JPH10340818A - Winding for induction electrical appliance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the series capacitance of a winding for an induction electrical appliance formed by piling up coil blocks in several stages without reducing the space factor of the winding so as to improve the surge voltage characteristic of the electrical appliance, by forming a conductive coating film on the surface of an insulating coating covering each coil conductor in each coil block of the winding. SOLUTION: Conductive coating layers 3 and 13 are formed around the insulating coating layers 2 of coil conductors 1 and 11 constituting each coil block 4 of a discoid winding, and adjacent conductive coating layers 3 and 13 are electrically brought into contact with each other. When the coating layers 3 and 13 are constituted in such a way, the capacitance, namely the so-called interlayer capacitance between the adjacent coil conductors 11 and the whole electrostatic coupling in the same coil because larger, because the equivalent facing areas in the electrostatic capacity between the coil conductors 1 and 11 increase and separated conductors are also electrostatically coupled with each other. In addition, the series capacitance of the windings and the surge voltage characteristics of a transformer can improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction winding and, more particularly, to a highly reliable transformer winding having improved shock voltage characteristics used for electric power.

[0002]

2. Description of the Related Art As an important characteristic related to the reliability of a power transformer, there is a shock voltage characteristic against a surge such as lightning. This is the transient characteristic inside the transformer when a surge voltage containing high-frequency components enters, so-called potential oscillation characteristic. If this characteristic is bad, an overvoltage will occur inside the transformer, and in some cases, it will be destroyed. There is also. As a method for improving the potential oscillation characteristics of a transformer, it is common to increase the series capacitance of the winding by changing the winding structure of the winding, and an interleaved winding or a winding including a shield conductor is used. Often used.

[0003] An interleaved winding is formed by bundling and winding two conductors and electrostatically coupling the separated turns.
This increases the series capacitance of the windings and has the advantage of a high space factor. However, if the number of turns per coil is small, the effect is low, and it is difficult to adjust the amount of increase in the series capacitance. There are drawbacks, such as the inability to convert the product.

On the other hand, as shown in FIG. 6, a shield conductor 5 wound between the coil conductors 1 and 11 and a shield conductor 25 at another position are separated by a shield conductor connection line 6 into a unit located at a distance from the unit. The method of equivalently increasing the series capacitance of each coil by electrostatically coupling the coils 4 and 24 can provide a high effect even with a small number of turns, and optimize the potential oscillation characteristics by adjusting the number of times the shield is wound. There is an advantage that conversion can be achieved. However, there is a problem that the space factor is reduced by the presence of the shield conductor.

In this method, since the electrostatic coupling between the coil conductor and the shield conductor is important, when a coil conductor having a non-flat contact surface with another conductor such as a dislocation wire is used as shown in FIG. 7, for example. According to the method, the transposition of the transposed electric wire element conductor 7 weakens the electrostatic coupling between the transposed electric wire element conductor 7 and the shield conductor 5, and the effect may be reduced. Incidentally, as a method of improving the shock voltage characteristics by using this kind of shield conductor, for example, Japanese Patent Application Laid-Open
No. 9-9622.

[0006]

The prior art using the above-mentioned shield conductor is an effective means for improving the shock voltage characteristic and improving the reliability of the transformer, but on the other hand, it causes a decrease in the space factor. This has been one of the problems in reducing the size and weight of the transformer. Further, when a dislocated electric wire is used to reduce the loss, the electrostatic coupling between the coil conductor and the shield conductor is reduced. Therefore, in some cases, the number of turns of the shield needs to be increased, and the space factor may be further reduced.

SUMMARY OF THE INVENTION An object of the present invention is to increase the series capacitance of a winding without lowering the space factor and improve the shock voltage characteristics, thereby making it possible to reduce the size and weight of a transformer. It is to provide an induction appliance.

[0008]

In order to achieve the above object, a first aspect of the present invention is to provide a winding comprising a coil conductor and an insulating coating layer covering the surface of the coil conductor, and forming the winding on the outer periphery of the iron core. And a plurality of coil blocks arranged on the inner peripheral side, wherein the coil block is stacked in a plurality of stages, wherein the conductive coating is applied to an insulating coating surface covering each coil conductor surface in the coil block. It has been provided.

According to a second aspect of the present invention, there is provided a winding comprising a coil conductor and an insulating coating layer covering the surface of the coil conductor, and a coil block having a plurality of windings arranged from the outer periphery to the inner periphery of the core. An induction winding wound by stacking coil blocks in a plurality of stages and cooling the plurality of coil blocks by circulating an insulating refrigerant, wherein the insulating coating surface covers each coil conductor surface in the plurality of coil blocks. The conductive coating is provided by exposing a part of the insulating coating, and the exposed insulating coating layer is disposed downstream of the insulating refrigerant.

[0010] The third aspect of the present invention is to dispose the coil block having the conductive coating and the exposed insulating coating layer exposed on a part of the conductive coating in correspondence with each other. The present invention is to arrange the coating and the exposed insulating coating layer of the other coil block correspondingly.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a transformer winding according to the present invention will be described below with reference to FIGS.

FIG. 1 shows a part of a disk winding extracted and a simplified cross section thereof. In FIG. 1, the coil conductor 1 is continuously wound, and the wound structure itself is the same as a basic disc winding without taking measures to improve the impact voltage characteristics. FIG. 2 schematically shows a structure of one of the coil conductors shown in FIG.

That is, as shown in FIG. 1, in this embodiment, each of the coil conductors 1,
Conductive coatings 3 and 13 are provided around the 11 insulating coating layers 2, and the adjacent conductive coatings 3 and 13 are electrically contacted with each other. With such a configuration, the equivalent opposing area in the electrostatic coupling between the adjacent coil conductors is increased, and further, the distant coil conductors are also electrostatically coupled. 11, so-called inter-turn capacitance, and the overall electrostatic coupling within the same coil increases.

The series capacitance of the disc winding is mainly determined by the combination of the inter-turn capacitance and the inter-coil capacitance between the coil lock 4 and the coil lock 14 with the insulating refrigerant 10 interposed therebetween. As it is determined, the series capacitance of the winding is increased without lowering the space factor as when a shield conductor is involved, and without connecting the shield conductors, improving the shock voltage characteristics of the transformer. Can be done.

The way of increasing the inter-turn capacitance depends on the cross-sectional shape of the coil conductor 1. For example, in the case of a square coil conductor, the equivalent facing area in the electrostatic coupling between adjacent coil conductors is about 4 Double. The manner in which the equivalent series capacitance of the winding increases due to the increase in the inter-turn capacitance depends on the number of turns of the coil, but increases to about 1.5 times for about 5 or 6 turns. Actually, not only the capacitance between turns but also the total electrostatic coupling in the same coil increases, so that the equivalent series capacitance of the winding can be further increased. In addition, when a material having a high dielectric constant is used for the insulating coating layer 2 of the coil conductor, a larger series capacitance can be obtained.

Further, even when there is unevenness in the surface facing the adjacent coil conductor as in the case of using a displaced electric wire, the equivalent opposing area between the coil conductors can be made large, so that the same coil as in the case of using the rectangular electric wire is used. The capacitance between conductors and the equivalent series capacitance of the winding can be obtained.

As the conductive coating 3 applied around the insulating coating layer 2 of the coil conductor, for example, as schematically shown in FIG. 2, a metal foil tape having a thickness on the order of μm to 0.1 mm, Metal deposition tape, conductive adhesive tape,
What wound the tape etc. by a conductive polymer material is considered. Further, it is also conceivable to apply metal deposition, application of a conductive paint, or the like to the surface of the insulating coating. In this embodiment, the conductive coating is applied to the entire periphery of the insulating coating layer of all the coil conductors constituting the coil block, but the conductive coating is applied to a part of the coil conductor or a part of the periphery of the insulating coating. By doing so, it is also possible to adjust the increase in the series capacitance of the winding.

Embodiments 2 and 3 of the present invention will be described with reference to FIGS. FIG. 3, which is an embodiment of the second embodiment, shows a winding 3 'composed of a coil conductor 1 and an insulating coating layer 2 covering the surface of the coil conductor, and a plurality of windings 3' arranged from the outer peripheral side to the inner peripheral side of the core. This is zero when the coil blocks 4 and 14 and the coil blocks 4 and 14 are stacked in a plurality of stages and the plurality of coil blocks are cooled by circulating the insulating refrigerant 10. In this case, a conductive coating 3 is provided on the surface of the insulating coating layer covering the surface of each coil conductor in the coil block 4 so as to become an exposed insulating coating layer 15 exposed on a part of the insulating coating layer 2. The coating layer 15 is applied to the insulating refrigerant 10
, That is, on the upper side 13A of the winding 3 '. 13B is the lower side of the winding 3 '.

Generally, the downstream side of the insulating refrigerant 10, that is, the upper side 1
3A has lower cooling than the lower side 13B and has a higher temperature than the lower side 13B. Therefore, in this embodiment, the upper side 13A where the temperature is high
The exposed insulating coating layer 15 is disposed on the lower side 13 where the temperature is low.
B, a conductive coating 3 is arranged, and the conductive coating 3 that expands and contracts according to the magnitude of the load capacity is absorbed by the exposed insulating layer 15. For example, the conductive coatings 3 are extended and come into contact with each other and protrude. Is prevented from doing so. In addition, since the exposed insulating coating layer 15 is exposed on a part of the conductive coating 3, the winding 1
The air and oil flow during drying or oil impregnation of 3 'can be improved.

Further, the coil block 4 of the third aspect is the lower side 1.
The conductive coating 3 and the coil block 14 arranged in 3B correspond to the exposed insulating coating layer 15 on the upper side 13A, for example, by exposing the exposed insulating layer 15 and the exposed insulating coating layer 15 to each other.
Since the series electrostatic capacitance of each coil block winding can be averaged as compared with the case where they are arranged correspondingly, it is possible to disperse a shock current such as lightning and to prevent insulation destruction.

Another embodiment of the present invention will be described with reference to FIG. This embodiment is characterized in that the conductive coatings 3 and 23 applied around the insulating coating layer 2 of the coil conductors 1 and 21 of the coil 2 and the coil 24 at the remote coil positions are formed by using the conductive coating connecting wires 8. In this case, the conductive coatings 3 and 23 also have the role of a conventional shield conductor. Other configurations are the same as those of the embodiment shown in FIG. With such a configuration, FIG.
It is possible to obtain a larger series capacitance of the winding than in the embodiment shown in FIG.

In this embodiment, as the connection pattern between the conductive coatings, the conductive coatings of the coils 4 and 24 which are four apart from each other are connected. This is a pattern frequently used in the case of the conventional electrostatic coupling using a shielded conductor as shown in FIG. There is also. Further, according to the present invention, since the electrostatic coupling between the coil conductor and the shield conductor is stronger than in the conventional case, a sufficient effect can be obtained even when the conductive coatings of closer coils, for example, adjacent coils are connected.

Another embodiment of the present invention will be described with reference to FIG. The present embodiment is characterized in that an insulating coating layer 9 is further provided outside the conductive coating 3 provided around the insulating coating of the coil conductor, and the other configuration is the same as the embodiment shown in FIG. 1 or FIG. Is the same as

By preventing the surface of the conductive coating from being directly exposed to the refrigerant in this way, it is possible to prevent the occurrence of corona and the incorporation of the conductive material into the refrigerant, and to achieve insulation reliability equivalent to that of the conventional structure. Can be secured. When applying the insulating coating layer 9 outside the conductive coating 3, it is necessary to keep the electrical connection between the conductive coatings between adjacent coil conductors.

Although the present invention has been described with reference to several embodiments, a combination of these embodiments or a combination with a conventional configuration is also possible. Further, in each of the embodiments, the disc winding has been described, but the present invention can be applied to a transformer winding having another winding structure such as a cylindrical winding or a helical winding.

[0026]

According to the above-described induction winding of the present invention, the series capacitance of the winding can be increased without lowering the space factor of the winding, and the shock voltage characteristics of the transformer can be increased. Can be improved. Therefore, it is possible to reduce the size and weight of the transformer without deteriorating the surge resistance of the transformer.

In addition, a conductive coating provided on the coil block and an insulating coating layer exposed on a part of the conductive coating are provided, and the exposed insulating coating layer is disposed on the downstream side of the insulating refrigerant, so that the load capacity can be adjusted according to the load capacity. The conductive coating that expands and contracts can be absorbed by the exposed insulating coating layer. For example, the conductive coating is stretched,
It can be prevented that they come into contact with each other and protrude.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a cross section of a transformer winding according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a structure of a coil conductor in the embodiment of FIG.

FIG. 3 is a schematic diagram showing a structure of a coil block of FIG. 1;

FIG. 4 is a schematic view showing a cross section of a transformer winding according to another embodiment of the present invention.

FIG. 5 is a schematic diagram showing a cross section of a transformer winding in another embodiment of the present invention.

FIG. 6 is a schematic diagram showing the structure of a conventional transformer winding.

FIG. 7 is a schematic diagram showing a structure when a shield conductor is used for a conventional dislocation electric wire.

[Explanation of symbols]

1, 11, 21 ... coil conductor, 2 ... insulating coating layer, 3, 1
3, 23: conductive coating, 4, 14, 24: coil block, 10: insulating refrigerant, 13: winding, 15: exposed insulating coating layer.

Claims (3)

[Claims] 1. A winding comprising a coil conductor and an insulating coating layer covering the surface of the coil conductor, and a coil block in which a plurality of windings are arranged from the outer peripheral side to the inner peripheral side of the iron core. And a conductive coating is provided on an insulating coating surface covering each coil conductor surface in the coil block. 2. A winding comprising a coil conductor and an insulating coating layer covering the surface of the coil conductor, and a coil block in which a plurality of windings are arranged from the outer peripheral side to the inner peripheral side of the iron core. An induction winding wound to cool the plurality of coil blocks by circulating an insulating refrigerant, and a part of the insulating coating on an insulating coating surface covering each coil conductor surface in the plurality of coil blocks. A conductive coating is provided by exposing the conductive coating, and the exposed insulating coating layer is disposed downstream of the insulating refrigerant. 3. When the coil blocks each having a conductive coating and an exposed insulating coating layer exposed on a part of the conductive coating are arranged corresponding to each other, the conductive coating of one coil block and the other coil block are arranged. 3. The induction winding according to claim 2, wherein the exposed insulating coating layers are arranged correspondingly.