JPH065435A - Stationary induction electric apparatus - Google Patents

Abstract

PURPOSE:To realize an excellent stationary induction electric apparatus in which cooling capacity can be largely improved while incorporating high insulating reliability in a winding and vibration.noise can be further suppressed and which has high electrical.mechanical reliability and is adapted for a high voltage.large capacity apparatus. CONSTITUTION:Windings 4, 5 formed by winding conductors on a leg 1 of a core are contained in a sealed vessel 9. Foamed material 10 having excellent insulation is filled partly or entirely in the vessel 9, and the windings 4, 5 are contained in the material 10. In this case, as the material 10, foamed material having excellent insulation such as silicone series, urethane series or acrylic series can be employed. Generally, a cooling duct 6 or a heat pipe is incorpolatedly contained in the windings 4, 5. Or, the pipe can be used as the conductor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a static induction electric device in which a winding formed by winding a conductor around an iron core leg is housed in a hermetically sealed container.

[0002]

2. Description of the Related Art As is well known, the insulation methods of static induction electrical equipment are roughly classified into dry type and wet type. Among such static induction electrical equipment, the wet type of transformer is the oil-filled transformer, but this oil-filled transformer has the risk of oil leakage and explosion due to fire, etc. The use of oil-filled transformers, such as in underground substations in buildings, is decreasing. On the other hand, typical dry type transformers include varnish-treated transformers and molded transformers. Among them, varnish-treated transformers have the drawback that their insulation characteristics deteriorate due to dust and stains. Molded transformers are used as the mainstream of dry type.

Here, the mold transformer is a transformer of a type in which the winding of the transformer is placed in a mold and impregnated with a synthetic resin under reduced pressure to insulate the winding. Therefore, it has an excellent appearance, and has an advantage that maintenance is easy, such as dust and stains from the outside and even water washing in an extreme case.

[0004]

By the way, in recent years, in particular, as the demand for higher voltage and larger capacity of transformers and further non-combustibility of transformers has increased, the winding capacity has a high dielectric strength and the cooling capacity is high. It is an important issue to significantly improve That is, as the voltage and capacity of a transformer increase, the amount of heat generated by winding loss during transformer operation also increases, which may exceed the allowable heat resistance temperature of the insulating material. Deterioration will occur and its reliability will be reduced. Therefore, it is necessary to avoid such inconvenience and perform sufficient cooling.

However, the mold transformer has a structure in which all of the windings are wrapped in the impregnated resin, so that its cooling efficiency is generally a fraction of that of the insulating oil system. That is, the insulating oil that is the insulating medium of the oil-filled transformer acts as a refrigerant by circulation, whereas the impregnated resin of the mold transformer does not have such a cooling function by circulation. Moreover, in the molded transformer, even if the refrigerant is forced to circulate inside the winding, the impregnating resin that wraps the winding becomes an obstacle, so the refrigerant cannot be circulated inside the winding. Due to such cooling limitation, it has been difficult to use the molded transformer as a high-voltage / large-capacity transformer. Furthermore, when manufacturing a molded transformer, as mentioned above, a special process of putting the winding of the transformer into the mold and impregnating it with synthetic resin under reduced pressure is necessary, so work efficiency is improved. However, the mold used is expensive and the manufacturing cost is high.

On the other hand, in a device of the type in which gas or liquid is used as an insulating medium for insulation, a wedge-shaped gap or a minute gap is formed between the winding and a solid insulator supporting the winding. There is also a problem that local electric field concentration occurs due to the difference in dielectric constant between the solid insulator and the gas or liquid insulating medium in the gap portion. Further, in the transformer, various insulating materials such as the impregnating resin for the winding wire and the supporting insulating material that supports the winding wire as described above are used, but by repeating the heat cycle by the operation, Due to the difference in thermal expansion, cracks are generated in the insulating material in each part, and as a result, there is a problem that insulation reliability and mechanical reliability are reduced. Furthermore, vibration of the winding wire and noise accompanying it occur during operation, which lowers mechanical reliability and poses a problem in terms of environment.

The present invention has been proposed in order to solve the problems of the prior art as described above, and an object thereof is to provide a winding with high insulation reliability and to greatly improve the cooling capacity. Further, it is an object of the present invention to provide an excellent static induction electric device capable of suppressing vibration and noise, having high electrical and mechanical reliability, and suitable as a high-voltage, large-capacity device.

[0008]

A static induction electric device according to the present invention is a static induction electric device in which a winding formed by winding a conductor around a leg of an iron core is housed in a closed container. Part or all of the foam material is filled with a foam material having excellent insulation properties, and the winding is housed in the foam material. In this case, as the foam material, it is possible to use a silicone-based, urethane-based, or acrylic-based foam material having excellent insulating properties. Generally, a cooling duct or heat pipe is built in the winding. Alternatively, it is also possible to use a heat pipe as the conductor. As the winding, a foil-shaped winding made of a foil-shaped conductor is typically used.

On the other hand, in the present invention, the foam material can be filled in the entire closed container, but it is also possible to divide the housing portion of the winding and fill the foam material only in this portion. Is. In this case, for example, the winding may be housed in an insulating container, the insulating container may be filled with a foam material, and then the insulating container may be housed together with an insulating medium in a closed container.

[0010]

In the static induction electric device of the present invention having the above-mentioned structure, the cooling duct or heat pipe is incorporated between the cooling duct or the heat pipe and the winding so that the refrigerant is circulated between the cooling duct or the heat pipe and the winding. By the heat transfer of, the inside of the winding can be forcibly cooled. In addition, the entire winding can be insulated by wrapping it in a foam material having excellent insulation properties. Further, according to the present invention, since the foam material can be adhered to the periphery of the winding wire, even in a device in which a gas or a liquid is used as an insulating medium for insulation, a wedge-shaped gap or a minute gap is formed around the winding wire. Gap is not generated and electric field concentration is not generated.

On the other hand, according to the structure of the present invention, even if expansion and contraction due to the difference in the coefficient of thermal expansion of the material is repeated due to repeated heat cycles due to operation, such expansion and contraction can be absorbed by the foam material. The occurrence of cracks in the insulator does not occur. Further, even if vibration of the winding occurs during operation, there is an advantage that the vibration can be absorbed by the foam material. Further, when manufacturing the static induction electric device of the present invention, it is not necessary to separately prepare a special mold or container, and it is said that the closed container is filled with the foam material for foaming, or the foamed foam material is filled. The winding can be easily insulated only by performing a simple process.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Two embodiments in which a static induction electric device according to the present invention is applied to a foil winding transformer will be described below with reference to FIG.
And it demonstrates concretely with reference to FIG.

First, FIG. 1 is a sectional view showing a first embodiment of a foil winding transformer according to the present invention. That is, as shown in FIG. 1, a low-voltage winding 4 and a high-voltage winding 5 formed by winding a metal sheet 2 and an insulating sheet 3 in an overlapping manner are wound around the main leg iron core 1, and A hollow cooling duct 6 is incorporated in the windings 4 and 5 so as to be wound therein. Both ends of the cooling duct 6 are connected to a liquid collecting pipe 8 via insulating pipes 7, and a condensable or non-condensable refrigerant is enclosed in a narrow gap in the hollow portion of the cooling duct 6. Has been done. Then, by an external pump (not shown), the circulation of the refrigerant is repeated between the cooling duct 6 and the external cooling system (not shown) via the insulating pipe 7 and the liquid collecting pipe 8. The windings 4 and 5 having such a cooling duct 6 built therein are housed in a tank (closed container) 9. In this tank 9, silicon type,
It is filled with a foam material 10 having excellent insulation such as urethane-based or acrylic-based.

In the present embodiment having the above-mentioned structure, by circulating the cooling medium through the cooling duct 6 built in the windings 4 and 5, the cooling duct 6 and the cooling duct 6 are wound regardless of the foam material 10. Due to the heat transfer between the wires 4 and 5,
The inside of the windings 4 and 5 can be forcibly cooled. Therefore, the cooling efficiency can be remarkably improved as compared with the above-described mold transformer and the like.

Further, the entire windings 4 and 5 can be insulated by being wrapped with the foam material 10 having an excellent insulating property. In this case, the windings 4, 5 are cooled independently of the foam material 10, and therefore the insulating and cooling functions are completely separated between the foam material 10 and the cooling duct 6, so that Insulation performance can be sufficiently exerted, and insulation reliability can be improved.
Further, since the foam material 10 can be adhered to the periphery of the windings 4 and 5, no wedge-shaped gap or a minute gap is formed around the windings 4 and 5. Therefore, electric field concentration due to the gap does not occur, and the insulation reliability can be improved also from this point.

On the other hand, even if the heat cycle due to the operation of the transformer is repeated and the expansion and contraction due to the difference in the coefficient of thermal expansion of the material occurs, such expansion and contraction can be absorbed by the foam material 10, so that cracks in the insulator can occur. And the insulation reliability and mechanical reliability can be improved. Further, even if vibrations of the windings 4 and 5 occur during operation, the vibrations can be absorbed by the foam material 10, so that vibrations and accompanying noises can be greatly suppressed, and mechanical reliability is improved. Can be improved and is also environmentally convenient.

Furthermore, in manufacturing the molded transformer, as described above, a special process of putting the winding of the transformer in the mold and impregnating the synthetic resin under reduced pressure was required. However, in the foil wound transformer of the present embodiment, it is not necessary to separately prepare a special mold or container, and the foil winding transformer can be easily wound by performing a simple process of filling the foam material 10 in the tank 9 and foaming. The wires 4, 5 can be insulated. Therefore,
The work efficiency is good, and the manufacturing cost is kept low.

Next, FIG. 2 is a sectional view showing a second embodiment of the foil winding transformer according to the present invention. That is, in the second embodiment shown in FIG. 2, the windings 4 and 5 are housed in the upper opening type insulating container 11, and the insulating container 11 is filled with the foam material 10. And the insulating container 1 in which the windings 4 and 5 and the foam material 10 are housed in this way
1 is stored in the tank 9 together with the insulating medium 12. In this case, as the insulating medium 12, it is possible to use an insulating oil, a liquid having an insulating property such as silicon oil, an insulating gas such as SF ₆ gas, or the like.
It is also possible to cast a solid insulator such as epoxy. The configuration of the other parts is the same as that of the first embodiment.

In the present embodiment thus constructed,
Similar to the first embodiment, the cooling efficiency can be improved and the foam material 10 can be provided by the cooling duct 6.
By this, it is possible to insulate the windings 4 and 5 by enclosing them. In particular, in this embodiment, the windings 4 and 5 are once housed in the upper opening type insulating container 11 and the insulating container 1
Since the foam material 10 is filled in the inside 1, the work of filling and foaming the foam material 10 becomes easy, and the work efficiency is further improved.

Further, in the above-mentioned constitution, specifically, the cells of the foam material 10 are made into continuous cells, or a liquid or gas is used as the insulating medium 12,
It is desirable to use a foam material having excellent permeability of the insulating medium 12, for example, a silicone foam material.
In such a case, the insulating medium is filled in the bubbles of the foam material 10 and the difference in the dielectric constant between the insulating medium 12 and the foam material 10 is reduced, so that the insulation reliability is significantly improved. Can be improved.

Further, when the foam material 10 is foamed, the foam material 10 is foamed by an insulating gas, or by causing the insulating gas to be enclosed or generated inside. Dielectric strength can be significantly improved. Further, the size of the bubbles formed in the foam material 10 depends on the foam material 10
Although it depends on the type, by setting the diameter to a size of 1 to 2 mm or less, the dielectric strength of the insulating medium of gas or liquid inside the bubbles becomes the highest, and the insulation reliability can be further improved.

The present invention is not limited to the above-mentioned embodiments, but may be applied to various transformers other than the foil winding transformer, such as a transformer formed by winding a rectangular conductor. It is applicable as well. Further, the present invention can be similarly applied to a transformer in which a heat pipe is incorporated in the winding and a transformer in which the conductor itself is formed of a heat pipe. Furthermore, in the above-mentioned embodiment, the foam material was filled into the container and then foamed.However, after foaming and molding the foam material into a required shape in advance, the foam material was filled into the container. It is also possible to do so.

[0023]

As described above, according to the present invention,
By filling a part or all of the airtight container with a foam material with excellent insulation properties and housing the winding in this foam material, the winding has high insulation reliability and the cooling capacity is greatly improved. In addition, vibration and noise can be suppressed, electrical and mechanical reliability is high, and high voltage
It is possible to provide an excellent static induction electrical device suitable as a large capacity device.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment in which a static induction electric device according to the present invention is applied to a foil winding transformer.

FIG. 2 is a sectional view showing a second embodiment in which the static induction electric device according to the present invention is applied to a foil winding transformer.

[Explanation of symbols]

 1 ... Main landing gear core 2 ... Metal sheet 3 ... Insulation sheet 4 ... Low voltage winding 5 ... High voltage winding 6 ... Cooling duct 7 ... Insulation pipe 8 ... Liquid collecting pipe 9 ... Tank (sealed container) 10 ... Foam material 11 ... Insulation Container 12 ... Insulating medium

Claims (1)

[Claims] 1. A static induction electric device in which a winding formed by winding a conductor around a leg portion of an iron core is housed in a closed container, wherein a part or the whole of the closed container is filled with a foam material having an excellent insulating property. A static induction electric device characterized in that the winding is housed in the foam material.