of the line E connected to the outside can be performed by disconnecting the two disconnecting switches 4c and 4d while operating the respective main buses 1a and 1b.

Further, by selectively operating the disconnectors 4c and 4d, only one main bus bar can be stopped, so that the external connection line E can be operated regardless of the stop of one main bus bar. is there. Therefore, the external connection line E can be effectively used as a line that constitutes a constantly operating circuit such as a starting transformer circuit of a power plant or a substation circuit of a substation.

Further, since the devices constituting the main bus lines D1 and D2, such as the instrument transformers 3a and 3b and the main bus grounding switches 5a and 5b, are arranged in the circuit of the bus section line A, FIG. The number of lines can be reduced as compared with the conventional configuration shown, and the installation area of the gas insulated switchgear can be significantly reduced.

Further, between the first main busbar disconnector 4a and the busbar breaker 9a, and between the first busbar disconnector 4d on the auxiliary busbar 1c and the external connection line breaker 9b. Since the other disconnecting switches 7a and 7b are installed respectively, for example, in the case of conducting a local withstand voltage test of the second main bus 1b during operation of the first main bus 1a, the The operating voltage can be separated by the two disconnectors 4a, 7a, 4d, 7b, and the field test can be safely performed. Moreover, since the work grounding switches 6a and 6c are arranged between the disconnecting switches 4a and 7a and between the disconnecting switches 4d and 7b, respectively, it is possible to ensure higher safety.

[Other Embodiments] The gas-insulated switchgear of the present invention is not limited to the above-described present embodiment. For example, in the above-mentioned present embodiment, a phase separation type is used. As described above, the same effect can be obtained also in the case of applying the three-phase collective type gas insulated switchgear. Further, as an embodiment corresponding to the invention of claim 2, the main busbars arranged on the same axis are also included. Further, as an embodiment corresponding to the invention of claim 5, it also includes one in which an auxiliary bus is arranged between two main buses, which contributes to a rational arrangement in which the arrangement of the auxiliary bus can be appropriately applied to various conditions. be able to.

[0055]

According to the gas-insulated switchgear of the present invention as described above, a disconnecting switch is connected to each of the two main busbars divided by the busbar-dividing circuit breaker, and a disconnector for external connection is provided between these disconnecting switches. It is possible to connect two main buses with each other and to configure a line that can be connected to both main buses with a minimum number of devices by an extremely simple configuration of connecting the devices. It can be made compact.

[Brief description of the drawings]

FIG. 1 is a single line connection diagram according to an embodiment of the present invention.

FIG. 2 is a plan view of the present embodiment.

FIG. 3 is a side view of OO in FIG.

FIG. 4 is a side view of P-P in FIG.

5 is a side view of Q-Q in FIG.

FIG. 6 is a single wire connection diagram of a general gas insulated switchgear.

7 is a plan view of a gas-insulated switchgear based on the single wire connection diagram shown in FIG.

FIG. 8 is a side view of XX in FIG.

9 is a YY side view of FIG. 7. FIG.

10 is a ZZ side view of FIG. 7. FIG.

[Explanation of symbols]

A ... Bus line section line B ... Normal line C ... Transformer line D, D1, D2 ... Main bus line E ... External connection line 1a, 1b, 101, 102 ... Main bus line 1c ... Auxiliary bus line 2a, 2b, 2c ... Connection bus line 3a, 3b, 30 ... Instrument transformers 4a, 4b, 4c, 4d, 41, 42 ... First busbar disconnectors 5a, 5b, 5c, 50, 51 ... Busbar grounding switches 6a, 6b, 6c, 6d, 61, 62, 63 ... Working grounding switch 7a, 7b ... Second busbar disconnecting switch 8a, 8b, 8c, 8d, 81, 82, 83 ... Instrument current transformer 9a, 90 ... For busbar segmenting Circuit breaker 9b, 91 ... Circuit breaker for external connection 10 ... Cable head 21, 22, 23, 24, 25, 26, 27, 28 ... Branch connection part

Claims (8)

[Claims] 1. A gas-insulated switchgear having a main busbar and a busbar section breaker for dividing the main busbar into two and connecting the main busbars to each other. A gas-insulated switchgear, characterized in that a disconnecting switch is connected to each of the two main busbars, and an external circuit breaker for forming a line to be connected to the outside is connected between the disconnecting switches. 2. A line having at least two lines
In a pair of single-bus type gas-insulated switchgear, the main bus bar is arranged on the same axis, the auxiliary bus bar is arranged in parallel with the main bus bar, and a disconnecting switch is connected to each of the main bus bar ends,
A busbar section breaker for connecting two main busbars is connected between these disconnectors, and each main busbar and the auxiliary busbar are connected via a disconnector to form a line for connecting to the outside. A gas-insulated switchgear, wherein an external circuit breaker is connected to the auxiliary bus bar. 3. A line having at least two lines
In a pair of single-bus type gas-insulated switchgears, main busbars are arranged so that their axes are parallel to each other and their ends overlap, and disconnectors are connected to the positions where the main busbars overlap, and the disconnector The connecting busbar is arranged in the direction perpendicular to the main busbar, the busbar section breaker for connecting the two main busbars is connected to the connecting busbar, and the auxiliary busbar is arranged in parallel with the main busbar. A disconnecting switch is arranged at a position where the busbar and each main busbar overlap, and an external circuit breaker for connecting the main busbar and the auxiliary busbar through these disconnectors to form a line to be connected to the outside is provided. A gas insulated switchgear which is connected to the auxiliary bus bar. 4. An instrument transformer and a grounding switch for the main bus are arranged at positions where the main bus and the auxiliary bus, which are arranged such that their axes are parallel to each other and whose ends are overlapped with each other, overlap each other. The gas-insulated switchgear according to claim 3, wherein 5. The gas insulated switchgear according to claim 3, wherein the auxiliary busbar is arranged between two main busbars. 6. The gas insulated switchgear according to claim 3, wherein the auxiliary bus bar is arranged outside two main buses. 7. A disconnector is arranged between the breaker for dividing the busbar and the disconnector on the main busbar, and between the disconnector on the auxiliary busbar and the breaker for external connection, respectively. The gas insulated switchgear according to claim 1, 2, 3, 4, 5 or 6. 8. A disconnector is provided between the breaker for dividing the busbar and the disconnector on the main busbar, and between the disconnector on the auxiliary busbar and the breaker for external connection, respectively. The gas-insulated switchgear according to claim 1, 2, 3, 4, 5 or 6, wherein a grounding switch is arranged between the disconnectors.