JPS6133628Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to an oil-immersed capacitor with improved impregnation properties and improved tanδ characteristics. Capacitors are generally made of polypropylene as a dielectric, metallized paper (made by vapor-depositing metal on insulating paper) as an electrode, and impregnated with insulating oil as an impregnating agent.They have an excellent effect on improving withstand voltage and are in demand. is also expanding year by year. Furthermore, due to the recent expansion of applications such as commutation capacitors, the demand for products with even better withstand voltage has increased, and in order to obtain this property, polypropylene as a dielectric had to be made thicker. However, when the thickness of polypropylene is, for example, 15 μm or more, there is a problem that impregnation becomes insufficient despite the oil passage provided by the metallized paper. Therefore, a structure in which the impregnation property is improved by using roughened polypropylene as a dielectric material has been put into practical use. Conventionally, these structures have generally been made on one side as shown in Figure 1, since it is more convenient to wind up the material and to provide more impregnating agent on the surface in contact with the electrode, which is advantageous in terms of corona and other problems. A polypropylene film 4 with a roughened surface 3 on one side is sandwiched between a pair of metallized papers 2 on which electrodes 1 are formed, and in this case, the roughened 3 side of the polypropylene film 4 is the electrode 1 side of the metallized paper 2. It is wound so that it is in contact with the
However, with this structure, there is a gap between the electrode 1 and the polypropylene film 4, so impurity ions generated between the gaps move and the tan δ
This has the disadvantage that abnormal variations occur in the insulation resistance or that the insulation resistance decreases. The present invention was developed in view of the above points. A polypropylene film with one side roughened is sandwiched between a pair of single-sided metallized papers, and the roughened side is in contact with the non-metalized paper side, and the film is wound with insulating oil. The purpose of this invention is to provide a capacitor with good characteristics impregnated with . An embodiment of the present invention will be described below with reference to the drawings. That is, as shown in FIG. 2, one side of the capacitor thin paper 11 is embossed, for example, between a pair of single-sided metallized papers 13 on which electrodes 12 are formed by vapor-depositing metals such as aluminum, zinc, copper, etc.; A single-side roughened polypropylene film 15 is interposed, which has been roughened 14 by rubbing with a surface roughening agent, by mixing a large amount of inorganic additives to form a film, or by coating with a matting agent. . In this case, the roughened surface 14 of the single-sided roughened polypropylene film 15 is brought into contact with the non-metalized surface of the single-sided metalized paper 13. After winding the capacitor element by a known method and forming metallicon electrodes on both end faces of the capacitor element, %CA component (monoprime number of benzene ring/monoprime number of benzene ring + monoprime number of side chain) A capacitor is constructed by a known method by impregnating it with an impregnant consisting of one or more mixed insulating oils such as vegetable oil, phthalate ester, alkylbenzene, silicone oil, etc. with a %CA of 40 or less.
If an insulating oil with a component exceeding 40 is used, the long-term withstand voltage will decrease, which is not practical. According to the capacitor constructed as described above, impurity ions generated in the gap between the roughened surface 14 and the non-metalized surface of the single-sided metalized paper 13 are absorbed by the single-sided metalized paper 1.
3. Since it penetrates from the non-metalized surface and is absorbed into the paper fibers, it has the advantage of stable tan δ characteristics or insulation resistance characteristics. Next, based on experimental examples, various characteristics at 20°C of the present invention and a conventional example having the configuration shown in FIG. 1 were investigated, and the results are shown in Table 1. The samples used in both the present invention and the conventional example were rated at 800WV.AC using a pair of single-sided metallized paper with a width of 100 mm and a thickness of 9μ and a polypropylene film with a roughened surface on one side and a width of 100 mm and a thickness of 15μ.
-2.5 μF oil-immersed capacitor, and the characteristic value is the average value of 20 capacitors.

[Table] As is clear from the above table, the present invention has better absolute value characteristics of tan δ than the conventional example, and at the same time there is less variation in tan δ between each capacitor. Furthermore, it can be seen that the insulation resistance characteristics are excellent. As described above, according to the present invention, a polypropylene film with a roughened surface on one side is sandwiched between a pair of metalized papers on one side, and the polypropylene film is wrapped with one or more of vegetable oil, phthalate ester, alkylbenzene, silicone oil, etc. with a %CA content of 40 or less. In a capacitor impregnated with an insulating oil consisting of a mixture of more than 1,000% of insulating oil, tanδ characteristics and insulation resistance characteristics can be improved by configuring the roughened surface of the polypropylene film to be in contact with the non-evaporated surface of single-sided metal paper. We can provide excellent oil-immersed capacitors.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the structure of a conventional oil-immersed capacitor, and FIG. 2 is a cross-sectional view showing the structure of an oil-immersed capacitor according to an embodiment of the present invention. 12... Electrode, 13... One side metallized paper, 14...
...Roughened surface, 15... Single-sided roughened polypropylene film.

Claims (1)

[Scope of utility model registration request] One-sided metallized paper and one-sided roughened polypropylene film are polymerized and wound together with vegetable oil, phthalate ester,
In a capacitor impregnated with an insulating oil consisting of one or more mixtures of alkylbenzene, silicone oil, etc., the roughened surface of the polypropylene film is in contact with the non-deposited surface of the metallized paper. Characteristic capacitors.