JPH0576022U - Sheet winding transformer - Google Patents

Abstract

(57) [Abstract] [Purpose] Relaxing the electric field concentration on the electrostatic shield by coating the gap between the insulating ring, which is the support material, and the electrostatic shield body with conductive paint or completely filling it with semi-conductive tape. In addition, a compact sheet winding transformer with high insulation strength is provided. In a sheet winding transformer in which a metal sheet and an insulating sheet are superposed and wound, and an electrostatic shield is arranged at a winding end, the electrostatic shield body 3 is embedded in a groove 7 of an insulating ring 2. 3 and the groove 7 of the insulating ring 2 are filled with the conductive paint 4 or the winding of the semi-conductive tape 6, and the electrostatic shield body 3 and the insulating ring 2 are filled.
A sheet-wound transformer having an electrostatic shield 1 in which the outer periphery is insulated as a single body.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a structure of an electrostatic shield for mitigating an electric field at a winding end portion of a sheet winding transformer.

[0002]

[Prior Art]

 In the winding of a transformer, a sheet winding in which a metal sheet and an insulating sheet are stacked and wound is a promising winding method for automating the winding work, but since the winding end has a small curvature, For high voltage windings, it is necessary to place an electrostatic shield for electric field relaxation at the end of the winding.

In a conventional sheet winding transformer, as shown in FIG. 3, a low voltage winding 13 is wound around an outer circumference of an iron core leg 11 via an insulating cylinder 12, and a high voltage is applied outside the low winding 13 via a main insulation 14. A winding wire 15 is wound. The sheet winding is formed by stacking a metal sheet and an insulating sheet wider than the metal sheet, and the insulating fillers arranged on both sides of the metal sheet and the metal sheet are equal in width to the insulating sheet. It is then wound (not shown). The high-voltage winding 15 is wound by arranging a cooling duct 17 between a plurality of sheet winding blocks 16.

Upper and lower sides of the low voltage winding 13 are supported by spacers 18, and electrostatic shields 19 for relaxing an electric field are arranged at upper and lower ends of the outer periphery of the low voltage winding 13. The upper and lower sides of the high voltage winding 15 are supported by spacers 20, and electrostatic shields 21 and 22 for mitigating the electric field are provided at the upper and lower ends of the inner and outer circumferences of the high voltage winding 15, respectively. Supported by 24. Further, the entire winding is supported by the spacer 25.

[0005]

[Problems to be solved by the device]

 However, in such a conventional sheet winding transformer, a support material is used to fix the electrostatic shield, but if a triangular δ gap occurs between the electrostatic shield and the insulating ring that is the support material. Since the electric field concentrates on that portion, it becomes a weak point in insulation. Therefore, the support structure itself of the electrostatic shield becomes unstable because it is necessary to reduce the thickness of the support material in order to prevent the triangular δ gap from occurring. In order to improve this, a method of integrating the electrostatic shield and the support material is considered.

FIG. 4 shows a structure of a conventional Polster isolathione system having such an integrated structure. In FIG. 4, the electrostatic shield main body 26 and the insulating ring 27 also serving as a supporting member are overlapped, and the electrostatic shield main body 26 is arranged on the winding side of the insulating ring 27. The side end is formed to have a required curvature. Then, in order to eliminate the gap at the joint between the insulating ring 27 and the electrostatic shield main body 26, a filling 28 made of an insulating material is filled, and an insulating tape 29 is wrapped around the both to insulate. However, since the gap cannot be completely collapsed with the padding, a large increase in insulation strength cannot be expected. In particular, gas insulation has little gap length effect (insulation strength improves as gap length decreases), so there is almost no increase in insulation strength due to the Polster isolatione method.

The present invention has been made in view of the above points, and the gap between the insulating ring, which is a supporting material, and the electrostatic shield body is more completely filled by applying a conductive paint or winding a semiconductive tape. The purpose of the present invention is to provide a compact sheet-winding transformer with high insulation strength by relieving the concentration of electric field on the electrostatic shield by filling it in.

[0008]

[Means for Solving the Problems]

 In the sheet winding transformer of the present invention, the body of the electrostatic shield is embedded in the groove of the insulating ring, which is a supporting member of the electrostatic shield, and the gap between the body of the electrostatic shield and the groove of the insulating ring is made of conductive paint. It is characterized in that it is filled with coating or winding of semi-conductive tape, and the outer circumference is insulated and taped to form an electrostatic shield.

[0009]

[Action]

 Since the sheet winding transformer of the present invention is configured as described above, the electric field concentration on the electrostatic shield is alleviated and the insulation strength is enhanced, so that the sheet winding transformer is compact and has high insulation reliability. Becomes

[0010]

【Example】

 Hereinafter, the present invention will be described based on an embodiment shown in FIGS. 1 and 2.

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

FIG. 1 is a cross-sectional view of an embodiment of the present invention. Similar to FIG. 3, electrostatic shields 1 are provided at the upper and lower ends of the inner and outer circumferences of the high voltage winding 15 to reduce electric field concentration in this part. is doing. This proposal relates to the improvement of the electrostatic shield part, which will be described in detail with reference to FIG.

FIG. 2A is a sectional view of an electrostatic shield portion according to an embodiment of the present invention, and FIG. 2B is a detailed explanatory view thereof. In these figures, the electrostatic shield 1 has an electrostatic shield body 3 arranged on the winding side of an insulating ring 2, and the end portion of the electrostatic shield body 3 on the side of the insulating ring 2 is formed to have a required curvature. Has been done. A conductive paint 4 is applied to the gap between the insulating ring 2 and the electrostatic shield body 3, and the whole is taped with an insulating tape 5. Instead of applying the conductive paint 4, the semiconductive tape 6 may be wound and filled. As shown in FIG. 2B, as shown in FIG. 2B, the insulating ring 2 is coated with the conductive paint 4 on the inner surface of the groove 7 and the electrostatic shield body 3 is coated with the conductive paint 4 or a semi-conductive tape. 6 is wound, 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]

[Effect of the device]

 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 by the Polster isolathione method.

(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 such as the above can be obtained.

[Brief description of 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 electrostatic shield embodiment of the sheet winding transformer of the present invention.

FIG. 3 is a cross-sectional view of a main portion showing a winding portion of a sheet winding transformer.

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

[Explanation of symbols]

 1 ... Electrostatic shield 2 ... Insulation ring 3 ... Electrostatic shield main body 4 ... Conductive paint 5 ... Insulating tape 6 ... Semi-conductive tape 7 ... Groove

Claims (1)

[Scope of utility model registration request] 1. A sheet winding transformer comprising a metal sheet and an insulating sheet which are superposed and wound, and an electrostatic shield is disposed at a winding end portion of the sheet winding transformer. Electrostatic shield formed by embedding the electric shield body and filling the gap between the electrostatic shield body and the groove of the insulating ring with conductive paint or semiconductive tape to insulate the outer periphery by integrally forming the electrostatic shield body and the insulating ring. A sheet winding transformer characterized by having.