JPH0576018U - Sheet winding transformer - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a sheet winding transformer with high insulation reliability, which allows the sheet winding to be adopted for higher voltage windings. A cross-section of a winding support piece 11 for axially tightening and supporting a sheet winding formed by stacking and winding a metal sheet and an insulating sheet has a shape in which hollow pipes are assembled.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a winding support structure for a sheet winding transformer.

[0002]

[Prior Art]

 In the sheet winding transformer, the mechanical force in the axial direction at the time of short circuit is smaller than that of the disk winding, so the winding support structure can be simplified. In addition, since the sheet winding has sharp edges at the winding edges, it is necessary to install an electrostatic shield ring for relaxing the electric field. Since the δ gap is generated, which is a weak point of insulation, it is advisable to adopt a structure in which the electrostatic shield is not directly supported by the support piece.

In a conventional sheet winding transformer, as shown in FIG. 4, a low voltage winding 3 is wound around an outer circumference of an iron core 1 via an insulating cylinder 2, and a high voltage winding 3 is wound on the outside thereof via a main insulation 4. 5 is wound. Electrostatic shield rings 6 are provided at the upper and lower ends of the outer periphery of the low voltage winding 3, and electrostatic shield rings 7 are provided at the upper and lower ends of the inner periphery of the high voltage winding 5. Duct pieces 8 for winding tightening support are arranged above and below the low-voltage winding, and duct pieces 9 for winding tightening support are arranged above and below the high-voltage winding 5, respectively. The upper and lower parts of the duct pieces 8 and 9 are fastened via a winding support piece 12. The electrostatic shield rings 6 and 7 are arranged in the notch portion 13 provided in the winding support piece 12 so that the winding support pieces 12 and the electrostatic shield rings 6 and 7 do not come into direct contact with each other. The electrostatic shield rings 6 and 7 are fixed to the duct pieces 8 and 9 by an appropriate method.

[0004]

[Problems to be solved by the device]

 However, in such a conventional sheet winding transformer, the duct pieces 8 and 9 and the winding supporting piece 12 are made of an insulating material. The winding support piece 12 is typically machined from a solid insulation material. When the winding support piece 12 is made of a bare insulating material, the electric field in the vicinity of the electrostatic shield rings 6 and 7 is significantly higher than that in the portion without the winding support piece 12, and the insulation strength is reduced. This is because the relative permittivity of the insulating medium in the insulating space near the electrostatic shield rings 6 and 7 (insulating oil is about 2.3, gas is about 1.0) is that of the winding support piece (3.5 to This is because the electric field concentrates on the side of the insulating medium having a small relative permittivity. In order to avoid this, a method of separately supporting the high voltage and low voltage windings can be considered, but the stability of the support is unsatisfactory. If the winding support piece 12 is made large in order to obtain stability, the influence of electric field concentration on the electrostatic shield rings 6 and 7 becomes large.

The present invention has been made in view of the above points, and an object of the present invention is to provide a transformer with high insulation reliability, which can adopt a sheet winding for a higher voltage winding. And

[0006]

[Means for Solving the Problems]

 The winding support structure of the sheet winding transformer of the present invention is characterized in that the cross section of the winding support piece has a shape in which hollow pipes are assembled.

[0007]

[Action]

 Since the cross section of the winding support piece is a collection of hollow pipes, the relative permittivity of the winding support piece is small and is close to that of the insulating space. Is lower and the insulation strength is improved.

[0008]

【Example】

 An embodiment of the sheet winding transformer of the present invention will be described below with reference to FIG. In FIG. 1, a low-voltage winding 3 is wound around an outer periphery of an iron core 1 via an insulating cylinder 2, and a high-voltage winding 5 is wound outside the iron core 1 via a main insulation 4. Electrostatic shield rings 6 are provided at the upper and lower ends of the outer periphery of the low voltage winding 3, and electrostatic shield rings 7 are provided at the upper and lower ends of the inner periphery of the high voltage winding 5. Duct pieces 8 for winding tightening support are arranged above and below the low-voltage winding 3, and duct pieces 9 for winding tightening support are arranged above and below the high-voltage winding 5, respectively. The upper and lower parts of the supporting duct pieces 8 and 9 are fastened via a winding supporting piece 10. The electrostatic shield rings 6 and 7 are arranged in the notch 11 provided in the winding support piece 10 so that the winding support piece 10 and the electrostatic shield rings 6 and 7 do not come into direct contact with each other. The electrostatic shield rings 6 and 7 are fixed to the duct pieces 8 and 9 by a suitable method.

As shown in FIG. 2, the winding support piece 10 is U-shaped, and has a hollow cross section in the shape of a collection of pipes. 3A and 3B are cross-sectional views taken along the line AA in FIG. 2. FIG. 3A shows the case where the circular pipes are assembled, and FIG. 3B is the assembly of polygonal pipes. An example of the cross section is shown.

As a result, the equivalent relative permittivity of the entire winding support piece is close to the relative permittivity of the insulating medium. Since it is a sheet winding, the mechanical force in the axial direction at the time of short circuit is small, and therefore even such a hollow winding can support the winding without any problem.

[0011]

[Effect of the device]

 As described above, by using a hollow winding supporting piece, the equivalent relative permittivity of the supporting piece can be made closer to the relative permittivity of the insulating medium. The rise of the electric field can be suppressed low. As a result, the winding can be supported by a small-sized winding supporting piece, and the sheet winding can be used for higher voltage winding, and the reliability is improved.

[Brief description of drawings]

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

FIG. 2 is a perspective view of a winding support piece of an embodiment of the sheet winding transformer of the present invention.

FIG. 3 is a sectional view of a winding support piece of an embodiment of the sheet winding transformer of the present invention.

FIG. 4 is a cross-sectional view of essential parts showing a conventional sheet winding transformer.

[Explanation of symbols]

 1 ... Iron core 2 ... Insulation cylinder 3 ... Low voltage winding 4 ... Main insulation 5 ... High voltage winding 6, 7 ... Electrostatic shield ring 8, 9 ... Duct piece 10 ... Winding support piece 11 ... Notch

Claims (1)

[Scope of utility model registration request] 1. A sheet winding transformer formed by stacking and winding a metal sheet and an insulating sheet, the winding supporting piece for axially tightening and supporting the winding having a cross-section of a hollow pipe. A sheet winding transformer characterized in that