JPS61150208A - Transformer - Google Patents

Abstract

PURPOSE:To prevent corona discharge by a method wherein the titled transformer is constituted, so that an electric potential fixing plate is constituted of conductive foil and is wound to two and more multilayer inserting an insulated sheet, then each conductive foil of an outside layer is put upon each slit of an inside layer and the conductive foil of each layer is connected electrically and mutually. CONSTITUTION:An outside electric potential fixing plate section 5b, which possesses plural slits 12b... on a winding face of an insulated sheet 15, is wound. In this case, each slit 12b... of the outside electric potential fixing plate section 5b is put upon each conductive foil 13a of an inside electric potential fixing plate section 5a and each conductive foil 13b of the outside electric potential fixing plate section 15b is disposed at the state of covering each slit 12... of the inside electric potential fixing plate section 5a, then the conductive foil 13b is fixed adhereing on the winding face of the insulated sheet 15 by a double-faced adhesive tape. One end section of the outside electric potential fixing plate section 5b is welded to the connecting section 14 of the inside electric potential fixing plate section 5a, thereby both the inside and the outside electric potential fixing plate section 5a and 5b are made electrical poten tial fixture. Thereby, corona discharge at disposition part of the electric potential plate is prevented surely.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a small current, high voltage transformer such as a test transformer, and the present invention reduces local heat due to leakage magnetic flux and prevents corona generation. The present invention relates to a transformer that is suppressed.

<Prior Art> Conventionally, as shown in FIG. 6, this type of high-voltage transformer has a winding 4 on a low-voltage side wire 3 which is wound around an iron core l through a winding 2. A potential fixing plate 5 made of a conductive material is wound around the winding form 4 so as not to form one turn, and the starting end of the coil is connected to the potential fixing plate 5. The coil and the interlayer insulating sheet are alternately wound on the winding form 4 to form a high-voltage side wire ring 6.
and connects the end of the winding end of this high voltage side wire ring 6 to a high voltage shield 7 and a high voltage terminal 8 arranged on the outermost periphery of the high voltage side wire ring 6 to form the contents of the transformer. There is a known device in which a pressure vessel (not shown) is filled with an insulating gas.

By the way, as mentioned above, the potential fixing plate 5 is incorporated in a high-voltage transformer with a large leakage magnetic flux in order to prevent local overheating due to eddy current, and in the conventional example, the potential fixing plate 5 As shown in the figure, it is made of a conductive foil in which a plurality of slits 12 are formed parallel to the axial direction of the high-voltage side wire ring 6 at predetermined intervals, for example, on a multilayer insulating sheet 15 made of plastic film. using double-sided adhesive tape, and the winding form 4? This is wrapped around.

<Problems to be solved by the invention> However, in such a conventional potential fixing plate 5,
As shown by thick lines in FIG. 7, distortion occurs in the potential distribution at each slit 12... portion. This allows each slit 1
2... There is a problem that the electric field is concentrated on the edge portions e, e of the conductive foil 13 sandwiched between them, and corona discharge occurs.

In view of such conventional problems, the present invention prevents corona discharge at the location where the potential fixing plate is arranged when a potential fixing plate is provided between the high voltage side wire ring and its winding in order to reduce eddy current. The purpose is to prevent.

<Means for Solving the Problems> In order to achieve the above object, the present invention has a potential fixing plate provided between the high-voltage side wire ring and the winding thereof, with a plurality of slits spaced at predetermined intervals. The potential fixing plate is wound in at least two or more layers with an insulating sheet in between, and in this multilayered state, each of the inner layers It is characterized in that the conductive foils in the outer layer above the slit overlap and the conductive foils in each layer are electrically connected to each other.

<Example> Hereinafter, the present invention will be described in detail based on an example shown in the drawings. In this example, the present invention is applied to a transformer for gas insulation testing.

Fig. 1 is an enlarged sectional view showing the main parts of the present invention, Fig. 2 is a partially cutaway front view of the transformer of this embodiment, and Fig. 3 is an enlarged sectional view showing the main parts taken out. It is. In these figures, reference numeral 1 indicates an iron core made of silicon steel plate or the like. A winding form 2 is attached to a part of this iron core I, and this winding form 2
A low-voltage side wire ring 3 is formed thereon by alternately winding a coil made of, for example, a synthetic resin-coated copper wire and a glabella insulating sheet made of a plastic film sheet. The winding start end and winding end of this low-voltage side wire ring 3 are each connected to a low-voltage terminal (not shown).

A winding 4 is mounted on the low voltage side wire ring 3, and a potential fixing plate 5 made of a conductive thin plate of copper, aluminum, etc. is wound around the outer peripheral surface of the winding 4. On this potential fixing plate 5, there is formed a multilayer high voltage side coil 6 which is made by alternately winding coils and interlayer insulating sheets similar to those of the low voltage side coil 3.

A high voltage shield 7 and a high voltage terminal 8 are provided on the outermost periphery of the high voltage side wire ring 6, and the winding end of the high voltage side wire ring 6 is connected to this high voltage shield 7. Further, the winding start end of the high voltage side wire ring 6 is connected to the potential fixing plate 5, and is also connected to the ground side terminal 10 via a lead wire 9 drawn out from the potential fixing plate 5.

The contents of the transformer constructed in this manner are housed in a pressure vessel 11 made of iron and filled with a nonflammable insulating gas such as sulfur hexafluoride (S Fe).

FIG. 4 is a perspective view showing the potential fixing plate 5 in the upper square of the winding 4, and FIG. 5 is a longitudinal sectional view at the center thereof.

In these figures, the potential fixing plate 5 consists of inner and outer potential fixing plate parts 5a and 5b made of conductive foil such as copper foil or aluminum foil.

A plurality of slits 12a are formed at predetermined intervals in a direction perpendicular to the winding direction of the inner potential fixing plate portion 5a. At one end of each slit 12a, there is a strip-shaped connection part 14-- (however, it does not appear in FIG. 5 due to the position of the longitudinal section), which electrically connects the conductive foils 13a between adjacent slits 12a. ) is formed. This inner potential fixing plate portion 5a has the above-mentioned winding shape 4.
A double-sided adhesive tape (not shown) is wound around the outer circumferential surface of the sheet so as not to form a single turn, and an insulating sheet 15 made of, for example, a plastic film is wound several times on this wound surface. It's true.

On the winding surface of this insulating sheet 15, an outer potential □ fixing plate portion 5b having a plurality of slits 12b, similar to the inner potential fixing plate portion 5a, is wound.

In this case, each slot 1 of the outer potential fixing plate portion 5b
2b... are each conductive foil 1 of the inner potential fixing plate portion 5a.
The outer potential fixing plate portion 5t+o'' each conductive foil +3b overlaps each slit 12 of the inner potential fixing plate portion 5a.
・These conductive foils 13
b is pasted and fixed onto the wound surface of the insulating sheet 15 with double-sided adhesive tape.

In this way, the outer potential fixing plate portion 5b is placed in the same manner on the right.
connects its one end to the connection part 1 of the inner potential fixing plate portion 5a.
4, whereby the inner potential fixing plate portion 5a,
5 b are fixed in potential.

However, the conductive foil 13b at the end of the winding of the outer potential fixing plate portion 5b is not welded to the connection portion 14 and is insulated with an insulating sheet 15 so as not to form a closed circuit. Then, this insulating sheet 15 is wound on the winding surface of the outer potential fixing plate portion 5, and the high voltage side wire ring 6 is electrically connected to the potential fixing plate 5 at its winding start end on this winding surface. and is wound.

In FIG. 1, in the potential fixing plate 5 having the above structure, the conductive foil 13a of the inner potential fixing plate portion 5a overlaps with each slit 12b of the outer potential fixing plate portion 5b.
This slit 12b acts as a back electrode for...
・Average the potential distribution (indicated by the thick line in the figure) of the part,
Electric field concentration at the edge portions e, e of the conductive foil 13b of the outer potential fixing plate portion 5b is suppressed and alleviated.

Incidentally, each of the potential fixing plates 5a, 5b may be made of an insulating sheet 15'' with a plurality of slits 12a, 12b, etc. provided at predetermined intervals and layered by wrapping it twice. good.

<Effects of the Invention> As described above, according to the present invention, the potential fixing plate wound between the winding form and the high-voltage side raceway has a plurality of slits formed at predetermined intervals in the axial direction of the high-voltage side raceway. The potential fixing plate is wound in at least two or more layers with an insulating sheet in between, and in this multilayered state, each conductive foil in the outer layer is placed on each slit in the inner layer. They were arranged so that they overlapped. Therefore, since the conductive foil of the inner potential fixing plate acts as a back electrode for the slit of the potential fixing plate located outside, the electric field concentration on the edge portion of the conductive foil of the outer potential fixing plate is suppressed and alleviated. This action can reliably prevent corona discharge at the location where the potential fixing plate is arranged, and can also reduce eddy currents due to leakage magnetic flux.

[Brief explanation of drawings]

1 to 5 show an embodiment of the present invention, FIG. 1 is an enlarged sectional view showing the main parts of the present invention, FIG. 2 is a partially broken front view of the transformer of this embodiment, and FIG. 3 is an enlarged sectional view showing the main parts thereof, FIG. 4 is a perspective view showing the potential fixing plate, FIG. 5 is a central vertical sectional view thereof, and FIG. 6 is a sectional view of the main parts showing a conventional example. FIG. 7 is an enlarged sectional view of the main part. 4... Winding shape, 5... Potential fixing plate, 6... High voltage side wire ring, 12a, 12b-slit, 13a, 13b...
Conductive foil, 15...insulating sheet.

Claims (1)

[Claims] (1) A transformer in which a potential fixing plate is wound around the outer peripheral surface of a winding, and a high-voltage side wire ring is wound on the winding through the potential fixing plate, and the potential fixing plate has a plurality of It is made of a conductive foil with slits formed at predetermined intervals in the axial direction of the high-voltage side ring, and the potential fixing plate is wound in at least two or more layers with an insulating sheet in between, and in this multilayered state, the inner layer A transformer characterized in that each conductive foil of the outer layer overlaps each slit of the transformer, and the conductive foils of each layer are electrically connected to each other.