JPS63289911A - Separate type foil-wound transformer - Google Patents

Abstract

PURPOSE:To enable the title transformer even in high voltage and large capacity to be made compact for facilitating transportation thereof by a method wherein a solution pipe of cooling duct builtin an iron core is fixed to the side of iron core to make a tank compact. CONSTITUTION:Sheet type windings 3-5 are formed by laminatedly winding a metallic sheet 7 and an insulating sheet B around the leg part of an iron core while the transformer main body with its iron core 2 and the sheet type winding 3-5 respectively buildingin cooling ducts 9a and 9 is contained in a tank 1 sealed with insulating medium 12. Besides, the circulating systems 10, 11 of coolant flowing in the cooling ducts 9a, 9 are provided separately from that of an insulating medium 12. Furthermore, for example, a solution duct 14a to connect the cooling duct 9a of said iron core 2 to the outer circulating systems 10, 11 is fixed to the side of the iron core 2. Through these procedures, any solution pipe conventionally fixed to the lower end of the cooling duct 9a can be eliminated so that the height of the tank 1 may be reduced by the protrusion of the solution pipe enabling the transportation size to be reduced.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a foil-wound transformer equipped with a sheet-like winding formed by overlapping and winding a metal sheet and an insulating sheet. In particular, it relates to the improvement of cooling ducts provided within the iron core.

(Prior art) Foil-wound transformers equipped with sheet-shaped windings have a good winding space factor and can be made smaller and lighter, so they can be used with small capacities at relatively low voltages of several KV or several hundred KVA. It has already been put into practical use and widely used in transformers.

Recently, in view of the excellent advantages of foil-wound transformers, higher voltage and larger capacity transformers such as 275KV and 300MVA have been developed.
Research is underway to expand its application to class transformers, but the biggest technical issues are as follows: improving the cooling capacity for the windings, providing the windings with high insulation capacity and short-circuit strength, and meeting strict transportation restrictions. The question is whether to clear it. The cooling method for the core and windings in such foil-wound transformers is to incorporate a cooling duct inside the core and windings, and send a refrigerant with excellent insulation properties to directly cool the heat generated from winding losses. do,
A so-called heat pipe type is being considered.

FIG. 3 shows an example of a conventionally known structure of such a foil-wound transformer. In the same figure, tank 1
An insulating medium 12 such as SF6 gas is sealed at high pressure in the tank 1, and an iron core 2 is provided inside the tank 1. A low-voltage winding 3, a medium-voltage winding 4, and a high-voltage winding 5 are sequentially wound concentrically on the outside of the main leg 2a of the iron core 2 with an insulation gap 6 in between. These low voltage windings 3 and medium voltage windings 4
, and the high-voltage winding 5 includes a metal sheet 7 made of aluminum foil or the like and an insulating sheet 8 made of polyester film or the like.
It is made up of sheet-like windings made by overlapping and winding. Note that each winding 3, 4.5 is insulated by the insulating medium 12 enclosed in the tank 1. Moreover, a cooling duct 9 extending in the axial direction is wound around and built into the low-voltage, intermediate-voltage, and high-voltage windings 3 to 5. The cooling duct 9 is hollow so that a refrigerant such as Freon 113 or 70 Linate FC75 can pass therethrough. Here, the refrigerant cools the windings 3 to 5 while passing through the cooling duct 9. Then, this refrigerant passes through the liquid guide pipe 14 and the insulating pipe 13 to the tank 1.
The pump 1 is cooled by an external cooler 11.
It is designed to circulate by 0.

In addition, a cooling duct 9 is also installed in the iron core 2 as well as in each of the windings 3 to 5.
a is built-in, and has a structure that similarly cools the iron core 28. The shape of the cooling duct 9a of this iron core 2 is shown in FIG. As shown in FIG. 4, the cooling duct 9a corresponds to the shape of the iron core 2, and is composed of divided cooling ducts 21 to 23 each divided into a main leg part, a side leg part, and a yoke part. Liquid guiding pipes 14a are attached to both ends of 23 so as to protrude upward and downward.

The conventional foil-wound transformer described above is generally called a separate foil-wound transformer because the cooling system in which the refrigerant circulates and the insulating medium 12 for insulation are completely separated.
Compared to conventional transformers using rectangular wire conductors and insulating oil, this transformer can be significantly smaller and lighter, making it promising as a large-capacity transformer. This type of transformer is USP-4039990
It has been known.

Incidentally, in such a separate foil-wound transformer, the size of the tank 1 is determined by the height dimension of the cooling duct 9a of the iron core 2, which has the largest height dimension among the components of the transformer main body. .

However, in the conventional separate type foil-wound transformer, as shown in FIG. 4, the liquid guide pipes 14a are attached to the upper and lower ends of the cooling duct 9a, so that only the protrusion of the liquid guide pipes 14a The dimensions of tank 1 become unnecessarily large. As a result, when a transformer with a higher voltage and a larger quantity is used, the dimensions of the tank 1 become too large to be transported. Furthermore, when the tank 1 becomes larger, an extra amount of the insulating medium 12 is required, which also has the disadvantage of increasing costs.

(Problems to be solved by the invention) As mentioned above, in conventional separate foil-wound transformers, the shape of the core cooling duct makes the tank size unnecessarily large, making it impossible to transport. Was.

The present invention was made to eliminate the drawbacks of conventional separate foil-wound transformers.The purpose of the present invention is to change the shape of the cooling duct built into the core and reduce the size of the tank. It is an object of the present invention to provide a separate transformer that is compact enough to be transported without any problems even in high-voltage, large-capacity models.

[Structure of the Invention] (Means for Solving the Problems) The separate foil-wound transformer according to the present invention has a cooling duct built into each of the core and the sheet winding, and a circulation system for the refrigerant flowing through the cooling duct. The structure is characterized by the fact that the liquid guiding pipe of the cooling duct built into the separate iron core is installed on the side surface of the separate iron core, which is separated from the insulating medium that insulates the windings.

(Function) In the present invention having the above configuration, the height of the cooling duct can be reduced by eliminating the liquid guide pipe provided at the lower end of the cooling duct of the iron core, and the tank can be made smaller. I can accomplish it.

(Example) Hereinafter, an example of a separate foil-wound transformer according to the present invention will be specifically described with reference to FIGS. 1 and 2. In addition,
The same parts as those in the prior art described above are given the same reference numerals.
The explanation will be omitted.

In this embodiment, as shown in FIG. 1, the lower liquid guiding pipe 14a of the cooling duct 9a of the iron core 2 is attached to the side surface. That is, as shown in FIG. 2, the divided cooling duct of the main leg part and the divided cooling duct of the lower yoke part are integrally constructed to form an L-shaped divided cooling duct 21a, and a liquid guide pipe is installed on the side of the divided cooling duct 21a. 14a is attached. Accordingly, the lower side of the divided cooling duct 22 of the side leg portion is made into a right-angled shape, and the liquid guiding pipe 14a is attached to the side surface thereof. Liquid guide pipe 14a attached to the side of each divided cooling duct 218.22
are connected to the cooler 11 through insulated pipes 13, respectively.

In this embodiment having the above configuration, as shown in FIG. 4, since the liquid guide pipe that was conventionally attached to the lower end of the cooling duct 9a of the iron core 2 is removed, the height of the tank 1 is increased by the amount of the protrusion. The size can be made smaller, and the transportation size can be reduced. Therefore, there is no problem that even high-voltage, large-capacity equipment cannot be transported. Furthermore, the number of times the insulating medium is used can be reduced, which has the advantage of significantly reducing costs.

[Effects of the Invention] As explained above, in the present invention, by simply improving the structure of attaching the liquid conduction pipe of the cooling duct of the iron core to the side surface, the size of the tank can be reduced, and high voltage and large It is possible to provide a compact separate foil-wound transformer that does not cause any trouble in transporting even large-capacity equipment.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an embodiment of a separate foil-wound transformer according to the present invention, Fig. 2 is a front view showing the shape of the cooling duct of the core shown in Fig. 1, and Fig. 3 is a conventional separate foil-wound transformer. FIG. 4 is a cross-sectional view showing the structure of the winding transformer, and FIG. 4 is a front view showing the shape of the core cooling duct shown in FIG. 3. 1...tank, 2...iron core 1.3...low voltage winding,
4... Medium voltage winding, 5... High voltage winding, 6... Insulating gap, 7... Metal sheet, 8... Insulating sheet, 9
...(Winding) cooling duct, 9a...(Iron core) cooling duct, 10...Pump, 11...Cooler, 12
...Insulating medium, 13...Insulating pipe, 14.14a
...Liquid pipe, 21, 21a, 22, 23...Divided cooling duct.

Claims (2)

[Claims] (1) A transformer body is constructed by overlapping and winding a metal sheet and an insulating sheet around the legs of an iron core to form a sheet winding, and each of the iron core and sheet winding has a built-in cooling duct. 1. A separate foil-wound transformer, characterized in that the transformer is housed in a tank containing an insulating medium and has a circulation system for the refrigerant flowing through a cooling duct separated from the insulating medium. (2) The separate according to claim 1, characterized in that the cooling duct of the iron core has a liquid guide pipe for connecting to an external circulation system installed so as to be located on a side surface of the iron core. foil-wound transformer.