JPS62259414A - Winding apparatus for foil wound transformer - Google Patents

Abstract

PURPOSE:To improve the reliability of an insulator in a foil wound transformer by detecting a value based on the inductance variation of the transformer during winding work of a foil wound coil to discover the shortcircuit of the coil during the winding work. CONSTITUTION:An insulating cylinder 15 is attached to a winding machine 14, and a lead 16 is started to be wound. In this case, a foil wound coil 17 is made of an insulating sheet 18 and a metal sheet 19, and fed by guide rollers 20, 21. An inductance measuring unit 22 is provided between the lead 16 and the roller 21 to measure the inductance of the coil. Since the sheet 19 is not insulated and the roller 21 used metal, it can be used as the terminal of the coil to eliminate the influence of the metal sheet feeding side can be eliminated by grounding at 23. Thus, when a shortcircuit occurs between the turns of the coil 17, a voltage drops or a current increases. Thus, the malfunction of the coil can be early discovered to largely improve the reliability of the insulator.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention uses a foil-like winding formed by overlapping and winding a metal sheet such as copper or aluminum foil and an insulating sheet. The present invention relates to a winding device for a foil-wound transformer.

(Prior Art) A foil-wound transformer has a good winding space factor and can be made smaller and lighter. It has already been put into practical use in small capacity transformers with relatively low voltages of several KV and several hundred KVA.6 In recent years, in view of its excellent advantages, it has been put into practical use in higher voltage, larger capacity transformers such as 275 KV and 30 OMVA class. Although research is underway to expand its application, the biggest technical issues are how to improve cooling efficiency and provide high insulation capacity to the windings, and how to withstand radial mechanical force in the event of a short circuit accident. It depends on whether you can do it. Although such high-voltage, large-capacity transformers have not yet been put into practical use, as shown in Figure 3, a cooling duct is built into the windings, and a refrigerant with excellent insulation properties is fed into this cooling duct. A heat pipe-type foil-wound transformer, which uses the latent heat of vaporization of a refrigerant to cool the heat generated from winding loss, is a promising option.

That is, in this foil-wound transformer, a low-voltage winding 4 and a high-voltage winding 5, which are made by overlapping metal sheets 2 and insulating sheets 3, are wound around a leg 1 of an iron core. A hollow cooling duct 1-6 is built-in.

In the thin gap in the hollow part of the cooling duct 6, Freon R-1
A refrigerant such as 13 or Fluorinert FC75 is sealed in the refrigerant, which is circulated by a pump 7, and the heat generated within the winding is absorbed by the latent heat of the refrigerant, and the vapor is cooled and condensed in a condenser 8 through a cooling water pipe 9. ing. The liquefied refrigerant is
The refrigerant is stored in the refrigerant tank 10.

Furthermore, a cooling system is constructed in which the pump 7 feeds the inside of the winding.

The liquid guide pipe 11 constituting the cooling system is made of metal such as stainless steel, and the liquid guide pipe 11 and the cooling duct 6 are connected via an insulating pipe 12 made of Teflon resin or the like. The liquid guide pipe 11 is also connected to the ground potential of the tank 13 and the like. On the other hand, since the cooling duct 6 is built into the winding, it is electrically connected to the same potential as the adjacent winding. Furthermore, insulation of each part of the first winding is ensured by an insulating gas such as SF or gas sealed in the tank 13.

(Problem to be solved by the invention) By the way, this type of foil-wrapped transformer utilizes the latent heat of vaporization of the refrigerant, so it can be expected to have excellent cooling characteristics, so it is promising for large-capacity transformers. However, on the other hand, there are the following problems.

The insulating sheet 3 is torn due to a manufacturing defect or due to a large amount of force being applied during winding of the foil-wound coil.

Failure to do so may result in poor insulation and the formation of a short circuit.

In particular, when a polymer film is used as an insulating sheet, it is easily cut by contact with the edges.

Also, because it is transparent or nearly transparent, it is difficult to detect with the naked eye.

Defects in the stiffness are difficult to detect during the winding operation, and are difficult to detect even by visual inspection after the winding operation is completed.

Defects due to short circuits caused by tears were discovered for the first time during electrical tests after assembly, necessitating disassembly and rework, resulting in significant losses to the manufacturing process. Therefore, it is desirable to discover defects early. If defects are discovered immediately during the winding operation and repairs can be made on the spot, losses in the manufacturing process can be reduced.

In view of the above-mentioned points, an object of the present invention is to provide a winding device for a foil-wound transformer in which a short circuit in a foil-wound coil due to a defect in an insulating sheet is discovered during the winding operation and insulation reliability is improved.

[Structure of the invention]

(Means and actions for solving the problem) The inductance of a coil changes depending on the number of turns and the size and shape of the coil. Furthermore, if there are objects with other inductances nearby, the inductance of each will change due to the combined inductance. If there is a metal sheet inside the coil whose turns are short-circuited due to a break in the insulating sheet, etc., the impedance of the entire coil becomes small. The rate of decrease varies depending on the impedance, electrical resistance, or coupling coefficient of the shorted circuit.The impedance of the zero winding is continuously measured, and by detecting the decrease in impedance, it is determined whether there is a short circuit inside the coil. be able to. Alternatively, the determination can be made by detecting a voltage drop or current increase due to a decrease in impedance, without directly measuring impedance.

The determination can also be made by placing another detection coil near the coil and detecting fluctuations in the impedance, voltage, or current of the detection coil by utilizing the coupled impedance between the coils.

(Example) FIG. 1 shows the configuration of the present invention.

Attach the insulating cylinder 15 to the winding machine 14, and
Start winding from 6. The foil-wound coil 17 consists of an insulating sheet 18 and a metal sheet 19, each of which has a guide roller 20.
21. The inductance of the foil-wound coil is measured by an inductance measuring device 22 between the lead-out 16 and the metal sheet guide roller 21. metal sheet 1
9 is not insulated and is a guide roller 21 for metal sheet.
Since it uses metal, it can be used as a coil terminal, and by grounding 23, the influence of the metal sheet feeding side can be eliminated.

The inductance of the foil-wound coil 17 increases approximately in proportion to the square of the number of turns, but if a short circuit occurs between the turns of the metal sheet 19 due to a defect in the insulating sheet 18, the inductance of the foil-wound coil 17 rapidly decreases. Therefore, the winding machine was stopped and the defective part of the coil was repaired. Changes in inductance can be monitored by humans or automatically measured and controlled by a microcomputer, etc. 1.Also, instead of an inductance measuring device, an AC power source can be applied between the outlet 16 and the guide roller 21 for the metal sheet, and the voltage or current can be measured. It is also possible to measure changes in .

When a short circuit occurs between turns in the foil-wound coil 17, a decrease in voltage or an increase in current is observed.

Another embodiment is shown in FIG. Foil-wound coil 1 on winding machine 14
A short-circuit detection coil 24 is installed next to 7. In this case as well, it is better to ground the metal sheet guide roller 21. The closer the short-circuit detection coil 24 is to the foil-wrapped coil 17, the larger the coupled inductance becomes, and the better the detection sensitivity for short-circuits between turns of the foil-wound coil 17. . The inductance of the short circuit detection coil 24 is measured, and a short circuit is detected from a change in inductance. Furthermore, instead of measuring the inductance, an alternating current voltage may be applied to the short-circuit detection coil 24 and changes in voltage or current may be measured.

For example, even if the insulating sheet 18 is torn, contact between the metal sheets 19 may not occur due to the tension between the metal sheet 19 and the insulating sheet 18 during winding. To solve this problem, pressure may be applied to the foil-wound coil 17 partially or entirely so that the metal sheets 19 come into contact with each other to increase the detection sensitivity.

〔Effect of the invention〕

As described above, according to the present invention, in a winding device for a foil-wound transformer in which a metal sheet and an insulating sheet are overlapped and wound around an iron core leg to constitute a foil-wound coil, the winding operation of the foil-wound coil is performed. Insulation defects in the insulation sheet can be detected by detecting values based on changes in inductance of the foil-wound coil.

It can detect coil abnormalities early and greatly improve insulation reliability.

[Brief explanation of drawings]

FIG. 1 is a side view showing one embodiment of the invention, FIG. 2 is a plan view of another embodiment of the invention, and FIG. 3 is a sectional view showing the structure of a foil-wound transformer. 1... Legs of iron core 2... Metal sheet 3...
・Insulating sheet 4...Low voltage winding 5...High voltage winding 6...Cooling duct 7...Pump
8... Condenser 9... Cooling water pipe 10
... Refrigerant duct 11 ... Liquid guide pipe 12.
...Insulated pipe 13...Transformer tank 14...
・Winding machine 15...Insulating cylinder 16...Output 17...Foil-wound coil 18...Insulating sheet 19...Metal sheet 20...Insulating sheet guide roller 22...Inductance measuring device 23 ...Grounding 24...Short circuit detection coil representative Patent attorney Noriyoshi Chika Yudo Hirofumi Mitsumata Figure 1

Claims (1)

[Claims] In a winding device for a foil-wound transformer, in which a foil-wound coil is constructed by stacking a metal sheet and an insulating sheet and winding them around a core leg, changes in the inductance of the foil-wound coil occur during the winding operation of the foil-wound coil. A winding device for a foil-wound transformer, characterized in that an insulation defect in an insulating sheet is detected by detecting a base value.