JPS6028369B2 - Transformer with on-load tap changer and its assembly method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a novel on-load tap changer (hereinafter abbreviated as LTC).

) related to transformers. Generally, a transformer with LTC is equipped with a switching switch, a tap selector, and a mechanical box on the side of the transformer, which is housed in a tank.
A plurality of tap lead wires drawn out from the inside of the transformer are connected to the tap selector of this LTC.

As shown in Figure 1, a normal transformer with LTC has a lower tank 21A with the division position at the upper part and its height dimension increased.
and a small upper tank 21B with a height dimension of 4 connected to this.
A tank 20 consisting of at least two tanks is used.

The transformer contents 23 consisting of an iron core, windings, etc. are stored in this tank 20, and a closed part 2 provided in the upper tank 21B
2, the switching switch 1 and the tap selector 2 are built into the tank 20, and the tap lead wire 4 drawn out from the transformer contents 23 is connected to each fixed contact of the selector 2. (not shown). To assemble the transformer with LTC of this structure, first, the transformer contents 23 are stored in the lower tank 21A, and then the upper tank 218 is attached to form the tank 20 as an integrated tank. L
TC is a cutting switch 1 in which internal structures are arranged inside an insulating cylinder 4.
The tap selector 2 connected to the lower part of the insulating tube 4 is constructed integrally with the mechanism box 3 in advance using the upper mounting bracket 5 of the insulating tube 4, and this LTC with a horizontal structure is constructed as shown by the two-dot chain line. Lift it up using a lifting device and open the opening 2 of the upper tank 21B.
2. Connect the switching switch and tap selector 2 parts to the lower tank 2.
1A, the flange 3A of the mechanism box 3 is oil-tightly attached and supported to the upper tank 21B via packing, and is further installed on the side of the tank 20 via the drive shaft 7 to the mechanism box 3. An electric operating mechanism 6 is used in combination. In the case where the integrated LTC is suspended in the tank 20, it is necessary to wire and connect the plurality of tap lead wires 24 drawn out from the inside of the transformer 23 to the tap selector 2, and also to connect them inside the tank 20. Transformer contents 2
3. Perform drying treatment on the built-in tank part of LTC.
After this, the tightening of the connection points is carried out by a contractor who enters the tank 20 through a manhole (not shown) to complete the LTC transformer. In this way, the transformer with LTC, in which various operations are performed inside the tank 20, not only has poor assembly workability, but also requires a large working space, which makes it uneconomical because the dimensions of the transformer must be increased. There is a drawback. In order to improve this drawback, conventionally, a transformer with LTC as shown in FIG. 2 has been constructed.

This transformer uses a tank 20 formed by a lower tank 21A with a small height dimension and an upper tank 21B with a large height dimension coupled thereto. The LTC is separated into the tank built-in part of the switching switch 1 and tap selector 2 and the tank external part of the mechanism box 3 shown by the two-dot chain line at the position of the upper mounting bracket 5 of the insulating tube 4, and the transformer is assembled. It is something that is joined together in the process. The transformer contents 23 housed in the tank 20 are provided with a metal support arm 8 whose one end is fixed to a core fitting (not shown) on the upper part of the transformer contents 23.
The other end of the support arm 8 is designed to support the switching switch 1 and the tap selector 2, which are built-in parts of the LTC tank, when the transformer is assembled. In this assembly, the lower tank 21A is not combined with the upper tank 21B.
After installing the transformer contents 23, the plurality of tap lead wires 24 are connected with the switching switch 1 and the tap selector 2 supported at the other end of the support arm 8, which has one end fixed to the transformer contents 23.
The tap selector 2 is wired and predetermined connections are made. Then, with the upper tank 21B removed, a separate drying device (not shown) is used to perform a prescribed drying process on the transformer contents 23 and the built-in portion of the LTC tank, and the subsequent retightening work is completed. After this is completed, the upper tank 21B is connected to the lower tank 21A as shown by the two-dot chain line. Finally, as shown by the two-dot chain line, the mechanism box 3 that is attached to close the entrance part 22 of the upper tank 21B with the flange 3A is installed using the upper mounting bracket 5 of the switching switch 1.
C is integrated, and connected to the electric operating mechanism 6 by a drive shaft 7, so that it can be hung up. however,
The assembly method in which the built-in part of the LTC tank is supported by the support arm 8 fixed to the transformer contents 23 can eliminate the conventional drawbacks, but the dimensions of the support arm 6 are limited in order to support the built-in part of the tank, which is heavy. If the size is too large, it will require a large amount of work, and its dimensional accuracy will tend to vary, so there is a risk that it will not be easy to assemble the internal part of the LTC tank and the external part of the tank. Further, since the metal support arm 6 is present near the upper part of the transformer body 23, there is a problem in that the transformer needs to be enlarged when insulation dimensions are taken into consideration. L of the present invention
The purpose of the transformer with TC is to make the transformer smaller by improving the support structure of the built-in part of the tank of the LTC, and to facilitate the assembly work so that it can be manufactured economically.

In order to achieve the above object, the present invention stores the contents of a transformer in a tank formed by combining a lower tank with a height dimension of at least 4 cm and an upper tank with a lotus shape, and also stores the contents of a transformer in the tank. When arranging a switching switch and a tap selector and providing a mechanism box in the upper tank that connects to the switching switch and tap selector, one of the switching switch and tap selector is equipped with a plurality of supporting metal fittings. These support columns are connected to one end of each support column, and the switch switch and tap selector are configured to be supported by the lower tank only when the transformer is assembled internally. It is characterized by its use.

The LTC-equipped transformer of the present invention will be described below with reference to FIGS. 3 to 10, in which parts that are the same as those of the prior art are designated by the same reference numerals.

The ones in FIGS. 3 to 5, which are examples of the present invention, are LTC
The tank 20 of the attached transformer is formed of at least two parts, a lower tank 21B having a small height dimension and an upper tank 21B provided with a closing part 22 for LTC.

Ma. In addition, the LTC placed on the side of the transformer contents 23 housed in the tank 20 is also configured to be able to be divided into a switching switch 1, a tap selector 2, and a mechanism box 3 shown by a chain double-dashed line. As shown in FIG. 5, the mechanism box 3 can be connected using a mounting bolt 9 screwed into an upper mounting bracket 5 provided at the upper end of the insulating cylinder 4 of the switching switch 1. The switching switch 1 and the tap selector 2 are integrally constructed,
In order to support these on the lower tank 21B during assembly,
In this example, four support fittings 10 are fixed to the upper mounting fitting 5 of the switching switch 1 according to the present invention. One end of a support column 11 made of, for example, an insulator is connected to each of these support fittings 10, and the other end of the support column 11 is provided in the lower tank 21A and engaged with a positioning fitting 12 that can be used as a steady rest. The switching switch 2 is supported only when the transformer is internally assembled, and this support is released after the assembly is completed. When using the support column 11 made of an insulating material, a hollow insulating tube made of synthetic resin or fiber-reinforced synthetic resin and having a predetermined strength is used, and its mounting structure is shown in more detail in FIG. The upper end is fixed with the support metal fitting 1 and the bolt 13.
For example, bolt 1 is attached to the lower end to absorb manufacturing errors.
The end fitting 15 fixed at 4 is interposed to fit onto the protrusion 12A of the positioning fitting 12. It is long. LTC configured like this
To assemble the transformer, install the contents of the transformer into the lower tank 21A from which the upper tank 21B has been removed. When the switching switch 1 and the tap selector 2 are supported at predetermined positions by a plurality of support columns 11, and then a plurality of tap lead wires '24 from the transformer contents 23 are wired to the tap selector 2. At the same time, the connection work is carried out, and furthermore, the tank storage parts are dried and the fixed parts are tightened.

After fitting the upper tank 218, in which the mechanical box 3 having the flange 3A is placed in the opening 22 of the upper tank 21B, to the lower tank 21A as shown by the two-dot chain line in FIGS. 3 and 4, as shown in FIG. The switching switch 1 and the mechanical box 3 are combined together to form an LTC. The two are connected with a packing 16 interposed therebetween to provide an oil-tight structure. By using a plurality of mounting bolts 9 arranged on the flange 3A of the mechanism box 3 and screwing them into the upper mounting bracket 5 at the upper end of the insulating cylinder 4, the switching switch 1 and the tap selector 2 are pulled upward and integrated. . Therefore, each support column 11 that supported the switching switch 1 and the tap selector 2 has its lower end connected to the positioning metal fitting 1.
Looking at the protrusion 12A of No. 2, it moves upward by a dimension of 6 and becomes a simple steadying structure, so it becomes a free end and no unreasonable force is applied to it. An electric operating mechanism 6 is finally connected to the mechanism box 3 via a drive shaft 7 to complete a transformer with LTC. In this way, the support fitting 10 and the support column 1
If the cutter switch 1 and the tap selector 2 are supported when assembling the contents of the transformer according to 1, the transformer with LTC can be easily configured and its assembly can be easily performed. 10 and support columns 11 are used only during assembly and do not apply bending stress, so they do not need to be particularly large.
Furthermore, since the number of transformers can be arbitrarily determined in consideration of the supporting weight, there is no need to increase the size of the transformer as in the past due to assembly work.

Moreover, in the above example, the support column 11 made of insulator is used, so the insulation strength of the transformer contents 23 and LTC is not reduced, and it can also be used as a support insulator for the wiring of the tap lead wire 24. It is something that can be done. In the above embodiment, the support metal fitting 10 is fixed to the upper mounting metal fitting 5, but if there is no problem with insulation, the support metal fitting 10 is fixed to the connection part between the switching switch 1 and the tap selector 2 as shown in FIG. It is also possible to provide support at the time of assembly by shortening the length and connecting one end of a support column to the support column, thereby achieving the same effect as described above.

In other embodiments shown in FIGS. 7 to 10, a plurality of support fittings 1011 fixed to the upper mounting fitting 5 form an engagement groove 10A. In addition, a metal support column 31 with high strength is used, and its upper end is connected to the engagement groove 10A of the support fitting 10 using a nut 32 that is screwed into the support column 31 so that it can be removed. Positioning metal fitting 33 fixed in advance to the bottom of the tank 21A
The switching switch 1 and the tap selector 2 of the transformer with LTC are supported only when the internal line of the transformer is on. In the structure using the metal support column 31 as described above, for example, as shown in FIG.
An opening 35 is provided to be sealed with a hole 4, so that the metal support column 31 can be removed to the outside after the assembly of the transformer is completed to avoid problems with insulation.

That is, this metal support column 31 supports the switching switch 1 and tap selector 3 during assembly, and after coupling the switching switch 1 and mechanism box 3, loosen the nut 32 as shown in FIG. The metal support column 31 is connected to the engagement groove 10 as shown by the double-dot line.
The supporting column 31 can be reused by removing it from A, making it oblique, removing it from the entrance part 35, and sealing it in the closing plate 34. The metal support columns that support the switching switch 1 and the tap selector 2 are made of, for example, a steel material with high mechanical strength, and are manufactured in an appropriate shape and in the required number.

In this structure as well, the LTC transformer can be assembled in the same steps as those shown in FIGS. 3 to 5, so the same effect can be achieved, and The structure is simple because it is used, and since it is removed outside the tank, there is no problem with the insulation inside the tank, so the internal structure of the tank can be simplified and the transformer can be made even more compact. .

By configuring a transformer with LTC as in the present invention, the inside of the transformer is simplified without requiring a large-scale structure as in the past, and the switching switch, which is a built-in part of the tank, can be easily supported when assembling the internal register. This allows the transformer to be made compact and economical.

Furthermore, the internal assembly work and drying process of the transformer with LTC can be easily carried out in a continuous process by using the support pillars, which has the effect that the assembly of the transformer can be carried out extremely easily.

[Brief explanation of drawings]

1 and 2 are schematic vertical cross-sectional views showing examples of conventional transformers with on-load tap changers, respectively, and FIG. 3 shows a transformer with on-load tap changers that is an embodiment of the present invention. 4 is a plan view of FIG. 3, FIG. 5 is a detailed view of the lozenge of FIG. 3, and FIGS. 6 and 7 are different embodiments of the present invention. A schematic vertical cross-sectional view showing a transformer with a tap changer on load, Fig. 8 is a plan view of Fig. 7, Fig. 9 is a detailed view of the main part of Fig. 7, and Fig. 10 is a main part of Fig. 9. FIG. 1...Switching switch, 2...Tap selector, 3...
... Mechanism box, 4 ... Insulation cylinder, 5 ...
...Top mounting bracket, 9...Mounting bolt, 10...
...Support fitting, 11, 31...Support column, 12, 3
3...Positioning metal fittings, 20...Tank, 21A...Lower tank, 21B...Upper tank, 23...Transformer contents, 24.・・・・・・
・Tap lead wire. Figure 8 Sun'o Figure Tsutomu Figure Leopard 2 Figure 3 Grandchild 4 Figure Leopard Figure Tag Figure Leopard 7 Figure Leopard? figure

Claims (1)

[Scope of Claims] 1. The contents of the transformer are housed in a tank formed by combining at least a lower tank with a small height dimension and an upper tank connected thereto, and a switching switch of a tap changer on load is housed in the tank. and a tap selector built in, and a mechanism box connected to the switching switch is attached to the tank, wherein either one of the switching switch and the tap selector is provided with a plurality of supporting metal fittings, and the supporting metal fittings are provided with a plurality of supporting metal fittings. is characterized in that one end of each support column is connected to each other, and the switch switch and the tap selector are supported by the lower tank only when the transformer is assembled inside the transformer. transformer. 2. A transformer with an on-load tap changer according to claim 1, wherein each of said supporting metal fittings is constructed by connecting one end of a supporting column made of an insulating material. 3. The load according to claim 1, wherein each of the support fittings is connected to one end of a metal support column that is removed outside the tank after the switching switch and the mechanism box are connected. Transformer with hour tap changer. 4. A switching switch and a tap selector integrated into a lower tank with a small height dimension in which the contents of a transformer are installed are supported by a support column connected to a plurality of support fittings provided on either one of these. After connecting the tap lead wires inside the transformer to the tap selector and drying them, the upper tank with a mechanism box provided in the opening is connected to the lower tank, and then the switching switch and mechanism box are connected. A method for assembling a transformer with an on-load tap changer, characterized in that the transformer is configured by connecting the two in an oil-tight manner.