JPH07335485A - Gas-insulated metallized-film capacitor - Google Patents

Abstract

PURPOSE:To allow fine adjustment of tightening pressure by a method wherein an insertion piece having a diagonally-cut tip is inserted between an insulating plate and a tightening band and an element unit together with a tip part of the insertion piece is pretightened by means of a tightening band and the insertion piece is further deep inserted. CONSTITUTION:A capacitor element unit 3 is fabricated by a method where a metallized film is wound, the winding is flattened to form a capacitor element 5, a plurality of capacitor elements 5 are joined, insulation plates 6 are attached to both sides of the joined elements 5 and fixed by a tightening band 7 and insertion pieces 8 having each a diagonally-cut tip are inserted between the insulation plate 6 and the tightening band 7. A plurality of these element units 3 are arranged to be connected to an insulation bushing so as to be housed in a case and further dried and filled with SF6 gas 10 in order to manufacture an insulating high-voltage phase-advancing capacitor. Thereby, fine adjustment of capacitance is allowed and coming-off from the tightening band is eliminated even if contraction of the capacitor element is generated at the time of impressing voltage.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to gas insulated metallized film capacitors.

[0002]

2. Description of the Related Art The structure of a conventional gas-insulated metallized film capacitor is shown in FIGS. Of these, element unit 3
In the above, a plurality of flattened capacitor elements 5, two insulating plates 6 and a tightening auxiliary plate 9 are fixed by tightening with a tightening band 7.

[0003]

In the element unit 3 having the above-described structure, it is difficult to finely adjust the tightening dimension (tightening pressure) after once fixing it with the tightening band 7, so that the capacity of each element unit is finely adjusted. I couldn't adjust it. Further, while a voltage is being applied to the capacitor, the capacitor element 5 contracts to loosen the tightening, the tightening auxiliary plate 9 falls off, a change in the capacity or partial discharge occurs, and the dielectric is damaged by insulation. There was a problem.

[0004]

DISCLOSURE OF THE INVENTION The present invention has solved the above-mentioned problems and involves winding a metallized film into a flat shape.
A capacitor element 5 is formed, a plurality of them are assembled, insulating plates 6 are arranged on both sides, and after tightening with a tightening band 7, a difference in the tip between the insulating plate 6 and the tightening band 7 is obliquely cut. The insert piece 8 is inserted to make the tightening dimension (tightening pressure) of the element unit constant. That is, case 1
A gas-insulated metallized film capacitor comprising: an insulating bushing 2, an element unit 3, a lead wire 4, and an insulating gas 10. A case 1 has a plurality of insulating bushings 2 on the outside, A plurality of element units 3 are housed and filled with an insulating gas 10. The element units 3 are composed of a plurality of flattened capacitor elements 5 wound with a metallized film, and insulating plates 6 are arranged on both sides of the capacitor elements 5. It is a gas-insulated metallized film capacitor which is fixed with an attached band 7, and an insert piece 8 whose tip is obliquely cut is inserted between the insulating plate 6 and the tightening band 7.

[0005]

When the insert piece 8 whose tip is obliquely cut as a tightening pressure adjusting plate is inserted between the insulating plate 6 and the tightening band 7, the element unit is tightened by the tightening band 7 and the tip of the insert piece 8 is fixed. By inserting the insertion piece 8 that has been pre-tightened together with the part and then obliquely cut, the size of the element unit can be finely adjusted, the tightening pressure can be adjusted, and thus the capacity can be finely adjusted. It is possible to prevent the conventional auxiliary defects such as the conventional tightening auxiliary plate 9 from falling off and the insulation damage to the dielectric caused by the loosened tightening of the element unit after the drop.

[0006]

Example 1 An example of the gas-insulated metallized film capacitor of the present invention will be described with reference to a gas-insulated high-voltage phase-advancing capacitor. The gas-insulated high-voltage phase-advancing capacitor (hereinafter referred to as "capacitor") is a dry capacitor having a structure as shown in FIG. 1, and is filled with SF ₆ gas as an insulating gas.

FIG. 2 shows the structure of the element unit 3 of the above-mentioned capacitor. A metallized film is wound and flattened to form a capacitor element 5, and a plurality of these are assembled to dispose the insulating plates 6 on both sides. The structure is such that the fastening pressure of the element unit is finely adjusted by fixing the fastening pressure with the fastening band 7 and inserting the insertion piece 8 whose tip is obliquely cut between the insulating plate 6 and the fastening band 7.

FIG. 3 shows an insertion piece 8 in which the tip inserted between the insulating plate 6 and the tightening band 7 of the element unit 3 of the capacitor is obliquely cut. One end and the other side of the rectangular insulating plate are shown. The two sides are diagonally cut, and the side base is
To prevent it from falling off, it is left without being cut diagonally. The insertion piece having such a shape and structure may be slightly tapered toward one end on the insertion side where either one of the upper surface and the lower surface in FIG. 3 is obliquely cut to facilitate insertion. .
This is also advantageous for fine adjustment of the capacity and correction of a slight looseness of the element clamping pressure after the element is dried. The contact area between the tightening band 7 and the insertion piece 8 is made larger to prevent loosening, and the corners of the two sides of the side portion may be arcuate.

A plurality of element units 3 having the above-described structure are arranged and connected, connected to the insulating bushing 2 and housed in a case, dried and filled with SF ₆ gas 10 to manufacture the gas-insulated high-voltage phase-advancing capacitor. did.

Further, the conventional gas-insulated high-voltage phase-advancing capacitor, which is a comparative sample, has the structure shown in FIGS. 4 to 6 and the insertion piece 8 whose tip is obliquely cut like the capacitor of the present invention.
Instead, it is a structure using a horn-shaped tightening auxiliary plate 9.

The above two types of capacitor samples have a rating of 3
Phase, 60 Hz, 6600 VAC, 100 kvar.

The test of the above-mentioned capacitor is conducted as a continuous durability test at an ambient temperature of 20 ° C., 60 Hz, 8250 VA.
C (rated voltage × 1.25) was applied for 3000 hours. The test results are shown in FIGS. 7, 8 and 9.

FIG. 7 shows the test time characteristics of the rate of change in capacity. The capacitor of the present invention shows a negative rate of change in capacity after 3000 hours.
While the value was 0.9%, which was extremely small and stable, the conventional capacitor had a large capacitance change rate of -4.8%.

FIG. 8 shows a tan δ test time characteristic. The tan δ value after 3000 hours of the capacitor of the present invention is 0.
While 030% or less showed extremely good characteristics, the tan δ of the conventional capacitor was 0.025 to 0.12.
It changed greatly with%.

FIG. 9 shows the test time characteristics of the tightening dimensional change rate of the element unit. The capacitor of the present invention has a stable dimensional change rate of the element unit after 3000 hours of 1.2%, which is extremely small and stable. On the other hand, the tightening dimensional change rate of the element unit of the conventional capacitor greatly changed to 6.0%. The tightening dimensional change rate of the element unit was calculated from the following formula.

[0016]

[Equation 1]

Further, although SF ₆ (sulfur hexafluoride) was used as the insulating gas in this embodiment, the insulating gas such as nitrogen gas, carbon dioxide gas, carbon tetrachloride gas, etc. similarly changes in capacity, tan δ, and element unit. It is possible to obtain a stable gas-insulated high-voltage phase-advancing capacitor with a small change in tightening dimension.

[0018]

In the gas-insulated metallized film capacitor of the present invention, by inserting the insert piece 8 whose tip is obliquely cut between the insulating plate 6 of the element unit 3 and the tightening band 7, fine adjustment of the capacity is performed. In addition, even if the capacitor element 5 contracts when a voltage is applied, the base portion on the side of the insertion piece 8 whose tip is obliquely cut is not obliquely cut and remains, so that it does not fall off from the tightening band.

Further, as shown in FIGS. 7 to 9 by comparing the characteristics of the present invention with those of the conventional capacitor, the capacitor of the present invention has excellent electrical characteristics, is stable, has a long life, and has high reliability. Can be obtained industrially and practically with great value.

[Brief description of drawings]

FIG. 1 is a structural diagram of a gas-insulated high-voltage phase-advancing capacitor that is an embodiment of the present invention.

FIG. 2 is a perspective view showing a structure of an element unit of a gas-insulated high-voltage phase-advancing capacitor which is an embodiment of the present invention.

FIG. 3 is a perspective view showing an example of the structure of an insertion piece with a tip cut obliquely, which is inserted between an insulating plate and a tightening band of an element unit according to an embodiment of the present invention.

FIG. 4 is a structural diagram of a conventional gas-insulated high-voltage phase-advancing capacitor.

FIG. 5 is a perspective view showing a structure of an element unit of a conventional gas-insulated high-voltage phase-advancing capacitor.

FIG. 6 is a perspective view showing a structural example of a tightening auxiliary plate of an element unit of a conventional gas-insulated high-voltage phase-advancing capacitor.

FIG. 7 is a test time characteristic of a capacity change rate.

FIG. 8 is a test time characteristic of tan δ.

FIG. 9 is a test time characteristic of the tightening dimensional change rate of the element unit.

[Explanation of symbols]

 1 Case 2 Insulation bushing 3 Element unit 4 Lead wire 5 Capacitor element 6 Insulation plate 7 Tightening band 8 Insert piece with a beveled tip 9 Tightening auxiliary plate 10 Insulating gas

Front page continuation (72) Masaaki Matsubara, Masaaki Matsubara, Oike Dori, Karasuma Higashiiri, Nakagyo-ku, Kyoto Prefecture Nakaike, Oike Dori, Karasuma Higashiiri 1st line, 191 Nakabori-cho, 4 Uehara Building, 3rd floor, Nichicon Corporation

Claims (1)

[Claims] 1. A case (1) and an insulating bushing (2)
A gas-insulated metallized film capacitor comprising an element unit (3), a lead wire (4), and an insulating gas (10), wherein the case (1) has a plurality of insulating bushings (2) on the outside. A plurality of element units (3) are housed inside and filled with an insulating gas (10). The element unit (3) is a plurality of flattened capacitor elements (5) wound with a metallized film. Collect, arrange the insulating plates (6) on both sides, fix with the tightening band (7), and insert the insert piece (the tip is obliquely cut between the insulating plate (6) and the tightening band (7). 8) Gas-insulated metallized film capacitor in which 8) is inserted.