JP2003272928A - Transformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transformer wherein no power cable nor bus duct is required and the number of site installation steps can be greatly reduced. <P>SOLUTION: A cable 8 is installed through an insulation bushing insulator pipe 7 that is provided by penetrating an upper plate 20 of a tank 1 wherein an insulating oil 5 is sealed. A lower end of the cable 8 is projected downward from the lower end of the insulation bushing insulator pipe 7 into the insulating oil 5, and a lead wire 6 of a primary wire ring 3 is connected with the lower end of the cable 8 in the insulating oil 5. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer that is often used in power receiving and transforming equipment.

[0002]

2. Description of the Related Art As is well known, an oil-filled transformer of a power receiving and transforming facility is constructed by immersing an iron core around which a primary wire wheel and a secondary wire wheel are wound in insulating oil in a tank to The end of the next coil is connected to the end of the through conductor of the insulating through bushing having the external connection terminal arranged on the tank surface.

In order to connect the transformer to electrical equipment such as switches installed on the primary side and the secondary side, a bus duct composed of a power cable and a conductor covered with a ground metal jacket is used. ing. Power cables and bus ducts with a capacity that considers the short-term withstand current of the power supply system electrically and mechanically are used. The connection terminal of the transformer and the switch is fully insulated.

[0004]

In the prior art, the connection between the transformer and the electric equipment installed on the primary side and the secondary side of the transformer is as follows.
Since power cables and bus ducts are used, large-capacity power cables and bus ducts are required, and sufficient on-site adjustment work requires a lot of man-hours for on-site adjustment work because the transformer primary terminal section must be sufficiently insulated. It has the problem of being necessary. An object of the present invention is to provide a transformer that does not require equipment such as a power cable or a bus duct and can significantly reduce the number of on-site installation steps.

[0005]

The feature of the present invention resides in that a cable is disposed through an insulating bushing insulator tube provided through an upper plate of a tank in which an insulating material is hermetically sealed. The lower end projects downward from the lower end of the insulating bushing porcelain tube and is located in the insulating material, and the lead wire of the primary coil is connected to the lower end located in the insulating material of the cable.

According to the present invention, since the on-site construction work is completed simply by connecting the power cable attached to the transformer to the other equipment, the equipment for connection with other equipment such as a bus duct and the on-site construction and the bushing terminal portion on the surface of the transformer are completed. No need for air insulation processing in the field, and the field work process can be greatly shortened.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 show an embodiment of the present invention. FIG. 2 is a left side view of FIG. Note that FIG. 1 shows an example of an oil-filled transformer.

In FIG. 1, an insulating oil 5 as an insulating substance is hermetically sealed inside a tank 1. The iron core 2 is formed by laminating silicon steel sheets through which magnetic flux easily passes, and a primary coil 3 and a secondary coil 4 are wound for each phase (u, v, w phases in FIG. 2). The iron core 2 is immersed in the insulating oil 5 and arranged.

An insulating bushing insulator tube 7 is fixed to the upper plate 20 of the tank 1 by a fixing member 12. A cable 8 is provided so as to penetrate through the insulating bushing insulator tube 7. FIG. 1 shows the insulating bushing insulator tube 7 for only one phase. A switch terminal 1 is provided on the upper end of the cable 8 outside the tank 1.
There is provided a plug 22 for connecting with 5. In addition, the transformer secondary terminal 14 is fixed to the upper plate 20 of the tank 1 by the fixing metal fitting 21.
It is fixed by.

FIG. 3 shows a detailed enlarged view of the insulating bushing insulator tube 7. In FIG. 3, the insulating bushing insulator pipe 7 is fixed to the upper plate 20 of the tank 1 by a fixing member 12. A cable 8 is provided so as to penetrate through the insulating bushing insulator tube 7. The cable 8 is arranged so that its lower end 8 a projects downward from the lower end of the insulating bushing insulator pipe 7 and is located in the insulating oil 5.

The upper end of the insulating bushing porcelain insulator 7 (tank 1
An O-ring 9-1 is provided on the inner wall (outer side of) of the cable 8 and is closely attached to the jacket of the cable 8. Further, an insulator 10 is provided on the outside of the insulating bushing insulator 7 between the O-ring 9 and the cable 8.
-1 is filled, and the surfaces of the insulating bushing insulator tube 7 and the cable 8 are heat shrink material (heat shrinkable material) 11-1.
To prevent water from entering from the outside. These O-ring 9-1, insulator 10-1, and heat shrink material 11-1 constitute a sealing member.

Similarly, an O-ring 9-2 is provided on the inner wall of the lower end portion (inside the tank 1) of the insulating bushing porcelain bushing 7 so as to be in close contact with the jacket of the cable 8. In addition, an insulator 10-2 is filled between the O-ring 9 and the cable 8 on the outside of the insulating bushing insulator pipe 7, and the surfaces of the insulating bushing insulator pipe 7 and the cable 8 are heat-shrinkable (heat shrinkable) 11-2. To prevent the insulating oil 5 from seeping out from the tank 1. These O-ring 9-2, insulator 10-2, and heat shrink material 11-2 also constitute a sealing member.

At the lower end of the insulating bushing porcelain tube 7, an electric field relaxation material 13 is inserted at the end of the cable 8 so that the electric field at the end of the cable 8 is relaxed so that the terminal processing size can be shortened.

In this structure, the switch terminal 15 which is an electric device on the primary side has a cable 1 which penetrates into the insulating bushing porcelain bushing 7 so that the tank 1 having an excellent dielectric strength.
It is possible to directly draw a high voltage from the inside of the tank to the outside of the tank 1 and directly connect it. Therefore, it is possible to eliminate the work of air insulation terminal treatment of the high-voltage power cable at the primary side terminal of the transformer, and the primary side of the transformer is electrically and mechanically matched to the short-term capacity of the system. It eliminates the need for high-capacity power cables and bus ducts, and eliminates the need for production costs and on-site installation and adjustment work, thus significantly reducing the number of local man-hours.

FIG. 4 shows another embodiment of the present invention. The embodiment of FIG. 4 is different from the embodiment of FIG. 1 in that nitrogen gas 16 having a high dielectric strength is sealed and sealed between the insulating oil 5 in the tank 1 and the tank 1, and nitrogen gas is charged in the upper portion of the tank 1. That is, the lead wire 6 of the primary winding wheel 3 and the power cable 8 are connected in part.

Also in the embodiment of FIG. 4, it is possible to eliminate the work of air insulation terminal treatment of the high voltage power cable at the primary side terminal portion of the transformer, and the primary side of the transformer has a short-term capacity of the system. In addition, it eliminates the need for electric cables and bus ducts of a capacity that is electrically and mechanically commensurate with each other, eliminating the need for production costs such as installation costs and on-site installation and adjustment work, thus significantly reducing the number of local man-hours. Moreover, by connecting the lead wire 6 of the primary winding wheel 3 and the power cable 8 with the nitrogen gas portion 16, the terminal treatment of the connecting portion can be simplified.

As described above, according to the present invention, a cable is provided by penetrating an insulating bushing porcelain tube provided through an upper plate of a tank in which an insulating material is hermetically sealed, and a lower end of the cable is provided with the insulating bushing porcelain tube. It is arranged so as to project downward from the lower end and be located in the insulating material, and the lead wire of the primary coil is connected to the lower end located in the insulating material of the cable.

Therefore, since the on-site construction work can be completed simply by connecting the power cable attached to the transformer to other equipment, it is possible to use the equipment connected to other equipment such as a bus duct or the on-site construction and the bushing terminal portion on the surface of the transformer. No need for air insulation processing, etc., and it is possible to greatly shorten the on-site work process.

In the above-mentioned embodiment, the insulating material filled in the tank is insulating oil, but it is needless to say that the same effect can be obtained by the transformer in which the insulating gas such as SF6 gas is filled.

Further, it is obvious that high-pressure dry air may be filled in the tank instead of the nitrogen gas in which the insulating oil and the nitrogen gas are filled.

Further, in the above-mentioned embodiment, the cable passing through the insulating bushing insulator tube is provided only on the primary side, but it is obvious that it may be provided on the secondary side.

[0022]

According to the present invention, therefore, the on-site construction work can be completed simply by connecting the power cable attached to the transformer to the other equipment. No need for air insulation processing at the bushing terminals on the surface of the transformer, which can greatly shorten the on-site work process.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a left side view of FIG.

FIG. 3 is a detailed configuration diagram of a main part of the present invention.

FIG. 4 is a configuration diagram showing another embodiment of the present invention.

[Explanation of symbols]

1 ... Oil-filled transformer tank, 2 ... Transformer core, 3 ... Primary wire ring, 4 ... Secondary wire ring, 5 ... Insulating oil, 6 ... Primary wire wheel terminal lead wire, 7 ... Insulating bushing insulator tube, 8 ... Cable, 9 ... O
Ring, 10 ... Insulator, 11 ... Heat shrink material, 1
2, 21 ... Fixing hardware, 13 ... Electric field relaxation material, 14 ... Transformer secondary terminal, 15 ... Switch terminal, 16 ... Nitrogen gas, 20 ...
Upper plate of tank 1, 22 ... Plug.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazuyuki Kiuchi             Co., Ltd., 120, Saiwaicho, Inazawa City, Aichi Prefecture             Within the Hitachi AI system (72) Inventor Akio Saruta             Co., Ltd., 120, Saiwaicho, Inazawa City, Aichi Prefecture             Within the Hitachi AI system F-term (reference) 5E050 HA06                 5E059 JL02 KK16

Claims (6)

[Claims] 1. A transformer in which an iron core wound with a primary coil and a secondary coil is arranged in an insulating material hermetically sealed in a tank, the core being penetrated through the upper plate of the tank and fixed to the tank. Insulating bushing porcelain tube, a cable penetrating through the insulating bushing porcelain bushing, the lower end protruding downward from the lower end of the insulating bushing porcelain bushing and located in the insulating material, and the upper and lower ends of the insulating bushing porcelain bushing A sealing member for sealing a portion, wherein the lead wire of the primary coil is connected to a lower end of the cable located in the insulating material. 2. A transformer in which an insulating oil and an insulating gas are hermetically sealed in a tank, and an iron core around which a primary coil and a secondary coil are wound is arranged in the insulating oil. An insulating bushing porcelain tube that penetrates a plate and is fixed to the tank; and a cable that is disposed so as to penetrate through the insulating bushing porcelain bushing and has a lower end protruding below the lower end of the insulating bushing porcelain bushing and located in the insulating gas. And a sealing member for sealing an upper end portion and a lower end portion of the insulating bushing porcelain tube, wherein the lead wire of the primary coil is connected to the lower end of the cable located in the insulating gas. A transformer. 3. The transformer according to claim 1, wherein the insulating substance is insulating oil. 4. The insulating material according to claim 1, wherein the insulating material is SF6.
A transformer characterized by being gas. 5. The transformer according to claim 2, wherein the insulating gas is nitrogen gas. 6. The transformer according to claim 2, wherein the insulating gas is high-pressure dry air.