JPH012311A - High voltage AC capacitor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to high voltage AC capacitors.

[Conventional technology]

Conventionally, high-voltage AC capacitors are broadly classified into those using metal foil and those using metal foil.In the case of the former, they are partially vaporized capacitors in which metal is deposited on the entire surface of one side of the dielectric film except for the margins. After winding the films in alternating layers so that the margins are at the opposite ends, the 7 metal parts at both ends of the roll are grounded and connected by metal spraying, etc., and several are placed side by side in a sealed container, and insulating oil is applied. It is enclosed.

In the latter case, the dielectric film or the dielectric material-impregnated base material and the foil electrode are alternately stacked and wound, connected to ground, and then placed in a sealed container and filled with insulating oil or gas.

Alternatively, in the latter case, it is known to reduce the concentration of electric field at the end of the foil electrode by folding the end of the foil electrode and winding it with a dielectric material.

[Problems to be solved by the invention]

However, in the case of the metal-coated electrode mentioned above, the electrode surface is extremely thin, so a capacitor with a large capacity is required! ! ! When manufacturing, electrical resistance cannot be ignored, and if the actual metallized film 11 is around 300 mm or more, t7 due to heat generation.
Due to the problem of decreased reliability due to increased loss of 4 and increased l+U degree, customer use with negative elements is restricted, and many small capacity elements must be installed in parallel, and insulating oil is filled in. The container also becomes large, making it difficult to meet the demand for miniaturization, and the cost of incidental parts increases.

In addition, in the case of foil electrodes, the -1 rolled metal foil is cut to the desired width, so cut edges remain at the ends of the foil.
Extreme electric field concentration occurs, and a considerable safety factor must be taken for the potential gradient calculated from the withstand voltage at the center of the electrode foil, which increases the design electrode area and also causes pinholes etc. This increases the probability of insulation breakdown accidents.

Furthermore, a method to alleviate the electric field concentration that occurs at the cutting edge by folding back the ends of a single electrode foil is also being considered, but this method inevitably results in a decrease in the Ily of the dielectric at the ends. As a result, not only the capacity of the central part of the electrode foil cannot be utilized and the dielectric capacitance ratio becomes large, but also
Due to the 1×11 degree characteristic of metal foil, protrusions are likely to occur locally, making it difficult to obtain sufficient electric field relaxation.

The present invention is intended to solve the above-mentioned problems, and by folding the whole surface of a laminate in which a dielectric material and a foil electrode are airtightly coated or laminated, a high-voltage capacitor sealed with insulating oil, especially an AC dielectric (AC dielectric) The purpose of this project is to reduce the number of elements and downsize the entire device by using wide electrode foils and increasing the potential gradient in AC high-voltage capacitors with a small amount of electricity.

Means for Solving Problem C] To this end, the AC high-voltage capacitor of the present invention comprises a laminated film in which one side of a long foil electrode is coated or laminated with a dielectric material, the dielectric material is the outer surface, and a margin portion is provided at the end. A capacitor element is formed by alternately stacking and winding the capacitor element, which is folded in half and each folded part is the opposite end, and sealed in a sealed container with insulating oil or gas. It is characterized by

[Effect]

The present invention consists of a laminated film in which one side of a long foil electrode is coated or laminated with a dielectric material, the dielectric material is the outer surface, and the film is folded in half with a margin section left at the end. A capacitor element is formed by winding the TL electrode in alternating layers, and this is sealed in a sealed container with insulating oil or gas to prevent electric field concentration at the end of the TL electrode and increase the potential gradient. This makes it possible to reduce the number of elements and downsize the device.

〔Example〕

Examples will be described below with reference to the drawings.

FIG. 1 is a sectional view of a laminate according to the present invention, FIG. 2 is a sectional view of the laminate shown in FIG. 1 folded in half, and FIG.
A cross-sectional view showing a state in which two laminates in the state shown in the figure are stacked, No. 4
The figure is a partial cross-sectional view of the high-voltage AC capacitor of the present invention. In the figure, l is a foil electrode, 2 is a dielectric, 3 is a laminate, 4 is a folded part, 5 is a capacitor element, 6 is a sealed container, 6a
7 is insulating oil, 8 is a lead wire, 9 is a terminal, 11 is an electrode end, and 12 is a margin.

As shown in Fig. 1, two long laminates 3 each having a foil electrode 1 and a dielectric 2 facing each other are placed, and as shown in Fig. A folded part 4 is formed, and the folded part is folded back leaving a margin part 12.

The thus folded laminate 3 is stacked and wound so that the folded portions 4 are opposite ends, as shown in FIG. 3, to form a capacitor element.

In this case, there may be two or more laminated bodies. :1.

As the foil electrode l, for example, A1 foil, lead foil, Zn foil, Fe
Foil can be used, and as the dielectric 2, for example, polypropylene, polycarbonate, polystyrene, polyethylene, polyester, and modified resins thereof can be used.

Further, the dielectric 2 can be made by laminating two or more types of resin, but from the viewpoint of electrical properties, particularly corona resistance, it is desirable that at least one layer is a stretched resin film.

Next, as shown in FIG. 4, it is sealed together with insulating oil or insulating gas 7 in a sealed container 6 made of metal or the like whose inner surface is insulated.

The lead cotton 8 connected to the capacitor layer 5 is connected to a terminal 9 formed on the lid 6a of the sealed container 6.

Further, in the above embodiment, the foil electrode 1 and the dielectric material 2 can be laminated with a preferable airtightness by using a hot-melt resin coating lamination.

Furthermore, by making the other side of the laminate of the +IQ body 2 matte, it becomes easier for the insulating oil 7 to penetrate between the wound laminates 3, thereby improving the insulation properties.

Furthermore, since the inner surface of the folded insulating foil 1 is electrically at the same potential, even if there are voids, the effect on insulation breakdown is small. It is possible to prevent air from remaining, to evenly wind the laminate 3, and to manufacture a tight capacitor element 5.

FIG. 5 is a sectional view of another embodiment of the present invention, in which 21 is Alfn, 22 is biaxially oriented polypropylene, and 23 is polyethylene.

In this example, one side of biaxially stretched polypropylene 22 with a thickness of 7 μm is subjected to corona discharge treatment as an electrode foil, and then a 15 μm thick second laminated portion of dielectric 2 is applied to the surface coated with an isocyanate-based anchoring agent. Thickness polyethylene 2
The laminate 3 is obtained by heat-melting and extrusion coating the polyethylene 23 and sandwich-laminating it with the AI foil 21 using the polyethylene 23 as an adhesive layer.

This laminated film was folded in half so that the 21 sides of the A1 foil were in contact with each other and the length of one folded side from the folded part was two lengths longer than the other side.

Next, the two folded laminated films are alternately stacked and wound so that the folded portions are opposite ends to form a capacitor element.

Lead wires 8 were attached to parts of both end faces of this capacitor element, and the wires were connected to terminals 9 formed on the lid 6a of the sealed container 6, and then the capacitor element was sealed in the sealed container 6 together with the insulating oil 7.

Since the present invention is constructed as described above, the Al t
Since there is no cutting surface of ea, extreme electric field concentration due to cutting edges can be avoided.

In addition, metal foil with a thickness of about 5 to 15 μm is usually used for the foil electrode, and when this foil electrode alone is used, not only the ends but also the
Folding it in half evenly with a width of 0.0cm or more can cause problems such as tearing and pinholes, which is extremely difficult in practice, and the radius of the folded part is uneven and the stiffness that is unique to metal foil. Protrusions are likely to occur.

On the other hand, in the case of the present invention, the electrode foil 1 and the dielectric 2 are prepared in advance.
After stacking the electrodes, fold them in half uniformly to form the electrode end 11.
electric field concentration can be sufficiently alleviated.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to obtain a high-voltage AC capacitor with a high potential gradient, which can sufficiently relax the electric field at the end of the electrode, is inexpensive to manufacture, and is stable.

Further, by adjusting the length of the two folded pieces, a margin can be easily obtained, and the connection between the capacitor and the external terminal can be easily performed.

Furthermore, by changing the position of the folded portion, the margin portion can be easily obtained.

Further, by integrating the laminates in a planar manner alternately, it is easy to obtain a high-voltage AC capacitor in the form of a flat plate piece.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a laminate according to the present invention, and FIG.
Figure 3 is a cross-sectional view of the laminate folded in half.
FIG. 4 is a partial cross-sectional view of a high-voltage AC capacitor of the present invention, and FIG. 5 is a cross-sectional view of another embodiment of the present invention. l... Foil electrode, 2... Dielectric, 3... Laminate, 4
... Folded portion, 5... Capacitor element, 6...
・Sealed container, 6a...lid, 7...insulating oil, 8...
Lead wire, 9...terminal, 11...electrode end, 12...
...Margin part, 21...A1' foil, 22...biaxially stretched polypropylene, 23...polyethylene. Applicant Dai Nippon Printing Co., Ltd. Agent Patent Attorney Masanobu Hirukawa (2 others) Figure 1 Figure 2 Figure 3

Claims (5)

[Claims] (1) A laminated film made by coating or laminating a dielectric on one side of a long foil electrode, with the dielectric as the outer surface, is folded in half with a margin left at the end, and each folded part is the opposite end. A high-voltage AC capacitor characterized in that a capacitor element formed by alternately stacking and winding the capacitor element is sealed in a sealed container together with insulating oil or insulating gas. (2) The high-voltage AC capacitor according to claim 1, wherein the dielectric material is an olefin resin. (3) The high-pressure AC capacitor according to claim 1, wherein the coating method is a hot melt coating of olefin resin. (4) The high-voltage AC capacitor according to claim 1, wherein the other surface of the foil electrode coated is matte. (5) The high-voltage AC capacitor according to claim 1, wherein the dielectric surface of the laminated film is matte.