JPS58222511A - Foil wound stationary induction electric apparatus - Google Patents

Abstract

PURPOSE:To increase frictional force between foil winding and a sheet-shaped insulating member, and to prevent displacement in the vertical direction by winding the whole foil winding in a barrel shape of which the outer circumferential surface of a central section expands. CONSTITUTION:The thickness of a cylindrical wound core 16 existing on the outer circumference of the leg section 1 of a core is thickened in the central section, and thinned toward upper and lower end sections. Metallic foil 2 and the sheet-shaped insulating members 3 are wound around the barrel-shaped wound core 16, and the foil winding is constituted. When the metallic foil 2 on the right side intends to be displaced downward, strong tensile force equal to force required for stretching the metallic foil 2 only by pi.d is generated in a sheet because a point S on the metallic foil 2 shifts to S' and the circumferential length of the point S' is longer than that of the point S only by pi.d, and large frictional force is generated, and functions as force preventing displacement in the vertical direction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a foil-wound stationary induction electric device having a foil winding formed by overlappingly wound a metal foil and an insulating sheet.

[Technical Background of the Invention] Foil-wrapped stationary induction electrical equipment having foil windings, such as foil-wound transformers, have a good space factor, so they can be made smaller and more flexible. It has already been put to practical use in small capacity transformers with relatively low voltages of several KV and several hundred KVA. Furthermore, recently, in view of its excellent advantages, research has been conducted to expand its application to higher voltage and larger capacity 275 KV, 300 MV delta transformers, for example. There are various problems in the practical application of such high-voltage, large-capacity transformers, but foil-wound transformers, which are already known and are being researched, have cooling ducts built into the windings, and improve insulation properties. There is a so-called heat pipe type in which a high-quality refrigerant is pumped and circulated to directly cool the heat generated from winding loss.

Figure 1 shows the structure of this heat vib type foil-wound transformer.

A metal foil 2 is wound many times around the outer periphery of the leg portion 1 of the iron core with a sheet-like insulating material 3 interposed therebetween to form a C1C1 low voltage wire 4 and a high voltage foil winding 5. A hollow metal cooling duct I-6 is built in between these low high voltage windings 4.5. This cooling duct 6 has a cylindrical shape or a divided cylindrical shape along the winding direction of the foil winding, and inside the thin gap that is the hollow part, there is a material such as Freon R-113 or "C75". A refrigerant 7 is enclosed.This refrigerant is circulated by a pump 8 of a cooling device provided outside the transformer.
The heat generated within the winding is taken away by the latent heat of vaporization of the refrigerant, and the vapor is
The liquid is collected by a collection pipe 10 via an insulated pipe 9 connected to a cooling duct 6 and led to a cooling device installed above the windings. Then, it is cooled by a water-cooled Ml pipe 12 in a condenser 11 of the cooling device and condensed again. The condensed and liquefied refrigerant 7 is stored in a refrigerant tank 13 provided below the winding, and is sent again to the cold comb 11 duct 6 inside the winding by the pump 8.

The main body of the foil-wound transformer, in which a refrigerant circulation circuit has been installed in this way, is coated with an insulating medium such as insulating oil or S Fs gas.
4 and are housed and sealed in a tank 15. In this case, the liquid collecting pipe 10 made of metal such as stainless steel is connected to the ground potential of the tank 15, etc., and the cooling duct [6 is installed between the foil windings 4 and 5, It is electrically connected to the same potential as the winding.

In the transformer having the structure described above, the refrigerant for cooling and the insulating medium 14 for insulation are completely liquid-tightly separated. For this reason, this type of foil-wound transformer is particularly called a separate foil-wound transformer.

[Problems with the background technology] Since the transformer of this method uses the latent heat of vaporization of the refrigerant,
It is promising for large-capacity transformers because it can be expected to have excellent cooling characteristics.

However, the conventional 1-set double-wound transformer shown in FIG. 1 has the following problems.

Immediately 5, foil wrapping change □3 and contact 31! 1 location 6, transport, 6, processing
) Vibrations and other external forces, forces generated on the windings by electromagnetic force during operation, and gravity may cause the foil winding lm14
A force from above and below of A acts on °5. It is necessary to prevent vertical displacement of the foil windings 4 and 5 due to these forces, but since the insulating vibrator 9 is thin and flexible, it is not a heavy item. It cannot serve as a support for certain foil windings 4 and 5. Also, it is not possible to bring some kind of support into contact with the top and bottom of the foil winding 4.5. That is, as shown in FIG. 2, the sheet 1-shaped insulating material 3 protrudes above the metal foils 2 in order to obtain insulation between adjacent metal foils 2.

Since the sheet-shaped insulating material 3 is an insulating material with a thickness of about 0.05 mm, if you try to hold it down with a support from above or below, it will easily become deformed and the insulation and support will deteriorate. You will not be able to achieve your goal.

Therefore, in order to prevent the foil winding 4.5 from shifting vertically, conventionally, as shown in FIG. Volume I] Gno, from now on,
The metal foil 2 and the sheet-like insulating material 3 are brought into close contact with the winding core 16, so that the frictional force of the metal foil 2 and the sheet-like insulating material 3 prevents vertical displacement of these materials. . but,
In such a conventional M6 ``Itl'', when the monthly rate expands and contracts and the tensile force decreases due to soil processing due to temperature during drying after assembling electrical equipment and during operation, the frictional force becomes extremely low. There was a drawback that the foil winding was easily displaced in the vertical direction in whole or in part.

[Objective of the Invention] The present invention provides a foil-wound stationary induction electric device that can effectively prevent the foil winding from shifting in the vertical direction without pressing any supports above and below the foil winding. Write with the purpose of writing.

[Summary of the Invention] The foil-wound stationary induction electrical equipment of the present invention has a structure in which the entire foil winding is wound into a barrel-shaped shape with a bulged central outer circumferential surface. Between ll1iIl! It has a structure that improves strength and prevents displacement in the vertical direction.

[★Embodiment of the Invention] An embodiment of the present invention will be described with reference to FIG. On the outer periphery of the leg portion 1 of the iron core, there is a winding core 16 for wrapping the metal foil 2 and the sheath 1-shaped insulating member 3, but the thickness of this cylindrical winding core 16 is as follows. The cylinder is thick at the center in the axial direction and becomes thinner toward the upper and lower ends. As a result, the entire outer surface of the winding core 16 forms a gentle barrel shape. Around this barrel-shaped winding core 16, a metal foil 2 and a sheet-like insulating member 3 are wound, as in the conventional case, to form a foil winding 4.5.

Therefore, the entire foil winding 4.5 is also wound in a gentle barrel shape in accordance with the shape of the winding core 16.

Next, according to FIG. 5, the foil winding with the above structure is 4.5
It will be explained that vertical deviation is difficult to occur.

FIG. 5(Δ)(B) is a diagram illustrating the friction nozzle between the metal foil 2 and the seam 1-shaped insulating member 3 in the conventional structure. The tensile force of the foil winding 4.5 causes the distance between the metal foil 2 and the sheet-like insulating member 3 to be L. The force acting in the direction of contraction is P, and the coefficient of friction between the metal foil 2 and the sheet-like insulating member 3 is μ. , the resistance force against vertical displacement of each metal foil 2 and sheet-like insulating member 3 becomes f−μ·P. Since this frictional force f is the only force that opposes the vertical force F acting on each metal foil 2 and the sheet-like insulating member 3, if the tensile force decreases, L[detection force P decreases. In this case, a vertical shift easily occurred in the foil winding 4.5.

FIG. 5(C) is a diagram illustrating the frictional force between the metal foil 2 and the sheet-like insulating portion jlA 3 in the structure of the present invention.

According to this structure, first of all, the following large frictional force can be obtained. That is, if we consider the case where the metal foil 2 on the right side is about to displace downward, and if we assume that the point S of the metal foil 2-t moves to S' and covers it, then the circumference of the 81st point is smaller than the circumference of the 8th point. π・(1
() Because it is long, a strong tensile force equal to the force required to extend the metal W12 to this length is generated within the sheet, and this tensile force generates a large frictional force that prevents vertical displacement. C acts.

Secondly, by forming the inclined surface, this structure obtains a beneficial frictional force as described below. That is, the metal foil 2 and the sheet]・
If the inclination angle of the shaped insulating member 3 is θ, the frictional force due to the tensile force of the foil winding 4.5 becomes μ·p −cos θ...■. Further, due to the vertical force F acting on each metal foil 2 and sheet-like insulating member 3, each metal foil 2 and sheet-like insulating member 3 receive a force that is pressed against each other, and the resulting frictional force is μ・F− sin θ...■. Therefore, the frictional force fo in the case of this structure becomes U°C fo=tl·P−cosθ+μ·F−8inθ. Furthermore, the actual force that causes the displacement of each metal foil 2 and sheet-like insulating member 3 is smaller than in the case of the conventional structure, and becomes F-cos θ.

Based on these, metal foil 2 in the conventional structure and this structure
Comparing the resistance to displacement of the sheet-like insulating member 3 and the frictional force f1 in the conventional structure, the compressive force decreases as the tensile force of the metal foil 2 and the sheet-like insulating member 3 decreases. If it were to occur, it would immediately diminish, and there would be no other force to counteract the occurrence of the sew. On the other hand, the frictional force, fo, which falls on this structure, even if the compressive force decreases,
The force FCO8θ in the term (2) exists regardless of the compressive force P, and functions to prevent displacement.

Next, the ratio of the friction force of the conventional structure to the force that causes shear and the ratio of the friction force of the wooden structure to the force that causes shear is calculated using the SI.
In my opinion, (,A/F-cosθ)/(f/F) = ((μ・p-cosθ→−μ・“・sinθ)/F・
COSθ)/(μ・P/F) = 10F/P・tanθ Now, for clarity, IJ, the conventional force that causes deviation and avoids F
Considering the case where is equal to the frictional force f, F-μ・P C
=f> Therefore, the ratio is 1-1-/l-tanθ. If we assume that θ-5° and μm 0.5, then the ratio will be approximately 1+0.05, and even under normal conditions where the tensile force of the metal heat 2 and the sheet-like insulating member 3 does not decrease, the anti-slip effect will not occur. It will increase.

Note that the present invention is not limited to the illustrated embodiment, and in order to form the entire foil winding into a barrel shape, the wall thickness of the cylindrical winding core 16 must be set such that the center portion ru<y. Instead of using an ordinary winding core, a narrow sheet of insulating material in the shape of a sheet can be wound around the center of the core to form a similar barrel shape.

[Effects of the Invention] As described above, according to the present invention, the foil has a simple structure in which no supports are brought into contact above and below the foil winding, and the foil winding is not deformed due to misalignment. Winding stationary induction electrical equipment can be obtained.

[Brief explanation of drawings]

□llll'1 Figure 1 is a right sectional view of a conventional heat) bubb type foil-wound transformer, Figure 2 is a partially enlarged view of Figure 1, and Figure 3 is the winding work of winding I1 (). Diagrams showing the state, FIG. 4 is a right sectional view of the winding in one embodiment of the foil-wrapped stationary induction electric device of the present invention, and FIG. 5 (△) is a horizontal sectional view of the conventional winding. (B) is the fifth
FIG. 5(C) is a vertical cross-sectional view of a winding in one embodiment of the foil-wound stationary induction electric device of the present invention. 1... Legs of the iron core Part, 2...Metal heat, 3...Sheet-shaped insulating material, 4...Low voltage winding, 5...High voltage winding, 6...
...Cooling duct 1~. 7... Refrigerant, 8... Pump, 9
... Insulated pipe, 10 ... Liquid collection pipe, 11 ... Condenser, 12 ... Water cooler, 13 ... Refrigerant tank, 14
... Insulating medium, 15 ... Tank, 16 ... Winding core,
[)... Compressive force, f , , fa... Frictional force, F.
...' = force acting in the downward direction, μ...friction coefficient. 7317 Representative Patent Attorney 1111 Kensuke Chika (and 1 other person) 1: @1 Figure 7 Iυ Figure 2 Figure 3 Figure 4

Claims (3)

[Claims] (1) In static induction electrical equipment in which foil winding is formed by wrapping metal foil and sheet-like insulating material in a stacked state around a winding core, the winding core has a barrel-shaped shape with a bulge in the center in the axial direction. This foil-wrapped stationary induction electric device is characterized in that the entire foil winding wound around the outer periphery of the core is barrel-shaped with a bulging center. (2) The foil-wound stationary guide according to claim 1, wherein the barrel-shaped winding core is formed by increasing the thickness of the cylindrical winding core at the center of the axial curve. electrical equipment. (3) Claim 1, wherein the barrel-shaped winding core is formed by winding a narrow sheet-like insulating material around the central part of a cylindrical winding core in one direction of the axis. The foil-wrapped stationary induction electrical equipment described.