JPH10256045A - Transformer and bushing for transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transformer for connecting a primary side to a power distribution line without going through a high-voltage load switcher. SOLUTION: A fuse 303 is inserted into a bushing body 301 of a primary bushing 3 that is mounted to a case 1 for accommodating a transformer body, and a terminal 303b at one terminal side of the fuse is brought into contact with a contact 302 that is provided in the bushing body. A terminal 303c at the other terminal side of the fuse is brought into contact with a contact 304 in a connector 305 that is mounted to the tip side of the bushing body removably. An arc-extinguishing mechanism is constituted of an arc-extinguishing cylindrical part 305a3 that is provided at the connector and an arc-extinguishing rod 303d that is mounted to the tip of the terminal 303c of the fuse. The contact 302 is connected to the primary coil of a transformer body via a bushing conductor 309, and a contact 304 is connected to a lead wire 5 that is connected to a power distribution line.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer in which a transformer main body is housed in a case, and a transformer for connecting between a lead wire drawn out of the transformer main body and an external lead wire. The present invention relates to a bushing for a transformer attached to a case of a transformer.

[0002]

2. Description of the Related Art In a distribution line, a high-voltage load switch (cut-out) is provided between a distribution line and a primary side of a transformer in order to switch a primary current of a transformer and cut off an accident current. Switch). The high-voltage load switch must have a function of switching the primary current of the transformer and a function of cutting off the fault current. As a conventional switch of this type, as disclosed in Japanese Utility Model Publication No. 63-27415, a fuse is built in the movable side of the switch, and the fault current is cut off by the fuse. Have been.

A high-voltage load switch disclosed in Japanese Utility Model Publication No. 63-27415 discloses a support insulator attached to a utility pole via a mounting bracket, a hinge electrode and a fixed electrode attached to the support insulator, and a hinge. A fuse housing cylinder having one end hinged to the electrode, a fuse housed in the fuse housing body, and a hinge electrode provided at the other end of the fuse housing cylinder via a fuse in the fuse housing body. A movable electrode to be connected is provided, and the load current is opened and closed by rotating the fuse accommodating cylinder to bring the movable electrode into contact with the fixed electrode or disconnect the movable electrode from the fixed electrode. . If an accident current flows while the high-voltage load switch is closed and the transformer is energized, the accident current is cut off by blowing the fuse housed in the fuse housing cylinder. ing.

[0004]

As described above, conventionally, in order to open and close the primary current of the transformer and cut off the fault current, a high voltage is placed between the distribution line and the primary side of the transformer. Since the voltage load switch is provided, the number of components required to configure the distribution facility increases, and there is a problem that the cost required for the distribution facility increases. When a high-voltage load switch is placed between the distribution line and the primary side of the transformer, the high-voltage load switch is placed above the primary bushing that is mounted so as to protrude greatly from the mounted transformer case. Since the insulators that make up the equipment are arranged, the equipment placed between the transformer and the distribution line gives a complicated and strange impression, and the harmony between the appearance of the mounted equipment and the surrounding environment There was also a problem that it was difficult to plan.

It is an object of the present invention to provide a transformer capable of connecting the primary side to a distribution line without a high voltage load switch, and a bushing for a transformer to be attached to the transformer.

[0006]

According to the present invention, a primary bushing is attached to a case containing a transformer main body, and a lead wire drawn from a primary coil of the transformer main body is connected to an external lead wire through the primary bushing. A function related to the transformer, the function of switching the load current to the primary bushing,
It is characterized by having a function to cut off the fault current.

The primary bushing used in the present invention is:
A bushing body having a rear end attached to the case, having a hollow inside, and the hollow being open to the front end,
A transformer-side contact provided in a hollow portion of the bushing main body in a state positioned near the rear end of the bushing main body, and terminals on one end side and the other end side in the axial direction, respectively. The fuse has a fuse that is inserted into the hollow portion so as to be able to be pulled out, and one terminal of which is in contact with the transformer contact, and a lead contact that contacts the terminal of the other end of the fuse. A connector detachably attached to the end of the bushing body so as to close the opening of the bushing, and an arc generated between the terminal on the other end of the fuse and the lead-side contact when the connector is removed is extinguished. And an arc extinguishing mechanism.
A lead wire and an external lead wire drawn from the primary coil of the transformer body are connected to the transformer-side contact and the lead-side contact, respectively.

As described above, the fuse is housed in the primary bushing, the terminal on one end of the fuse is brought into contact with the contact on the transformer side provided in the primary bushing, and the terminal on the other end of the fuse is contacted. A connector having a lead-side terminal to be detachably attached to the primary bushing, and an arc extinguishing mechanism for extinguishing an arc generated between the terminal on the other end of the fuse and the lead-side contact when the connector is detached is provided. In other words, the primary current of the transformer can be opened and closed by attaching and detaching the connector. The fault current can be cut off by blowing the fuse.

As the above-mentioned arc extinguishing mechanism, a mechanism using a narrow arc extinguishing method can be used. In a preferred example, the connector includes a cylindrical portion having an open distal end, a base end for closing a rear end of the cylindrical portion, and an arc-extinguishing cylindrical portion provided on an inner periphery of a portion near the distal end of the cylindrical portion. A connector shell is provided which is inserted into the hollow portion of the bushing main body from the front end side of the bushing main body with the front end of the cylindrical portion facing the fuse side, and is detachably attached. In this case, the lead-side contact is mounted in the connector shell while being positioned between the arc-extinguishing tubular portion and the base end of the connector shell. The terminal at the other end of the fuse has an electrode portion that is brought into contact with the lead-side contact through the inside of the arc-extinguishing tube portion, and has a size that can pass through the inside of the arc-extinguishing tube portion at the tip end of the electrode portion. Arc extinguishing rod is provided. The arc-extinguishing cylinder and the arc-extinguishing rod are formed of a synthetic resin material that generates an insulating gas when heated. It is preferable to use a polyacetal resin as the synthetic resin material. When the arc-extinguishing tube portion passes the position of the arc-extinguishing rod in the process of disconnecting the connector, an arc-extinguishing tube is formed so that an arc-extinguishing gap is formed between the arc-extinguishing tube portion and the arc-extinguishing bar. The arc extinguishing mechanism is formed by the arc extinguishing cylinder and the arc extinguishing rod.

When the connector is pulled out while a primary current is flowing from the distribution line through the primary bushing to the transformer, a lead-side contact provided on the connector is provided on a terminal on the other end of the fuse. An arc is generated between the lead-side contact and the electrode part at the moment when the rod moves away from the electrode part and moves on the arc extinguishing rod. This arc is sucked into the gap between the arc-extinguishing cylinder and the arc-extinguishing rod by the attraction force generated by the relative displacement generated between the arc-extinguishing cylinder and the arc-extinguishing rod due to the displacement of the connector. . When the arc is sucked into the slit, the arc heats the arc-extinguishing cylinder and the arc-extinguishing rod, and the resin forming the arc-extinguishing cylinder and the arc-extinguishing rod is vaporized to generate an insulating gas. The arc is cooled and extinguished by the insulating gas.

[0011]

FIG. 1 shows an example of the construction of a pole transformer according to the present invention, and FIG. 2 shows a primary bushing used for the transformer. In these figures, reference numeral 1 denotes a transformer case which is attached to a utility pole by a pole fitting (not shown);
Is a transformer main body housed in the case 1, and the transformer main body 2 is formed by winding a coil 202 including a primary coil and a secondary coil around an iron core 201.

Two primary bushings 3 are mounted on the side surface of the case 1 with their central axes oriented in the horizontal direction, and lead wires 4 drawn from primary coils of the transformer body 2 pass through the primary bushings 3. External lead wire 5
It is connected to the. The end of the external lead wire 5 opposite to the primary bushing 3 is connected to a high-voltage distribution line (not shown).

On the side surface of the case 1, two secondary bushings 6 each having an insulator 601 penetrating the case 1 and a bushing conductor 602 penetrating the insulator 601 face the opposite side to the primary bushing 3. And is mounted in a position higher than the primary bushing 3,
Lead wire 7 drawn from the secondary coil of transformer main body 2
Are connected to the bushing conductor 602 of the secondary bushing 6.

The insulating oil 8 is injected into the case 1 to a level higher than that of the primary bushing 3, and the opening at the upper end of the case 1 is closed by a cover plate 9.

As shown in FIG. 2, the primary bushing 3
Is a connector 305 having a bushing body 301 made of an insulator tube, a transformer contact 302, a fuse 303, a lead contact 304, and an arc extinguishing mechanism 306.
And

The bushing main body 301 has a cylindrical mounting portion 301a formed at the rear end thereof, a main body portion 301b formed at the outer periphery thereof with a fold, and a cylindrical front end portion 301c.
The mounting portion 301a and the main body portion 301
A flange 301d is formed at a boundary portion between the mounting portion 301b and the inside of the mounting portion 301a, and a partition wall 301e that partitions the inside of the mounting portion 301a in the axial direction is formed. Also, by making the inner diameter of the distal end portion 301c slightly larger than the inner diameter of the main body portion 301b, a step portion 301f for positioning the connector at the boundary between the inner periphery of the distal end portion 301c and the inner periphery of the main body portion 301b. Is formed and the tip 3
An annular groove 301g for locking the connector is provided around the inner periphery near the opening of 01c. Body part 301
b, a fuse 3 is provided on the inner periphery near the tip 301c.
A projection 301h for positioning the position No. 03 is provided around.

A mounting hole 101 for mounting a bushing body 301 is formed in a side wall of the transformer case 1, and a seal member 307 is fitted in the mounting hole 101. The bushing main body 301 is arranged in a state where the mounting portion 301a is fitted into the mounting hole 101 via the sealing member 307, and the flange 301d is in contact with the peripheral portion of the mounting hole 101 via the sealing member 307. The mounting bracket 308 abutting on the flange 301d is fastened to the case 1 by a bolt (not shown),
The bushing body 301 is fixed to the case 1.

A bushing conductor 309, which shares a central axis with the bushing body, is mounted so as to penetrate the center of a partition wall 301e formed inside the mounting portion of the bushing body 301. The illustrated bushing conductor 309 has a threaded portion 309a penetrating the partition wall 301e at its tip, and a flange 309b formed on the rear end side of the threaded portion 309a abuts on the partition wall 301e and is positioned. ing.

On the surface of the partition wall 301e on the side of the main body portion 301b, a transformer-side contact 302 is arranged so as to share an axis with the bushing main body. The transformer-side contact 302 is formed of a known tulip contact in which a plurality of slits extending in the axial direction are formed in a peripheral wall portion of a cylindrical conductor to form a contact portion having elasticity, and a base portion of the tulip contact is formed by a partition wall. It is arranged in a state of contact with 301e. At the center of the base of the transformer-side contact 302, a hole is provided for allowing the threaded portion 309a of the bushing conductor to penetrate, and the nut 310 is attached to the threaded portion 309a that has passed through the partition wall 301e and the base of the contact 302. The nut 310 is screwed into the through conductor 30.
9 are fastened together with the contact 302 and fastened to the partition wall 301e.

The connector 305 is connected to the bushing body 301.
a connector shell 305a which is inserted into the hollow portion of the bushing body from the tip side of the connector shell 305 and is detachably attached.
It has. The connector shell 305a includes a tubular portion 305a1 having an open front end, a base end portion 305a2 for closing the rear end of the tubular portion, and an arc-extinguishing tubular portion fixed to an inner periphery of a portion near the front end of the tubular portion. 305a3, and a conductor for connecting the core of the lead wire 5 is molded in the base end portion 305a2. A lead wire lead-out portion 305a4 is provided at the base end portion 305a2.
Are provided integrally, and a lead wire 5 in which one end of a core wire is connected to a conductor molded in the base end portion 305a2 is led out through a lead wire leading portion 305a4.

In the illustrated example, the cylindrical portion 30 of the connector is used.
On the outer periphery of a portion near the base end portion 305a2 of 5a1, a locking projection 305a5 which is resiliently fitted and locked in a groove 301g provided in the bushing main body 301 is formed.

In the connector shell 305a, a lead-side contact 304 is disposed so as to be located between the arc-extinguishing tube 305a3 and the base end 305a2. The lead side contact 304 is formed of a tulip contact having the same structure as the transformer side contact 302, and the center of the base of the contact 304 is located at the base end 3 of the connector shell.
It is fastened by screws 311 to the conductor molded in 05a2.

The connector shell 305a has a cylindrical portion 3
05a1 to the fuse 30 in the bushing body 301.
The bushing main body 301 is inserted into the hollow portion of the bushing main body 301 from the front end side thereof and attached. The connector shell 305a is inserted into the hollow portion until the locking projection 305a5 fits into the groove 301g, and the connector 305 is fixed to the bushing body 301 by fitting the locking projection 305a5 with the groove 301g. With the connector 305 attached to the bushing main body in this manner, the transformer 305 and the lead side contact 304 are assembled such that the central axes of the transformer-side contacts 302 and the lead-side contacts 304 coincide with the central axes of the bushing main body 301.

The fuse 303 is a cylinder 3 made of an insulating material.
03a, a fuse conductor (fusible body) is housed inside, and a terminal 3 is provided at one end and the other end of the cylindrical body 303a in the axial direction.
03b and 303c are attached. The terminal 303b at one end of the fuse 303 has a cap shape (cylindrical shape).
And is fitted to one end of the cylindrical body 303a. The terminal 303c at the other end of the fuse 303 is
03a, and a cylindrical base 303c1 fitted to the other end of the base member 303a, and a round bar-shaped electrode 30 having a rear end connected to the base 303c1.
3c2, and a round bar-shaped extinguishing rod 303d is connected to the tip of the electrode portion 303c2. This fuse 303
A terminal 303b at one end of the bushing main body 301 is inserted into the hollow portion of the bushing main body 301 from the tip end thereof, and the terminal 303b at one end thereof is brought into contact with the transformer-side contact 302. , Arc-extinguishing tube 305
The contact is made to contact the lead side contact 304 through the inside of a3.

A female screw portion is formed at the axial center of the terminal 303 b on one end of the fuse, and the female screw portion is screwed to a screw portion at the tip of the bushing conductor 309, and one end of the fuse 303 is connected to the bushing conductor 309. Fixed.

The extinguishing rod 303d is formed so as to have a slightly smaller outer diameter than the electrode portion 303c2, and is arranged with its central axis aligned with the central axis of the electrode portion 303c2. The outer diameters of the electrode portion 303c2 and the arc-extinguishing rod 303d are set slightly smaller than the inner diameter of the arc-extinguishing tube portion 305a3.
When 05a3 passes through the position of the arc extinguishing rod 303d, an arc extinguishing gap is formed between the arc extinguishing cylinder 305a3 and the arc extinguishing rod 303d.

In the example shown, the base 303c1 of the terminal 303c at the other end of the fuse 303 is fitted to a projection 301h formed on the inner periphery of the bushing body 301, and the fuse 3
03 and the terminal 30b on the transformer side.
2 and the base 303c1 of the terminal at the other end of the fuse.
The fuse 303 and the protrusion 301h allow the fuse 303 to be positioned concentrically within the bushing even when the connector 305 is removed.

The arc-extinguishing cylinder 305a3 and the arc-extinguishing rod 303d are
It is made of a synthetic resin material, such as polyacetal resin, which vaporizes when heated by an arc to generate an insulating gas.

In the above-mentioned transformer, a lead wire 5-lead-side contact 304-electrode 303c2-fuse conductor-terminal 303b-transformer-side contact 302-bushing conductor 309-outlet 4- The transformer body is energized through the primary coil path of the transformer body 2. When interrupting the load current, the connector 305 is detached. In the process of disconnecting the connector 305, an arc is generated between the lead-side contact 304 and the electrode 303c2 at the moment when the lead-side contact 304 separates from the electrode 303c2 of the terminal on the other end of the fuse 303 and moves on the arc-extinguishing rod 303d. Occurs. This arc is extinguished by an attractive force generated by a relative displacement generated between the electrode portion 303c2 and the arc-extinguishing tube portion 305a3 and between the arc-extinguishing tube portion 305a3 and the arc-extinguishing rod 303d due to the displacement of the connector. It is sucked into the narrow gap between the cylindrical portion 305a3 and the arc extinguishing rod 303d. When an arc is sucked into this gap, the arc extinguishes the arc-extinguishing cylinder 30.
Since 3a3 and the arc extinguishing rod 303d are heated, the resin forming the arc extinguishing cylinder and the arc extinguishing rod is vaporized to generate an insulating gas. The arc is cooled and extinguished by the insulating gas.

If an accident current flows during energization,
The fuse 303 is blown to cut off the fault current and protect the transformer body 2. When the fuse 303 is blown, the fuse 303 is rotated by a tool (not shown), and the terminal 303 b on one end side and the bushing conductor 309 are rotated.
And the fuse 303 is removed from the bushing body 301. After that, the fuse 303 is replaced with a new one and the connector 3050 is attached to close the circuit between the transformer main body and the distribution line.

In the above example, a female thread is provided at the terminal 303b at one end of the fuse 303, and the female thread is screwed to the thread at the tip of the bushing conductor 309. The terminal 303b on one end of the fuse 303 is not required to be configured.
The structure may be such that it is simply brought into contact with the tip of the head and positioned. In this case, the spring force of the transformer-side contact 302 is set to be stronger than the spring force of the lead-side contact 304, or a member for preventing the fuse 303 from coming off is provided in the bushing body, and the connector 305 is pulled out. In this case, it is necessary to prevent the fuse 303 from coming off.

[0032]

As described above, according to the present invention, a fuse is housed in a primary bushing, and a terminal on one end of the fuse is brought into contact with a transformer-side contact provided in the primary bushing. A connector having a lead-side terminal with which the terminal on the other end contacts is detachably attached to the primary bushing, and an arc generated between the terminal on the other end of the fuse and the lead-side contact when the connector is pulled off. Since the arc extinguishing mechanism for extinguishing is provided, the primary bushing itself attached to the transformer case can have the function of opening and closing the load current and the function of interrupting the fault current.
Therefore, it is not necessary to separately provide a conventionally required high-voltage load switch, and the power distribution equipment can be simplified and the cost can be reduced. Further, when mounting a transformer, the primary side of the transformer can be connected to a distribution line without passing through a high-voltage load switch, so that the appearance of the periphery of the transformer can be simplified, Harmony with the surrounding environment can be easily achieved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration example of a transformer according to the present invention.

FIG. 2 is a sectional view showing a structure of a primary bushing used in the transformer of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Case 2 Transformer main body 3 Primary bushing 301 Bushing main body 302 Transformer side contact 303 Fuse 303b Terminal 303c Terminal 303c2 Electrode part 303d Arc extinguishing rod 304 Lead side contact 305 Connector 305a Connector shell 305a1 Cylindrical part 305a2 Base end 305a3 Arc extinguishing Tube part 309 Bushing conductor 5 External lead wire

Claims (4)

[Claims] 1. A transformer in which a primary bushing is attached to a case accommodating a transformer main body, and a lead wire drawn from a primary coil of the transformer main body is connected to an external lead wire through the primary bushing. The primary bushing includes: a bushing body having a rear end attached to the case, having a hollow portion inside, and the hollow portion being open to the front end; and a position near the rear end of the bushing main body. A transformer-side contact provided in the hollow portion of the bushing main body in a state where the bushing main body is located, terminals are provided at one end side and the other end side in the axial direction, respectively, and are inserted into the hollow portion of the bushing main body so as to be drawn out. A fuse whose terminal on one end side is brought into contact with the contact on the transformer side; and a contact on the lead side which contacts a terminal on the other end side of the fuse. A connector which is detachably attached to a tip end of the bushing main body so as to close an opening of the hollow portion, and a terminal on the other end side of the fuse when the connector is removed. An arc extinguishing mechanism for extinguishing an arc generated between the lead-side contact and the lead-side contact, wherein the lead wire and the external lead wire are connected to the transformer-side contact and the lead-side contact, respectively. Transformer. 2. The connector according to claim 1, wherein the connector has a tubular portion having an open distal end, a base end for closing a rear end of the tubular portion, and an arc-extinguishing tubular portion provided on an inner periphery of a portion near the distal end of the tubular portion. A connector shell which is inserted into the hollow portion of the bushing main body from the front end side of the bushing main body in a state where the front end of the cylindrical portion is directed to the fuse side, and which is detachably attached, The lead-side contact is mounted inside the connector shell while being positioned between the arc-extinguishing tube portion and the base end of the connector shell, and a terminal on the other end side of the fuse is provided in the arc-extinguishing tube portion. An arc extinguishing rod having a size that can pass through the inside of the arc extinguishing tube portion is provided at an end of the electrode portion, the arc extinguishing rod having an electrode portion that is brought into contact with the lead-side contact through the inside. The part and the extinguishing rod are heated by the arc When the arc-extinguishing tube portion passes the position of the arc-extinguishing rod in the process of pulling out the connector, the arc-extinguishing tube portion and the The arc-extinguishing cylinder and the arc-extinguishing rod are formed such that an arc-extinguishing gap is formed between the arc-extinguishing rod and the arc-extinguishing mechanism. 2. The method according to claim 1, wherein
Transformer. 3. A transformer bushing attached to a case containing a transformer main body and connecting between a lead wire drawn out of the transformer main body and an external lead wire, wherein the bushing for a transformer is provided on a rear end side thereof. A bushing body having a mounting portion attached to the case, having a hollow portion inside, and the hollow portion being open to the front end side; and a bushing body positioned at a position near a rear end portion of the bushing body. A transformer-side contact provided in a hollow portion of the bushing main body, and a lead-side contact that contacts a terminal on the other end side of the fuse, wherein the bushing main body is closed so as to close an opening of the hollow portion. A connector detachably attached to the distal end portion, having a terminal at one end side and the other end side in the axial direction, respectively, and being inserted into the hollow portion of the bushing body so as to be able to be pulled out. A fuse having a terminal on one end contacting the contact on the transformer, and an arc quencher for extinguishing an arc generated between the terminal on the other end of the fuse and the contact on the lead when the connector is tripped. A bushing for a transformer, comprising: a lead wire and an external lead wire connected to the transformer-side contact and the lead-side contact, respectively. 4. The connector according to claim 1, wherein the connector has a tubular portion having an open end, a base end for closing a rear end of the tubular portion, and an arc-extinguishing tubular portion provided on an inner periphery of a portion near the tip of the tubular portion. A connector shell which is inserted into the hollow portion of the bushing main body from the front end side of the bushing main body in a state where the front end of the cylindrical portion is directed to the fuse side, and which is detachably attached, The lead-side contact is mounted inside the connector shell while being positioned between the arc-extinguishing tube portion and the base end of the connector shell, and a terminal on the other end side of the fuse is provided in the arc-extinguishing tube portion. An arc extinguishing rod having a size that can pass through the inside of the arc extinguishing tube portion is provided at an end of the electrode portion, the arc extinguishing rod having an electrode portion that is brought into contact with the lead-side contact through the inside. Parts and extinguishing rods vaporize when heated When the arc-extinguishing tube portion passes the position of the arc-extinguishing rod in the process of pulling out the connector, an insulating gas is generated between the arc-extinguishing tube portion and the arc-extinguishing bar. The arc extinguishing cylinder and the arc extinguishing rod are formed so that an arc extinguishing gap is formed in the arc extinguishing mechanism, and the arc extinguishing mechanism is constituted by the arc extinguishing cylinder and the arc extinguishing rod. Claim 3
A bushing for a transformer according to item 1.