JPS5893207A - Transformer structure - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to at least one rolled sheet made from sheets of metal foil and polymeric film wrapped several times over each other, the metal foil being wrapped in a rolled notebook. A transformer or a reactor having a wound sheet comprising the entire conductor and the film 11 itself comprising the entire insulator.
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Wound sheets for transformers or reactors usually consist of several turns of the sheet 14, consisting of a layer of metal foil and an insulating layer of polymeric film and cellulose paper.
After drying, the rolled sheet is impregnated with an insulating fluid to fill all the cavities present in the rolled sheet and completely suppress corona discharge. Drying and impregnation are complex and time-consuming operations, since the rolled sheets may be several meters wide and pre-stressed before being rolled. It is undesirable to use paper for wrapped insulation. This is because the drying of the rolled sheet becomes very time consuming and results in an overall increase in the size of the transformer without a corresponding improvement in performance. However, in reality, it was not possible to do without paper. This is because it has not been possible to satisfactorily impregnate the entire rolled sheet without taking full advantage of the paper's ability to draw insulating fluid into the interior of the roll, ie, to act as a core.

The invention makes it possible to obtain completely impregnable rolled sheets for transformers or reactors without using the above-mentioned paper layers.

At the same time, the present invention reduces the risk of damage caused by metal particles that may get into the winding during manufacture, and yet reduces the risk of damage caused by plastic deformation of the polymeric material that is the insulator of the winding. This has the advantage of also reducing the risk of damage caused by During the manufacture of rolled sheets in a factory environment, it is practically impossible to avoid small metal particles such as small particles of iron, copper and aluminum from the surroundings from entering the rolled material as impurities. Such particles that occur within a factory environment often have sharp edges that can damage the insulation or, if they are large enough, cause lacerations in the insulation and cause immediate or After time operation, a short circuit may occur. The fact that even very small particles, with a particle size comparable to the thickness of the insulator, which can be much thinner than 100 μm, can cause damage of the type described above, makes it unlikely that the windings will be completely damaged by metal particles. It is very difficult in practice to avoid this, even when using expensive cleaning plans. Plastic deformation of the polymeric material within the winding will reduce the insulation distance and make complete impregnation of the winding more difficult to achieve.

The present invention comprises at least one wound sheet consisting of several turns of a sheet laminated one on top of the other, consisting of a metal foil acting as a conductor and at least two polymeric films acting as an insulator in the wound sheet. In a transformer or reactor with a sheetra, polymeric films contain particles of inorganic filler uniformly distributed and embedded therein, and both sides of the films are provided with irregular elevations. The result is the existence of voids between the opposing surfaces of the metal foil and the polymeric film and between the opposing surfaces of the polymeric film, the voids being in communication with the space outside the end surface of the rolled sheet. Regarding transformers or reactors.

The metal foil is, for example, aluminum or copper, and usually has a thickness of 5 to 0.
008 m, preferably 50 to 100011 m. .

The polymeric film should be able to continuously withstand temperatures of at least 90°C. Examples of polymers suitable for films include polyethylene glycol terephthalate, polypterene glycol terephthalate, polycarbonate, polyimide, cellulose acetate and polyamide gold.

The suitable thickness of the film is 5 to 200 μm1, preferably C1
It is 0 to 100 μm. The polymer film is wider than the gold leaf, with the polymer film extending beyond the edges of the metal foil to prevent electrical sparks from forming between the wrapped layers of metal foil or along the edges of the roll. It's good to do that. Particularly preferred are films of polyethylene glycol terephthalate. 1 because such films meet the four requirements for thermal, mechanical, and electrical properties, as well as for resistance to transformer oil and other insulating fluids used in transformers. It is.

Among others, the fillers consist of particles of silicon dioxide, aluminum oxide, kaolin, dolomite and lime.

Since the particles are inorganic materials, the risk of damage caused by metal particles to the roll is reduced and the predetermined distance between the layers of metal foil in the roll is The particles have sufficient hardness to reduce the risk of unsustainable plastic deformation of the polymer. The filler content is between 0.5 and 5.5% of the total volume of polymer and filler.
%, preferably 0.5 to 2.5%. At least some of the particles, preferably at least 25% of the total volume of the particles, have a particle size greater than 1 μm, preferably between 2 and 1 μm.
Preferably, the particles have a particle size of 5 μm, with at least 5% of the total volume of the particles having a particle size of at least 5 μm.

Some of the particles may have a particle size up to about 25 ttm. The irregular irregularities may have different heights. Preferably, the main portion of the uneven material is contained in ridges having a height of 0.5 to 5 μm measured from the lowest point on the surface of the film.

The present invention will be described in more detail by describing one embodiment with reference to the accompanying drawings.

Figures 1 and 2 show the iron core foot 1 for the electric quadramp.
0a1 upper and lower yokes 10b and 10C are shown. The core foot 10a is an inner scroll 11 in the form of a low pressure scroll.
and is surrounded by an outer roll 12 in the form of a high-tension roll 11. Both rolls are prestressed rolled sheets. They have a lip 13 of presspode, Bakelite or glass fiber reinforced polyester, arranged coaxially with an intermediate cylindrical region arranged parallel to the axis of the roll. The inner scroll is wound around the support cylinder 14.

According to FIG. 3, the rolls 11 and 12 consist of several turns of a sheet 15 of aluminum foil and two films 16 and 17 of polyethylene glycol terephthalate containing 0.9% by volume of silicon dioxide k. the silicon dioxide is in the form of particles uniformly dispersed in the film, the largest particle having a particle size of 10 μm, and 80% of the total volume of the particles having a particle size of at least 2 μm;
20% of the total volume of particles has a particle size of at least 5 μm.

Alternatively, the maximum particle size may have a particle size of 25 μm. The surface of the polymer film has irregularities in the form of peaks 18 with a height of 0.5 to 5 μm on the main part of the material, which is entirely uneven; the thickness of the aluminum foil is 600 μm; The thickness of each polymer film is 25 μm.

The gap 19 between the opposing surfaces of the metal foil and the polymeric film and between the opposing surfaces of the polymeric film includes the end surfaces 22 and 23 of the roll 11 and the end surfaces 24 and 2 of the roll 12.
It communicates with a space 21 outside of 5.

During manufacture of the transformer, the rolls are vacuum dried at elevated temperatures and then subjected to vacuum impregnation with a suitable insulating fluid such as transformer oil or a suitable insulating gas such as SF6. Instead of using two polymer films, three or more polymer films placed adjacent to each other may be used.

[Brief explanation of drawings]

FIG. 1 is a sectional view across its core of a transformer with two windings If. 2 is a longitudinal cross-sectional view of the transformer of FIG. 1 shown at different sizes; FIG. FIG. 6 is an enlarged cross-sectional view taken in a direction perpendicular to one axis of the rolled sheet of FIGS. 1 and 2; 10a-core foot, 10b 110cm yoke, 11.12
- Wrapped sheets, 16.17 - Polymer films. Representatives: Asamura and 4 people

Claims (6)

[Claims] (1) At least one rolled sheet made by winding several times a sheet consisting of a metal foil (15) and at least two polymeric films (16, 17), said metal foil being one of the parts of the rolled sheet. In a transformer or reactor having a winding sheet in which the entire conductor is comprised and the polymer film is an insulator, particles of an inorganic filler are uniformly dispersed and embedded in the polymer film. Both sides of the film are irregularly textured, so that gaps (19) exist between the opposing surfaces of the metal foil and the polymer film, and between the opposing surfaces of the polymer film. The gap between the edges of the rolled sheet (22, 2
3, 24, 25) A transformer or reactor characterized in that it communicates with the outside space. (2) The transformer or reactor according to claim 1, characterized in that the polymer film is a film of polyethylene glycol terephthalate. (3) The transformer or reactor according to claim 1 or 2, characterized in that the filler consists at least essentially of silicon dioxide. (4) Filler content is 0 of the total volume of polymer and filler
．． Claim 1 characterized in that the amount is 5% to 5%.
The transformer or reactor according to any one of Items 6 to 6. (5) The method according to any one of claims 1 to 4, characterized in that at least 25% of the total volume of the particles has a particle size larger than 1 μm. lance or reactor. (6) at least 25% of the total volume of the particles is between 2 and 15 μm;
The transformer or reactor according to any one of claims 1 to 5, having a particle size of . Claims characterized in that most of the material exhibiting irregularities is contained in the shape of mountains with a height of 0.5 to 5 μm measured from the lowest point on the surface of the film. Transformer or actuator according to any one of paragraphs 1 to 6 - 8