JP2002034110A - Transformer apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a transformer apparatus that enables reduction of installation time on site and to shorten a power interruption time for a change-over work to a stand by transformer. SOLUTION: The primary windings of transformers 31 to 33 of single phase provided in each of units 1 to 4 are connected in delta by the fixing part 18 and removing part 19 of a change-over bus 16 and by three units of disconnectors 21 to 23. The secondary windings are Y-connected by single-pole double-throw switches 41 to 43 and a secondary change-over bus 45. When the transformer 31 is changed over to the standby transformer 34, for example, the power interruption time for the change-over can be shortened, because the disconnector 21 is opened to connect the stand transformer with a selective switch 24. When transported, the removing part 19, the secondary change-over bus 45, a neutral point connecting wire 47 and a connecting wire 48 are removed, so as to divide the apparatus into individual units 1 to 4. The installation time can be reduced, because the apparatus can be transported in units and it merely needs to simply install in place the removed part 19 and 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 substation, particularly a substation configured by combining a plurality of single-phase transformers.

[0002]

2. Description of the Related Art In conventional transformers, generally, a plurality of three-phase transformers are installed, some of them are used as service transformers, and others are used as spare transformers. In such a case, a system for switching to a backup transformer is employed. In such a device, there is a problem that a three-phase backup transformer must be provided, and the installation space is increased and the equipment cost is increased.

Further, instead of placing a three-phase backup transformer, for example, as shown in Japanese Patent Application Laid-Open No. Hei 8-214421, three regular single-phase transformers and one backup single-phase transformer are provided. In order to reduce the installation space and equipment costs, in the case of maintenance or failure of the single-phase working transformer, without moving the single-phase working transformer and spare single-phase transformer,
In some cases, the service transformer can be switched to the spare single-phase transformer in a short time.

[0004]

However, in the above-described substation apparatus composed of a plurality of single-phase transformers, when switching from the working transformer to the standby transformer,
The work to change the connection to the primary common bus that is stretched over the anchors supported by the stranded iron structure must be performed, and preparation of working crane trucks, etc. is required for the connection change work at high places,
In addition, since the connection was changed manually, there was naturally a limit in shortening the power outage time for the switching work.

[0005] Further, Japanese Unexamined Patent Application Publication No. 8-214421 discloses a transformer in which both a working transformer and a spare transformer are connected to an air-insulated power transmission line, and the installation space is reduced. It could not meet the demands for reduction and reduction of installation work on site.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems and can reduce the installation time on site, facilitate quality assurance, and shorten the power outage time for switching to a spare transformer. The aim is to obtain a device.

[0007]

In order to achieve the above-mentioned object, in a substation according to the present invention, there is provided a first to third transformers each having a single-phase working transformer having primary and secondary windings. A unit, a fourth unit provided with a single-phase backup transformer having primary and secondary windings, and a power receiving switchgear provided in at least one of the four units and receiving three-phase power A power distribution switchgear provided in at least one of the first to fourth units to distribute three-phase power, a primary side provided over at least three units of the first to fourth units Three-phase connection of the primary winding of the service transformer connected to the connection switching line and this primary-side connection switching line to connect to the switchgear for power reception, and a spare in place of any one primary winding of the service transformer Primary winding of transformer A primary-side connection switching device having a primary-side switching switch that can be switched to a secondary-side connection switching line provided over at least three of the first to fourth units; The secondary winding of the three-phase connected working transformer connected to the secondary connection switching line is connected in three-phase connection to the distribution switchgear, and any one primary winding of the working transformer is used as a spare. A secondary-side connection switching device having a secondary-side switching switch that is switchable to the secondary winding of the backup transformer instead of the secondary winding of the service transformer when switched to the transformer. Each unit is configured to be transportable by removing at least a part of the primary-side connection switching device and the secondary-side connection switching device from each unit. Switching from the service transformer to the backup transformer is performed by the primary side switching switch and the secondary side switching switch. Since the connection work does not need to be performed and can be performed quickly, the power outage time for switching can be shortened. Also, at the site, it is only necessary to attach at least a part of the removed primary-side connection switching device and secondary-side connection switching device to each unit, which can shorten the installation time on site and reduce the number of assembly parts on site, so quality assurance Is easy.

The power receiving switchgear, the primary side connection switching line, and the primary side switchgear have their conductive parts housed in a housing case in which an insulating gas is sealed. The side-connection switching line and the secondary-side switching switch are characterized in that their conductive parts are air-insulated with a shielding case. If a unit in which an insulating gas is sealed is used, each unit can be reduced in size and transportation can be facilitated. In addition, if air-insulated ones are employed, the work of attaching and detaching them is easy, and the working time in the field can be further reduced.

Further, the primary-side connection switching line is a three-phase primary-side switching bus detachably connected to the power receiving switching device, and the primary-side switching switch is detachably connected to the primary-side switching bus. A primary-side triangular connection switch and a primary-side switch, which are provided in each unit corresponding to the service transformer and connect each terminal of the primary winding of the service transformer to a predetermined phase of the primary switching bus to form a triangular connection, respectively. A primary-side selection switch, which is detachably connected to the side-switching bus and is adapted to connect each terminal of the primary winding of the spare transformer to an arbitrary phase of the primary-side switching bus. Each unit can be transported by removing at least a part of the secondary-side connection switching device and the primary-side switching bus. Since the primary-side switching switch is provided in each unit corresponding to each service transformer, the size of each unit is equalized, and transport becomes easy. When the primary side has a triangular connection, each unit can be transported by removing at least a part of the secondary side connection switching device and the primary side switching bus.

The secondary-side connection switching line has a three-phase secondary-side switching bus, a secondary-side neutral point connection line, and a backup transformer secondary-side connection line, and has a secondary-side switching bus. Is detachably connected to the distribution switchgear, and the secondary neutral point connection line is connected in common to one terminal of each of the secondary windings of the service transformer and the standby transformer, and the secondary side of the standby transformer The connection wire is detachably connected to the other terminal of the secondary winding of the spare transformer, and the secondary-side switching switch is connected to the secondary-side switching bus and the secondary side of the spare transformer. The other terminal of the secondary winding of the service transformer is detachably connected to the wire and corresponds to each service transformer, and the other terminal of the secondary winding of the service transformer is connected to a predetermined phase of the bus for switching on the secondary side, respectively. Connect and disconnect the other terminal of any service transformer to the other terminal of the spare transformer via the secondary connection line of the spare transformer. In addition, each unit has a secondary-side star-connection switch that can be connected to a predetermined phase of the secondary-side switching bus, and each unit has a primary-side switching bus, a secondary-side switching bus, and a secondary-side switching bus. It is characterized in that it can be transported by removing the secondary side neutral connection line and the secondary connection line for the backup transformer. The secondary-side switching switch is provided in each unit corresponding to each service transformer, so that the size of each unit is equalized and transportation becomes easy. If the primary side has a triangular connection and the secondary side has a star connection, each unit has a primary switching bus, a secondary switching bus, a secondary neutral point connection line, and a spare transformer secondary connection line. And can be transported.

The primary-side connection switching line has a three-phase primary-side switching bus, a primary-side neutral point connection line, and a backup transformer primary-side connection line, and the primary-side switching bus is a power distribution switchgear. The primary-side neutral point connection line is connected to one terminal of each of the primary winding of the service transformer and the backup transformer, and the primary connection line of the backup transformer is connected to the backup transformer. The primary side switching switch is detachably connected to the other terminal of the primary winding, and the primary side switching switch is detachably connected to the primary side switching bus and the standby transformer primary side connection line and corresponds to each service transformer. The other terminal of the primary winding of the service transformer provided in each unit is connected to a predetermined phase of the primary switching bus to form a star connection, and the other terminal of any service transformer is connected. Disconnect the other terminal of the backup transformer via the primary connection line of the backup transformer. Alternatively, a primary star connection switch which can be connected to a predetermined phase of the primary switching bus, wherein each unit includes at least a part of the secondary connection switching device and the primary switching It is characterized in that it can be transported by removing the bus bar, the primary side neutral point connecting line and the primary side connecting line. Since the primary-side switching switch is provided in each unit corresponding to each service transformer, the size of each unit is equalized, and transport becomes easy. Also, when the primary side is a star connection, each unit can be transported by removing at least a part of the secondary side connection switching device, the primary side switching bus, the primary side neutral point connection line and the primary side connection line. Become.

Further, the secondary-side connection switching line is a three-phase secondary-side switching bus removably connected to the power receiving switching device, and the secondary-side switching switch is detachably connected to the secondary-side switching bus. Possible and connected to each unit in correspondence with each service transformer, each terminal of the secondary winding of the service transformer is connected to a predetermined phase of the bus for switching on the secondary side to form a triangular connection. The secondary triangular connection switch and the secondary switching bus are detachably connected to each other so that each terminal of the secondary winding of the spare transformer can be connected to an arbitrary phase of the secondary switching bus. Each unit is made transportable by removing the primary-side switching bus, the primary-side neutral connection line, the primary-side connection line, and the secondary-side switching bus. Characterized in that: The secondary-side switching switch is provided in each unit corresponding to each service transformer, so that the size of each unit is equalized and transportation becomes easy. If the primary side has a star connection and the secondary side has a triangular connection, each unit is transported by removing the primary-side switching bus, the primary-side neutral point connection line, the primary-side connection line, and the secondary-side switching bus. Will be possible.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a connection diagram of a transformer, and FIG. 2 is a detailed connection diagram of a backup transformer. FIG. 3 is a layout view of the substation, FIG. 3A is a plan view, and FIG. 3B is a side view. FIG. 4 is a plan view showing details of a portion for removing the switching bus. FIG. 5 is an explanatory view for explaining the installation procedure. FIG.
(B) is a side view. FIG. 6 is a connection diagram showing a connection state when switching to the backup transformer.

In this embodiment, for example, a receiving voltage (primary voltage) of 132 kV, a distribution voltage (secondary voltage) of 11 kV, and a transformer bank capacity (total capacity of three single-phase working transformers) of 60 MVA The connection of the three single-phase service transformers is triangular connection (Δ connection) on the primary side and star connection (Y connection) on the secondary side, and is a neutral point direct grounding method.

First, the connection on the primary side will be described with reference to FIG. In FIG. 1, a three-phase two-line power transmission cable 11a,
Electric power is supplied from 11b to the three-phase bus 14 via the switching devices 13a and 13b. The switching devices 13a and 13b are
Although not shown, each has a disconnecting switch unit, a circuit breaker unit, and a grounding switch unit. The connection part 17 of the three-phase switching bus 16 is connected to the three-phase bus 14 via a three-pole disconnector 15. Although details will be described later, the switching bus 16 is shown in FIG.
As shown in FIG. 1A, a connecting portion 17, a fixing portion 18, and a removing portion 19 are provided.

A switching bus 16 as a primary connection switching line
, Three single-phase oil-filled service transformers 31, 32, 33 are connected via two-pole disconnectors 21, 22, 23 as primary-side switching switches and primary-side star-connected switches. I have. The disconnectors 21, 22, and 23 are normally closed, and the three service transformers 31, 32, and 33 have a primary-side Δ-connection.

The single-phase oil-filled spare transformer 34 has four primary terminals (hereinafter referred to as U terminals and V terminals) via the four-position selection switch 24. T
It can be connected to either phase. Of the four positions of the selection switch 24, one of the positions is such that the U terminal and the V terminal of the backup transformer 34 are connected to the R, S,
T is not connected to any phase.

That is, the selection switch 24 has a pair of selector switches 24a and 24b as shown in FIG.
The U and V terminals of the backup transformer 34 are connected to the selector switches 24a and 24b. Selector switch 2
4a and 24b are selected such that the U and V terminals on the primary side of the backup transformer 34 are not normally connected to any of the R, S and T phases of the switching bus 16;
4 is in a state of being disconnected from the switching bus 16. The selector switches 24a and 24b each have a metal container in which sulfur hexafluoride gas is sealed as an insulating gas.
An arbitrary one of the four positions can be selected independently of each other by operating the handle from outside the metal container.

The switching devices 13a, 13 described above
b, the three-phase bus 14, the disconnector 15, the switching bus 16, the disconnectors 21 to 23, and the selector switch 24, all of which have a conductive part as a storage case in which sulfur hexafluoride gas is sealed as an insulating gas. They are of the gas-insulated type housed in a metal container and constitute a gas-insulated switchgear.

Next, the connection on the secondary side will be described. The three single-pole double-throw switches 41, 42, and 43 as secondary switching switches and secondary star connection switches have a total of three terminals, a common terminal and terminals on one side and the other. Each of the terminals has a terminal, and the switching closes the circuit between the common terminal and the terminal on one side or between the common terminal and the terminal on the other side. One of the secondary terminals of the working transformers 31, 32, 33 (hereinafter referred to as u terminal) is connected to one terminal of the single pole double throw switch 41, 42, 43, respectively.

The common terminals of the single-pole / double-throw switches 41, 42 and 43 are connected to the r, s and t phases of the secondary bus 46 via the secondary switching bus 45, respectively. The terminals are respectively connected to connection lines 48 described later. The other of the terminals on the secondary side of the working transformers 31, 32, 33 (hereinafter, referred to as v terminal) and the v terminal of the spare transformer 34 described later are commonly connected by a neutral point connection line 47, Directly grounded.

In the standby transformer 34, one of the terminals on the secondary side (hereinafter referred to as u terminal) is connected to a connection line 48 as a secondary connection line for the standby transformer, and the other terminal (hereinafter referred to as v terminal). ) Are commonly connected to the respective v terminals of the above-mentioned service transformers 31, 32 and 33 by a neutral point connection line 47.
The single-pole / double-throw switches 41, 42, and 43 are normally connected to one terminal side to electrically connect the common-side terminal and the one-side terminal. That is, the three service transformers 31 to 33 are Y-connected. The v terminal of the spare transformer 34 is in an open state.

The secondary bus bar 46 has a plurality of switchgears 49a having an air-insulated disconnector and an air circuit breaker or a vacuum circuit breaker housed in a metal box as a shielding case.
Is connected to the switchboard, and power is distributed to the load. The single-pole / double-throw switches 41 to 41 described above are used.
43, the secondary-side switching bus 45, the secondary-side bus 46, the neutral point connection line 47, and the connection line 48 are of an air-insulated type covered with a metal case.

Next, the arrangement of the substation will be described with reference to FIGS. In FIG. 3, the substation includes four units 1 to 4 and a switching bus 16 on the primary side for gas insulation connecting these units 1 to 4, a secondary switching bus 45 for aerial insulation, and a secondary side. It has a bus bar 46, a neutral point connection line 47, and a connection line 48.

The units 1 to 4 are almost the same size,
For example, primary voltage 132 kV, secondary voltage 11 kV, capacity 6
0MVA (Total capacity of three service transformers 31-33)
In the substation of the degree, the size of each unit is 3.
It is about 4m x 10m in height x 4.5m in height, and is sized to be disassembled into units and transported to the installation site. Note that the connection relationship between the devices is as described in FIGS. 1 and 2, and thus the description thereof will be omitted in the following description unless particularly necessary.

First, details of the unit 1 will be described. The cables 11a and 11b are pulled in on the gantry 1a to the upper left in FIG.
3b. Each of the switching devices 13a and 13b has a three-phase disconnecting switch, a circuit breaker, and a grounding switch. The circuit breakers are arranged vertically, that is, perpendicular to the mounting surface of the gantry 1a.

The three-phase buses 14 of the three-phase package form the R, S, and T phases in a cylindrical container filled with an insulating gas (see FIG. 1).
The conductor is disposed adjacent to the opening / closing devices 13a and 13b in the vertical direction in FIG. 3A and parallel to the mounting surface of the gantry 1a. The three-phase collective gas-insulated disconnector 15 is disposed at the same height as the three-phase bus 14 so that the opening and closing direction from the three-phase bus 14 is the left-right direction in FIG.

The three-phase switching bus 16 has a connecting portion 17, a fixing portion 18, and a detaching portion 19. After the connecting portion 17 is connected to the disconnector 15 and once rises from the disconnector 15, FIG.
As shown in (a), the fixing portion 18 is extended in the horizontal direction toward the service transformer 31. The removal unit 19
As shown in FIG. 5, it has flange portions 19a to 19d, and as shown in FIG.
6 are detachably connected at the flange portion 18a of the fixing portion 18.

The single-phase service transformer 31 is an oil-feed air-cooled type, has a transformer main body 31a, a radiator 31b, and an oil / gas bushing 31c, and as shown in FIG.
It is arranged at the lower part of. A gas-insulated two-pole disconnector 21 is disposed adjacent to and connected to an oil / gas bushing 31c provided on the transformer main body 31a, and is connected to the fixed portion 18 of the switching bus 16. Although a transformer is provided in the transformer main body 31a, illustration thereof is omitted. Transformer bodies 32a, 33a, 3 to be described later
The illustration of the conservator for 4a is also omitted.

The u terminal and v on the secondary side of the transformer body 31a
The terminal is pulled out in the horizontal direction from substantially the same height as the oil / gas bushing 31c, and is a single pole double throw switch 41 of air insulation.
It is connected to the. An air-insulated secondary-side switching bus 45 and a connecting line 48 extending in the left-right direction in FIG. 3A are detachable from the single-pole double-throw switch 41 below the single-pole double-throw switch 41. Are located in The neutral point connection line 47 is
It is housed in the same metal case as the connection line 48, and is similarly detachably connected to the respective v terminals of the service transformers 31 to 33 and the spare transformer 34. The unit 1 is configured as described above.

Next, the unit 2 includes the disconnector 22, the transformer main body 32 a and the radiator 32 b of the service transformer 32, and the single-pole double-throw switch 42, the disconnector 21 and the service transformer 31 of the unit 1.
Transformer body 31a and radiator 31b, single pole double throw switch 4
1, it is arranged on the gantry 2a. Also,
The flange portion 19 b of the detaching portion 19 of the switching bus 16 is detachably connected to the flange portion 22 a of the disconnector 22.

U terminal and v on the secondary side of the transformer body 32a
The terminal is pulled out from the oil / gas bushing 32c in a horizontal direction from substantially the same height as the oil / gas bushing 32c.
It is connected to the. Below the single-pole double-throw switch 42, a secondary-side switching bus 45 and a connection line 48 are arranged detachably from the single-pole double-throw switch 42. In addition, FIG.
In the upper part of (a), a monitoring / control / protection panel 51, a control line connection box 52, and a battery 53 for supplying DC power to the substation are provided.

The unit 3 includes a disconnector 23 and a service transformer 3
The third transformer body 33a, the radiator 33b, and the single pole double throw switch 43 are arranged on the gantry 3c in the same manner as each device of the unit 1. Also, the detaching section 1 of the switching bus 16
9 is a flange portion 23a of the disconnector 23.
Are detachably connected.

U terminal and v on the secondary side of the transformer body 33a
The terminal is pulled out in the horizontal direction from substantially the same height as the oil / gas bushing 33c, and is a single-pole, double-throw switch 43 with air insulation.
It is connected to the. Below the single-pole double-throw switch 43, a secondary-side switching bus 45 and a connection line 48 are arranged detachably from the single-pole double-throw switch 43.

A closed switchboard 49 is provided above the mount 3c in FIG. 3 (a). Secondary bus 46
Are connected to the secondary-side switching bus 45 in a T-shape on the left side of the gantry 3a from the up-down direction in FIG. 3A and extend to the upper closed switchboard 49. An auxiliary power supply transformer 55 is installed in a space below the removal portion 19 of the switching bus 16.

The unit 4 includes a spare transformer 34 and a frame 4
The auxiliary transformer 34 has a transformer main body 34a and a radiator 34b arranged on the gantry 4d in the same manner as the service transformer 31 of the unit 1. The selection switch 24 is connected to the oil / gas bushing 34c of the spare transformer 34. Removal part 1 of switching bus 16
Numeral 9 is detachably connected to the flange 24d of the selective switch 24 via the flange 19d.

The transformer main body 34 of the spare transformer 34
The u terminal and the v terminal on the secondary side of a are pulled out in the horizontal direction from substantially the same height as the oil / gas bushing 34c, fall once, and are detachably connected to the connection line 48.
Further, a closed switchboard 49 is provided above the mount 4c in FIG. 3A, and is connected to the closed switchboard 49 provided in the unit 3. In addition, a distribution board 56 is disposed in an extra portion of the gantry 4a. Note that the secondary-side switching bus 45, the neutral point connection line 47, and the connection line 48 are the secondary-side connection switching lines in the present invention.

The substation constructed as described above is assembled in a factory as shown in FIG. 3 and a test is performed.
Thereafter, the removal part 1 of the switching bus 16 for transportation is provided.
9 at the flange portions 19a to 19d, the flange portion 18a of the fixing portion 18 of the switching bus 16 and the disconnector 2
2, 23 flange portions 22a, 23a and selective switch 2
4 from the flange portion 24d. The other flange portions 18a, 22a, 23a, and 24d from which the flange portions 19a to 19d of the removal portion 19 have been removed are covered with a temporary lid for transportation, the fixing portion 18 of the switching bus 16 and the disconnectors 21 to 21.
23 and the selective switch 24 are filled with insulating gas again.

On the other hand, the secondary-side switching bus 45, the neutral point connection line 47, and the connection line 48 are also separated from the single-pole / double-throw switches 41 to 43, the spare transformer 34, and the secondary-side bus 46. In addition, control lines, low-voltage power lines, DC power lines, and the like (not shown) wired between the units 1 to 4 are removed. From the above,
Each of the units 1 to 4 can be individually transported.

The individually transported units 1 to 4 are assembled on-site in the reverse order to that described above to complete the substation. In addition, the removal part 19 of the switching bus 16 arrange | positions the units 1-4 in a field as shown in FIG. 5, suspends it from an upper part, and gradually lowers and leftward in FIG. While moving, each flange 1
8a to 18d are aligned with the mating flange and mounted. As described above, since the gas-insulated portion only needs to be provided with the detaching portion 19 of the switching bus 18, the connection time can be reduced.

The detaching section 1 of the switching bus 16
The connection between the flanges 19a to 19d of FIG. 9, the flange 18a of the fixing part 18 of the switching bus 16, the flanges 22a and 23a of the disconnectors 22 and 23, and the flange 24d of the selective switch 24 is performed by using a bellows. By doing so, the time for position adjustment on site can be further saved.
The connection between the secondary side switching bus 45 and the secondary side bus 46, the neutral point connection line 47, the connection line 48 and the service transformers 31 to
33, the connection with the spare transformer 34, etc., can also be made by using a flexible conductor, and the trouble of position adjustment can also be omitted.

Next, the operation will be described with reference to FIG. For example, when the service transformer 31 is stopped due to a failure and the spare transformer 34 is used instead, the following is performed. First, the switching devices 13a and 13b are opened to temporarily stop power reception. Next, the disconnector 21 on the high voltage side is opened, and the single pole double throw switch 41 on the low voltage side is switched to disconnect the service transformer 31 from the switching bus 16 and the secondary switching bus 45.

Next, the selector switch 24a (see FIG. 2) of the selection switch 24 is switched to switch the U
The terminal is connected to the R phase of the switching bus 16, and the selector switch 24b is switched to connect the V terminal to the S phase. In addition,
When the single-pole / double-throw switch 41 is switched to disconnect the service transformer 31 from the secondary bus 46, the backup transformer 3
The u terminal 4 is connected to the r-phase of the secondary-side switching bus 45.

The neutral point connection line 47 connected to the service transformer 31 is left as it is to save time for disconnection and to recover it early. As described above, since the auxiliary transformer 34 is connected instead of the working transformer 31, the switching devices 13a,
13b is closed, and power reception is resumed. The same applies to the case where the other service transformers 32 and 33 and the spare transformer 34 are switched.

As described above, according to the present invention, the primary side of the transformer is switched by the disconnectors 21 to 23 and the selective switch 24, and the secondary side is switched by the single pole double throw switches 41 to 43. Since switching is performed, there is no need to move the service transformer or backup transformer or manually switch connection lines to replace the faulty working transformer and backup transformer, which significantly increases the amount of switching work and switching time. The reduction and shortening are possible. Furthermore, the switching devices for this switching are housed in a metal container, which contributes to work safety.

The switching devices 13a, 13 on the high pressure side
b, the three-phase bus 14, the disconnector 15, the switching bus 16, the disconnectors 21 to 23, and the selection switch 24 are all configured as gas-insulated switchgear having a metal container filled with insulating gas, and The size has been reduced to facilitate transportation. Aerial insulation is used for the secondary-side switching bus 45, the neutral point connection line 47, and the connection line 48 on the low voltage side, so that the attachment / detachment work is easy and the work time in the field is further increased. Can be shortened.

Further, the disconnectors 21 to 23 and the single pole double throw switches 41 to 43 are provided in each of the units 1 to 3 in correspondence with the service transformers 31 to 33, respectively. Since the unit 4 is provided corresponding to the unit 24, the size of each unit can be equalized, and the unit can be transported as a unit even in a larger capacity substation.

Also, the unit can be transported to the site as a plurality of units assembled to the maximum extent that can be transported.
6, the secondary side switching bus 45, the neutral point connection line 47, and the connection line 48. Therefore, it is possible to reduce the number of assembling parts at the site, to reduce the cost of local construction, and to easily and reliably guarantee the quality.

Embodiment 2 Hereinafter, another embodiment of the present invention will be described with reference to FIGS. 7 is a connection diagram of the substation, FIG. 8 is a layout diagram of the substation of FIG. 7, FIG. 8A is a plan view, and FIG. 8B is a side view. FIG.
In FIG. 8, for example, a receiving voltage (primary voltage) 132
kV, distribution voltage (secondary voltage) 11 kV, transformer bank capacity (total capacity of three single-phase service transformers) 60 MV
A. The connection of the three single-phase service transformers is of the Y-connection on the primary side and of the neutral point direct grounding type, and the Δ-connection on the secondary side. First, the connection will be described with reference to FIG.

In FIG. 7, power transmission cables 11a, 11
b, a three-pole disconnector 15 is connected to each phase R, R, T of the three-phase bus 14 to which power is supplied via the switching devices 13a, 13b.
Is connected. Three single-pole double-throw switches 71, 72,
73 has a total of three terminals, a common side terminal, one side terminal and the other side terminal, and is switched between the common side terminal and one side terminal or the common side terminal and the other side terminal by switching. The circuit closes. These three single-pole double-throw switches 71, 7
The common terminals 2 and 73 are connected to the disconnector 15 via three-phase switching buses 74, respectively. The common transformers 31 to 31 are connected to the terminals on one side of the single-pole double-throw switches 71, 72, 73
33 U terminals are connected.

The other terminals of the single-pole / double-throw switches 71, 72 and 73 are connected to the U
Connected to terminal. Further, the V terminals of the service transformers 31 to 33 and the V terminal of the backup transformer 34 are commonly connected by a neutral connection line 77 and are directly grounded. In addition,
Since the neutral point connection line 77 is directly grounded, there is no need for gas insulation, and a conductor that is accommodated in a metal case and supported by an insulator is used.

The single-pole double-throw switches 71, 72, 73 are normally closed between the common terminal and one of the terminals, and the three working transformers 31, 32, 33 are connected on the primary side. It is Y-connected, and the neutral point is directly grounded via the neutral point connection line 77. The switching devices 13a, 13 described above
b, three-phase bus 14, disconnector 15, single pole double throw switch 71-
73, the connection line 78, the conductive portion of which is accommodated in a metal container filled with sulfur hexafluoride gas and sulfur gas, and constitutes a gas insulated switchgear.

Next, the connection on the secondary side will be described. 3
The u and v terminals on the secondary side of the service transformers 31, 32, and 33 are connected to r, s, and t of the switching bus 86 via two-pole disconnectors 81, 82, and 83, respectively. . Disconnector 8
1, 82, and 83 are always closed, and the three working transformers 31, 32, and 33 have a Δ connection on the secondary side.

The four-position selection switch 84 has the same circuit configuration as the selection switch 24 shown in FIG. 2, and the standby transformer 34 has the u terminal and the v terminal connected via the selection switch 84, respectively. Thus, it can be connected to any of the r, s, and t phases of the switching bus 86. One of the four positions of the selection switch 84 is the u terminal and the v terminal of the spare transformer 34.
The terminals are not connected to any of the phases of the switching bus 86.

The selection switch 84 is normally used for the backup transformer 3.
U and v terminals on the secondary side of r are the r, s and t of the switching bus 86
A position that is not connected to any of the phases is selected, and the spare transformer 34 is disconnected from the switching bus 86. The selection switch 84 is of an air insulation type covered with a metal case, and one of four positions can be selected from outside the metal case by operating a handle.

The above-described single-pole / double-throw switches 71 to 7
3. The selection switch 84 and the switching bus 86 are of the air insulation type covered with a metal case.

Next, the arrangement of the substation will be described with reference to FIG. In FIG. 8 (a), a substation includes four units 91 to 94, a primary-side switching bus 74 for gas insulation connecting these units 91 to 94, and a connection line as a primary connection line for a spare transformer. 78, an air-insulated neutral connection line 77, and an air-insulated secondary-side switching bus 86.

The units 1 to 4 are almost the same size,
For example, primary voltage 132 kV, secondary voltage 11 kV, capacity 6
0MVA (Total capacity of three service transformers 31-33)
In the substation of the degree, the size of each unit is 3.
It is about 4m x 10m x 4.5m in height, and can be disassembled into units and transported to the installation site. Note that the connection relationship between the devices is as described with reference to FIG. 7, and the description thereof will not be repeated below unless otherwise necessary.

First, details of the unit 91 will be described with reference to FIG. The cables 11a and 11b are drawn on the gantry 91a to the upper left in FIG.
3a and 13b. Switchgear 13a, 13
b has a three-phase disconnecting switch, a circuit breaker, and a grounding switch, and the circuit breaker is arranged vertically, that is, perpendicular to the mounting surface of the gantry 1a.

The three-phase one-phase three-phase bus 14 has R, S, and T-phase conductors housed in a cylindrical container filled with insulating gas, and its axial direction is as shown in FIG. In the vertical direction and parallel to the mounting surface of the gantry 91a,
13b. The three-phase one-piece gas-insulated disconnector 15 has an opening and closing direction from the three-phase bus 14 shown in FIG.
It is arranged at the same height as the three-phase bus 14 so as to be in the left-right direction in FIG.

The switching bus 74 has a fixed portion 75 and a detached portion 76. After the fixed portion 75 is connected to the disconnector 15 and once rises up from the disconnector 15, as shown in FIG. The container 31 is extended in the horizontal direction toward the container 31. The detaching portion 76 has flange portions 76a to 76c, and the flange portion 76a is connected to the switching bus 7 as shown in FIG.
4 is detachably connected to the flange portion 75a of the fixing portion 75.

A gas-insulated single-pole double-throw switch 71 is arranged adjacent to an oil / gas bushing 31c provided in the transformer main body 31a, and a fixing portion 75 of a switching bus 74 is provided.
It is connected to the. Further, the flange portion 78a of the gas-insulated connection conductor 78 is detachably connected to the single pole double throw switch 71. Further, a neutral point connection line 77 is detachably connected to the V terminal of the transformer main body 31a. In addition,
Since the neutral point connection line 77 is directly grounded, the insulation class is 2
No. 0 air insulated bus duct is used.

U terminal and v on the secondary side of the transformer body 31a
The terminal is pulled out in the horizontal direction from substantially the same height as the oil / gas bushing 31c, and is connected to the air-insulated two-pole disconnector 81. Further, an air-insulated secondary-side switching busbar 86 is disposed below the disconnector 81 so as to be detachable from the disconnector 81. The unit 1 is configured as described above.

Next, the unit 92 is a single pole double throw switch 7
2. The transformer main body 32a and the radiator 32 of the service transformer 32
b, disconnector 82 is single pole double throw switch 7 of unit 91
1. Transformer main body 31a and radiator 31 of service transformer 31
b, arranged on the gantry 92a in the same manner as the disconnector 81. The flange portion 76b of the detaching portion 76 of the switching bus 74 is detachably connected to the flange portion 72a of the single pole double throw switch 72. Further, a flange portion 78b of a gas-insulated connection conductor 78 is detachably connected to the single-pole double-throw switch 72. Further, V of the transformer main body 32a is
A neutral point connection line 77 is detachably connected to the terminal.

U terminal and v on the secondary side of the transformer body 32a
The terminal is pulled out in the horizontal direction from substantially the same height as the oil / gas bushing 32c, and is connected to an air-insulated two-pole disconnector 82. A secondary switching busbar 86 is disposed below the disconnector 82 so as to be detachable from the disconnector 82.

The unit 93 is composed of a single pole double throw switch 73, a transformer main body 33a and a radiator 33b of the service transformer 33, and a disconnector 83. The unit 93 is a transformer of the single pole double throw switch 71 and the service transformer 31 of the unit 91. Container body 31a, radiator 31b, disconnector 81
In the same manner as described above, it is arranged on the gantry 93a. The flange portion 76c of the detaching portion 76 of the switching bus 74 is detachably connected to the flange portion 73a of the single pole double throw switch 73. Further, the flange portion 78c of the gas-insulated connection conductor 78 is detachably connected to the single pole double throw switch 73. Further, a neutral point connection line 77 is detachably connected to the V terminal of the transformer main body 33a.

The u terminal and v on the secondary side of the transformer body 33a
The terminal is pulled out in a horizontal direction from substantially the same height as the oil / gas bushing 33c, and is connected to a disconnector 83 having aerial insulation. A secondary-side switching busbar 86 is disposed below the disconnector 83 so as to be detachable from the disconnector 83. Secondary bus 4
6 is connected in a T-shape to the secondary-side switching busbar 86 horizontally arranged on the left side of the gantry 93a, and is extended to the upper closed switchboard 49.

The unit 94 has a spare transformer 34 mounted on a gantry 94a. The spare transformer 34 is similar to the service transformer 31 of the unit 1 and has a transformer main body 34.
a, the radiator 34b is arranged on the gantry 94d. The flange portion 78d of the connection conductor 78 is detachably connected to the oil / gas bushing 34c of the spare transformer 34. Further, a neutral point connection line 77 is detachably connected to the V terminal of the transformer body 34a.

The u and v terminals on the secondary side of the transformer main body 34a of the spare transformer 34 are connected to an oil / gas bushing 34c.
And is pulled out from the same height as in the horizontal direction, and is connected to an air-insulated selective switch 84. A secondary switching busbar 86 is detachably connected to the selection switch 84. The switching bus 74, the neutral point connection line 77, and the connection conductor 78 are the primary side connection switching lines in the present invention. Other configurations are the same as those of the embodiment shown in FIG. 3, and the corresponding components are denoted by the same reference numerals and description thereof is omitted.

The substation constructed as described above is assembled in a factory as shown in FIG. 8 and a test is performed.
Thereafter, the detached portion 76 of the switching bus 74 is connected to the flange portion 75a of the fixed portion 75 of the switching bus 74 at the flange portions 76a to 76c, and the single-pole double-throw switches 72, 7 are provided.
3 from the flange portions 72a and 73a. The other flange portions 75a, 72a, 73a of the detached portion 76 from which the flange portions 76a to 76c have been removed are covered with a temporary lid for transportation, and the fixed portion 75 of the switching bus 74, the single pole double throw switch 72, 73 is filled with an insulating gas again.

The connecting conductor 78 is connected to its flange 78
a to 78d, remove the single pole double throw changers 71 to 73 and the auxiliary transformer 34 from the oil / gas bushing 34c,
The detached single-pole / double-throw switches 71 to 73 and the oil / gas bushing 34c of the auxiliary transformer 34 are temporarily covered and filled with insulating gas. Further, the neutral point connection line 77 of the air insulation is provided.
From the V terminals of the transformer bodies 31 to 34a.

On the other hand, the secondary-side switching bus 86 is connected to the disconnector 8
1 to 83, remove from the selection switch 84. In addition, control lines, low-voltage power lines, DC power lines, and the like (not shown) wired between the units 91 to 94 are removed. As described above, each of the units 91 to 94 can be individually transported.

Units 1-4 which were individually disassembled and transported
Are assembled on site in the reverse order as described above, and the substation device is completed.

The detaching section 7 of the switching bus 74
6, the flange portion 75a of the fixing portion 75 of the switching bus 74, the single pole double throw switch 72,
By connecting the flange 73 to the flange portions 72a, 73a and the flange portions 78a to 78d of the connection conductor 78 to the mating flange portion via the bellows, it is possible to further save the time for on-site position adjustment. . Also, the connection between the secondary-side switching bus 86 and the disconnectors 81 to 83 and the selective switch 84 can be similarly performed by using a flexible conductor, so that the time and effort for position adjustment can be similarly reduced.

Next, the operation will be described. For example, the service transformer 31 is shut down due to a failure, and the backup transformer 34
When using, do as follows. First, the switchgear 13
Circuits a and 13b are opened and power reception is temporarily stopped. Next, the single pole double throw switch 71 on the high voltage side is switched so that the common terminal and the other terminal are electrically connected, and the service transformer 31 is disconnected from the switching bus 74. Also, a low-voltage side bipolar disconnector 8
Release 1. The service transformer 31 is connected to the switching bus 74.
When the single-pole / double-throw switch 71 is switched in order to disconnect the switch, the primary U terminal of the backup transformer 34 is connected to the R phase of the switching bus 74.

Next, the selector switch 84 is switched to connect the u terminal on the secondary side of the backup transformer 34 to the r phase of the switching bus 86 and the v terminal to the s phase of the secondary switching bus 86. Connect to The neutral point connection line 77 connected to the transformer main body 31a is left as it is in order to save the time for disconnection and to restore it promptly. As described above, since the standby transformer 34 is connected instead of the working transformer 31, the switchgears 13a and 13b are closed to resume power reception.

In the embodiment shown in FIG. 3, the switching bus 16 for gas insulation has a connecting portion 17, a fixing portion 18 and a removing portion 19, but the present invention is not limited to this. It is sufficient if the unit can be disassembled into a transportable unit.
Between the unit 2, the unit 3 and the unit 3 and between the unit 3 and the unit 4, and the separated detached portions may be connected by bellows or the like. In this case, there is no need to remove the removal section 19. The same applies to the detached portion 76 of the switching bus 74 and the connection conductor 78 in FIG.

The disconnecting parts 19 of the switching bus 16 in FIG. 3 are not removed from the disconnecting switches 22 and 23 and the selective switch 24, and the disconnecting switches 22 and 23 and the selective switch 24 are connected to the service transformers 32 and 33 and the spare switch. You may make it remove from the transformer 34. In this case, for transportation, the oil / gas bushings 32c to 34c of the transformer main bodies 32a to 34a are temporarily covered and filled with sulfur hexafluoride gas. The same applies to the switching bus 74 and the detaching section 76 in FIG.

The selection switch 24 and the single pole double throw switches 41 to 43 in FIG. 1 and the single pole double throw switch 7 in FIG.
1 to 73, a plurality of disconnectors may be combined and switched instead of the selective switch 84.

Further, in the above-described embodiment, an example is shown in which the connection of the single-phase working transformer is Δ-Y or Y-Δ.
Even in the case of a delta-connected tertiary winding or a Y-Y connection with a dummy delta connection winding, it is possible to similarly configure four units and connect these units on site. it can. In this case, the primary-side Y connection is switched to the spare transformer in the same manner as the primary-side Y connection shown in FIGS. 7 and 8, and the secondary-side Y connection is shown in FIGS. Switching is performed in the same manner as in the case of the Y connection on the secondary side. The Δ-connected tertiary winding or the dummy Δ-connection is also switched from the winding of the working transformer to the winding of the backup transformer in the same manner as in the case of the Δ-connection on the secondary side shown in FIGS. .

In addition, although one spare transformer is provided for every three working transformers, one spare transformer is provided for two transformer banks composed of six working transformers. A transformer can also be provided.

[0082]

Since the present invention is configured as described above, it has the following effects.

The first to third units in which a single-phase service transformer having primary and secondary windings are provided, and the single-phase backup transformer having primary and secondary windings are provided. Fourth unit, a power receiving switching device provided in at least one of the four units and receiving three-phase power,
A power distribution switchgear provided in at least one of the first to fourth units for distributing three-phase power, a primary connection provided across at least three units of the first to fourth units A three-phase connection of the primary winding of the service transformer connected to the switching line and this primary-side connection switching line to connect to the switchgear for power reception, and to use a spare instead of any primary winding of the service transformer A primary-side connection switching device having a primary-side switching switch switchable to a primary winding of a transformer, and a secondary side provided over at least three of the first to fourth units. The connection switching line and the secondary winding of the three-phase connected working transformer connected to the secondary side connection switching line are connected in three-phase connection to the power distribution switchgear and any one of the working transformers is connected. Primary winding is a backup transformer A secondary-side connection switching device having a secondary-side switching switch capable of being switched to the secondary winding of the backup transformer instead of the secondary winding of the working transformer when replaced. And each unit is configured to be transportable by removing at least a part of the primary-side connection switching device and the secondary-side connection switching device from each unit. Switching to the primary side switching switch and secondary side switching switch is performed, so it is not necessary to move the working transformer or the spare transformer for switching, or to perform the manual wiring work, Since it can be performed quickly, the power outage time for switching can be shortened. Also, at the site, it is only necessary to attach at least a part of the removed primary-side connection switching device and secondary-side connection switching device to each unit, which can shorten the installation time on site and reduce the number of assembly parts on site, so quality assurance Is easy.

The power receiving switch, the primary-side connection switching line, and the primary-side switching switch have their conductive portions housed in a housing case in which insulating gas is sealed. The side connection switching line and the secondary side switching switch are characterized in that their conductive parts are aerial insulation covered with a shielding case. Can be miniaturized, and transportation becomes easy. In addition, if air-insulated ones are employed, the work of attaching and detaching them is easy, and the working time in the field can be further reduced.

Further, the primary-side connection switching line is a three-phase primary-side switching bus detachably connected to the power receiving switching device, and the primary-side switching switch is detachably connected to the primary-side switching bus. A primary-side triangular connection switch and a primary-side switch, which are provided in each unit corresponding to the service transformer and connect each terminal of the primary winding of the service transformer to a predetermined phase of the primary switching bus to form a triangular connection, respectively. A primary-side selection switch, which is detachably connected to the side-switching bus and is adapted to connect each terminal of the primary winding of the spare transformer to an arbitrary phase of the primary-side switching bus. The primary side switching switch is provided in each unit corresponding to each service transformer, so that the size of each unit is equalized, transportation is facilitated, and each unit is connected to the secondary side connection switching device. At least part and primary side cut Each unit can be transported by removing at least a part of the secondary-side connection switching device and the primary-side switching bus. Installation time can be reduced.

The secondary-side connection switching line has a three-phase secondary-side switching bus, a secondary-side neutral point connection line, and a backup transformer secondary-side connection line, and has a secondary-side switching bus. Is detachably connected to the distribution switchgear, and the secondary neutral point connection line is connected in common to one terminal of each of the secondary windings of the service transformer and the standby transformer, and the secondary side of the standby transformer The connection wire is detachably connected to the other terminal of the secondary winding of the spare transformer, and the secondary-side switching switch is connected to the secondary-side switching bus and the secondary side of the spare transformer. The other terminal of the secondary winding of the service transformer is detachably connected to the wire and corresponds to each service transformer, and the other terminal of the secondary winding of the service transformer is connected to a predetermined phase of the bus for switching on the secondary side, respectively. Connect and disconnect the other terminal of any service transformer to the other terminal of the spare transformer via the secondary connection line of the spare transformer. And a secondary-side star-connected switch that can be connected to a predetermined phase of the secondary-side switching bus. The secondary-side switched switch has a unit corresponding to each service transformer. Each unit, the size of each unit is equalized, transportation is easy, and each unit has a primary switching bus, a secondary switching bus, a secondary neutral connection line, and a spare It is characterized by being able to be transported by removing the transformer secondary side connection line, so if the primary side is triangular connection and the secondary side is star connection, each unit is connected to the primary side switching bus. By removing the secondary-side switching bus, the secondary-side neutral point connection line, and the backup transformer secondary-side connection line, transportation becomes possible, and installation time on site can be reduced.

The primary-side connection switching line has a three-phase primary-side switching bus, a primary-side neutral point connection line, and a backup transformer primary-side connection line, and the primary-side switching bus is a power distribution switchgear. The primary-side neutral point connection line is connected to one terminal of each of the primary winding of the service transformer and the backup transformer, and the primary connection line of the backup transformer is connected to the backup transformer. The primary side switching switch is detachably connected to the other terminal of the primary winding, and the primary side switching switch is detachably connected to the primary side switching bus and the standby transformer primary side connection line and corresponds to each service transformer. The other terminal of the primary winding of the service transformer provided in each unit is connected to a predetermined phase of the primary switching bus to form a star connection, and the other terminal of any service transformer is connected. Disconnect the other terminal of the backup transformer via the primary connection line of the backup transformer. Alternatively, it has a primary star connection switch that can be connected to a predetermined phase of the primary switching bus, and the primary switching switch is provided in each unit corresponding to each service transformer. Since the units are provided, the size of each unit is equalized, transportation is facilitated, and each unit includes at least a part of the secondary-side connection switching device, a primary-side switching bus, a primary-side neutral point connection line, and a primary-side neutral connection line. When the primary side is a star-shaped connection, each unit has at least a part of the secondary-side connection switching device and a primary-side switching bus. By removing the primary-side neutral point connection line and the primary-side connection line, transportation becomes possible, and installation time on site can be reduced.

Further, the secondary-side connection switching line is a three-phase secondary-side switching bus removably connected to the power receiving switching device, and the secondary-side switching switch is detachably connected to the secondary-side switching bus. Possible and connected to each unit in correspondence with each service transformer, each terminal of the secondary winding of the service transformer is connected to a predetermined phase of the bus for switching on the secondary side to form a triangular connection. The secondary triangular connection switch and the secondary switching bus are detachably connected to each other so that each terminal of the secondary winding of the spare transformer can be connected to an arbitrary phase of the secondary switching bus. Each unit is made transportable by removing the primary-side switching bus, the primary-side neutral connection line, the primary-side connection line, and the secondary-side switching bus. The secondary-side switching switches correspond to each service transformer. Since each unit is provided on the knit, the size of each unit is equalized, transportation is easy, and when the primary side is star-connected and the secondary side is triangular connection, each unit is connected to the primary switching bus and the primary side By removing the neutral point connection line, the primary side connection line, and the secondary side switching bus, transportation becomes possible, and the installation time on site can be reduced.

[Brief description of the drawings]

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

FIG. 2 is a detailed connection diagram of the backup transformer of FIG. 1;

FIG. 3 is a layout diagram of the substation device of FIG. 1;

FIG. 4 is a plan view showing details of a portion for removing a switching bus of FIG. 1;

FIG. 5 is an explanatory diagram illustrating an installation procedure of a substation device.

FIG. 6 is a connection diagram showing a connection state when switching to a backup transformer.

FIG. 7 is a connection diagram of a substation according to another embodiment of the present invention.

FIG. 8 is a layout diagram of the substation device of FIG. 7;

[Explanation of symbols]

1-4 units, 11a, 11b cable, 13
a, 13b switchgear, 14 three-phase bus, 15 disconnector, 16 switching bus, 18 fixing part, 19 detaching part, 21-23 disconnector, 24 selective switch, 31-3
3 working transformer, 34 spare transformer, 41-43 single pole double throw switch, 45 secondary side switching bus, 46 secondary side bus, 47 neutral point connection line, 48 connection line, 49 closed switchboard, 71-73 Single-pole double-throw switch, 74 Switching bus, 75 Fixing part, 76 Removal part, 77 Neutral point connection line, 78 Connection conductor, 81-83 Disconnector, 84 Selection switch, 86 Secondary side switching Bus, 91-94 units.

Claims (6)

[Claims] 1. A first to third unit in which a single-phase service transformer having primary and secondary windings is provided, and a single-phase backup transformer having primary and secondary windings is provided. A fourth unit, a power receiving switching device provided in at least one of the four units and receiving three-phase power, provided in at least one of the first to fourth units. A distribution switchgear that distributes three-phase power, a primary-side connection switching line provided over at least three of the first to fourth units, and the service transformer connected to the primary-side connection switching line. And the primary winding is connected to the power receiving switchgear by three-phase connection, and the primary winding of the spare transformer can be switched to the primary winding of the spare transformer instead of any one of the primary windings of the working transformer. With primary side switching switch A primary-side connection switching device, a secondary-side connection switching line provided over at least three of the first to fourth units, and the three-phase connection connected to the secondary-side connection switching line. When the secondary winding of the service transformer is connected to the distribution switchgear by three-phase connection and the primary winding of any one of the service transformers is switched to the backup transformer, A secondary-side connection switching device having a secondary-side switching switch capable of being switched to the secondary winding of the backup transformer instead of the secondary winding of the working transformer, A substation, wherein each of the units is configured to be transportable by removing at least a part of the primary-side connection switching device and the secondary-side connection switching device from each of the units. 2. The power receiving switchgear, the primary-side connection switching line, and the primary-side switchgear, the conductive portions of which are housed in a housing case in which an insulating gas is sealed.
2. The substation according to claim 1, wherein the secondary-side connection switching line and the secondary-side switching switch are air-insulated whose conductive portions are covered by a shielding case. 3. 3. The primary-side connection switching line is a three-phase primary-side switching bus removably connected to a power receiving switching device, and the primary-side switching switch is detachably connected to the primary-side switching bus. A primary-side triangular connection switch provided in each unit corresponding to each service transformer and connecting each terminal of a primary winding of the service transformer to a predetermined phase of the primary-side switching bus to form a triangular connection. And a primary-side selection switch, which is detachably connected to the primary-side switching bus and is configured such that each terminal of a primary winding of the spare transformer can be connected to an arbitrary phase of the primary-side switching bus. 3. The unit according to claim 1, wherein each unit is made transportable by removing at least a part of the secondary-side connection switching device and the primary-side switching bus. 4. The substation device as described. 4. A secondary-side switching bus having a three-phase secondary-side switching bus, a secondary-side neutral point connecting line, and a spare transformer secondary-side connecting line. Is detachably connected to the distribution switchgear, and the secondary neutral point connection line is connected in common to one terminal of each of the secondary windings of the service transformer and the standby transformer, and the secondary side of the standby transformer The connection wire is detachably connected to the other terminal of the secondary winding of the spare transformer, and the secondary-side switching switch is connected to the secondary-side switching bus and the spare transformer secondary. The other terminal of the secondary winding of the service transformer is detachably connected to the side connection line and is provided in each unit corresponding to each service transformer, and is connected to a predetermined phase of the secondary-side switching bus, respectively. And connect the other terminal of any service transformer to the other terminal of the spare transformer using the secondary connection line for the spare transformer. A secondary-side star-connected switch that can be connected to a predetermined phase of the secondary-side switching bus by switching each unit via a primary-side switching bus and the secondary-side switching bus. 4. The substation according to claim 3, wherein the switching bus, the secondary-side neutral point connection line, and the backup transformer secondary-side connection line are removed to enable transportation. 5. . 5. The primary-side connection switching line has a three-phase primary-side switching bus, a primary-side neutral point connection line, and a backup transformer primary-side connection line, and the primary-side switching bus is a power distribution switchgear. The primary-side neutral point connection line is connected to one terminal of each of the primary winding of the service transformer and the backup transformer, and the primary connection line of the backup transformer is connected to the backup transformer. A primary switching switch detachably connected to the other terminal of the primary winding, wherein the primary switching switch is detachably connected to the primary switching bus and the spare transformer primary connection line, and each of the service transformers The other terminal of the primary winding of the service transformer provided in each unit is connected to a predetermined phase of the primary-side switching bus to form a star connection, and the other terminal of the arbitrary service transformer is connected. To the other terminal of the spare transformer A primary star connection switch that can be connected to a predetermined phase of the primary switching bus by switching through each unit, wherein each unit includes at least a part of a secondary connection switching device and 3. The substation according to claim 1, wherein the bus is made transportable by removing the primary-side switching bus, the primary-side neutral point connection line, and the primary-side connection line. . 6. The secondary-side connection switching line is a three-phase secondary-side switching bus removably connected to a power receiving switching device, and the secondary-side switching switch is connected to the secondary-side switching bus. Each terminal of the secondary winding of the working transformer is detachably connected to each unit and is connected to a predetermined phase of the secondary switching bus to form a triangular connection. The secondary side triangular connection switch and the secondary side switching bus are detachably connected and each terminal of the secondary winding of the spare transformer can be connected to an arbitrary phase of the secondary side switching bus. Each unit is transported by removing the primary switching bus, the primary neutral connection line, the primary connection line, and the secondary switching bus. The substation according to claim 5, wherein the substation is enabled.