JPH04123410A - Transformer - Google Patents

Abstract

PURPOSE:To obtain a transformer which easily allows size adjustment and ensures high voltage resistance through suppression of generation of partial discharge resulting from a fine gap by utilizing an insulator which can be obtained by stacking a synthetic resin material mold and a fiber insulating material laminating a plurality sheets of insulating material. CONSTITUTION:An insulator 10 is formed by stacking a synthetic resin insulating material 11 consisting of a thermosetting resin mold having a low dielectric constant and a fiber insulating material 12 such as a press board or insulating paper under the condition that these are stucked with each other or combined. In the case where size adjustment of an insulator 10 is required for eliminating size allowance between the wirings l and 2, total thickness of insulator 10 can be reduced by peeling the fiber insulating material sheet 12 from the insulator 10 as many as corresponding to the size to be adjusted. Moreover, since thickness of the insulator 10 can be reduced in unit of a sheet of the fiber insulating material, the protruded and recessed areas which generate fine gaps at the surface of insulator 10 can be eliminated and a transformer having a high insulation strength can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a transformer in which the insulation structure of an insulator attached between windings is improved.

(Prior Art) Currently, electrical stations such as substations are often installed underground, and in such cases, nonflammable transformers are required. As such a non-flammable transformer,
The most commonly used transformer is a gas insulated transformer in which the windings are housed in a tank filled with an insulating gas having excellent insulation properties, such as SF6 gas.

FIG. 2 shows an example of such a gas insulated transformer. In the figure, reference numeral 1 indicates a low-voltage winding, and 2 indicates a high-voltage winding, and these windings 1 and 2 are arranged coaxially around the iron core 6. Between the windings 1 and 2, for example, there is an insulating tube 3 for winding the high voltage winding 2, and an insulating tube 4 for reinforcing the insulation of the low voltage winding 1.
are fixed to each winding 1.2, respectively, and an insulator 5 is attached to maintain the gap and insulation between these insulating cylinders 3, 4 and the windings 1, 2.

This insulator 5 is, for example, a columnar one with a square cross section, and also plays the following role.

That is, when manufacturing a transformer, the manufacturing tolerance of the windings 1 and 2 is insulated by inserting the low voltage winding 1 into the iron core 6, then inserting the high voltage winding 2, and then inserting the insulator 5. Thing 5
I try to absorb it.

For example, when the outer diameter of the low voltage winding 1 is large and the inner diameter of the high voltage winding 2 is small, the insulator 5 is made thinner and inserted between the windings,
We are trying to adjust the dimensions.

(Problems to be Solved by the Invention) By the way, the gas insulated transformer using the insulator 5 as described above has the following problems.

As is well known, in a gas insulated transformer, if a minute gap is created between insulators, the electric field will be concentrated in that part, so by eliminating the minute gap, the occurrence of partial discharge is prevented. At the same time, if a synthetic resin material with a low dielectric constant is used as the insulator 5, the concentration of electric field will be reduced accordingly, resulting in a transformer with high insulation strength. Therefore, as the insulator 5, a molded product made of a synthetic resin material has conventionally been generally used.

However, when the above-mentioned dimensional adjustment becomes necessary during transformer assembly work, the insulator 5 made of synthetic resin molding becomes necessary.
However, there is a problem in that the size adjustment function cannot be achieved as it is. In addition, even if the molded product is scraped off with a knife to a predetermined thickness suitable for dimensional adjustment, the cutting process with a knife will inevitably leave unevenness on the surface, which will create minute gaps and cause partial discharge at low voltages. may occur.

Such problems in adjusting the dimensions of the insulator are noticeable in the gas-insulated transformers as described above, but they are also the same in oil-immersed transformers, and improvements have been desired.

The present invention solves the problems of the prior art as described above, and provides a transformer that is easy to adjust dimensions, effectively suppresses the occurrence of partial discharges caused by minute gaps, and has a high withstand voltage. The purpose is to

[Configuration of the Invention (Means for Solving the Problem) In order to achieve the above object, the present invention arranges a plurality of windings coaxially around an iron core, and places an insulator between these windings. The attached transformer is characterized in that the insulator is formed by laminating a molded synthetic resin material and a fibrous insulating material formed by laminating a plurality of sheets of insulating material. .

(Function) In the present invention having the above-mentioned configuration, when it is necessary to adjust the dimensions of the insulator when installing the insulator between the windings, a fibrous insulating material laminated in a sheet form is required. The overall thickness of the insulator can be easily reduced by peeling off the insulator by the same amount. In this case, since the fibrous insulating material can be peeled off in the form of a sheet, the surface of the insulating material can be scraped to a uniform thickness, eliminating unevenness on the surface and suppressing the occurrence of minute gaps. .

(Example) An example of the present invention will be specifically described below with reference to FIG.

FIG. 1 is a partially enlarged perspective view of an insulator 10 used in the transformer of this embodiment. 1
1 and a fibrous insulating material 12 such as pressboard or insulating paper are laminated together or in a combined state. In this case, the fibrous insulation material 12
For example, a stack of a plurality of sheets of fibrous insulating material having a predetermined thickness is used. Further, these insulating materials 11 and 12 are selected so that the dielectric constant of the synthetic resin insulating material 11 is smaller than that of the fibrous insulating material 12.

The insulator 10 of this embodiment thus constructed is attached between the windings 1.degree. 2 in the same manner as the conventional insulator 5 shown in FIG. If dimensional adjustment of the insulator 10 is required to eliminate the dimensional tolerance between the windings 1.2,
By peeling off the laminated sheet-like fibrous insulating material 12 from the surface of the insulator 10 by the number corresponding to the size to be adjusted, the overall thickness of the insulator 10 can be reduced. Since this dimension adjustment work is as simple as peeling off the sheet, work efficiency is significantly improved compared to conventional cutting work using a knife or the like. Further, since the fibrous insulating material 12 is composed of a plurality of sheet-like materials, it is possible to easily adjust the size to be adjusted by simply changing the number of sheets to be peeled off. Furthermore, the insulator 10
Since the surface of the insulating material 10 can be thinned to the same size in units of one sheet, unevenness that causes minute gaps does not occur on the surface of the insulating material 10, and a transformer with high insulation strength can be obtained.

Furthermore, the synthetic resin insulating material 11 generally has a lower dielectric constant and superior insulation strength than the fibrous insulating material 12, but in this example, as shown in the figure, the synthetic resin insulating material 11 has a low dielectric constant. The material 11 is thick and the fibrous insulating material 12 has a high dielectric constant.
Because the insulator is thinner, the dielectric constant is lower than when all the insulators are made of fibrous insulating material, and there is less concentration of electric field even between the windings where there is an insulator, and the insulation strength is excellent. .

[Effects of the Invention] As described above, according to the present invention, a winding wire whose dimensions can be easily adjusted to the dimensional tolerance of the winding wire can be obtained by simply combining a fibrous insulating material made of a laminate and a synthetic resin insulating material. It is possible to provide a high-voltage transformer that is provided with an inter-winding insulator and has a low dielectric constant between the windings, and in which partial discharge due to a minute gap is effectively suppressed.

[Brief explanation of drawings]

FIG. 1 is a partially enlarged perspective view of an insulator used in the transformer of the present invention, and FIG. 2 is a sectional view showing the windings and insulator portion of a conventional transformer. ■...Low voltage winding, 2...High voltage winding, 3, 4...Insulating tube, 5...Conventional insulator, 6...Iron core, 10...
- Insulators used in the transformer of the present invention, 11... synthetic resin insulating material, 12... fibrous insulating material consisting of a laminate.

Claims (1)

[Claims] A transformer in which a plurality of windings are arranged coaxially around an iron core, and an insulator is attached between these windings, wherein the insulator is formed of a molded product of a synthetic resin material and a plurality of windings. A transformer characterized by using a fibrous insulating material formed by laminating sheets of insulating material.