JPS58125810A - Resin molded transformer - Google Patents

Abstract

PURPOSE:To obtain the resin molded transformer having excellent corona characteristics by alternately arranging metallic foil and sheet-shaped insulating members among primary winding and secondary winding and constituting a predetermined main insulating layer. CONSTITUTION:The main insulating layer 11 is constituted by alternately stacking and winding the sheet-shaped insulating members such as sheet-shaped plastic films 11a and the metallic foil 11b. The potential of the metallic foil 11b is obtained by separately applying voltage divided by the electrostatic capacity of the sheet-shaped plastic film 11a. Consequently, the generation of coronas can be prevented when the number of the layers of the metallic foil 11b is determined so that potential difference value among the metallic foil 11b reaches approximately 200V. Accordingly, the resin molded transformer having excellent corona characteristics can be acquired.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the primary insulating layer between the primary windings of a resin molded transformer ILC.

A sheet-shaped insulating member is wound between the primary windings of a conventional insulated molded coil.

Some form the main insulating layer. As an example.

FIG. 1 of the accompanying drawings shows a sectional view of a coil of a conventional resin molded transformer.

In the figure, / is a resin molded coil, C is a seventh winding, 3 is a co-th order winding, and Da is a main insulating layer, for example, formed by winding a plastic film to a predetermined thickness. These are molded with a synthetic resin 1, for example, a molding resin 5 such as epoxy resin to form a resin molded coil, and an iron core is combined with this.

A resin molded transformer is constructed.

Next, a conventional main insulating Ni insulating layer will be explained. A high voltage is applied to the main insulating layer 4IK between the primary winding 3 and the primary winding 3. Furthermore, integrally molding the main insulating layer 41 with only the molding resin 5 means that the main insulating layer 41 can
Cracks occur.

As a result, it may lead to the generation of corona or dielectric breakdown, as shown in FIG.

By configuring the main insulation 1-4I in which a sheet-like member made of plastic film or the like is wound, the 7th winding IIs and the λth winding 3 can be removed during the cooling process after heating and hardening, or during the cooling/heating cycle during use. A method is used to alleviate the thermal stress between the main insulation layer and the main insulation layer by using the above-mentioned sheet-like member. When molding with mold resin jtK, voids (gaps) are likely to occur due to poor impregnation in the main insulating layer G or in the small gap between the main insulating layer D and the primary winding K or the λth order winding 3. However, there was a drawback that corona discharge occurred in this void.

The present invention eliminates the drawbacks of conventional resin molded transformers as described above, and prevents corona from occurring within the main insulation layer or between the main insulation 1 and the primary or co-order windings λ, 3. The object of the present invention is to provide a resin molded transformer that is constructed so that there is no

In order to achieve this object, the present invention constitutes a predetermined main insulating layer by alternately disposing metal foil and sheet-like insulating members between the primary winding and the secondary winding. It is characterized by this.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be explained based on the attached drawing cylinder λ diagram showing one embodiment thereof.

In the figure, the primary winding λ, the λth winding 3. The mold resin S is the same as that in the conventional device, and the symbol IO is a resin mold coil according to the present invention, and the main insulating layer /l is a sheet-like insulating member 1 (for example, polyethylene terephthane). (PET) or polypropylene (PP), etc., and a metal foil 1, for example.

Aluminum towing I/I! It is constructed by winding A-edge tin foil//I' multiple times alternately a predetermined number of times.

In addition, instead of the aluminum foil//b, a miniram vapor-deposited film may be used, or alternatively, a metal foil heat-sealed to an insulating sheet may be wound a predetermined number of times to form the main insulating layer//b.
It is also possible to configure l.

Resin molded coil io of resin molded transformer of the present invention
is constructed in this way, and its operation will be explained next.9 Generally, since a high voltage is applied between the l/th winding 3 and the co-th order winding 3, voids may occur in the main insulating layer. When exists, the relative dielectric constant of the void is smaller than that of the insulating layer, so
In most cases, a voltage is applied between the voids, and corona is generated in the voids at relatively low voltages.

In order to address this issue, the resin molded coil 10 of the present invention has a main insulating layer//as shown in FIG.
A sheet-like insulating member, for example, an iodine-like plastic film //a and a metal foil llb are alternately stacked and wound.

The potential of this metal foil //b is the sheet-like positive winding λ
If the metal foil //b is arranged between and the co-th order winding 3 at approximately equal intervals lh, its potential is given by the following equation.

e = TL / (n + / ) Here, e is the potential difference between gold lI4 foil //b, and E
is the voltage between the primary and secondary windings, n is the metal foil //
The number of layers of b is 8. Therefore, if the number of layers of the metal foil 11b is determined so that the value of e is approximately λOOV, the generation of corona can be prevented. This generally means a voltage of 2oO
This is because, below V, no corona occurs even if voids exist.

As described above, according to one aspect of the present invention, the main insulating layer can be formed by winding the sheet-like insulating member 1, for example, a plastic film and a metal foil alternately.

Even if voids exist, it is possible to obtain a resin molded coil with good corona characteristics, that is, a resin molded transformer.
Moreover, it has the effect that the resin molded transformer can be made smaller by making the main insulating layer thinner.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a conventional resin molded coil. FIG. 2 is a sectional view of one embodiment of the resin molded coil of the resin molded transformer of the present invention. / , 10...Resin molded coil, Co...Primary winding, 3...Primary winding, Da, //...Main insulation layer, //a...
・Sheet-like insulation member (plastic film), //b
...Metal foil (aluminum foil) S...Mold resin. Agent Shin Kuzuno - Figure 1 Figure 2 41-

Claims (3)

[Claims] (1) A main insulating layer in which a sheet-like insulating member is wound is provided between the primary windings, and the primary insulating layer is provided between the primary windings.
In a resin molded coil in which both primary windings are integrally molded with a synthetic resin member, metal foil and sheet-like insulating members are alternately arranged between the primary winding and the primary winding. A resin molded transformer characterized in that a predetermined main insulating layer is made of (2) The resin molded transformer according to claim 1, wherein the metal foil of the main insulating layer consisting of metal foil and sheet-like insulating member is an aluminum vapor-deposited film. (3) Claim 1, wherein the main insulating layer composed of metal foil and sheet-like insulating member is a metal foil heat-sealed insulating sheet.
Resin molded transformer as described in section.