JPS6066412A - Foil-wound transformer - Google Patents

Abstract

PURPOSE:To prevent a slip-down to a lower section of a winding to electromagnetic mechanical power generated in the winding on a short circuit by supporting an introducing nozzle by a core or a clamping fitting through an insulator when a refrigerant enters to a cooling panel from a lower section and a drawing nozzle by the core or the clamping fitting through the insulator when the refrigerant goes out of the lower section from an upper section. CONSTITUTION:Spacers 21 consisting of insulators (e.g. epoxy resin or the like), to both ends thereof shielding metals 22 are packed, are arranged among introducing nozzles 7 positioned at the lower sections of windings 4, 5 in the introducing nozzles 7 or drawing nozzles 8 as inlets and outlets for a refrigerant in a cooling panel 6 and a core 1 or a grounding metal such as a clamping fitting 20 for clamping the core 1, and the windings 4, 5 are supported.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a foil-wound transformer in which a cooling panel is built into a winding made of overlapping layers of metal/teeth and insulating sheets.

[Technical background of the invention and its problems]

A foil-wound transformer, in which a metal sheet and an insulating sheet are layered and wound around a core leg to form a foil winding, has a good space factor for the wrapped conductor, so it can be used as a transformer using an ordinary rectangular wire-shaped conductor. It has the characteristics of being smaller and lighter than other containers.

However, in order to realize high voltage, large capacity transformers, it is essential to further improve the cooling efficiency of the windings and provide the windings with high insulation capacity.
For this reason, a cooling panel is built into the winding through which refrigerant flows.
It has been considered that the heat generated from the windings is directly cooled.

This conventionally proposed foil-wound transformer, for example,
As shown in the figure, the outer V of the iron core 1 is connected to the insulation 7.
- It is made by winding wires 3 and 3 on top of each other to form a winding. This winding consists of an inner winding 4 and an outer winding 5, and a clay-shaped cooling panel 6 is built into each of these winding legs.

As shown in FIG. 2(at), this cooling panel 6 is composed of an introduction nozzle 7 into which the refrigerant enters, an outlet nozzle 8 through which the refrigerant 12 exits, and a flow path section 9 for the introduced refrigerant. ing.

The cooling panel 6 is made up of two metal plates stacked one on top of the other with a narrow gap through which the coolant 12 flows, and the periphery of the plates is sealed by welding or the like. A pump 13 pumps a refrigerant 12 such as Freon R-113 or Fluorinert Ii"0-75 into the gap in the cooling panel 6.
The refrigerant 12 is used to absorb the heat generated within the foil-wound wire, thereby cooling the wire. The refrigerant 12 that has absorbed this heat is sent out to the outside of the winding through the four nozzles 8, cooled in the cooling 614 provided outside the tank 18, and sent into the cooling channel 6 again. , refrigerant 12
(cooling) (The phlegm collection pipe 16 that is pumped into the flannel 6)
However, this liquid collection area 16 maintains the same ground/vL level as the tank 18, etc., and the metal sheet 2
An insulating pipe 17 is provided in the middle in order to connect to the cooling panel 6 having the same potential. The cooling panel 6 is in contact with the metal sheet 2 or the insulating sheet 3 in order to cool the metal sheet 2 by thermal conduction. , approximately the same voltage is applied to the cooling channel 6, and this metal sheet 2 and the cooling panel 6
This insulation between the tank 18 and the outside is provided by an insulating gas 19 such as sulfur hexafluoride (SFe) sealed in the tank 18.

The foil-wound transformer described above is called a separate foil-wound transformer because the circulation circuit through which the refrigerant 12 for cooling flows and the insulating gas 19 are completely separated, and it is called a separate foil-wound transformer. Significantly smaller and smaller than transformers using shaped conductors.
It has advantages such as being lightweight and having high insulation reliability.

By the way, in the winding of this type of foil-wound transformer, in order to insulate the voltage generated between the matched turns, a metal sheet 2 and a wide insulating sheet 3 are overlapped and wound, and after winding, the winding is completed. The insulating sheet 3 protrudes beyond the metal sheet 2 at both ends in the axial direction. For this reason, for example, 300 M
In order to prevent the winding, which weighs several tons, from slipping down to the bottom after assembly in the case of a large-capacity VA, an attempt was made to insert an insulating support between the winding and the iron core 1 or the clamping fitting 20 that tightens the iron core. Also, the lower part of the winding protrudes from the insulating sheet 3, making it unstable because it has a flexible groove structure.

゛Also, in a separate foil-wound transformer, the boundary surface between the metal sheet 2 and the cooling panel 6 wrapped around it has a misalignment in Q.The reason for this is (1) the aluminum of the metal sheet 2 Since the cooling panel 6 is made of stainless steel, its specific gravity is approximately three times higher.
C Unavoidable surface irregularities. Therefore, metal 7-
Comparing the contact area Vζ between sheet 2 and insulating sheet 3, gold sheet 2
(3) Compared to the thin metal plate 2, the cooling panel 6 is made of highly rigid gold 4, so the winding For example, it is difficult to apply sufficient surface pressure when wrapping the material around the material.

Normally, when manufacturing the winding, by winding the VC metal sheet 2 under tension, sufficient surface pressure can be obtained between the metal sheet 2, the insulating sheet 3, and the /1i cooling panel 6, so that there is no problem during transportation. Although the coil can be supported without support when driving in a separate seat, the biggest problem is when electromagnetic mechanical force is applied during a short circuit. Figure 2 (In the case of the simplest two-winding winding structure shown in Tochi), when a short circuit occurs, the inner winding 4 has an electromagnetic force 1 that tends to compress the winding inward in the radial direction.
An electromagnetic force 15b is applied to the outer winding 5a1 to stretch the winding outward in the radial direction. Since the inner winding 4 is supported by the iron core 1 located inside it, the winding does not fall off, but as for the outer winding #5, a force is applied in the direction of increasing the winding diameter, so the contact surface pressure increases. In the lower part, that is, in the part between the cooling panel 6 and the metal plate 2, or the insulation sheet 3, a deviation occurs as shown in FIG. 2(b).

[Purpose of the invention]

The present invention was made in consideration of the above-mentioned circumstances, and its purpose is to wind &! when a short circuit occurs. The purpose of the present invention is to provide a strong and reliable thin foil-wound transformer that prevents the winding from sliding down to the bottom due to the electromagnetic mechanical force generated in the process.

[Summary of the invention]

In the foil-wound transformer of the present invention, when the refrigerant enters the cooling nozzle from the bottom, the inlet nozzle is supported by an iron core or a clamping metal fitting through an insulator. This is characterized by preventing the windings from shifting.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG.

In this embodiment, in order to support the inlet nozzle 7 or the outlet nozzle 8 at the lower part of 'C', a spacer 21 is used which supports the conductor of the gas switching device as shown in FIG. The main body of this is made of epoxy resin, and there are two metal shields on both ends.
It incorporates 2.

As mentioned above, the metal 22 at both ends has the potential of the metal sheet 2 in the vicinity of the cooling panel 60 that the cooling panel 6, the inlet nozzle 7, and the outlet nozzle 8 are wrapped around. 5th between 24 and the nozzle.
As shown in the figure, there is a small gap 23, and the electric field in this part becomes high, and since this part becomes a weak point in gas insulation, it is filled in to reduce the strength of this electric field.

By using the above spacer, the iron core can be tightened by supporting the winding with the metal fittings 20. This means that the part where misalignment is most likely to occur is supported, so the winding should be strong against electromagnetic mechanical force. I can do it.

Unfortunately, as mentioned above, the winding loosens due to electromagnetic force.
: Because it is only the outer winding *z As shown in Figure 6, it may be a ( ) structure that supports only the introduction nozzle or the outlet nozzle of the outer winding.

〔Effect of the invention〕

As described above, according to the present invention, metal sorting and M! In a foil-wound transformer that has a built-in cooling panel in which refrigerant is circulated inside the foil-shaped winding with three edge sorting overlapped, an introduction nozzle or A spacer made of an insulating material with shield metal embedded at both ends is placed between the nozzle located at the bottom of the inner winding of the lead-out nozzle and a grounded metal such as the iron core or a clamping fitting for tightening the iron core. Since the wire is supported, it is possible to obtain a strong and reliable foil-wound transformer in which the winding does not slide down to the bottom due to the electromagnetic mechanical force generated in the winding during a short circuit.

[Brief explanation of the drawing]

Figure 1 shows a schematic cross section L:1 of a conventional foil-wound transformer, and Figure 2 (a) shows a cross-section of a conventional sleeve-wound transformer. A cross-sectional view showing the direction of the electromagnetic mechanical force during a short circuit applied to the
Fig. fb1 is a sectional view showing the state in which the windings fall off after electromagnetic mechanical force is applied, Fig. 3 is a perspective view showing an embodiment of the present invention, and Fig. 4 is a cooling panel according to the present invention. A curved view showing the structure of the supporting spacer, Fig. 5 is an explanatory drawing showing the minute gap that occurs when an insulator and a nozzle or a lead-out nozzle come into contact with each other, and Fig. 6 shows a method of supporting only the outer coil in the present invention. FIG. J...Iron core 2...Metal sheet 3...Insulating sheet 4...Inner winding 5...Outer winding 6...Cooling panel 7...Introduction nozzle 8...Output nozzle 9...・Refrigerant flow path 12...Cooling medium 13・
・B/P 14...Cooling story 15...Radial direction mechanical force 16...Liquid collection pipe 17...
Insulating pipe 18...Tank 19...Insulating gas 2
o... Iron core tightening fitting 21... Support spacer 22 Shield metal 23... Minute gap 24... Insulator agent Patent attorney Noriyuki Chika (and 1 other person) I5 1
Figure/Otsu Figure 2 (b) Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] In a foil-wrapped transformer with a built-in cooling panel, the nozzle and iron core are located in one part of the inner winding of the inlet nozzle or outlet nozzle, which is the inlet and outlet of the refrigerant of the cooling panel. A foil-wound transformer characterized in that a spacer made of an insulating material filled with shield metal at both ends is disposed between a ground metal such as a clamping fitting for a screw to support the winding. .