JPS5875811A - Leaf wound transformer - Google Patents

Abstract

PURPOSE:To improve intensity of a cooling duct and increase the cooling efficiency, by a method wherein the cooling duct is installed within a winding body, and a groove or projection is formed at least on one inner wall of the duct and passage for cooling medium is formed with other inner wall. CONSTITUTION:A metal sheet 2 of aluminium conductor and an insulation sheet 3 of polyester film are overlaid on outside of a core 1, thereby a low tension winding body 4 and a high tension winding body 5 are wound in leaf winding form. An annular cooling duct 17 is installed within the winding bodies. A groove 18 is provided in one inner wall of the cooling duct, and passage for cooling medium is formed by the groove 18 and other inner wall of the cooling duct 17. The cooling medium 9 is circulated in the passage by means of a pump 10. In this constitution, leaf winding is effected under the strong tension thereby the thermal contact resistance between windings is reduced and the cooling efficiency is increased.

Description

[Detailed description of the invention] The present invention relates to a nine foil-wound transformer with built-in cooling ducts.

Since the foil 4 transformer has a good conductor space factor, it has the advantage of making the device less dusty and lighter than the Amano transformer, which uses linear conductors. However, in order to construct a transformer a with a higher voltage, 4 voltages, and a larger capacity, cooling is required because the conductor is in the form of a foil.9.

Therefore, a cooling duct is installed inside the coil around which the foil conductor is wound.
A refrigerant with excellent insulating properties was sent into the duct to directly cool the heat generated from the conductor loss of the rolled foil.

An example of such a conventional foil-wound transformer is shown in FIG.

It is constructed as shown in FIGS. 2 and 3.

That is, a metal sheet 2 which is an aluminum conductor and an insulating sheet 3 made of polyester film are placed on the outside of the iron core l.
, and then wrap the foil-wrapped low pressure body 4 and the high pressure body 5,
A one-shaped cooling duct 6 is built inside these rolls. Inside this cooling duct, as shown in Fig. 3, there is a narrow gap 8 secured by inserting and joining a thin linear body 7 as a spacer.
By flowing cold #$9 such as #75 with the pump 10, the heat generated in the P1 foil roll is removed and cooled.

The refrigerant 9 whose temperature has increased by absorbing heat is used for external cooling 1! ) 11, it is cooled by cooling water 12, and is sent into the outer cooling duct. The liquid collecting pipe 13 is made of metal such as stainless steel, and since an insulated pipe 14 is used to connect it to the cooling duct, the liquid collecting pipe 13 and the pipe 15 have a ground potential.

On the other hand, the cooling duct and the winding layer are at almost the same potential because the cooling duct is housed inside the winding. This is done by gas 16.

In addition, in Figure 1, the leads of the first winding, which are not directly related to the present invention, and the bushings for pulling them out to the outside are omitted for the sake of clarity.

Such a foil-wound transformer is a separate type foil-wound transformer because the differential circuit through which the rounded refrigerant flows to cool the winding, the tank, etc., and the insulating medium 16 for insulating the winding are completely separated. Called a winding transformer, it has advantages such as being able to be significantly reduced in size and weight, and having high insulation reliability.

However, in conventional foil-wound transformers, the built-in cooling duct was supported by mending and inserting wires, which did not have sufficient strength, so the winding layers were The drawback was that it could not be wrapped tightly. This resulted in a very serious problem as the mechanical strength of the winding was weak, the contact thermal resistance of the winding layer was increased, and the cooling characteristics of the transformer were deteriorated. In addition, it is extremely difficult to manufacture a large number of rope wires by inserting and joining them into the cooling duct.

The present invention has been made in consideration of the above circumstances.The purpose of the present invention is to improve the strength of the cooling duct so that the winding layer can be tightly wound, thereby reducing the contact thermal resistance of the winding layer. A small, compact design provides a foil-wound transformer with high cooling efficiency.

In other words, 1. The present invention provides grooves or protrusions on at least one inner wall surface of the cooling duct built in the winding, and forms a flow path through which the cooling medium flows between it and the other inner 4 m surface. The purpose is to increase the strength of the duct and achieve the above object.

Hereinafter, embodiments of the present invention will be described in detail with illustrations.

FIG. 114 is a diagram showing a schematic configuration of an embodiment of the present invention. Note that the same parts as in FIG. This embodiment differs from the conventional example shown in Figures 1 to 3 in the following points:
#1 in the direction IIl of the cooling duct 17 as shown in Figure 15.
8 was established. This woman 18 is a cooling duct) 17
A refrigerant flow path is formed by the other inner #1 surface. This flow path may be formed by providing a plurality of protrusions instead of the grooves 18.

With such a configuration, the cooling duct 17 becomes extremely strong, and it becomes possible to wind the winding layer or the like with strong tension. As a result, not only the mechanical strength of the winding is increased, but also the contact thermal resistance between the winding layers is small, and the RTI winding transformer with high cooling efficiency can be easily installed.

First, if we focus on the inside of the cooling duct, it is possible to easily provide a number of ties or protrusions on its inner wall surface, so that the surface area inside the duct can be easily increased and the cooling efficiency can be further improved.

Note that the effects of the present invention are obtained by providing grooves or protrusions in the cooling duct, and therefore are not limited by the shape of the protrusions in the grooves or the flow direction of the cooling medium O.

The nine insulating media enclosed in the nine tanks are not limited to gaseous bodies,
For example, it may be a liquid such as insulating oil.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the schematic configuration of a conventional foil-wound transformer, Figure 2 is a partially enlarged view of Figure 1, and Figure 3 is a flow diagram of the cooling duct that constitutes the 1st EO foil-wound transformer. Cross-sectional diagram showing the road, No. 4
The figure is a cross-sectional view showing a schematic configuration of a foil-wound transformer according to an embodiment of the present invention, and FIG. 5 is a cross-sectional view showing a flow path of a cooling duct constituting the foil-wound transformer shown in FIG. 44. 2... Roll foil, 3... Insulating sheet. 17... Cooling duct, 18... Groove. Agent: Patent attorney Kensuke Chika (and 1 other person)

Claims (1)

[Claims] mfls is a round product with a built-in cooling duct inside the roll made by winding rice with a foil conductor and an insulating sheet around an iron core.
A foil 4I transformer characterized in that at least one inner surface of the iL+1 cooling duct is provided with a projection or a protrusion to form a cooling medium flow path between it and the other *tin.