JPS60102718A - Foil wound transformer - Google Patents

Abstract

PURPOSE:To stop a flow crossing a rib, and to prevent the partial temperature rise of a coil by fitting a metallic foil under the state in which the metallic foil is bent along the rib in a cooling panel. CONSTITUTION:Bent plates 23 of which metallic foils made of copper are bent along ribs 10 are fitted in a cooling panel 6. Since the metallic bent plates 23 are fast stuck on the upper and lower wall surfaces of the panel, the leakage of a refrigerant through clearances in the ribs can be prevented, the ribs sufficiently satisfy a function adjusting a flow, and stagnation in the cooling panel is not also generated. Accordingly, the cooling efficiency of a foil wound transformer can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a foil-wound transformer in which a cooling panel is built into a coil in which a foil conductor and an insulating sheet are wound in layers.

[Prior art and its problems]

Foil-wound transformers have a good space factor for the wrapped conductors.

Compared to transformers using wire conductors, it has the advantage of being smaller and more compact, but in order to be applied to higher voltage, larger capacity transformers, it is necessary to improve the cooling capacity of the coil and increase the insulation capacity. Therefore, a cooling panel through which a refrigerant flows is built into the coil to directly cool the heat generated from the conductor of the coil.

As shown in FIG. 1, this kind of conventional foil-wound transformer has a coil body formed by overlapping and winding an outer thin foil conductor 2 of an iron core 1 and an insulating sheet 3, and this coil body is a low-voltage coil. 4 and a high-voltage coil 5, and a ring-shaped stainless steel cooling panel 6 is built into each of these coils. This cooling panel is composed of a liquid inlet nozzle 7, a liquid outlet nozzle 8°, and a parallel flow path section 9, as shown in FIG.

Inside it, there are two panels that form a panel as shown in Figure 3.
There is a narrow gap 11 secured by plastically working one of the two stainless steel plates and providing a band-shaped protrusion (hereinafter referred to as lip) 10. By flowing the medium 12 with the pump 13, the Joule heat generated within the foil-wound coil is removed and the coil is cooled. The cooling medium 12, whose temperature has increased by absorbing heat, is cooled by cooling water 15 in an external cooler 14, and is sent into the panel again. The liquid collection pipe 16 is made of stainless steel 7 (whatever metal), but since an insulated pipe 17 is used to connect it to the cooling panel, the liquid collection pipe 16 takes the ground potential of the tank 18, etc.

On the other hand, the cooling panel and the foil conductor are at almost the same potential because the cooling panel is wrapped in a coil, and the insulation between them and the outside is an insulating SF or gas sealed in a tank]9 done by.

In FIG. 1, coil lead wires and bushings for leading them out of the tank, which are not directly related to the present invention, are omitted for clarity.

The foil-wound transformer described above is called a separate foil-wound transformer because the circulation circuit through which the cooling medium in the cooling reservoir flows and the insulating medium 19 are completely separated, and it is significantly smaller and smaller. It has the advantages of being quantifiable and having high insulation reliability.

Incidentally, the ribs 10 provided on the cooling panel 6 are extremely important not only as spacers for ensuring an internal gap in the cooling panel, but also for adjusting the flow of the cooling medium 12 inside the cooling panel. For example, the appropriate arrangement shape of the ribs 10 is as shown in FIG. 4.

However, in order to maintain productivity or shape and dimensional accuracy during finishing in the cooling panels used in this type of foil-wound transformer, the two stainless steel plates that make up the panel are joined by a bath around the panel. However, the band-shaped ribs are not in contact with the bath. Even if it comes into contact with a bath, it will only be a spot layer of liquid, and if the entire surface is welded by shim welding, the panel surface will deform and become unusable.

Therefore, as shown in Fig. 5, there is inevitably a pressure gap 20 at the location of the rib IO, and a portion of the cooling medium that should flow along the rib crosses the rib as shown by arrow B in the figure. It crosses and flows into the adjacent channel. Because of this leakage, it was extremely difficult to realize a flow that matched the heat distribution of the coil. Furthermore, this leakage tends to create stagnation areas within the panel where the liquid does not flow, making it impossible to prevent local temperature increases in the coil.

[Purpose of the invention]

The present invention was made in consideration of the above circumstances, and its purpose is to stop the flow across the ribs without touching the ribs, without reducing the productivity of the panel and the dimensional accuracy of the finished product. The object of the present invention is to easily provide a foil-wound transformer with high cooling efficiency by preventing a local temperature rise in the coil.

[Summary of the invention]

The present invention aims to achieve the above object by installing a curved metal foil along the ribs in the cooling panel to stop the flow of the cooling medium beyond the ribs.

〔Effect of the invention〕

According to the present invention, it is possible to prevent a local temperature rise in the coil and increase its cooling efficiency.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described in detail.

In the embodiment of the present invention, the configuration other than the cooling panel 6 is the same as that of the prior art, so the details thereof will be omitted.

Further, the appearance of this cooling panel is similar to that shown in FIG.

FIG. 6 is a sectional view of a cooling panel 6 constituting a foil-wound transformer according to an embodiment of the present invention. A curved plate 23 made of curved copper metal foil is installed.

Since this metal curved plate 23 is in close contact with the top and bottom walls of the panel, it is possible to prevent the cooling medium from leaking through the gaps between the ribs, and the ribs fully satisfy the flow adjustment function, preventing stagnation inside the cooling panel. It will no longer occur. This made it possible to easily provide a foil-wound transformer with high cooling efficiency.

[Other embodiments of the invention]

FIG. 8 is a cross-sectional view of a cooling panel 6 according to another embodiment of the present invention.

The cooling panel 6 has a corrugated metal plate 24 made of copper, for example, installed between ribs inside the panel. In this embodiment, the effect of stopping the flow beyond the rib 10 is similar to that of the previous embodiment, but in this case a further effect occurs. This is the fin effect of the corrugated metal plates installed inside the cooling panel. This improves the cooling characteristics of the cooling panel and provides a foil-wound transformer with even higher cooling efficiency.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a schematic configuration of a conventional foil-wound transformer, Fig. 2 is an external view of a cooling panel that constitutes a conventional foil-wound transformer, Fig. 3 is a partially enlarged view of Fig. 2, Fig. 4 is a diagram showing the rib arrangement shape of a cooling panel constituting a conventional foil-wound transformer, Fig. 5 is a sectional view taken along the line N-A in Fig. 4, and Fig. 6 is a diagram showing a foil-wound transformer according to the present invention. A cross-sectional view of the constituent cooling panel, Figure 7, is shown in Figure 6. A diagram showing the rib arrangement shape of the cooling panel, Figure 8.
The figure is a perspective view showing a metal curved plate, FIG. 8 is a partial sectional view of a cooling panel constituting a foil-wound transformer according to another embodiment of the present invention, and FIG. 9 is a corrugated plate-like plate according to FIG. 8. FIG. 3 is a perspective view showing a metal plate of FIG. 6... Cooling panel, 10... Rib, 23... Metal plate. Representative Patent Attorney Noriyuki Chika (and 1 other person) Figure 1 Figure 2 Procedure Amendment (Method) Showa, face 3. the law of nature. Mr. Commissioner of the Japan Patent Office■, Indication of the case, Patent Application No. 208934 of 1989 2, Name of the invention Foil-wound transformer 3, Relationship with the person making the amendment case Patent applicant (307) Tokyo Shibaura Electric Co., Ltd. 4 Agent Address: 100, Tokyo Shibaura Electric Co., Ltd. Tokyo Office, 1-1-6 Uchisara-cho, Chiyoda-ku, Kyoto February 28, 1982 (Date of shipment) 6. Brief explanation column of tlJ specification drawings subject to amendment 7 , content of correction

Claims (1)

[Claims] In a foil-wound transformer, which has a built-in cooling panel in which a cooling medium flows inside the coil, which is made by wrapping a foil conductor and an insulating sheet in layers on the outside of an iron core, A foil-wound transformer characterized in that the metal foil is bent and installed in close contact with both inner walls of a cooling panel.