JPS6030113A - Manufacture of oil-immersed electric apparatus - Google Patents

Abstract

PURPOSE:To raise the temperature of the innermost circumference insulator of a coil to the prescribed temperature in a short time when the insulator is dried by current heating by a method wherein a heat insulating insulator a part of which can be drawn out to the axial direction of the coil is provided between a core an the coil of an electric apparatus main body. CONSTITUTION:An insulator 2 is provided to the innermost circumference to the cor side of a cylindrical coil 1 composed of a coil conductor and an insulator. This insulator 2 is composed of, for instance, a thin plate pasteboard 2a and a plurality of long rectangular shape heat insulating insulators 2b, 2c arranged and bonded on the pasteboard 2a. One type of heat insulating insulator 2b are bonded by heat-softening adhesive and can be drawn out to the axial direction of the coil after the adhesive is softened. A coil 1 composed like this is put into a core 3 to form a transformer main body and, in the assembled state, a current is applied to the coil to produce the heat to vaporize the moisture from the part of the insulation touching the coil conductor and dry the insulator.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing oil-filled electrical equipment in which the main body of the air purifier is removed and the oil-filled electrical equipment is housed in a container together with oil.

[Technical background of the invention and its problems]

For example, an oil-immersed transformer is constructed by housing a transformer body consisting of a coil and an iron core in a container together with an insulating oil such as mineral oil or silicone oil.

The coil is provided with an insulator to electrically insulate the coil conductor through which current flows. Other insulators are
For example, insulating paper is used, which tends to absorb moisture when left in the atmosphere, and if used as is, the moisture in the insulator may seriously damage the insulation properties of the coil. Therefore, in order to evaporate this moisture, the entire transformer body is dried and lubricated as soon as it dries to prevent the insulator from absorbing moisture.

By the way, as a method for drying the above-mentioned coil insulator, a hot air drying method is generally adopted in which the entire transformer body is housed in a furnace and the entire inside of the furnace is heated.

However, in this method, the iron core is heated in addition to the coil, so the drying time of the insulator becomes longer by the amount of time required to cover the heat chamber of the iron core, and conversely, if you try to shorten the drying time, the drying time of the insulation will be longer. This increases power consumption, which is unfavorable in terms of energy conservation.

Therefore, recently, an electric heating method has been adopted. This energization heating method improves insulation performance by passing an electric current through the coil body itself and using the heat generated by the current to evaporate moisture in the insulator that is in contact with the coil conductor.
It is an efficient method as it consumes less power. However, in this method, the temperature of the insulator portion that is not in contact with the coil conductor hardly rises. In particular, even if the insulator on the innermost periphery of the coil, which insulates between the iron core and the coil, is heated, heat is radiated to the iron core by heat conduction, so the temperature rise is low, and as a result, less moisture evaporates, resulting in insulation resistance. becomes smaller. In other words, there is a problem that the insulation properties deteriorate.

[Purpose of the invention]

The present invention was made in order to solve the problem of ±HC, and its purpose is to raise the temperature of the innermost insulator of the coil to a predetermined temperature in a short time when drying the insulator by electrical heating. Therefore, it is an object of the present invention to provide a method of manufacturing oil-filled electrical equipment that more economically improves the insulation properties of an insulator and does not impair the cooling of the transformer body by the insulating oil.

[Summary of the invention]

The present invention is capable of drying the coil of the electrical equipment main body by heating it with electricity by disposing a heat insulating material between the iron core and the coil of the main body of the electrical equipment, a part of which can be pulled out in the axial direction of the coil. When doing so, a heat insulating material is used to prevent the heat of the coil from being conducted to the core, and then a part of the heat insulating material is pulled out to form an oil conduit. It is characterized by cooling the transformer body.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention that is not shown in the drawings will be described below.

FIG. 1 is a plan view showing an example of the structure of a transformer main body according to the present invention. In the figure, l is a cylindrical coil composed of a coil conductor that conducts current and an insulator that electrically insulates this coil conductor. is installed. As shown in the top and front views of FIGS. 2 and 3, this coil innermost insulator 2 has a plurality of strip-shaped heat-insulating insulators 2b, 2c on one side of a thin plate-like mount 2a. They are arranged side by side and pasted with adhesive. In this case, one of the heat-insulating insulators 2b arranged at intervals is fixed with a heat-softening adhesive (for example, an epoxy adhesive having a glass transition point of 100 to 150°C).

After the adhesive softens, it should be pulled out in the axial direction of the coil. As the heat-insulating materials 2b and 2c, for example, a breath pad or a polyester film is used. As the mount 2a, for example, kraft paper or parchment paper, which has relatively good thermal conductivity, is used.

Note that if the heat insulating insulator 2b to be pulled out later is made longer than the other heat insulating insulator 2C so as to protrude upward, it will be easier to pull out. Also, this heat-insulating insulator 2b is not provided in the part of the iron core located on the window side.
As shown in the plan view and front view of FIG. 5, it is inserted into the iron core 3 to form the transformer body. Since the iron core 3 is uniformly and firmly assembled inside the coil 1, the heat-insulating insulators 2b and 2c of the innermost periphery of the coil 2 are in close contact with the iron core 3 over the entire circumference.

Next, in order to dry the insulator by heating with electricity, in the assembled state as shown in Figs.
The coil conductor generates a heat amount of 0.241"R1 (cat), and as time t passes, moisture evaporates from the insulating material in contact with the coil conductor and dries the insulating material. Since the heat-insulating insulators 2b and 2C are disposed at the innermost periphery of the coil l, the generated heat is not radiated by heat conduction from the innermost periphery of the coil l to the iron core 3, unlike in the conventional case. Coil innermost insulator 20
Since the mount 2a is raised to a predetermined temperature together with the coil insulator, it is possible to sufficiently dry the entire insulator in a short time with energy saving.

Next, in the transformer body that has been dried in this way, the temperature immediately after drying is relatively high (for example, 150 to 160℃).
0°0), the heat-insulating insulator 2b is pulled out in the axial direction of the coil/l/J to form an oil path between the iron core 3 and the coil l. Thereafter, this transformer body is housed in a container together with insulating oil to form an oil-immersed transformer. Therefore, when this oil-immersed transformer starts operating, insulating oil flows through the oil passage formed between the core 3 and the coil I and cools the core 3 and the coil I. The objects 2b and 2C do not interfere with the cooling of the transformer body by the insulating oil.

In the above embodiment, a transformer is used as the oil-filled electrical equipment, but the present invention can be similarly applied to other equipment such as a reactor.

Furthermore, in the above embodiments, a case has been described in which the mount in the innermost insulator of the coil is made of a material different from that of the heat-insulating insulator, but it may be made of the same material as the heat-insulating insulator. In this case, the mount should be made as thin as possible to reduce its insulation effect.

〔Effect of the invention〕

As explained above, according to the method for manufacturing oil-filled electrical equipment of the present invention, a heat-insulating insulator is disposed between the iron core and the coil, a part of which is pulled out in the axial direction of the coil, and is provided with a filtration function. Since the main body of the electrical equipment was constructed using the following method, when drying the insulation by heating the main body with electricity, the innermost insulator of the coil is also raised to a predetermined temperature in a short time with energy saving, and it is completely ＜It becomes 0'' ability to improve the performance.

Furthermore, since an oil passage is formed between the iron core and the coil, cooling by insulating oil is not impaired.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the state of coil manufacturing in the method of manufacturing oil-filled electrical equipment of the present invention, and FIGS. 2 and 3 are plan views showing the configuration of the heat-insulating material used in the manufacturing method of the present invention. FIGS. 4 and 5 are a plan view and a front view showing the state of the electric appliance main body during manufacture in the manufacturing method of the present invention. 1...Coil, 2...Coil last. Inner circumference insulator, 2a・
... Mounting paper, 11b, 2c... Heat-insulating material, 3...
Iron core. Figure 1a Figure 2Figure 3Figure 4b Figure 5

Claims (1)

[Claims] A heat-insulating insulator, a part of which can be pulled out in the axial direction of the coil, is arranged between the iron core and the coil to form the main body of the electrical device, and after the coil of the main body of the electrical device is dried by electrical heating. A method for manufacturing oil-filled electrical equipment, comprising: pulling out a part of the heat-insulating material to form a road, and then housing the main body of the electrical equipment in a container together with insulating oil.