JPH0416408Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial field of application> The present invention relates to small current, high voltage transformers such as test transformers, and in particular takes measures to effectively cool the low voltage side wheels. Regarding gas insulated transformers.

<Prior Art> Conventionally, as shown in FIG. 5, for example, as shown in FIG. Winding shape 2
A low-voltage side wire ring 3 formed by alternately winding a coil and an interlayer insulating sheet is attached to. Next, a predetermined gap 4 is provided on this low-voltage side wire ring 3, and a second winding 5 is fitted therein, and a pair of winding support rings 6, 6 are adhesively fixed to both ends of this winding 5 in the axial direction. do. Next, a potential fixing plate 7 is wound around the outer peripheral surface of the wound form 5, and the winding start end of the coil is connected to this potential fixing plate 7, and this coil and an interlayer insulating sheet are alternately wound. A high voltage side wire ring 8 is attached to the winding form 5. The winding end of this high-voltage side wire ring 8 is connected to a high-voltage shield 11 and a high-voltage terminal 12 arranged on the outermost periphery of the wire ring 8 to form the contents of the transformer, and the contents of the transformer are filled with insulating gas. It is housed in a pressure vessel (not shown).

In such a conventional configuration, the potential fixing plate 7 is provided to prevent local overheating due to eddy currents and to equalize the electric field of the high voltage side rail 8 in cooperation with the high voltage shield 11. . Further, the gap 4 provided between the low-pressure side wire ring 3 and the winding form 5 communicates with notches 15, 15 formed in each winding form support ring 6, 6, and forms a gas flow passage 16. There is.

<Problems to be Solved by the Invention> Incidentally, in such a conventional transformer, the low-voltage side coil 3 is cooled by the insulating gas flowing into and out of the gas flow passage 16 by natural convection inside the container. However, in this case, since the gas flow passage 16 is open only to both ends of the wire in the axial direction, the insulating gas mainly flows only in the direction of arrow a' in the figure. Its distribution volume is also inevitably limited. Therefore, the gas flow path 1
There is a problem in that the heat generated in each of the high-pressure side and low-pressure side wire wheels 6 is trapped, and the low-pressure side wire wheel 3 cannot be sufficiently cooled.

In view of these conventional problems, the present invention provides a gas-insulated transformer that prevents local overheating of the high-voltage side coil and equalizes the electric field of the coil.
The purpose is to improve the cooling performance of the low-pressure side track wheels.

<Means for solving the problem> In order to achieve this purpose, this invention
A gas vent hole that communicates with the gas flow path is formed in the peripheral wall of the winding around which the high-voltage side wire is wound, and a potential fixing plate that is wound around the winding is opened externally and communicates with the gas vent hole. It is characterized by the formation of a through hole.

<Example> Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

FIG. 1 is a perspective view showing the middle of winding the potential fixing plate around the winding form, which is a component of the present invention;
The figure is a partially cutaway front view of the transformer of this embodiment, and FIG. 3 is an enlarged sectional view showing the main parts thereof. In these figures, reference numeral 1 indicates an iron core made of silicon steel plate or the like. A first winding 2 is attached to a part of the outer peripheral surface of the iron core 1, and on this winding 2, coils made of, for example, synthetic resin-coated copper wire and interlayer insulation sheets made of plastic film sheets are alternately wound. A winding low-voltage side wire ring 3 is attached, and a winding start end and a winding end end of the low-voltage side wire wheel 3 are respectively connected to a low-voltage terminal (not shown).

A predetermined gap 4 is provided on the low-pressure side track 3 to provide a second
A pair of winding support rings 6, 6 are fixed to both ends of the winding 5 in the axial direction with an adhesive. Further, a potential fixing plate 7 is wound on the outer circumferential surface of the winding 5, and a coil similar to the low voltage side coil 3 and an interlayer insulation sheet are alternately wound around the center of the potential fixing plate 7. A multilayered high voltage side track 8 is fitted and fixed. The winding start end of this high-voltage side wire ring 8 is connected to the potential fixing plate 7 , and is also connected to a grounding side terminal 10 via a lead wire 9 drawn out from this potential fixing plate 7 . Further, a high voltage shield 11 and a high voltage terminal 12 are provided on the outermost periphery of the high voltage side wire ring 8, and the winding end of the high voltage side wire ring 8 is connected to this high voltage shield 11. The contents of the transformer configured in this way are housed in an iron pressure vessel 13 filled with a nonflammable insulating gas such as sulfur hexafluoride (SF ₆ ).

Each of the winding support rings 6 is a donut-shaped flat plate that is fitted into the end of the outer peripheral surface of the first winding 2, and has a plurality of circular holes 14 and notches 15, 15 provided at equal pitches on the plate surface. and each circular hole 1
4... and the notches 15, 15 respectively communicate with the gap 4 provided between the low-pressure side wire ring 3 and the second winding 5, and form an annular gas flow passage 16 through which insulating gas flows.
is formed.

Further, a plurality of gas vent holes 17 communicating with the gas flow passage 16 are formed in the peripheral wall of the second winding 5. Each of the gas vent holes 17 is a small-diameter circular hole arranged at equal pitches on both sides of the winding portion of the high-voltage side wire ring 8 of the winding form 5.

The potential fixing plate 7 is composed of a belt-shaped sheet made of a highly conductive non-magnetic conductive foil such as copper or aluminum,
The gas vent holes 17 are provided on both sides of the sheet in the width direction.
A plurality of through holes 18 arranged at the same pitch intervals as...
is formed.

This potential fixing plate 7 is wound around the outer peripheral surface of the second wound form 5 with double-sided adhesive tape 19 so as not to form one turn, and in this wrapped state, each through hole 18... Coinciding with the gas vent holes 17 . . . , they communicate with the gas flow passage 16 and open into the internal space of the container 13 on both sides of the high-pressure side raceway 8 in the axial direction.

As shown in FIG. 3, the insulating gas naturally convecting within the container 13
The gas flows into the gas flow passage 16 through the notches 15, 15 and the circular holes 14, and while the gas cools the low-voltage side coil 3, it flows through the gas vent holes 17 of the second winding 5 and the potential fixing plate 7. It flows out into the space inside the container 13 through the through holes 18.

FIG. 4 shows eight vent holes 17 and through holes 18 in the second winding 5 and the potential fixing plate 7, respectively.
The one that opened individually (A) and the one that opened 16 (B),
In addition, the results of a temperature rise test of the low-pressure side track 3 with the conventional one (C) in which these holes 17..., 18... are not formed are shown. In this figure, the horizontal axis I indicates the current value flowing through the low-voltage side track 3, and the vertical axis T indicates the temperature rise value of the low-voltage side track 3. As is clear from this figure, it can be seen that the more gas vent holes 17 are provided, the more the temperature rise in the low-pressure side track 3 can be significantly reduced.

Note that the potential fixing plate 7 may take various forms, such as one formed by connecting a plurality of strip-shaped conductive foils with conductive wires.

<Effects of the invention> As described above, according to the invention, a gas vent hole communicating with the gas flow path is formed in the peripheral wall of the winding around which the high-voltage side wire is wound, and the potential of the winding around which the high-voltage side ring is wound is fixed is fixed. Since the plate is formed with a through hole that opens to the outside and communicates with the gas vent hole, it is possible to prevent local overheating of the high-voltage side wire ring and the occurrence of corona discharge due to imbalance in the electric field of the wire ring. After preventing this with a potential fixing plate, it is possible to increase the circulation flow rate of insulating gas to the low-voltage side track with a relatively easy configuration. Therefore, the cooling performance of the low-pressure side track wheels can be significantly improved.

[Brief explanation of the drawing]

1 to 4 show embodiments of the present invention,
Fig. 1 is a perspective view showing the middle of winding the potential fixing plate around the winding form, which is a component of the present invention, Fig. 2 is a partially cutaway front view of the transformer of this embodiment, and Fig. 3 is the main part thereof. FIG. 4 is a diagram showing the results of a temperature rise test of the low-pressure side track, and FIG. 5 is an enlarged sectional view of the main part of the conventional example. 3...Low voltage side coil, 5...Wound type, 7...Potential fixing plate, 8...High voltage side coil, 16...Gas flow path,
17... Gas vent hole, 18... Through hole.

Claims (1)

[Scope of utility model registration request] A gas flow path with both ends open is formed between the low-voltage side wire ring and the winding that is fitted into it, and a potential fixing plate is wrapped around the outer circumferential surface of the winding, and the high-voltage side wire is passed through the potential fixing plate. The transformer is formed by winding a ring, and a gas vent hole is formed in the circumferential wall of the wound shape and communicates with the gas flow path, and the potential fixing plate is opened to the outside and communicates with the gas vent hole. A transformer characterized by having a through hole formed therein.