JPS59121810A - Foil-wound transformer - Google Patents

Abstract

PURPOSE:To make cooling ducts flat plate shape and reduce the manufacturing man-hour by providing a plurality of the divided flat plate shape cooling ducts in a winding along the circumference direction of the winding. CONSTITUTION:A metal sheet 2 which composes turns of a winding is wound spaced by an insulating sheet and every plurality of layers of the turns cooling ducts 21 are provided reasonably with a proper interval. These cooling ducts 21 are formed in flat plate shape and their width along the circumference direction is divided narrow enough to form the ducts with small width. With this configuration, the gap to let the coolant flow in the duct can be made uniform more easily compared to the cooling duct which has the cross section of a large width and a circular arc shape, and if the technology of flattening a round pipe is introduced, welding the edge is not necessary so that welding strain is eliminated and the cooling duct, which conforms to the requirements such as keeping a prescribed gap in the duct and being harmetic, can be produced relatively easily.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention uses a foil-like winding in which a metal sheet and an insulating sheet are layered, and a cooling duct is built into the winding to cool the winding. Concerning winding transformers.

[Technical cost of the invention] Since the foil-wound transformer has a good space factor, it has the feature that it can be made smaller and lighter. Small-capacity transformers with relatively low voltages of several KV to several 10 OKV have already been put to practical use, and are widely available on the market.

In recent years, in view of its excellent advantages, higher voltage/larger v1M
(7) For example, expansion of the application to 275KV, 300MVA transformer H is being studied, but the biggest key depends on how to improve the cooling 1.0 efficiency and provide high insulation ability to the windings. Such high-voltage, large-capacity transformers have not yet been put to practical use, but in order to increase cooling capacity, a cooling duct is built into the windings, and a refrigerant with insulating properties (a) is fed into the windings to reduce winding losses. Research is being conducted on things that can directly cool the heat generated by.

A known example is shown in FIG. A metal sheet 2 and an insulating sheet 3 are layered on the outside of the iron core 1 and wound 1 to form a low voltage winding 4 and a high voltage winding 1.
j15, and an annular cooling duct 6 is built in between these windings. There is a thin gap inside this cooling duct, and refrigerant 15 such as Freon-113 or Fluorinert FC75
is filled, and the vapor is flowed by a pump 7, and the heat generated in the foil-wound winding is taken away by the latent heat of vaporization of the refrigerant.The vapor is cooled and condensed by a condenser 8 and a water cooler 9. A refrigerant circulation cooling circuit is provided in which the liquefied refrigerant is stored in a refrigerant tank 14 and is further fed into the windings by a pump 7. That is, the refrigerant circulation circuit and the transformer winding are separated.

The liquid collecting pipe 10 is made of metal such as stainless steel, and the liquid collecting pipe 10 and the cooling duct are connected through an insulating vibrator 11, and the liquid collecting pipe 10 is also connected to the earth potential of the tank 12, etc. . On the other hand, the potential of the cooling duct is electrically coupled to the same potential as the winding because it is wound inside the winding.

Each part of the winding is insulated with an insulating medium 13 such as insulating oil or SF6 gas sealed in a tank.

[Problems with Background Art] As explained above, in the transformer of this system, the circulation circuit through which the refrigerant for cooling flows and the insulating medium 13 for insulation are completely separated. For this reason, this type of foil-wound transformer is generally called a separate foil-wound transformer. This Sepathy 1-type foil-wound transformer utilizes the latent heat of evaporation of the refrigerant, so it can be expected to have excellent cooling characteristics, and is promising for large-scale girder transformers. However, the conventional separate foil-wound transformer as shown in FIG. 1 has the following problems.

That is, although the foil-wound winding itself is easy to manufacture, various conditions are required for the cooling duct disposed between the layers of the winding, and the number of manufacturing steps is increased to meet these conditions. For example, the second
As shown in the horizontal cross-sectional view in the figure, the cooling duct has four
It is divided into arc shapes with an angle of approximately 90 degrees. For this cooling duct, ducts are required to be thin and spaced evenly over the entire surface in order to reduce thermal resistance and minimize the diameter of the winding to obtain a compact winding, while at the same time ensuring that the refrigerant does not leak. requires complete airtightness. However, in order to avoid eddy currents caused by leakage magnetic flux within the windings or deterioration due to chemical reactions with the refrigerant, cooling ducts are made of relatively easily moldable materials such as copper, aluminum, etc. Instead, stainless steel material is used, but this stainless steel material is inferior in workability compared to copper, aluminum, etc. This type of material with poor workability has uniform thin spacing, is airtight, and has a wide arcuate shape.
It is not easy to make the II duct, and the fabrication of the cooling duct 1 increases the number of man-hours required to fabricate the separate foil wrapping applicator body.

[Object of the Invention] The present invention has been made in view of the above points, and its object is to provide a foil-wound transformer having a cooling duct that is simple in structure and easy to manufacture.

[Summary of the Invention] The foil-wound transformer of the present invention is characterized in that a flat cooling duct divided into a plurality of pieces is disposed within the winding along the circumferential direction of the winding. By making it into a flat plate shape, the number of manufacturing steps is reduced.

[Embodiments of the invention] An embodiment of the present invention will be described based on FIG.

Note that the same parts as those of the conventional type shown in FIGS. 1 and 2 are designated by the same reference numerals, and the explanation thereof will be omitted.

The metal sheet 2 constituting the turns of the winding is wound with an insulating sheet 3 (not shown) interposed therebetween, and cooling ducts 21 are provided at appropriate intervals each time a plurality of layers are wound. This cooling duct 21 is formed into a flat plate shape, and the width in the circumferential direction is sufficiently divided into small widths. Furthermore, since the circumference of the outer circumferential layer is longer than that of the inner circumferential layer of the winding, the width of the flat cooling duct 210 in the circumferential direction is larger than that of the cold section duct 1-22 disposed on the outer circumferential layer. It is formed slightly wider than the cooling duct 21 arranged in the layer, and on the same circumference there are inner,
The same number of cooling ducts 21, 22 are arranged symmetrically on both outer circumferential layers. Therefore, the entire winding has a polygonal shape.

Polygonal windings are inferior to completely circular windings in terms of strength against mechanical forces in the radial direction, but by increasing the number of divisions of the cooling duct 21 according to the transformer capacity, it is actually almost The shape is close to circular, so there is virtually no problem.

According to this embodiment having such a configuration, compared to the cooling duct I-G which is wide and has an arcuate cross section, it is easier to create uniform gaps in the duct for passing the refrigerant, and Comparison of cooling ducts that meet the required conditions such as no welding distortion, a specified gap in the duct, and airtightness because the technology of flattening a circular pipe eliminates the need for end face welding. It can be easily manufactured.

In this embodiment, the width of the cooling duct in the circumferential direction of the winding is changed depending on the inner and outer peripheral layers, but the present invention is not limited to this, and as shown in FIG. ~21
The circumferential width of the inner layer and the outer layer may be the same. If such a cooling duct is used, all the ducts within one winding will have the same size, and the number of manufacturing steps can be further reduced. However, in this case, the cooling area of the outer duct is slightly smaller, which impairs the cooling capacity, but it is best to adjust the spacing between the ducts so that the entire winding can be cooled evenly. .

[Effects of the Invention] As shown in the above embodiments, according to the present invention, a cooling duct having a simple structure and easy to manufacture can be obtained, so that the number of man-hours for manufacturing a foil-wound transformer can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the structure of a conventional foil-wound transformer, Fig. 2 is a horizontal sectional view of the winding portion of a conventional foil-wound transformer, and Fig. 3 is an embodiment of the foil-wound transformer of the present invention. FIG. 4 is a horizontal sectional view of a winding portion showing an example of a foil-wound transformer according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Iron core, 2... Metal sheet, 3... Insulating sheet, 4... Low voltage winding, 5... High voltage valley wire, 6... Cooling duct, 7... Pump, 8 ...Condenser, 9...
Water cooler, 10...Liquid collection pipe, 11...Insulated pipe,
12...tank, 13...insulating medium, 14...refrigerant tank, 15...refrigerant, 21.22...cooling duct. 7317 Representative Patent Attorney Kensuke Norichika (one idiot) Figure 1 Figure 2 Figure 3

Claims (2)

[Claims] (1) An iron core, a foil-like high-voltage winding and a low-voltage winding wrapped around the iron core, and made of a metal sheet and an insulating sheet 1 wrapped in layers, and a refrigerant A cooling duct having passages, a pipe line for circulating a refrigerant to these cooling ducts 1~, and an insulating vibe connecting this pipe line and the cooling duct, and a cooling duct connected to the cooling ducts 1~ via the pipe line. By circulating the refrigerant, the cooling ducts 1~ will be cooled down.
A foil-wound transformer that cools a Z-shaped winding, characterized in that a flat cooling duct divided into a plurality of pieces is arranged within the winding along the circumferential direction of the winding. vessel. (2) The foil-wound transformer according to claim 1, wherein the flat cooling duct has an equal width in the circumferential direction within the same winding.