JPH0644537B2 - Foil winding transformer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention has a foil wound transformer having a foil winding formed by winding a metal sheet and an insulating sheet around each other around an iron core. Involved in
Particularly, it relates to a structure for supporting a winding.

(Prior Art) A foil winding transformer has a higher winding space factor and a lighter weight compared to a transformer using a normal rectangular wire. Is being developed.

A conventional foil wound transformer is shown in FIG. In the foil winding transformer shown in FIG. 3, the metal sheet 2 and the insulating sheet 3 are wound around the iron core 1 around the insulating cylinders 4 and 4 arranged around the iron core 1 so as to form a high voltage and a low voltage. The windings 5 and 7 are configured. The weights of the windings 5 and 7 have significantly increased as the voltage and capacity of the foil winding transformer have increased. As a result, the windings 5 and 7 cannot be fully supported only by the winding tightening force applied to the insulating cylinders 4 and 4, and the windings may be distorted and dropped. 11 and the magnetic shield 15 and the tank 6 are insulated and supported. The supporting insulators 10 and 12 have a block shape, and are divided into substantially equal parts on the circumference, and a plurality of them are arranged. Further, as the material for the supporting insulators 10 and 12, epoxy cast products are often used because of problems in mechanical strength.

In the foil winding transformer as described above, since the windings 5 and 7 are formed by stacking the thin metal sheet 2 and the insulating sheet 3, the winding space factor in the iron core window increases, but There are drawbacks.

That is, for example, in the foil winding transformer of FIG. 3, the windings 5 and 7 wound around the insulating cylinders 4 and 4 are the same as the insulating cylinders 4 and 4.
Are supported by supporting insulators 10 and 12 arranged on the outer circumferences of, respectively. Here, the respective support insulators 10 and 12 are
The inner circumference must be formed with high precision so as to contact the outer circumference of each insulating cylinder 4, and the supporting insulators 10 and 12 have different sizes, which complicates the manufacturing process and increases the cost. . Furthermore, when a gap is created between the insulating cylinders 4 and 4 and the supporting insulators 10 and 12, the metal sheet 2 and the insulating sheet 3 at this portion do not support each other. Will fall and become so-called bamboo shoots, leading to a decrease in reliability.

For such a problem, a foil wound transformer as shown in FIG. 4 has been proposed. In the foil winding transformer of FIG. 4, the insulating cylinders 4, 4 are cut off at the lower end surfaces of the windings 5, 7,
4 and both windings 5 and 7 are collectively supported by a common support insulator 13.

However, in the case of the configuration shown in FIG. 4, since the shape of the supporting insulator 13 that collectively supports both the windings 5 and 7 is too large, it is difficult to manufacture and handle it.
The cost is also high. In addition, the dielectric constant of the gas in the gap between the windings 5 and 7 is 1, whereas the dielectric constant of the supporting insulator 13 is about 3. Therefore, the end portion 16 of the metal sheet 2 is different due to the difference in the dielectric constant. There is also a problem that electric field concentration occurs in the device and the breakdown voltage becomes low. Furthermore, there is a possibility that creeping damage may occur at the creeping surface 17 of the supporting insulator corresponding to the gap length between the windings 5 and 7, which also causes a problem in insulation reliability.

Further, a foil wound transformer as shown in FIG. 5 has been proposed for the problem of the foil wound transformer shown in FIG. In the foil wound transformer of FIG. 5, the insulating cylinders 4 and 4 are cut off at the lower end surfaces of the windings 5 and 7, while the windings 5 and 7 are individually supported together with the insulating cylinders 4 and 4, respectively. It is a structure supported by 19.

However, in the configuration of FIG.
8 and 19 are individually supported by the magnetic shield 15, the supporting insulators 18 and 1 are
9 is displaced from the windings 5 and 7, and like the foil winding transformer of FIG.
The windings 5 and 7 may fall.

(Problems to be Solved by the Invention) As described above, in the conventional foil winding transformer, the winding cannot be reliably supported by the supporting insulator, causing the winding to drop or causing the supporting insulator. As a result, there has been a problem that the insulation reliability is lowered, or that the supporting insulator becomes too large, which makes manufacturing and handling difficult.

The present invention has been proposed in order to solve the drawbacks of the prior art, and its object is to improve the structure of a supporting insulator in a high voltage, large capacity foil wound transformer. Can reliably support the winding, has high insulation reliability,
It is to provide an excellent foil wound transformer that is easy to manufacture and handle.

[Structure of the Invention] (Means for Solving the Problems) The foil winding transformer according to the present invention includes, as a support insulator, an individual support insulator for supporting individual windings, and the individual support insulator. And a common support insulator supporting a plurality of windings are provided in an overlapping manner so that the width of the individual support insulator is larger than the width of the corresponding winding, and the winding is provided between the adjacent individual support insulators. The structure is characterized in that a gap is provided at a position corresponding to substantially the center of the gap between them.

(Operation) In the present invention having the above-described configuration, since the supporting insulator is larger than the width of each winding, there is no fear of the winding falling. In addition, the creepage distance between the windings is the total of the gap length between the individual support insulators and the height dimension of the gap, that is, twice the thickness of the individual support insulators. Will not occur. Therefore, insulation reliability can be improved.

Furthermore, since the individual support insulator and the common support insulator are used together, the size of the single support insulator can be reduced, and the manufacturing,
Easy handling.

(Embodiment) An embodiment of the present invention as described above will be specifically described with reference to the drawings. The same parts as those in the prior art shown in FIGS. 3 to 5 are designated by the same reference numerals and the description thereof will be omitted.

First Embodiment ... FIG. 1 In the embodiment of FIG. 1, on the magnetic shield 15,
A common support insulator 21 that collectively supports the windings 5 and 7 is fixed. On the common support insulator 21, individual support insulators 22 and 23 that support the windings 5 and 7 and have a width larger than the width of the windings 5 and 7 are arranged. It is fixed to 21. A gap is provided between the individual support insulators 22 and 23 at a position approximately corresponding to the center of the gap between the windings. The gap length g between the individual support insulators is the gap length between the windings. Is defined as d, where d / 10 <g.

The operation and effect of this embodiment having the above configuration are as follows.

First, since the individual support insulators 22 and 23 having a width larger than the widths of the windings 5 and 7 are fixed on the common support insulator 21 with an adhesive or the like, the windings 5 and 7 are completely width-wise. Can be supported by. Therefore, as compared with the prior art in which the windings 5 and 7 may fall, a highly reliable winding support structure can be obtained.

Further, since the gap having the gap length g is provided between the individual support insulators 22 and 23, the individual support insulators 22 and
The creepage distance of 23 is a long distance obtained by adding the gap length g to the gap height, that is, twice the thickness of the individual support insulators 22 and 23. This creepage distance is the same as the common supporting insulator 1.
Since the creepage distance in the conventional foil wound transformer using only 3 (Fig. 4) is only as short as the gap length between the windings, the breakdown voltage can be increased because it is significantly long.

Furthermore, in this embodiment, since the individual supporting insulators 22 and 23 and the common supporting insulator 21 are used together, the conventional foil winding transformer (FIG. 4) using only the common supporting insulator 13 is used. In comparison, the size of each supporting insulator is small, which facilitates manufacturing and handling.

The reason for limiting the range of the gap length g between the individual support insulators in this embodiment is as follows. That is, when the gap length g is zero, as described above as a problem of the prior art, a creeping stress on the surface of the insulator causes a dielectric breakdown between the windings 5 and 7. On the other hand, the gap length g is g <d / 1
In the range of 0, as is well known, the dielectric constant of the insulator is equal to or higher than the dielectric constant (1.0) of the gas in the gap. For example, in the case of epoxy, the dielectric constant is about 6. As is well known, the concentration of an electric field increases in inverse proportion to the dielectric constant. Therefore, for example, when epoxy is used as a supporting insulator, the average stress between the individual supporting insulators is 6 times the average stress. The above electric field is applied. Therefore, if the gap length is too small, electric field concentration occurs in the gap, and by providing the gap, there is a case where the breakdown occurs at a voltage lower than the creepage breakdown. The range in which such breakdown occurs depends on the type of the insulator or gas, but in the research of the inventor, it was found that the above gap breakdown occurred in the range of g <d / 10. is doing. For the above reason, the gap length g between the individual supporting insulators is g>
d / 10 is appropriate.

Second Embodiment ... FIG. 2 In the embodiment shown in FIG. 2, block-shaped support insulators 25 are fixed to both sides of the common support insulator 24 in the height direction by an adhesive or the like. That is, in this embodiment, the individual supporting insulator is divided into two in the height direction,
The common support insulator is sandwiched between them.

In the present embodiment having the above-mentioned structure, the individual support insulator is made into a block, so that it can be used as a standard part, and the manufacture and handling are facilitated. That is, by changing only the height direction, it can be used for a foil wound transformer of various standards.

[Effects of the Invention] As described above, according to the present invention, the conventional structure is not possible due to the improvement of the simple structure in which the individual supporting insulator and the common supporting insulator are used as the supporting insulator of the winding. It is possible to provide an excellent foil wound transformer that enables reliable support of existing windings, improves insulation reliability, and is easy to manufacture and handle.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of a foil winding transformer according to the present invention, FIG. 2 is a sectional view showing a second embodiment of a foil winding transformer according to the present invention, and FIGS. It is sectional drawing which shows the respectively different conventional foil winding transformer. 1 ... Iron core, 2 ... Metal sheet, 3 ... Insulation sheet, 4
...... Insulation cylinder, 5,7 ...... Winding, 6 …… Tank, 10,1
2, 13, 18, 19 ... Supporting insulator, 11 ... Yoke iron core, 13 ... Common supporting insulator, 15 ... Magnetic shield, 16 ... Edge of metal sheet, 17 ... Supporting insulator Creeping. 21, 24 ... Common supporting insulator, 22, 23 ... Individual supporting insulator, 25 ... Block-like supporting insulator.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hitoshi Okubo 2-1, Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Inside the Hamakawasaki Plant, Toshiba Corporation (56) Reference JP-A-60-261118 (JP, A) Kaisho 59-197114 (JP, A)

Claims (3)

[Claims] 1. A plurality of foil-shaped windings formed by stacking and winding a metal sheet and an insulating sheet are wound around an iron core, gaps are provided between the windings, and each winding is provided with a supporting insulator. In the foil winding transformer supported in a tank by means of the above, as the supporting insulators, individual supporting insulators individually arranged to support the individual windings and a plurality of individual supporting insulators are provided through the individual supporting insulators. A common support insulator that supports the windings is provided in an overlapping manner, and the individual support insulators have a width larger than the width of the corresponding windings, and between adjacent individual support insulators, there is a space between the windings. A foil wound transformer characterized in that a gap is provided at a position corresponding to substantially the center of the gap. 2. The gap length g of the individual support insulator is dimensioned to have a relationship of d / 10 <g, where d is the gap length between the windings. Foil winding transformer as described. 3. A foil winding transformer according to claim 1, wherein the individual supporting insulator is divided into two in the height direction of the winding, and a common supporting insulator is provided between them.