JPS60261117A - Foil-wound transformer - Google Patents

Abstract

PURPOSE:To clamp and fix a winding from the axial direction by disposing an end-section padding at the end section of a metallic sheet and mounting a clamp plate at the end surface of the end-section padding through an insulator. CONSTITUTION:A metallic sheet 3 and insulating sheets 4 constituted by superposing a plurality of insulating sheets are wound around an insulating cylinder 2 arranged around a leg section 1a for a core, and end-section paddings 10 in approximately the same thickness as the metallic sheet 3 are disposed at both end sections of the metallic sheet 3. The width of the end-section paddings 10 are set so as to be able to coat both end sections of the insulating sheets 4. A clamp plate 7 is mounted at the end surfaces of the end-section paddings 10 through an insulator 6, and the clamp plate 7 is clamped and fixed to the core 1 by an L- shaped clamping fitting 8.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention 1] The present invention relates to a foil-wound transformer using a foil-like winding formed by overlapping and winding a metal sheet such as copper or aluminum foil and an insulating sheet.

[Technical Background of the Invention 1 Foil-wound transformers have the advantage of good winding space and can be made smaller and lighter. Kokichi ω transformers, which have relatively low voltages of several KV and several hundred KVA, have been put into practical use. Expansion of application to △ class D- transformers is being studied, but the biggest key is how to improve the cooling capacity and provide the winding with high insulation capacity, and how to reduce the 21' diameter in the event of a short circuit accident. It depends on whether or not it can withstand directional mechanical force.Although such high-voltage input capacity transformers have not yet been put into practical use, there are already known foil-wound transformers that use wire-wound transformers. A cold N1 duct is built into the cooling duct, and a refrigerant with excellent insulation properties is fed into the cooling duct.
Alternatively, there is an evaporative cooling gas type insulation transformer in which a refrigerant (along with an insulating medium) is poured into a tank and the refrigerant is spread over the windings to directly cool the heat generated from winding losses.

This type of transformer uses the latent heat of vaporization of the refrigerant.
It can be expected to have excellent cooling properties and is promising for large capacity transformers. However, in actual use, there are the following problems.

In other words, in a foil-wound transformer of several KV, several 1 < 100K VΔ, the radius of the winding inside the transformer is small and the stack height is low, so the weight of the winding is light and its own weight is particularly There is no need to support it with other members. However, as higher voltage and larger capacity foil-wound transformers become available, the dead weight of the windings increases and the short-circuit mechanical force applied to the windings also increases. There is a risk that the wire will not be able to hold the wire and the winding may become distorted or fall.

This point will be specifically explained with reference to FIG. A metal sheet 3 and an insulating sheet 4 are layered and wound around an insulating tube 2 disposed around the insulating cylinder 2 to form a foil winding 5. Further, a clamping plate 7 is disposed at the lower end of the -F lower end of the foil winding 5 via an insulator 6, and this clamping plate 7 is connected to a clamping metal fitting 8.
The iron core 10vl is fixed to the base portion 1b. As described above, in a high voltage, large capacity foil wound transformer, it is essential to have a structure that supports the foil winding 5 as shown in FIG.

In addition, foil-wound transformers generally have a winding current x number of turns)
Depending on the value of
An electromagnetic mechanical force acts on the winding due to this leakage magnetic flux 9 and the current in the winding. On the other hand, in a foil-wound transformer, since the conductor width of the winding is wide, eddy currents flow in the conductor that try to cancel the radial magnetic flux in the conductor, so the leakage magnetic flux 9 is axially absorbed in the conductor part. It occurs in the direction, bends sharply at the end of the winding, and is distributed symmetrically under one of the windings. Therefore, in a foil-wound transformer, if the conductor widths of the low-voltage winding and high-voltage winding are the same and the conductor ends are aligned, the electric current will be lower. ! Only the radial component of the mechanical force was considered, and consideration was not given to tightening the winding in the axial direction (=t+:I and the winding support structure). For this reason, in conventional low-voltage, small-capacity foil-wound transformers, when a metal sheet or an insulating sheet is wound with a slight tension, the axial direction of the winding is affected by the friction horns between the sheets. It was effective enough as a support.

[Problems with Background Art] However, in the high-voltage, large-capacity foil-wound transformer as described above, it is necessary to support the foil-like winding 5 in an insulated state using an insulator 6.

However, since the foil winding 5 is made by alternately winding the metal sheets 3 and the insulating sheets 4, its ends are uneven, and the insulator 6 is applied to these uneven parts. In order to support the foil winding 5 by making contact with it, the shape of the insulator 6 must be very complicated to follow the unevenness of the end of the wire, and its installation is also difficult. was there.

In addition, if the insulating sheet 4 protrudes from the end of the winding, it will be difficult to suspend or lower the winding during winding manufacturing.
The insulating sheet 4 was damaged, causing a short circuit between turns. On the other hand, if the end surface of the metal sheet is uneven, an electromagnetic mechanical horn in the axial direction due to the current and the radial component of the leakage magnetic flux acts on the winding, and in a high-voltage, large-capacity foil-wound transformer, the operation The increase in the axial component of the winding vibration and short-circuit mechanical force becomes negligible, leading to buckling of the winding ends and problems with the strength of the clamping plates and clamping fittings.

However, in producing a foil winding, it is very difficult to simultaneously wind a wide metal sheet and an insulating sheet with a large number of windings without unevenness on the end surface of the foil. especially,
Insulating sheets are several tens of micrometers thick and are generally made up of multiple sheets for electrical and mechanical reliability reasons.They tend to wrinkle or tear during winding, so they should be rolled with their end surfaces aligned. It is almost impossible to rotate.

For this reason, there is a method of hardening the end faces of the windings with resin, etc. to make the ends flat, but this may cause cracks in the resin and the generation of corona due to long-term operation of the transformer. This is not preferable as a large capacity H-transformer.

[1'A aspect of the invention] This invention was proposed to eliminate the above-mentioned drawbacks of the conventional type, and its purpose is to Equipped with a winding support mechanism that can stably support the foil winding in an insulated state, and has excellent winding workability.1. :Providing foil-wrapped transformers.

[Summary of the Invention] The foil-wound transformer of the present invention has an end filling provided at the end of the metal sheath 1 and a clamping plate attached to the end face of the end filling via an insulator. This is to tighten and fix the winding from the axial direction.

[Embodiment of the Invention] Next, an embodiment of the present invention will be described with reference to FIG. Incidentally, the same parts as those of the conventional type shown in FIG. 1 are given the same reference numerals, and the description thereof will be omitted. 1 In Fig. 2, metal sheets 1 to 3 and an insulating sheet 4 formed by stacking a plurality of sheets are wound around an insulating cylinder 2 disposed around the leg portion 1a of the core. sheet 3
End padding 1 of approximately the same thickness as the metal sheet 3 is provided at both ends of the
0 is placed.

Further, the width of the end portion 10 is set so that both ends of the insulating sheet 4 can be covered.

Further, a clamping plate 7 is attached to the end face of this end filling 10 via an insulator 6, and this clamping plate 7 is tightened and fixed to the iron core 1 by a 1-shaped clamping fitting 8. .

In this embodiment having such a configuration, the metal sheet 3 has superior mechanical properties compared to the insulating sheet 4.
Since the winding does not wrinkle or tear during winding, it is easy to wind the winding with the ends aligned. Further, since the end filler 10 disposed at the end of the metal sheet 1-3 has approximately the same thickness as the metal sheet 3 and is narrow in width, it is easy to align the ends. On the other hand, the insulation sheets 1 to 4 are wider than the width of the metal sheet 3, but the width of the end filling 10 is set so that it does not protrude outward beyond the end surface of the end filling 10. , aligning the ends of the insulating sheet 4 becomes unnecessary, and furthermore, when raising and lowering the mark of the winding, the insulating sheet 4
Since the wire is covered with the end filler 10, there is no risk of breakage, and workability and reliability during winding production are improved. In addition, there is no unevenness at the end of the winding as in the conventional case.
Since it is flattened by the end stuffing 10, the shape of the insulating material 6 to be joined to the end stuffing 10 is also extremely simple, and the manufacturing process and installation process (9 steps) are greatly simplified.

Note that the present invention is not limited to the above-described embodiment, and instead of the fastening plate 7 shown in FIG. 2, a silicon vA treatment as shown in FIG. A C-shaped disk obtained by cutting one part of 1 may also be used.

When this silicon steel disk 11 is used, the leakage magnetic flux shown in FIG. Electrical and mechanical forces are significantly reduced.

[Effects of the Invention] As described above, the present invention has the advantage of providing a foil-wound transformer with a stable winding support mechanism and high workability and reliability.

[Brief explanation of drawings]

Figure 1 shows the structure of a conventional foil-wound transformer.
The figure is an enlarged sectional view of the main part of an embodiment of the foil-wound transformer of the present invention, and FIG. 3 is a perspective view showing a tightening disc used in the embodiment of the present invention. 1... Iron core, 1a... Leg part, 1b... Yoke part, 2
... Insulating tube, 3... Metal sheet, 4... Insulating sheet, 5... Foil winding, 6... Insulator, 7... Tightening plate, 8... Tightening Metal fittings, 9... Leakage magnetic flux, 10...
End filling, 11...disc. 7317 Agent Patent Attorney Aide Kensuke (1 other person) 1st
Figure 2 Figure 3

Claims (1)

[Claims] (1) In a foil-wound transformer having a foil winding formed by overlapping and winding metal sheets or insulating sheets around the legs of an iron core,
At the end of the metal sheet, mark a width that is approximately the same thickness as the metal sheet and covers the end of the insulating sheet.
′? Foil-wound transformer 1゜(2) characterized in that an end filling is arranged, a fastening plate is attached to the end of the end filling via an insulator. The plate is a C-shaped disc made by winding a silicon steel plate and cutting it at one point on the circumference.
F. The foil-wound transformer according to claim 1.