JP2000308220A - Gas-insulated switchgear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve bus-bar connections between a receiving unit, whose bus-bar lead-out positions are on its lower side and an MOF unit whose bus-bar entrance positions are on its upper side, reduce the size and weight of a row- arranged gas-insulated switchgear and realize workability improvement and cost reduction. SOLUTION: A gas-insulated switchgear has a receiving unit 1, in which an insulating gas is sealed and whose bus-bar lead-out position is on its lower side, and an air-insulating type MOF unit 2 whose bus-bar entrance position is on its upper side and both the units 1 and 2 are arranged in a row. Bus-bar lead-out terminals 22 of cable heads, etc., which are attached to the lower part of the side plate of the receiving unit 1 on the MOF unit side 2 to penetrate the side plate airtightly and whose inside ends positioned in the receiving unit 1, are connected to the bus-bars 3 of the receiving unit 1 and bus-bar connection elements between units (power cables 27), which comprise covered conductors such as power cables housed in the MOF unit, whose lower ends are connected to the outside ends of the bus-bar lead-out terminals 22 which are positioned in the MOF unit 2 and whose upper ends are connected to the bus-bars 4 of the MOF unit 2, are provided.

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 in which a power receiving unit having a lower bus lead-out position and an MOF unit having a higher bus lead-in position are formed on a train, and more particularly to a bus between the two units. Regarding the connection structure.

[0002]

2. Description of the Related Art Conventionally, in a gas insulated switchgear of 24/36 KV row type, a bus outlet position of a main circuit portion of a power receiving unit is located on an upper side or a lower side depending on a cable lead-in type, but is connected to the power receiving unit. When the MOF (power transformer for current supply and demand) is accommodated in the lower part of the unit, the bus lead position of the main circuit part of the MOF unit is limited to the upper side.

When the power receiving unit is a one-line power receiving unit of a cable ceiling lead-in type, the power receiving unit and the MOF unit are configured as shown in a skeleton of FIG.

In this case, the bus outlet position of the power receiving unit 1 and the bus outlet position of the MOF unit 2 are both on the upper side, and conversion of the bus position (bus conversion) is not required for bus connection between the units 1 and 2. , Units 1 and 2 are formed on adjacent rows, and the conductor of the bus 3 at the lead-out position of the power receiving unit 1 and the conductor of the bus 4 at the lead-in position of the MOF unit 2 are directly connected.

In the power receiving unit 1, a cable head 6 at the power receiving end is connected to the lead-in cable 5, and the head 6 is connected to a three-point disconnector 7, which operates as a grounding switch / disconnector, and a grounding switch for inspection. Gas circuit breaker 9 via circuit breaker 8
Is connected, and the conductor of the bus 3 is drawn out from the load side of the circuit breaker 9.

[0006] In the drawing, reference numeral 10 denotes a through-type current transformer attached to the lead-in cable 5, and reference numeral 11 denotes a voltage detector attached to the cable head 6.

The power receiving unit 1 is formed airtight using a bushing or the like, and the unit is partitioned into a plurality of gas compartments filled with an insulating gas (SF ₆ gas), and each gas compartment has a disconnector 7 and a switch. 8, main circuit components such as the circuit breaker 9 are accommodated.

On the other hand, the MOF unit 2
12 is formed in the air insulation method or the gas insulation method according to the insulation type.
Are connected to the terminals of the MOF 12.

Next, in the case where the power receiving unit is a one-line power receiving unit of a cable floor lead-in type, it is configured as shown in a skeleton of FIG.

[0010] In this case, since the bus outlet position of the power receiving unit 1 is on the lower side, the connection between the bus 3 located on the lower side of the power receiving unit 1 and the bus 4 located on the upper side of the MOF unit 2 is: Conventionally, a bus conversion unit 13 is used.

As shown in FIG. 6, in the unit 13, a connection port 14 opened at a lower portion of the side plate on the power receiving unit side is overlapped with a connection port 15 opened at a lower portion of the side plate on the MOF unit side of the power receiving unit 1. And is formed as a gas insulating unit integral with the power receiving unit 1, and is located between the power receiving unit 1 and the MOF unit 2.

The bus conversion unit 13 accommodates a vertical connecting conductor 16 such as a copper bar formed integrally with the bus 3 of the power receiving unit 1, and the upper end thereof is connected to the conductor of the bushing 17 of the MOF unit 2. The lever 4 is connected to the lead-in end of the bus 4 of the MOF unit 2.

FIG. 6 shows a structure in which the MOF unit 2 is of the air insulation type. The MOF 12 accommodated in the lower part of the MOF unit 2 has the terminals of the terminal parts 12 'of the respective phases on the upper left side. It is connected to the bus bar 4 shown in FIG.

As shown in the left side view of FIG. 7 (a) and the schematic cut front view of FIG. 7 (b), the bus conversion unit 13 has a rectangular container structure. Are formed with a plurality of connection ports, and the work handhole is hermetically closed by a cover plate 19. In the figure, reference numeral 16 'denotes a conductor of each phase of the connection conductor 16, and reference numeral 20 denotes a plurality of support insulators for keeping the insulation distance of the connection conductor 16.

[0015]

In the case of this type of conventional row-panel type gas insulated switchgear, if the power receiving unit is a single-line power receiving unit of a cable floor retract type, FIG.
As shown in FIG. 7, it is necessary to connect the bus conversion unit 13 to the power receiving unit 1 and provide the bus conversion unit 13 between the power receiving unit 1 and the MOF unit 2 to convert the bus position from the lower side to the upper side. .

At this time, the bus conversion unit 13 is formed in a relatively large and heavy metal rectangular container structure in order to accommodate the connection conductor 16 while keeping the insulation distance, and furthermore, the insulating gas is sealed therein.

Therefore, there is a problem that the large and heavy bus conversion unit 13 is required, the gas insulated switchgear becomes large and heavy, and the cost is increased.

When the MOF unit is of the gas insulation type, a gas-insulated bus conversion unit having an airtight rectangular container structure similar to that of the bus conversion unit 13 is required.

In the case of two-line power reception, for example, FIG.
As shown in (a) and (b), the bus conversion unit 13 is conventionally used, and has the same problem as in the case of single-line power reception.

FIG. 8A shows a skeleton in the case of two-line regular standby power receiving of the 1MOF system, and the power receiving unit 1 '.
Is composed of a two-line unit having a configuration in which a disconnecting switch 7 'similar to the disconnecting switch 7 is added to the power receiving unit 1, and the common bus 3 and the bus 4 of the MOF unit 2 are connected via the connecting conductor 16 of the bus conversion unit 13. Connected.

FIG. 8B shows a skeleton in the case of two-line regular standby power supply of the 2MOF system. In this case, two sets of power receiving units 1 and MOF units 2 are provided, and a bus between each unit 1 and 2 is provided. A conversion unit 13 is provided.

According to the present invention, in a gas insulated switchgear of a row type in which a bus outlet of a power receiving unit is at a lower side, a bus connecting structure between the power receiving unit and the MOF unit is improved to reduce the size and weight and to improve workability. It is an object to improve the cost and reduce the cost.

[0023]

According to the present invention, there is provided a gas-insulated switchgear according to the present invention.
In the case of, the insulating gas is sealed and the power receiving unit whose bus outlet is on the lower side and the air-insulated M unit whose bus outlet is on the upper side
The OF unit is formed on the side panel, and the MO of the power receiving unit is
Airtightly penetrates the lower part of the side plate on the F unit side,
A bus lead terminal such as a cable head having a bus bar of the power receiving unit connected to an end located in the power receiving unit;
An inter-unit bus connector composed of a coated conductor such as a power cable housed in the unit, the lower end of which is connected to the outer end of the bus lead terminal located inside the MOF unit, and the upper end of which is connected to the MOF unit bus. Prepare.

Therefore, the bus at the lower lead-out position of the power receiving unit and the bus at the upper lead-in position of the MOF unit are connected by an inter-unit connecting conductor of a coated conductor such as a power cable housed in the MOF unit. .

In this case, the conventional large and heavy bus conversion unit is not used, and the power receiving unit and the MOF unit are formed on the adjacent row, and the bus connection unit between the covered units in the MOF unit. The required insulation distance is significantly shorter than the bare connection conductor such as a copper bar of the bus conversion unit, and the storage space is extremely small.
The MOF unit can be efficiently accommodated by utilizing the empty space.

Therefore, in the gas insulated switchgear having the MOF unit of the air insulation type, the size and weight can be reduced, the workability can be improved, and the cost can be reduced.

According to a second aspect of the present invention, in the gas insulated switchgear of the first aspect, a connector on the extraction side connected to the outer end of the bus extraction terminal and having an insertion port facing upward,
A plug-in connector connected to the lead-in end of the bus of the unit, the plug-in connector facing downward so that the plug-in port faces the plug-in port of the connector on the pull-out side; Insert the lower end and upper end of the connection body and connect them.

Therefore, in this case, the lower end and the upper end of the inter-unit bus connector are the bus lead terminals of the power receiving unit, and the
A connector is connected to the lead-in end of the bus of the F unit, and the bus connection between the units can be performed very easily, so that the workability at the time of manufacturing is further improved.

Further, in the case of the third aspect, in the gas insulated switchgear of the first aspect, it is connected to the outer end of the bus lead-in terminal, and the lower end of the inter-unit bus connector is connected to the insertion port. And an upper end of the inter-unit bus connection body is formed in a bushing terminal, and is directly connected to the lead-in end of the bus of the MOF unit.

Therefore, in this case, when the inter-unit bus connection body is a flexible coated conductor such as a power cable, the number of components can be further reduced, and the bus connection between the units can be performed easily and cheaply.

Next, in the case of claim 4, the bus is arranged in the power receiving unit in which the insulating gas is sealed and the bus outlet is on the lower side, and the bus is arranged in the upper connection container portion in which the insulating gas is sealed and the bus inlet position. Is a gas-insulated MOF unit on the upper side, which is formed in a row board, is airtightly penetrated and attached to the lower part of the side plate on the side of the MOF unit of the power receiving unit, and has a bus of the power receiving unit at an inner end located in the power receiving unit. A bus lead terminal such as a cable head to which is connected and an airtightly penetratingly attached to an end plate of the connection container portion on the power receiving unit side, and a bus of the connection container portion is connected to an inner end located in the connection container portion. And a covered conductor such as a power cable provided outside of both units.
An inter-unit bus connector having a lower end connected to the outer end of the bus lead terminal and an upper end connected to the outer end of the bus lead terminal.

Therefore, when the power receiving unit and the MOF unit are both gas-insulated units and the power receiving unit has a lower line drawing position and the MOF unit has a higher line drawing position, the power outside the unit can be reduced. The buses of both units are connected by an inter-unit bus connection body of a coated conductor such as a cable.

Therefore, even when the MOF unit is a gas-insulated system similar to the power receiving unit, the bus between the two units can be connected without using a conventional large and heavy bus conversion unit. The same effect as in the case of 1 can be obtained.

Further, In the case of claim 5, in the gas insulated switchgear of claim 4, the connector is connected to the outside end of the bus lead-out terminal, and has an outlet facing upward, and the outside end of the bus lead-in terminal. A connector on the drop-in side facing down so that the plug-in port faces the connector on the pull-out side. The lower and upper ends of the inter-unit bus connector are inserted into the plug-in ports of both connectors and connected. .

Therefore, in this case, when the MOF unit is a gas-insulated unit, the inter-unit bus connector can be connected to the power receiving unit and the bus of the MOF unit by connector connection. Is obtained.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.
This will be described with reference to FIG. (First Embodiment) First, a first embodiment of the present invention will be described with reference to FIG. Figure 1 shows the MOF unit 2
5 shows the structure of the power receiving unit 1 and the MOF unit 2 in the case of the air insulation method. In the same figure, the same reference numerals as those in FIGS.

In the case of FIG. 1, the power receiving unit 1 and the MOF
The unit 2 is formed on an adjacent row, and the bus conversion unit 13 shown in FIGS. 5 to 7 is not provided.

The connection opening 15 formed in the lower part of the side plate on the MOF unit side of the power receiving unit 1 is closed by a cover plate 21, and a bus lead terminal 22 formed of a cable head is attached to the cover plate 21 in an airtight manner. Can be

The extraction terminal 22 has an inner end (tip).
Are located in the power receiving unit 1, the terminal conductor is connected to the end of the bus 3, and the outer end is located in the MOF unit 2 through the open connection port 23 of the MOF unit 2.

On the other hand, a support plate 24 is attached to the lower surface of the top plate of the MOF unit 2, and a bushing 17 'instead of the bushing 17 shown in FIG. A bus 4 is provided between them.

Further, an L-shaped lead-side connector 25 is attached to the outer end of the lead-out terminal 22 with the insertion port facing upward, and an L-shaped lead-side connector 26 is attached to the conductor end of the bushing 17 '. The insertion ports are attached with the insertion ports facing downward, and the insertion ports of both connectors 25 and 26 face each other.

The MOF unit 2 accommodates a vertical power cable 27 as a covering conductor. The lower end of the cable 27 is inserted into the insertion port of the connector 25 and connected to the bus 3, and the upper end of the cable 27 is connected to the connector 26. Of the bus 4 is connected to the insertion end of the bus 4.

At this time, the power cable 27 is covered,
Since it is not necessary to provide a sufficient insulation distance as in the case of the connection conductor 16 in FIG. It is omitted and stored in the MOF unit 2 along the side plate of the unit 2.

Therefore, in the case of the first embodiment, the lower bus 3 of the gas-insulated power receiving unit 1 and the upper bus 4 of the MOF unit 2 of the air-insulated system are connected to the conventional bus conversion unit 13. The connection is made by a simple connector connection by the power cable 27 as the inter-unit bus connector housed by efficiently utilizing the empty space in the MOF unit 2 without providing the power supply unit.

In this case, the large and heavy bus conversion unit 13 can be omitted, and the covered power cable 27 can be efficiently accommodated in the MOF unit 2 by utilizing the empty space. Thus, the size, weight, and cost of the gas insulated switchgear can be reduced.

Specifically, downsizing of 400 mm corresponding to the board width (width in the left-right direction) of the bus conversion unit 13 and weight reduction of 300 to 500 kg corresponding to the weight of the container are achieved. A cost reduction equivalent to the cost of the thirteen containers and the insulating gas is achieved.

Further, by omitting the bus conversion unit 13, the number of parts of the gas insulated switchgear is reduced. In addition, since the power cable 27 is formed by connecting the connector, the working efficiency during manufacturing and the like can be improved. There are advantages too.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. 2, the same reference numerals as those in FIG. 1 denote the same or corresponding components. In this embodiment, a power cable 28 with a bushing terminal is used instead of the power cable 27 in FIG.

The power cable 28 has the same lower end as the power cable 27 and is inserted into the insertion port of the connector 25 and connected to the bus 3 of the power receiving unit 1, but the upper end is formed at the bushing terminal 28 '. And this bushing terminal 2
8 'is connected directly to the lead-in end of the
It is connected to the terminal on the primary side of OF12.

Therefore, in this embodiment,
The connector 26 and the like on the upper side in FIG. 1 can be omitted, and there is an advantage that the number of parts is further reduced and the system is simplified.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIG. 3, the same reference numerals as those in FIGS. 1 and 2 denote the same or corresponding components. This embodiment is applied to the case of the gas-insulated type MOF unit 2 ', and the power receiving unit 1 and the MOF unit 2' are formed on adjacent rows.

A bus lead-out terminal 22 is attached to the lid plate 21 provided below the side plate on the side of the MOF unit of the power receiving unit 1 in an airtight manner, as in the first and second embodiments. A connector 25 is connected to and supported by the outer end with the insertion port facing upward.

On the other hand, the MOF unit 2 'accommodates a gas insulation type MOF 12 in the lower part, and the bus 4 is disposed in a connection container part 29 in which an insulation gas (SF ₆ gas) is sealed above the MOF 12.

The power receiving unit 1 of the connection container 29
A bushing 30 is hermetically penetrated and attached to the lid plate 29 'as an end plate on the side, and the lead-in end of the bus bar 4 is connected to the conductor at the inner end thereof.

Further, an L-shaped connector 26 is attached to the outer end of the bushing 30 with the insertion port facing downward, and the insertion ports of the connectors 25 and 26 face each other.

Then, the lower end and the upper end of the power cable 27 are inserted into the outlets of the air connectors 25 and 26 outside the units 1 and 2 ', and the buses 3 and 4 are connected via the air power cable 27. Is connected.

In order to prevent the power cable 27 between the units 1 and 2 'from increasing in size, the connection container 2
9 is formed with a dimension in the generatrix direction (the left-right direction in the figure) shorter than that of the related art.

Therefore, in the case of using the gas-insulated type MOF unit 2 ', the bus conversion unit 1
3, the bus connection between the units 1 and 2 'can be performed, and the power cable 27 does not increase the size of the MOF unit 2' or the like.
The same effect as in the first embodiment using the OF unit 2 can be obtained.

Incidentally, the power cable 2 of each of the above forms
The cables 7 and 28 may be so-called cable with connectors integrated with the connectors 25 and 26.

The unit-to-unit bus connecting body may be a covered conductor other than the power cable, for example, a so-called molded conductor in which a conventional connecting conductor such as a copper bar is covered (molded). The connection with the busbars 3, 4 and the like need not be a connector connection.

In each of the above embodiments, the case of one-line power receiving including the power receiving unit 1 and the MOF unit 2 or 2 'has been described. However, the present invention provides, for example, FIGS. In the case of receiving two lines, the same can be applied to the case of receiving multiple lines of three or more lines.

Incidentally, for example, the bus (cable) drawn from the MOF unit 2 is drawn into the transformer unit (Tr unit) of the train board. At this time, the direction of drawing the cable of the Tr unit is restricted, and the bus is drawn. If the position is different from the position where the bus bar of the MOF unit 2 is pulled out, as shown by a two-dot chain line in FIG.
1, it is necessary to interpose a bus conversion unit 13 'similar to the bus conversion unit 13. Instead of using this unit 13', for example, the connectors 25 and 26 and the power cable 27 shown in FIG. It is also possible to apply the bus connection structure of the present invention, and in this case, the same effect is obtained.

In FIG. 5, reference numeral 32 denotes a connecting conductor of the bus conversion unit 13 '.
disconnectors 33 and 34, cable head 3 of r unit 31
5 is connected, and this cable head 35 is connected to a transformer (T
r).

[0064]

The present invention has the following effects. First, in the case of claim 1, the bus 3 at the lower drawing position of the power receiving unit 1 and the bus 4 at the upper drawing position of the MOF unit 2 are covered with the power cable 27 or the like housed in the MOF unit 2. In this case, the power receiving unit 7 and the MOF unit 2 are formed on adjacent rows without the conventional large and heavy bus conversion unit, and the MOF unit 2, the insulation distance required for the covered inter-unit bus connector in the bus conversion unit is significantly shorter than the bare connection conductor such as a copper bar of the bus conversion unit, the storage space is extremely small, and the free space of the MOF unit is small. Can be stored efficiently.

Therefore, in the gas-insulated switchgear of the MOF unit 2 in the form of a row of air-insulated systems, the size and weight can be reduced, the workability can be improved and the cost can be reduced.

In the case of claim 2, in the structure of claim 1, the connector 25 on the drawing side and the connector 2 on the drawing side
6 and the lower and upper ends of the inter-unit bus connector are inserted and connected to the insertion ports of both connectors 25 and 26, so that the lower and upper ends of the inter-unit bus connector are connected to the bus lead terminals 22, MOF of the power receiving unit 1. By connecting a connector to the lead-in end of the bus 4 of the unit 2, the bus connection of the units 1 and 2 can be performed very easily, and workability during manufacturing is further improved.

Further, in the case of the third aspect, in the configuration of the first aspect, the connector 25 is provided, and the upper end of the inter-unit bus connector (power cable 28) is formed on the bushing terminal 28 'to form the MOF unit 2 Is connected directly to the lead-in end of the bus 4, and when the bus connection between units is a flexible coated conductor such as a power cable, the number of parts is further reduced and the bus connection between units can be reduced and easily. It can be carried out.

Next, in the case of claim 4, the power receiving unit and the MOF unit are both gas-insulated units 1 and 2.
2 ′ and the power receiving unit 1 has the
When the bus pull-in position of the OF unit 2 'is an upper row structure, the buses 3 and 4 of both units 1 and 2' are connected by a unit-to-unit bus connecting body of a coated conductor such as a power cable 27 outside the unit. Can be.

Therefore, when the MOF unit is a gas-insulated unit 2 ′ similar to the power receiving unit 1,
The buses 3 and 4 of both units 1 and 2 'can be connected without using a conventional large and heavy bus conversion unit, and the same effect as in the first embodiment can be obtained.

Further, in the case of claim 5, in the structure of claim 4, since the lower end and the upper end of the inter-unit bus connector are inserted and connected to the insertion ports of the connectors 25 and 26, the inter-unit bus connector is connected. Power receiving unit 1, M by connector connection
Can be connected to the buses 3 and 4 of the OF unit 2 ',
It can be formed more easily.

[Brief description of the drawings]

FIG. 1 is a schematic structural explanatory view of a part of a first embodiment of the present invention.

FIG. 2 is a schematic structural explanatory view of a part of a second embodiment of the present invention.

FIG. 3 is a schematic structural explanatory view of a part of a third embodiment of the present invention.

FIG. 4 shows a skeleton of a conventional example in which a cable receiving a single line is pulled into a ceiling.

FIG. 5 is a skeleton of a conventional example in which a cable floor of one line is received.

FIG. 6 is a schematic structural explanatory view of a part of FIG. 5;

7A and 7B are a schematic left side view and a cutaway front view of the bus conversion unit of FIG.

FIGS. 8A and 8B are skeletons of a conventional example of two-line power reception.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1 'Power receiving unit 2, 2' MOF unit 3, 4 Bus 12 MOF 22 Bus lead terminal 25 Connector on lead side 26 Connector on lead side 27, 28 Power cable 28 'Bushing terminal 29 Connection container part

Claims (5)

[Claims] 1. A power receiving unit in which an insulating gas is filled and a bus outlet position is lower, and an MOF unit of an aerial insulation type in which a bus outlet position is upper is formed on a row board, and the MOF of the power receiving unit is formed. A bus lead terminal, such as a cable head, which is attached to the lower part of the side plate on the unit side in an airtight manner and is connected to a bus of the power receiving unit at an inner end located inside the power receiving unit, and is housed in the MOF unit. A lower end is connected to an outer end of the bus lead-out terminal located in the MOF unit, and an upper end is formed of the M conductor.
A gas insulated switchgear comprising: an inter-unit bus connector connected to a bus of an OF unit. 2. A connector on the drawing side connected to the outside end of the bus lead terminal and having an insertion port facing upward, and connected to the drawing end of the bus of the MOF unit, and the insertion port is connected to the drawing side. A plug-in connector facing downward so as to face the insertion port of the connector, wherein the lower end and the upper end of the inter-unit bus connection body are inserted into the insertion ports of the two connectors to be connected. The gas insulated switchgear according to claim 1, wherein 3. A connector which is connected to the outer end of the bus lead-in terminal and has a connector into which the lower end of the inter-unit bus connector is inserted and connected, and the upper end of the inter-unit bus connector is connected to the connector. 2. The gas insulated switchgear according to claim 1, wherein the gas insulated switchgear is formed on a bushing terminal and is directly connected to a lead-in end of a bus of the MOF unit. 4. A gas-insulated system in which an insulating gas is sealed and a bus outlet is located at a lower position, and a bus is disposed in an upper connection container section in which the insulating gas is sealed, and the bus is drawn in an upper position. A MOF unit is formed on a side panel, and is mounted airtightly below a lower side plate of the power receiving unit on the side of the MOF unit, and a bus of the power receiving unit is connected to an inner end located in the power receiving unit. A bus lead terminal such as a cable head, and an airtightly penetratingly attached to an end plate of the connection container portion on the power receiving unit side, and a bus of the connection container portion is connected to an inner end located in the connection container portion. And a coated conductor such as a power cable provided outside the both units, the lower end of which is connected to the outer end of the bus outlet terminal, and the upper end of which is the busbar. A gas insulated switchgear comprising: an inter-unit bus connecting member connected to an outer end of the drop-in terminal. 5. A connector connected to and supported by an outer end of the bus lead terminal and having an insertion port facing upward, and a connector connected to and supported by an outer end of the bus lead terminal. And a plug-in connector facing downward so as to face the insertion port of the connector on the pull-out side. The lower end and the upper end of the inter-unit bus connector are connected to the insertion ports of the two connectors. The gas insulated switchgear according to claim 4, wherein