JPS609006A - Oil-filled condenser - 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 applications The present invention is applicable to electrical equipment including electric power.

This relates to oil-immersed capacitors used for communications, etc.

Structure of conventional examples and their problems Conventional oil-filled capacitors use synthetic insulating oils such as ester oils such as fucuric acid esters and phosphoric acid esters, and hydrocarbon-based insulating oils such as alkylbenzene (AB) and diallylalkane (DAA). Insulating oil was used alone or in combination. In reality, stabilizers such as epoxy stabilizers, phenol stabilizers, and phosphite stabilizers are added to the insulating oil in required amounts. During this time, the insulating oil deteriorates due to thermal and electrical energy, and decomposition products increase, which in turn causes a chain decomposition reaction that advances the decomposition reaction, making it impossible to maintain the initial electrical properties over a long period of time. , was added to stop such chain decomposition reactions. Some halogenated synthetic insulating oils had special silane compounds added to them for the same purpose, but in any case, conventional insulating oils caused chain decomposition due to chemical reactions with residual impurities and decomposition products in the insulating oil. Stabilizers were added to stop the reaction, and the initial electrical properties were maintained over a long period of time. These conventional insulating oils are used to create a capacitor element that is wound with aluminum foil as an electrode and paper or plastic film as a dielectric, or by evaporating both sides of the paper and winding the electrode paper and dielectric film to form one electrode. A -C oil-immersed capacitor has been constructed by metallizing a capacitor element, paper or plastic film, forming an electrode directly on a dielectric film, and impregnating the wound capacitor element with the electrode.

Figure 1 shows the conventional configuration of an oil-immersed capacitor V.
It shows the tan δ-voltage characteristics at °C, capacitor A impregnated with alkylbenzene (added 1% epoxy stabilizer), capacitor B impregnated with octyl fucrate (added 1% epoxy stabilizer), and noarylethane 6.
To 0vo1% and triisopropylphenylphos ~ Toy 0
These are the characteristics of a capacitor C impregnated with an insulating oil made by adding 1% of an epoxy stabilizer to a mixed oil of 4% of β. It's -1.
The structure of these capacitor elements is one in which two single-sided metalized polypropylene films are stacked and wound, and the film surface is a roughened film with unevenness formed thereon, so that the impregnating agent is easily impregnated between the film layers. ing. It's a size.
The electrode is made of zinc deposited by vacuum evaporation, and an electrode made of 1 aluminum evaporation has similar characteristics to that of zinc, but tan δ appears particularly large in the case of zinc, so the case of zinc will be explained. The measurement voltage was an AC 6 ohtz voltage, and the horizontal axis in FIG. 1 represents the potential gradient obtained by dividing the applied voltage by the film thickness. According to this, the higher the potential gradient, the higher the tan δ. Therefore, if these conventional oil-immersed capacitors impregnated with insulating oil are used under a high potential gradient, the heat generated by the increase in jan δ will be large and cause thermal breakdown. Its use was limited to areas with low potential gradients.

Furthermore, if this type of capacitor is left at a high temperature of 80°C to 100°C for a long period of time, the plastic film will swell or dissolve into oil, resulting in an extremely low adhesive strength between the plastic film and the vapor-deposited electrodes, which will cause the plastic film to swell and dissolve into the oil. Simply doing so will result in the electrode peeling off, resulting in extremely poor electrode stability.
Therefore, when a capacitor is used for a long time, the capacitance decreases and the dielectric loss rate tends to increase.

For these reasons, it has been difficult to commercialize the miniaturization and low-loss plastic films that have been sought for oil-immersed capacitors from the viewpoint of resource and energy conservation.

Purpose of the Invention The present invention aims to reduce the size of oil-immersed capacitors by using a dielectric film with a high potential gradient, or to reduce the size of oil-immersed capacitors by using a dielectric film with a high potential gradient. The aim is to make mapped plastic film capacitors practical and to save resources and energy.

Structure of the Invention As a structure for this purpose, the present invention impregnates a capacitor element consisting of at least two electrodes and a dielectric interposed between the electrodes with an insulating oil consisting of a main insulating oil and an additive gradually added thereto. The main insulating oil is either an insulating oil consisting essentially of unsaturated fatty acid glycerin ester or a mixture of an insulating oil consisting essentially of unsaturated fatty acid glycerin ester and an organic oil compound, and additives. is a silane coupling agent.

Description of Examples Unsaturated fatty acid glycerin esters are generally called vegetable oils, and include castor oil, linseed oil, soybean oil, cottonseed oil, rapeseed oil, sesame oil, camellia oil, olive oil, tung oil, corn oil, peanut oil, and sunflower oil. This includes oil, etc. Even if these vegetable oils are modified and used as necessary, there is no problem.

Sialylalkane is also an organic oily compound.

Triallyl alkanes, oligoallyl alkanes such as dibenzyltoluene, alkylbenzenes, alkylnaphthalenes, alkyldiphenyls, mineral oils.

Hydrocarbon insulating oils such as polybutene, phthalate esters, and fatty acid (dibasic) esters.

Ester oils such as fumaric acid ester, maleic acid ester, epoxylated ester, trimellitic acid ester, penzyl neoalkyl carbonate, xylyl tolylsulfone, alkyldiphenyl ether, etc. are used alone or in combination.

Even if various conventional stabilizers are added to these insulating oils, there is no problem.

The additive has the following general formula R, R3 11 (wherein R1 is hydrogen or C4-C4 alkyl,
R2 is C4-C8 alkylene or 06-018 substituted or unsubstituted arylene, R3 is C4-C8 alkyl, 01-CB alkoxy, 06-CI8 substituted or unsubstituted aryl, 01-C8 acyloxy or 06
~C18 substituted or unsubstituted meroxy; 5. R
4 and R5 are selected from C1-C8 alkoxy, C1-C8 acyloxy or C6-CI8 substituted or unsubstituted aryloxy), or the following general formula (wherein R1 is selected from C4-C8 Alkylene or 06-C1
8-substituted or unsubstituted arylene, R is 01-C
8 alkyl, 01-C8 alkoxy, 06-C18 substituted or unsubstituted aryl, 01-C8 acyloxy or C6/-C18 substituted or unsubstituted aryloxy, and R5 and R4 are C7-C8 alkoxy, 01-
C8 acyloxy or C8 substituted or unsubstituted aryloxy) or the following general formula (wherein R1 is hydrogen or C4-C4 aminoalkyl and SR2 is C4-C8 alkylene or C6-C18
Substituted or unsubstituted arylene, R6 is C4-C
8 alkyl, C1-C8 alkoxy, 06-''+8 substituted or unsubstituted aryl, C4-C8 acyloxy or 06-018 substituted or unsubstituted aryloxy, 6
! l, R4 and R5 are C1-C8 alkoxy, 01-
C8 acyloxy or 06-C18 substituted or unsubstituted aryloxy.
alt-substituted or unsubstituted arylene, R2 is 01
~C8 alkyl, 01~C8 alkoxy, 06~C48
substituted or unsubstituted aryl, 01-C8 acyloxy or 06-C+8 substituted or unsubstituted aryloxy, R3 and R4 are C1-C8 alkoxy, 01
-C8 acyloxy or C6-01B substituted or unsubstituted aryloxy), or 1 has the following general formula % (wherein R1 is 01-C8 alkylene or C6 ~C1
8-substituted or unsubstituted arylene, and 1R2 is C1-
G8 alkyl, C1-C8 alkoxy, 06~''+8 substituted or unsubstituted aryl, 01-C8 acyloxy or 06-C18 substituted or unsubstituted aryloxy, and zR3 and RaUC1-C8 alkoxy, C1~
C8 acyloxy or C6-018 substituted or unsubstituted aryloxy); C1-C8 alkoxy, p, R2 is hydrogen,
01-G8 alkyl, 01-c8 alkoxy, G6-C
+a substituted or unsubstituted aryl, C1-C8 acyloxy or 06-"1B substituted or unsubstituted aryloxy, R4 and R6 are hydrogen, 01-08 alkoxy, C4-G8 acyloxy or C6-Oj8 substituted or unsubstituted (selected from substituted aryloxy) are used alone or in combination.

Among them, preferred 7-run coupling agents are as follows.

(a) γ-methac 1noloxypropyltrimethoxysilane OH5 □ OH,,:= G -C-0-C3H,Si (OCH
3) 31 ((b) γ-glycidoxypropyltrimethoxysilane 0 N-β(aminoethyl)γ-aminopropyltrimethoxysilane H2N02H4NHC; 3H6S, (OCH3) to 5)
N-β (aminoethyl) γ-aminopropylmethylcymethoquine silane OH3 (e) γ-aminopropyltriethoxysilane H2N
G3H65i(OC,,H5)3(to) γ-mercaptopropyltrimethoxysilane H3C3H6S, (O
CH5)3 (g) γ-chloropropyltrimethoxysilane CβC
3H6S□(OCH5)3 H) Vinyltris(β-methoxyethoxy)silane OH2: CH8, (QC2H40CH6)3 The silane coupling agent mentioned here has two or more functional groups in its molecule, and usually The groups are silicon compounds with different reactivities. The silane coupling agent can usually be expressed by the general formula %. Here, x1 to x3 represent hydrolyzable groups bonded to the S□ atom, typical examples of which are alkoxy groups, acyloxy groups (especially acetoxy groups), and halogens (especially chlorine). Represents the organic functional group of each ridge, such as vinyl group, amino group, fuimino group,
Chlor group, epoxy group, mercagut group, peroxy group,
Typical examples are polyfunctional groups containing ureido groups and the like, which are bonded to the Si atom via an organic group R or directly.

In the oil-filled capacitor of the present invention, at least one type of silane coupling agent is applied to the insulating oil consisting essentially of unsaturated fatty acid glycerin ester alone or mixed with an organic oil compound. The effective amount is 0.02 wt % or more (N digits) or more, preferably 1 wt % or more, based on the insulating oil. Up to 3wt%, the initial dielectric properties of oil-immersed capacitors at high temperatures improve with the addition amount, but beyond 3wt%, the initial characteristics did not improve even if the addition amount increased. O exhibits excellent initial properties and exhibits excellent electrical dielectric properties even with a sliding amount of about 1 Qwt%.
When increasing to 30 wt%, the initial characteristics are temporarily bad, but by voltage aging treatment, the thermal characteristics are dramatically improved. However, current silane coupling agents are extremely expensive, resulting in extremely costly oil-immersed capacitors;
A preferable addition amount range is 0 wt Soybean.

As the electrodes constituting the capacitor, electrodes made by directly metallizing a dielectric material by depositing zinc, aluminum, etc., or aluminum foil are used as electrodes. If the edges of the aluminum foil are folded back to reduce the electric field concentration at the end of the electrode, round-edge electrodes can be used to suppress corona discharge.

Synthetic resin film or paper is used as the dielectric material constituting the capacitor. In particular, when using a roughened synthetic resin film (for example, a roughened polypropylene film) that increases impregnability, the dielectric loss of the film itself is small and the impregnability is good, so the corona onset voltage is high and the oil has particularly excellent high temperature and high voltage resistance properties. It is possible to provide input type capacitors.

Hereinafter, specific examples of the present invention will be described.

Figure 2 shows an oil-immersed capacitor according to the present invention at 100°C.
represents the initial jan δ at , and shows the case with a zinc-deposited electrode that increases tan δ.

It has been confirmed that a similar effect can be obtained for capacitors having aluminum-deposited electrodes.

The oil-immersed capacitor shown here has the same capacitor element configuration as shown in Figure 1, with the insulating oil being linseed oil and an epoxy stabilizer.
In the case of capacitor D impregnated with insulating oil containing 1wt% and 2wt% of γ-methacryloquinepropyltrimethoxysilane, two sheets of electrode paper with zinc deposited on both sides of the paper, and two sheets of polypropylene dielectric film. A capacitor element consisting of castor oil, 1 wt% epoxy stabilizer and γ-
1wt of methacrylocypprobil trimethoxysilane
This is the case of capacitor E which is impregnated with insulating oil containing 5%. As can be seen from Figure 2, the oil-immersed capacitors of the present invention exhibit much superior low tanδ characteristics than conventional oil-immersed capacitors, and can be used at higher temperatures and sufficiently higher potential gradients than conventional oil-filled capacitors. can. In addition, the oil-immersed capacitor according to the present invention has extremely low swelling property and has particularly strong adhesive strength between the metal thin film of the metallized plastic film and the plastic film. It has become.

Figure 3 also shows an oil-immersed type capacitor according to the present invention at 100°C.
The capacitor element configuration is the same as in FIG. 1. In this case, the insulating oil is capacitor F impregnated with an insulating oil made by adding 1 wt% each of epoxy stabilizer and γ-methacryloxypropyltrimethoxysilane to a mixed oil of 70 vol 1% linseed oil and 30 vo β dioctyl phthalate, and 90 vo β castor oil. This capacitor G is impregnated with an insulating oil obtained by adding 1 wt % of an epoxy stabilizer and 3 wt % of γ-methacryloxypropyltrimethoxysilane to a mixed oil of 10 vo β of diallylethane and diallylethane. These oil-immersed capacitors named V according to the present invention also have low tan δ characteristics and can be used at higher temperatures and higher potential gradients than conventional capacitors, and it has been confirmed that the adhesion strength of the electrodes does not pose any practical problems. There is. However, it is desirable that the mixing ratio of the hydrocarbon-based synthetic insulating oil is at most 40x0β or less.

In addition, what was mainly mentioned here was an oil-immersed capacitor having electrodes made of vapor-deposited zinc, which has particularly poor tanδ characteristics, but oil-immersed capacitors having electrodes made of vapor-deposited aluminum and aluminum foil were also mentioned. A similar effect can be obtained for oil-immersed capacitors made by winding dielectric materials such as plastic film or paper, either singly or in combination.

Effects of the invention (/cAccording to the present invention, the solubility and swelling property of the plastic film are extremely low, and the ta is unprecedentedly low.
Since we can provide oil-immersed capacitors with nδ characteristics,
For example, in oil-immersed metallized plastic film capacitors, the adhesive strength between the electrode and the plastic film is extremely strong, and the capacitor can be used even at high potential gradients where conventional capacitors cannot be used.

[Brief explanation of drawings]

FIG. 1 is an initial JAN δ-potential gradient characteristic diagram of a conventional oil-immersed capacitor, and FIGS. 2 and 3 are initial JAN i5-potential gradient characteristic diagrams of an oil-immersed capacitor according to an embodiment of the present invention. Name of agent: Patent attorney Toshio Nakao (1st person)
Picture compensation r branch i'14. 8 CV/, a) Figure 2 Den Itate 4 @ Guit ('7.u)

Claims (1)

[Claims] Impregnated with an insulating oil containing at least one type of silane coupling agent added to an insulating oil consisting essentially of an unsaturated fatty acid glycerin ester alone or a mixed oil of an insulating oil consisting essentially of an unsaturated fatty acid glycerin ester and an organic oil compound. Oil-immersed capacitor.