JP2001112128A - Gas insulation potential transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas insulation potential transformer provided with disconnection function for the case of withstand voltage test of a gas insulation switchgear. SOLUTION: Three-phase potential transformer main bodies 110u, 110v, etc., are accommodated in a transformer accommodating vessel 100, in such a manner that the respective high voltage terminals 115u, 115v face the direction rectangular to the axial line of an insulating spacer 106. A disconnecting part 131 for opening and closing the parts between penetrating conductors 106u, 106v embedded in the spacer 106 and the terminals 115u, 115v for the transformer is arranged in the vessel 100. An operating device 132 which opens and closes the disconneting part 131 from outside the vessel 100 is fixed on the end portion wall 103 of the vessel 100, toward which the high voltage terminals face.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In a gas insulated switchgear to which an instrument transformer is connected, when an AC withstand voltage test is performed by applying an AC test voltage of a commercial frequency, a test voltage is applied to the instrument transformer. If this is done, the coil of the instrument transformer will burn out, and it is necessary to disconnect the instrument transformer from the gas-insulated switchgear.

Further, when a withstand voltage test is performed on a cable, if an instrument transformer is provided at a location to which the test voltage is applied, it is necessary to disconnect the instrument transformer from the switchgear.

[0004] Therefore, in a gas insulated switchgear provided with a transformer for an instrument, prior to the AC withstand voltage test, the gas in the gas insulated switchgear is recovered and the transformer for the instrument is separated or the transformer for the instrument is disconnected. A disconnector is provided between the switch and the gas insulated switchgear, and the electrical connection between the instrument transformer and the gas insulated switchgear is disconnected by opening the disconnector.

FIG. 4 and FIG. 5 show an example of a bus meter transformer unit provided for connecting an instrument transformer to the bus. FIG. 4 is a cross-sectional view showing a mechanical configuration of the unit. FIG. 5 is a single-line diagram showing the electrical configuration of the unit. In FIG. 4, BUS is a bus, and VT is a bus B.
Instrument transformer connected to US via disconnector DS, E
SW is a ground switch.

In this gas insulated switchgear, as shown in FIG. 4, a three-phase bus conductor constituting a bus BUS is housed in a bus container 2 supported on an operation box 1. An earthed switch element E2 comprising a bus element E1 and a three-phase earth switch ESW housed in a container 4 connected to the bus container 2 via an insulating spacer 3.
A disconnector element E3 in which a three-phase disconnector DS is accommodated in a disconnector container 6 connected to the container 4 via an insulating spacer 5, and connected to the disconnector container 6 via an insulating spacer 7. Three-phase instrument transformer V in the transformer storage container 8
Transformer 10 for gas insulated instrument constructed by housing T body
The containers 2, 4, 6, and 8 are filled with SF ₆ gas. The earthing switch element E2, the disconnector element E3, and the transformer 10 for a gas insulation meter are supported on a gantry 11.

In this gas-insulated switchgear, the instrument transformer 10 is disconnected from the bus BUS by opening the disconnector DS during the AC withstand voltage test of the gas-insulated switchgear.

FIGS. 6 and 7 show an example of a transmission line unit of another gas insulated switchgear provided with a gas insulated instrument transformer. FIG. 6 is a sectional view showing a mechanical configuration of the unit. FIG. 7 is a single-line diagram showing the electrical configuration of the unit.

In FIG. 7, BUS1 and BUS2 are first and second buses, respectively, and one end of a circuit breaker CB is connected to these buses via bus disconnectors DS11 and DS12, respectively. The other ends of the circuit breakers CB are connected to the cable heads CHd1 and CHd via line-side disconnectors DS2.
Connected to 2. Grounding switches ESW1 and ESW for circuit breaker inspection are respectively provided between the conductors connected to the terminals of the circuit breaker CB on the bus disconnectors DS11 and DS12 side and ground, and between the conductors connected to the terminals of the circuit breaker CB on the disconnector DS2 side and ground.
2 is provided, and a current transformer CT is attached to a conductor connecting between the circuit breaker CB and the disconnector DS2.

The cable head CHd of the disconnector DS2
1 and ground switch ESW3 between CHd2 side terminal and ground
And an instrument transformer VT is connected to a conductor connecting between the disconnector DS2 and the cable heads CHd1 and CHd2.

The construction of the transmission line unit is as shown in FIG. 6, and is provided in a container 12 supported on an operation box 11.
The circuit breaker CB, the earthing switches ESW1 and ESW2, and the current transformer CT are housed together with necessary connection conductors and the like. On the side surface of the container 12, there are provided two nozzle sections vertically arranged, and bus vessels 15 and 16 are connected to these nozzle sections via insulating spacers 13 and 14, respectively. BUS1 conductor and bus disconnector D
In S11, a conductor constituting the bus BUS2 and a bus disconnector DS12 are accommodated in the bus container 16, respectively.

Further, a disconnector DS2 and a grounding switch ESW2 are provided in a container 18 connected to a nozzle portion provided on the side surface of the container 12 opposite to the busbar containers 15 and 16 via an insulating spacer 17. A three-phase cable head CHd1 and necessary connection conductors are housed in a container 20 that is housed and connected via a spacer 19 to a nozzle provided on the side surface of a container 18 located on the side opposite to the container 12. It is stored. A three-phase cable head CHd2 is housed in a container 22 connected to a nozzle portion provided on a side surface of the container 20 opposite to the container 18 via an insulating spacer 21.

A transformer storage container 24 is connected to an upper portion of a container 20 containing one cable head CHd1 via an insulating spacer 23, and a main body of a three-phase instrument transformer VT is stored in the container 24. I have. The container 24 and the main body of the instrument transformer VT constitute a gas-insulated instrument transformer 11 ′.

The cable heads CHd1 and CHd2 each have a cable (transmission line) C that has been set up from underground.
Terminals 1 and C2 are connected. S in each container
F ₆ gas is sealed at a predetermined pressure.

In the gas insulated switchgear shown in FIG.
When conducting a withstand voltage test of the cable, the S
After collecting the F ₆ gas, a gas insulated voltage transformer 11 '
Was cut off, and then the container 20 was refilled with gas to perform a withstand voltage test. After the withstand voltage test was completed, it was necessary to collect the gas in the container 20, connect the instrument transformer 11 ′, and refill the gas in the container 20.

[0016]

In the conventional gas insulated switchgear shown in FIG. 4, the disconnector element E3 is provided in preparation for the AC withstand voltage test. The costs were inevitable. In addition, the number of elements constituting the gas insulated switchgear increases, so that there is a problem that the size of the device is increased.

In the gas-insulated switchgear shown in FIG.
When performing the withstand voltage test, it is necessary to collect and refill the gas in the container 20, and it is necessary to collect and refill the gas even after the test is completed. There is a problem that it takes a lot of trouble.

As shown in Japanese Utility Model Application Laid-Open No. 63-24817, the main body of the instrument transformer is movably supported in the container, and the main body of the instrument transformer is moved by operation from outside the container. A gas insulation that provides a moving mechanism to move the instrument transformer main body inside the container during the withstand voltage test to disconnect the instrument transformer body from the embedded conductor of the insulating spacer. Instrument transformers have been proposed. According to this gas insulated switchgear, the instrument transformer can be separated from the switchgear by moving the instrument transformer main body by an external operation.
The disconnection and reconnection of the instrument transformer can be performed without recovering the gas. Further, since there is no need to provide a special disconnector element, the number of elements constituting the gas insulated switchgear does not increase.

However, in the gas-insulated instrument transformer already proposed, it is necessary to move the heavy instrument transformer main body, and therefore, there is a problem that a large force is required when disconnecting the instrument transformer. Was. 3 in one container
If the proposed structure is to be adopted when adopting a configuration in which the phase transformer main bodies are housed collectively, the structure of the part supporting the phase transformer main bodies becomes complicated, resulting in cost reduction. I couldn't avoid getting high.

An object of the present invention is to provide a disconnector for a gas-insulated instrument which has a disconnection function without using a complicated mechanism and can be easily separated from a gas-insulated switchgear during a withstand voltage test. Is to provide.

[0021]

SUMMARY OF THE INVENTION The present invention provides a transformer housing having an airtight holding structure in which both ends in the axial direction are closed by end walls, and a nozzle portion protruding from a side surface, and a three-phase through conductor. And an insulating spacer attached to the flange at the tip of the nozzle section of the transformer housing, and a three-phase instrument transformer body housed in the transformer housing. The nozzle of the container is connected to another container of the gas insulated switchgear through the insulating spacer, and the three-phase high-voltage terminals provided on the three-phase instrument transformer main body are embedded in the insulating spacer. The present invention relates to a gas-insulated instrument transformer connected respectively to three-phase circuits of a gas-insulated switchgear through through conductors.

In the present invention, the three-phase instrument transformer main body is arranged with the respective high voltage terminals oriented in the axial direction of the transformer housing. Further, disconnecting portions for respectively opening and closing between the three-phase through conductor embedded in the insulating spacer and the three-phase high-voltage terminal are disposed in the transformer storage container, and the three-phase high-voltage terminal is opposed to the three-phase high-voltage terminal. An operation device for opening and closing the disconnection portion from outside the transformer housing is attached to the end wall.

With the above configuration, the disconnection function can be provided without moving the instrument transformer main body itself, so that the instrument transformer can be opened and closed without requiring a large operating force during the withstand voltage test. Can be disconnected from Also, since the disconnecting part can be operated from the outside of the container,
Without collecting the gas in the container of the gas insulated switchgear,
The disconnection of the instrument transformer can be performed.

As described above, when the instrument transformer main body is arranged with the high-voltage terminal oriented in a direction perpendicular to the axis of the insulating spacer, a space for arranging the disconnecting portion in the transformer housing is provided. Can be easily secured,
The disconnection function can be provided without particularly increasing the size of the instrument transformer.

The disconnecting part includes a three-phase connection conductor having one end connected to the three-phase through conductor embedded in the insulating spacer, and a three-phase connection conductor attached to the other end of the three-phase connection conductor. Between the closed position where the current-carrying contact is in contact with the three-phase high-voltage terminal while being in contact with the three-phase current-carrying contact and the open position that is separated from the high-voltage terminal. It is preferable to adopt a configuration including a three-phase rod-shaped movable contact provided so as to be displaceable along the axial direction.

The operating device is provided in a state where the end wall of the transformer housing facing the three-phase high-voltage terminal is slidably and slidably penetrated, and one end is connected to a movable contact in the transformer housing. A three-phase insulated operating rod, a three-phase connecting plate for connecting the three-phase insulated operating rod outside the transformer housing,
An operation mechanism for displacing the three-phase connecting plate in the axial direction of the transformer housing so as to displace the three-phase movable contact between the open position and the closed position is preferable.

When the disconnecting portion is configured as described above, the high voltage terminal of the instrument transformer also serves as a fixed contact of the disconnecting portion, so that the configuration of the disconnecting portion can be simplified.

[0028]

1 to 3 show an example of the construction of a transformer for a gas-insulated instrument according to the present invention. FIG. 1 is a cross-sectional view of the transformer, and FIG. FIG. 3 is a longitudinal sectional view showing a state in which a disconnection portion is open, and FIG. 3 is a longitudinal sectional view showing a state in which a disconnection portion is open. In these figures, reference numeral 100 denotes a cylindrical transformer storage container. The container includes a container main body including a peripheral wall 101 and an end wall 102 closing one end of the peripheral wall in the axial direction. And an end wall 103 for airtightly closing the other end of the portion 101. The end wall 103 is fixed to a flange portion 101 a formed at the other end of the peripheral wall portion 101 by a bolt 104. End wall 10 on the side of peripheral wall 101 of container 100
A nozzle portion 105 protruding in a direction perpendicular to the axial direction of the peripheral wall portion 101 is formed at a portion closer to the third. The nozzle 105 is formed of a short pipe 105a having a rear end welded to the peripheral edge of a hole formed in the peripheral wall 101, and a flange 105b is formed at the front end thereof. An insulating spacer 106 is attached.

The insulating spacer 106 is of a three-phase package type, and is a spacer body 106a formed of insulating resin.
And three-phase through conductors 106u to 106w embedded in the spacer body 106a. The flange portion 106a1 of the spacer body 106a is fastened to the flange portion 105b of the nozzle 105 by bolts. The opening of the nozzle 105 is hermetically closed by the insulating spacer 106. Three-phase through conductors 106u to 106w
Are arranged with their respective axes perpendicular to the central axis of the container 101 and their respective centers located at the vertices of an equilateral triangle or an isosceles triangle. In the illustrated example, a middle-phase through conductor 106v is provided with its central axis aligned with the center axis of the insulating spacer 106, and the two-phase through-conductors 106u and 106w are more container than the medium-phase through conductor 106v. Are arranged at a position biased toward the end wall 103 side.

Inside the transformer housing 100, three-phase instrument transformer main bodies 110u to 110w are housed.

Each instrument transformer main body has a U-shaped yoke 1
An iron core 111 having 11a and legs 111b, a high-voltage coil 12 and a low-voltage coil 113 wound around the legs 111b of the iron core, and a non-ground side of the high-voltage coil 112 arranged to surround the high-voltage coil 112 A known shield provided with a ring-shaped shield 114 having a potential fixed to a terminal,
High-voltage terminals 115u to 115w (115u and 115w are not shown) are formed at the apex of each shield 114 of the three-phase instrument transformer main body. The three-phase instrument transformer main bodies 110u to 110w center the centers of the respective high-voltage terminals 115u to 115w in the transformer container 100.
Are positioned at the vertices of an equilateral triangle having the center on the central axis of the container, and fixed on the end wall 102 of the container.

The through conductors 106 u of the insulating spacer 106
One end of each of the three-phase connection conductors 120u to 120w is connected to an end of the 106w located inside the container 100 by fastening with bolts. These connection conductors 120u-12
0 w is provided so as to extend to positions opposed to the three-phase high-voltage terminals 115 u to 115 w along planes orthogonal to the central axis of the container 100.

The current-carrying contacts 121u to 121w made of tulip contacts are mounted in holes provided at the other ends of the connection conductors 120u to 120w facing the three-phase high-voltage terminals 115u to 115w, respectively. Movable contacts 122u-122
w is in sliding contact.

The current-carrying contacts 121u-121w have their respective central axes aligned with the three-phase instrument transformer main bodies 110u-110w.
The movable contacts 122u to 122w are provided so as to match the centers of the high-voltage terminals 115u to 115w of the 110w.
w, three-phase high-voltage terminals 115u-1
Contact portions 122u1 to 122w1 (122w1
Is not shown. ) Is formed.

As shown in FIG. 2, the movable contacts 122u to 122w have contact portions 122u1 to 122u1 at their respective ends.
As shown in FIG. 3, the closed position where 22 w1 comes into contact with the three-phase high-voltage terminals 115 u to 115 w with a predetermined contact pressure, and the contact portions 122 u1 to 122 w1 are three-phase high-voltage terminals 1
It can be displaced between the open position and the position apart from 15u to 115w.

Insulating operation rods 123u to 123w (123w is not shown) are directly connected to the movable contacts 122u to 122w, respectively. Insulated operation rod 123u-12
3w is a high-voltage terminal 115u of the three-phase instrument transformer main body.
A hole provided in the end wall 103 of the container facing the 115 w and an airtight fixing plate 124 fixed to the inner surface of the end wall 103.
And a guide member 125 fixed to the outer surface of the end wall 103.
Are slidably penetrated and led out. The hermetic fixing plate 124 is provided with an O-ring that is in sliding contact with the outer periphery of the insulating operating rods 123u to 123w, and the hermetic fixing plate is used to maintain the airtightness of the through portions of the insulating operating rods 123u to 123w. .

The ends of the insulating operation rods 123u to 123w located outside the container are mutually connected by a three-phase connecting plate 126. A screw rod 128 is rotatably supported by a bearing device 127 fixed to the outer surface of the end wall 103 of the container, and the screw rod 128 is screwed into a screw hole provided in the three-phase connecting plate 126. An operation handle 129 is attached to the tip of the screw rod 128. By rotating the operation handle 129, the three-phase connecting plate 126 is displaced in the axial direction of the container 100, and the three-phase movable contact 122u
To 122w are three-phase high voltage terminals 115u to 115
w and an open circuit position separated from the high voltage terminal. SF ₆ gas is sealed in the transformer container 100 at a predetermined pressure.

In the illustrated example, when the three-phase connecting plate 126 is in contact with the guide member 125, the movable contacts 122u to 122w are in the closed positions and the three-phase high-voltage terminals 115u to 115w are in a predetermined contact state. The lengths of the movable contacts 122u to 122w and the insulating operation rods 123u to 123w are set so as to make contact with pressure. Movable contacts 122u-1 during steady operation of gas insulated switchgear
In order to prevent incomplete contact between 22w and the three-phase high-voltage terminals 115u to 115w, the three-phase connecting plate 126 should be fastened to the guide member 125 by bolts 130 during normal operation. preferable.

The above-mentioned gas-insulated instrument transformer is provided in the container 10
No. 0 is connected to the nozzle of a predetermined container of the gas insulated switchgear through the insulating spacer 106 to attach the nozzle 105 to the gas insulated switchgear.
06 penetrated conductors 106u to 106w are connected to predetermined circuit portions of the gas insulated switchgear via connection conductors (not shown).

During the normal operation of the gas insulated switchgear, as shown in FIG.
22w is held in contact with the three-phase high-voltage terminals 115u to 115w, and the three-phase high-voltage terminals 115u to 115w
Are connected to a predetermined circuit portion of the gas insulated switchgear through movable contacts 122u to 122w, energizing contacts 121u to 121w, connection conductors 120u to 120w, and through conductors 106u to 106w of the insulating spacer 106.

In the above example, three-phase connection conductors 120u to 120w each having one end connected to three-phase through conductors 106u to 106w embedded in the insulating spacer 106.
And three-phase energizing contacts 121u to 121w attached to the other ends of the three-phase connecting conductors, respectively, and a closed circuit that comes into contact with the three-phase high-voltage terminals while being in contact with these energizing contacts 121u to 121w. An insulating spacer is provided by three-phase rod-shaped movable contacts 122u to 122w provided so as to be displaceable along the axial direction of the transformer accommodating container between the position and an open position separated from the high-voltage terminal. A disconnecting portion 131 that opens and closes each of the three-phase through conductors embedded in the through hole and the three-phase high-voltage terminal is configured.

The three-phase connecting plate 126 is screwed into the three-phase connecting plate 126, the screw rod 125 screwed into the screw hole, and the operating handle 129 to connect the three-phase connecting plate 126 to the axis of the transformer housing 100. An operation mechanism for displacing in the direction is configured,
An end wall of the transformer container facing the three-phase high-voltage terminals 115u to 115w is provided so as to penetrate in an airtight and slidable manner, and one end is connected to movable contacts 122u to 122w in the transformer container 100. Three-phase insulated operating rod 1
23u to 123w, and 3 outside the transformer container 100
The three-phase connecting plate 126 for connecting the phase insulating operation rods and the operating mechanism constitute an operating device 132 for opening and closing the disconnecting portion from outside the transformer housing.

When performing a withstand voltage test of the gas insulated switchgear, as shown in FIG. 3, after removing the bolt 130 (see FIG. 2), the operating handle 129 is rotated to disconnect the three-phase connecting plate 126. By displacing in the direction away from the transformer housing 100, the three-phase movable contacts 122u to 122u-12
2w is moved to the open position at once, and the movable contact 1
A gas gap G required to have a predetermined dielectric strength is formed between the 22u to 122w and the high-voltage terminal of the three-phase instrument transformer main body.

After the withstand voltage test is completed, the operating handle 129 is operated to move the three-phase connecting plate 126 to the container 100 side, whereby the movable contacts 122u to 122u are moved.
w is brought into contact with the three-phase high-voltage terminals 115 u to 115 w, and the three-phase connecting plate 126 is
And the movable contacts 122u to 122w are held at the closed position.

With the above configuration, the disconnection function can be provided without moving the instrument transformer main bodies 110u to 110w, so that the instrument transformer can be opened and closed without requiring a large operating force during the withstand voltage test. Can be disconnected from the device. Further, since the disconnecting portion can be operated from outside the container 100, the instrument transformer can be disconnected without collecting the gas in the container of the gas insulated switchgear.

Also, as described above, the high voltage terminals 115u-1
When the instrument transformer main bodies 110u to 110w are arranged with the 15w oriented in a direction perpendicular to the axis of the insulating spacer 106, a space for arranging the disconnecting section in the transformer housing is easily secured. Therefore, the disconnection function can be provided without particularly increasing the size of the instrument transformer.

When the disconnecting portion is configured as described above, the high-voltage terminals 115u to 115w of the instrument transformer also serve as fixed contacts for the disconnecting portion, so that the configuration of the disconnecting portion can be simplified.

When the disconnecting portion and the operating device are configured as described above, the operating mechanism is disposed in a direction perpendicular to the axis of the insulating spacer. When arranging, the position of the operation mechanism can be lowered to facilitate the operation.

Further, as described above, the three-phase instrument transformer main bodies 110u to 110w are supported on one end wall 102 of the transformer housing 100, and the nozzle 105 is connected to the three-phase high-voltage terminal. Is provided at a position deviated toward the other end wall 103 side of the opposing transformer storage container 100, the instrument transformer main body 1
Since a wide space can be secured between 10u to 110w and the end wall 103, the disconnecting portion can be easily arranged.

In the above example, the movable contacts 122u to 122w are held at the closed position by bolting the three-phase connecting plate 126 to the guide member 125, but the movable contacts 122u to 122w are set at the closed position. The holding means may be any means for fixing the three-phase connecting plate 126 to the container 100, and is not necessarily limited to the illustrated bolt 130.

In order to hold the movable contacts 122u to 122w in the closed position, for example, the three-phase connecting plate 126 may be directly bolted to the end wall 103 of the container 100, and the operation handle 129 may be externally mounted. In this state, a lock nut may be screwed into the screw rod 128, and the three-phase connecting plate 126 may be fixed by the lock nut.

[0052]

As described above, according to the present invention, since the disconnecting function can be provided without moving the instrument transformer itself, the instrument can be operated without requiring a large operating force during the withstand voltage test. The power transformer can be disconnected from the switchgear.

Further, according to the present invention, since the disconnecting portion can be operated from outside the container, the instrument transformer can be disconnected without collecting the gas in the container of the gas insulated switchgear. In addition, the operation for disconnecting the instrument transformer during the withstand voltage test can be simplified.

Further, according to the present invention, when the instrument transformer main body is arranged with the high-voltage terminal oriented in a direction perpendicular to the axis of the insulating spacer, the disconnecting portion is arranged in the transformer housing. Since the space can be easily secured, the disconnection function can be provided without particularly increasing the size of the instrument transformer.

According to the second aspect of the present invention,
Since the high-voltage terminal of the instrument transformer can also serve as the fixed contact of the disconnecting portion, there is an advantage that the configuration of the disconnecting portion can be simplified.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration example of a transformer for a gas-insulated instrument according to the present invention.

FIG. 2 is a longitudinal sectional view showing a state in which a disconnecting part of the transformer for a gas-insulated instrument according to the present invention is closed.

FIG. 3 is a longitudinal sectional view showing a state in which a disconnecting portion of the gas insulated instrument transformer according to the present invention is open.

FIG. 4 is a cross-sectional view showing a configuration example of a conventional gas insulated switchgear using a gas insulated instrument transformer.

5 is a single-line diagram showing an electrical configuration of the gas insulated switchgear of FIG. 4;

FIG. 6 is a cross-sectional view showing a configuration example of a gas-insulated switchgear using another conventional gas-insulated instrument transformer.

7 is a single-line diagram showing an electrical configuration of the gas insulated switchgear of FIG. 6;

[Explanation of symbols]

100: transformer storage container, 103: end wall, 106: insulating spacer, 106u to 106w: through conductor, 110u
~ 110w ... Transformer main body for instrument, 115u ~ 115w ...
High-voltage terminal, 120u-120w ... connection conductor, 121u-
121w: energizing contact, 122u to 122w: movable contact, 123u to 123w: insulating operating rod, 126
... three-phase connecting plate, 128 ... screw rod, 129 ... operation handle.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G015 AA07 AA09 AA10 AA27 CA01 DA02 5E081 AA02 AA11 BB03 CC22 DD17 EE13 GG01 5G017 BB02 BB15 JJ01

Claims (2)

[Claims] 1. A transformer housing having an airtight holding structure in which both ends in an axial direction are closed by end walls and a nozzle portion protruding from a side surface, and a three-phase through conductor are embedded therein. An insulating spacer attached to a flange at the tip of a nozzle portion of the storage container, and a three-phase instrument transformer main body stored in the transformer storage container, wherein the nozzle portion of the transformer storage container is The three-phase high-voltage terminals respectively connected to the three-phase instrument transformer main body and connected to the other container of the gas insulated switchgear through the insulating spacer are embedded in the insulating spacer. In a gas-insulated instrument transformer connected to a three-phase circuit of a gas-insulated switchgear through a conductor, the three-phase instrument transformer body has its high-voltage terminals oriented in the axial direction of the transformer housing. Arranged in a state Disconnecting portions for respectively opening and closing between the three-phase through conductor embedded in the insulating spacer and the three-phase high-voltage terminal are arranged in the transformer housing, and the three-phase high-voltage terminals are opposed to each other. A transformer for a gas insulated instrument, wherein an operating device for opening and closing the disconnection portion from outside the transformer housing is mounted on an end wall of the transformer housing. 2. The disconnecting portion has one end connected to each of three-phase through conductors embedded in the insulating spacer.
A three-phase connecting conductor, a three-phase energizing contact attached to the other end of the three-phase connecting conductor, and a state in which the three-phase connecting conductor is in contact with the three-phase high-voltage terminal while being in contact with the three-phase energizing contact. And a three-phase rod-shaped movable contact provided so as to be displaceable along an axial direction of the transformer storage container between a closed position and an open position separated from the high-voltage terminal. The operating device is provided in a state where the end wall of the transformer housing facing the three-phase high-voltage terminal is penetrated in an airtight and slidable manner, and one end of the movable contact is provided in the transformer housing. Connecting the three-phase insulated operating rod connected to the three-phase insulated operating rod to the outside of the transformer housing;
A phase connection plate, and an operation mechanism for displacing the three-phase connection plate in the axial direction of the transformer housing so as to displace the three-phase movable contact between an open circuit position and a closed circuit position. The transformer for a gas-insulated instrument according to claim 1.