JP2567811Y2 - Sheet winding transformer - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an electrostatic shield for alleviating an electric field at a winding end of a sheet winding transformer.

[0002]

2. Description of the Related Art In winding of a transformer, a sheet winding in which a metal sheet and an insulating sheet are superposed and wound is a promising winding method for automating the winding operation. Due to the small curvature, high voltage windings require an electrostatic shield to reduce the electric field at the end of the winding.

As shown in FIG. 3, a conventional sheet winding transformer has a low voltage winding 1 on an outer periphery of an iron core leg 11 through an insulating tube 12.
3 is wound, and a high-voltage winding 15 is wound around the outside thereof via a main insulation 14. The sheet winding is such that a metal sheet and an insulating sheet wider than this metal sheet are overlapped, and the width of the insulating sheet is equal to the width of the insulating sheet with the insulating filler and the metal sheet disposed on both sides of the metal sheet. (Not shown). The high-voltage winding 15 is wound with a cooling duct 17 arranged between a plurality of sheet winding blocks 16.

The upper and lower portions of the low-voltage winding 13 are supported by spacers 18, and an electrostatic shield 19 for alleviating an electric field is provided at the upper and lower ends of the outer periphery of the low-voltage winding 13. High voltage winding 15
The upper and lower sides are supported by spacers 20, and the upper and lower ends of the inner and outer peripheries of the high voltage winding 15 are provided with electrostatic shields 2 for electric field relaxation.
1 and 22 are provided and supported by supports 23 and 24, respectively. Further, the entire winding is supported by the spacer 25.

[0005]

However, in such a conventional sheet-winding transformer, a support member is used for fixing the electrostatic shield. However, between the electrostatic shield and the insulating ring serving as the support member. When a triangular δ gap is formed in the above, an electric field concentrates on that portion, which is a weak point on insulation. Therefore, it is necessary to reduce the thickness of the support material in order to prevent the triangular δ gap from being generated, and the support structure itself of the electrostatic shield becomes unstable. In order to improve this, a method of integrating the electrostatic shield and the support material has been considered.

FIG. 4 shows a conventional polster isolation type structure having such an integrated structure. In FIG.
Electrostatic shield body 26 and insulating ring 27 also serving as support material
The electrostatic shield main body 26 is disposed on the winding side of the insulating ring 27, and the end of the electrostatic shield main body 26 on the insulating ring 27 side has a required curvature. Then, in order to eliminate a gap at a joint between the insulating ring 27 and the electrostatic shield main body 26, the insulating ring 27 is filled with an insulating padding 28,
An insulating tape 29 is wound around both of them to insulate them. However, this gap cannot be completely crushed by the padding, so that a large increase in insulation strength cannot be expected.
Particularly, in gas insulation, since the gap length effect (the insulation strength is improved when the gap length is shortened) is small, there is almost no increase in the insulation strength by the polster isolation method.

The present invention has been made in view of the above points, and the gap between the insulating ring serving as a support member and the electrostatic shield main body is completely formed by applying a conductive paint or winding a semiconductive tape. An object of the present invention is to provide a compact sheet winding transformer having high insulation strength by filling and reducing electric field concentration on an electrostatic shield.

[0008]

In the sheet winding transformer of the present invention, the electrostatic shield main body is embedded in the groove of the insulating ring which is a support member of the electrostatic shield, and the groove of the electrostatic shield main body and the insulating ring is provided. Is filled with a conductive paint or wound with a semiconductive tape, and the outer periphery is insulated and taped to form an electrostatic shield.

[0009]

The sheet winding transformer of the present invention is constructed as described above, so that the electric field concentration on the electrostatic shield is reduced and the insulation strength is strengthened, so that the sheet winding is compact and has high insulation reliability. Become a transformer.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to one embodiment shown in FIGS.

In FIG. 1, portions corresponding to those of the conventional example shown in FIG. 3 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 1 is a sectional view of an embodiment of the present invention, and FIG.
Similarly to the above, at the upper and lower ends of the inner and outer peripheries of the high-voltage winding 15, the electrostatic shield 1 is provided to reduce the electric field concentration at this portion.
The present invention relates to the improvement of the electrostatic shield, and will be described in detail with reference to FIG.

FIG. 2A is a sectional view of an electrostatic shield according to an embodiment of the present invention, and FIG. 2B is a detailed explanatory view thereof. In these figures, an electrostatic shield 1 has an electrostatic shield main body 3 arranged on a winding side of an insulating ring 2,
The end of the electrostatic shield main body 3 on the insulating ring 2 side is formed with a required curvature. Then, a conductive paint 4 is applied to a gap between the insulating ring 2 and the electrostatic shield main body 3,
The whole is taped by an insulating tape 5. Note that, instead of applying the conductive paint 4, the semiconductive tape 6 is used.
May be filled. As shown in FIG. 2 (B), as shown in FIG. 2 (B), a conductive paint 4 is applied to the inner surface of the groove 7 on the insulating ring 2 and the conductive paint 4 is applied to the electrostatic shield body 3 or a semiconductive tape. 6, the electrostatic shield body 3 is embedded in the groove 7 of the insulating ring 2, and the whole is insulated with an insulating tape to form the electrostatic shield 1.

[0014]

As described above, in the sheet winding transformer of the present invention, (1) the electrostatic shield can be supported by a stable structure.

(2) The insulation strength can be improved by the electric field relaxation effect of the polster isolation system.

(3) The sheet winding can be applied to a high-voltage winding.

(4) A compact and highly reliable sheet winding can be formed.

Excellent effects can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a sheet winding transformer of the present invention.

FIG. 2 is a sectional view showing an embodiment of the electrostatic shield of the sheet winding transformer of the present invention.

FIG. 3 is an essential part cross-sectional view showing a winding part of the sheet winding transformer.

FIG. 4 is a longitudinal sectional view of a conventional electrostatic shield.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electrostatic shield 2 ... Insulation ring 3 ... Electrostatic shield main body 4 ... Conductive paint 5 ... Insulating tape 6 ... Semiconductive tape 7 ... Groove

Claims (1)

(57) [Scope of request for utility model registration] 1. A sheet winding transformer comprising a metal sheet and an insulating sheet stacked and wound on each other and an electrostatic shield disposed at an end of the winding, wherein a static electricity is inserted into a groove of an insulating ring which is a support member of the electrostatic shield. An electrostatic shield in which the electrostatic shield body is embedded and the gap between the electrostatic shield body and the groove of the insulating ring is filled with a conductive paint or semiconductive tape, and the outer periphery is insulated integrally with the electrostatic shield body and the insulating ring. A sheet winding transformer comprising: