JPS61110410A - Lead wire of transformer - Google Patents

Abstract

PURPOSE:To avoid that an insulation thickness on the low electric field side is made larger than needed, to reduce a working time for taping insulation, and to improve a cooling effect against a rise in the temperature of strands, by shaping the cross section of a lead wire so that it has a non-uniform thickness. CONSTITUTION:In a lead wire 9 of a tap winding 3, the insulation thickness thereof may be small on the side opposite to the lower end of a shunt winding 4 and the lower end of a series winding 5, since a potential is substantially the same on this side as these windings. To the contrary, a high electric field is formed on the side opposite to a tertiary winding 2, an iron core 1 and an iron core fastening metal fitting 6, since a generated voltage of the tap winding 3 is applied thereto as it is as a potential difference, and, accordingly, the insulation thickness of the lead wire needs to be large on this side. Therefore, the cross section of the lead wire is so shaped that the insulation thickness in the entire circumference is not uniform. In other words, a plurality of strands 10 are fixed by two or three winds of taping insulation 11 with oil spacers 13 and 14 interposed, and a U-shaped molded insulator 15 is packed on the high electric field side. Then, these elements are fixed into one body by taping insulation 12.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a winding lead wire in a transformer,
In particular, it relates to lead wires consisting of a plurality of windings in tap windings, low voltage windings, etc.

[Background of the invention]

Conventionally, the lead wire from the winding was connected to another electrode (other coil).

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As described in Japanese Patent No. 9140, the insulation strength is determined by the insulation strength on the high electric field side, and the insulation is uniformly thick all around.

Furthermore, since the temperature of the insulator increases due to the current flowing through the conductor, a cooling duct is provided inside.

As a result, the insulating coating is thick all around, and since the cooling duct is provided, the shape of the lead wire becomes large.

[Purpose of the invention]

An object of the present invention is to improve the cooling effect by changing the thickness of the insulation coating in the lead wire of the tap winding, low voltage winding, etc. placed on the inner diameter side according to the electric field strength facing the other wire and the ground electrode. The objective is to improve the winding end structure and make it more rational.

[Summary of the invention]

The present invention provides a tertiary winding and a tap winding 2 on the core leg from the inner diameter side.
In an autotransformer where shunt windings and series windings are arranged concentrically in that order, multiple strands of wire are bundled and pulled out from the tap winding, and the insulation of the lead wires that are collectively insulated creates a high electric field. It is characterized in that only the sides are filled with a molded insulator, the strands and the molded insulator are integrally insulated, and the surrounding insulation thickness is non-uniform.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. 2 and 3 show the winding structure of an autotransformer. A plurality of windings are wound around an iron core 1, and the tertiary winding 2. Tap winding 3° shunt winding #i4. Series winding, $
15 are arranged concentrically. From each winding 2 to 5, terminals (a, b, U, u, v
, tap) is pulled out. The lead m9 from the tap winding 3 is led out through the lower part of the shunt winding 4 and the series winding S.

In such a configuration, the upper and lower ends of the series winding S and the lower part of the shunt a4 are connected and have approximately the same potential as the tap winding 3. Furthermore, the tap winding 3 is connected to the tertiary winding 2. and iron core 1. A potential difference due to the voltage generated in the tap winding 3 is applied to the iron core fastening fitting 6. Here, in the outlet lead wire 9 of the tap winding 3, the lower end of the shunt winding 4 and the lower end of the series winding 5 are at almost the same potential, so the insulation thickness of the outlet lead Jli9 may be thin, but , tertiary winding 2. Iron core 1. The voltage generated in the tap winding 3 is directly applied as a potential difference to the opposite side of the iron core fastening fitting 6, resulting in a high electric field, so the insulation thickness of the lead wire needs to be large. Therefore, the cross-sectional shape of the lead wire is such that the insulation thickness around the entire circumference is different, as shown in FIG.

In other words, a plurality of wires 10 are connected to oil spacers 13°14
Fixed by taping insulation 11 2.3 times through
A U-shaped molded insulator 15 is filled on the high electric field side. These are fixed together with taping insulation 12. here,
The thickness of the taping insulation #12 may be the required insulation thickness on the low electric field side, and the thickness of the molded insulation may be the insulation thickness obtained by subtracting the thickness of the taping insulation 12 from the required insulation thickness on the high electric field side.

By making the cross-sectional shape of the lead wire have such a non-uniform thickness, the work time for taping insulation can be reduced without increasing the insulation thickness on the low electric field side more than necessary. Cooling effect can be improved.

FIG. 4 shows another embodiment of the present invention, which differs from FIG. 1 in that a U-shaped oil spacer 16 and a U-shaped filling insulator 17 are arranged in place of the molded insulator 15. be. Here, the U-shaped filling insulator 17 is arranged outside the U-shaped oil spacer 16, but it may be arranged inside the U-shaped oil spacer 16.

According to this embodiment, it is further possible to effectively cool the insulator on the high electric field side against a rise in the temperature of the wire.

In addition, in the figure, 7 is a winding lower clamp, and 8 is a winding lower insulator.

〔Effect of the invention〕

According to the present invention, the working time for taping insulation can be reduced. In addition, as an uneven insulation thickness, a part of the insulation 15 around the entire circumference
By reducing the stress, the cooling effect against the temperature rise of the strands can be improved.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the tap winding lead wire according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the lower part of the winding of an autotransformer according to an embodiment of the present invention, and FIG. A wiring diagram of an autotransformer according to one embodiment, and FIG. 4 is a sectional view of a lead wire of a tap winding showing another embodiment of the present invention. 10...Element wire, 11...Taping insulation, 12...
・Taping insulation, 13...Oil spacer, 14・
...Oil spacer, 15...U-shaped insulator.

Claims (1)

[Claims] 1. In a device in which a plurality of wires are pulled out in a bundle from a winding and the entire circumference is insulated all at once, the high electric field side of the bundled wires is filled with a U-shaped molded insulator. A transformer lead wire is characterized in that these are integrally insulated by taping so that the surrounding insulation thickness is non-uniform.