JPS6028106A - 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 Field of Industrial Application The present invention relates to an oil-immersed capacitor used for electric power, electrical equipment, communications, and the like.

Conventional structure and problems Conventional oil-filled capacitors use synthetic insulating oils such as ester oils such as phthalate esters and hydrocarbon-based insulating oils such as alkylbenzene (AB) and diallylalkane (DAA). Used alone or in combination. In practice, stabilizers such as epoxy stabilizers, phenol stabilizers, and phosphite stabilizers are added to the insulating oil in required amounts. These additives can cause chain decomposition reactions during long-term use of oil-immersed capacitors, such as the insulating oil deteriorating due to thermal and electrical energy, increasing decomposition products, and promoting the decomposition reaction. Because it becomes impossible to maintain the initial electrical characteristics for a long time,
It was added to stop such chain decomposition reactions. For the same purpose, a special silane compound was added to halogenated synthetic insulating oil1, but in any case, conventional insulating oil has a chemical reaction with residual impurities and decomposition products in the insulating oil. Stabilizers were added to stop the chain decomposition reaction, and the initial electrical properties were maintained over a long period of time. These conventional insulating oil all-aluminum foils are bound to electrodes, and capacitor elements are wound with paper scraps or plastisol fumelum as a dielectric material, and electrode paper and dielectric film are wound to form one electrode by vapor-depositing both sides of the paper. Oil-immersed capacitors have been provided by impregnating capacitor elements made by spinning a paper or plastic film, and by impregnating capacitor elements by forming all electrodes on a surface dielectric film soil and winding it. .

Figure 1 shows 100 oil-filled capacitors with a conventional configuration.
It shows the tanδ-voltage characteristics at °C. Capacitor A was impregnated with alkylbenzene (1% epoxy stabilizer added) and capacitor B was impregnated with dioctyl phthalate (1% epoxy stabilizer added). This is the case. The element structure of these capacitors is one in which electrode paper, which is formed by vapor-depositing both sides of the paper to form one electrode, and a polypropylene dielectric film are wound together.

In addition, the electrode is made of zinc deposited by vacuum evaporation, and electrodes made of aluminum evaporation have similar characteristics to those of zinc. However, in the case of zinc, the tan δ appears particularly large, so we will focus on the case of zinc. explain. The measured voltage was an AC 60H2 voltage, and the horizontal axis of 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 tan δ will be large and cause thermal breakdown. It was limited to areas with low potential gradients.

Purpose of the Invention The present invention provides an unprecedented low t in a high temperature and high electric field region.
It is an object of the present invention to provide an oil-immersed capacitor having an and delta characteristics, and therefore to provide a high voltage capacitor that is less likely to cause thermal breakdown. A capacitor element having at least two electrodes and a dielectric material interposed between the electrodes is impregnated with an insulating oil containing an additive.

Dioctyl adipate is used as the main insulating oil, and at least one type of silane coupling agent is used as the additive. Addition of various conventional stabilizers to this is not a problem and is included in the present invention.

EXAMPLE DESCRIPTION The additive has the following general formula % where RIFi hydrogen or l'iC1-C4 alkyl and R2 is C1-C8 alkylene or
Substituted or unsubstituted arylene, R3 is C1-C
8 alkyl, C1-C8 alkoxy, C6-01g substituted or unsubstituted aryl, 01-C8 acyloxy or C6-C18 substituted or unsubstituted aryloxy, and R4 and R5 are C1-C8 alkoxy, C1-C8
8 acyloxy or C6-018 substituted or unsubstituted aryloxy) or the following general formula (wherein R1 is 01-C8 alkylene or C6-C1
8 substituted or unsubstituted arylene, R2 is Cl
NC8 alkyl, 01-C8 alkoxy, 06-C18
substituted or unsubstituted aryl, 01-C8 acyloxy or 06-01s substituted or unsubstituted aryloxy, where R3 and R4 are C1-C8 alkoxy, 01
-C8 acyloxy or U6-C18 substituted or unsubstituted aryloxy) or the following general formula (wherein R1 is hydrogen or 01-C4 aminoalkyl and R2 is ClNC8 Alkylene or 06-C18
Substituted or unsubstituted arylene, R3 is Cx-0
8 alkyl, C1-0s alkoxy, C6-018 substituted or unsubstituted aryl, 01-C8 acyloxy or C6-C18 substituted or unsubstituted aryloxy, R4 and R5 are Ox-Ca alkoxy, 01-C
8 acyloxy or 06-018 substituted or unsubstituted aryloxy) or the following general formula (wherein R1 is 01-C8 alkylene or 06-C1
8-substituted or unsubstituted arylene, R2 is ClN
C8 alkyl, 01-C8 alkoxy, 06-018 substituted or unsubstituted aryl, C1-C8 acyloxy or C6-C18 substituted or unsubstituted aryloxy, R3 and R4 are C1-cII alkoxy, Cx
-1cs acyloxy spanning 06-018 substituted or unsubstituted aryloxy) or the following general formula % (wherein R1 is 01-C8 alkylene or C6-C1
8 substituted or unsubstituted arylene, R2IdC1
~C8 alkyl, C1-C8 alkoxy, C6-C18
substituted or unsubstituted aryl, 0r-Cs acyloxy or C6-G1g substituted or unsubstituted aryloxy, R3 and R4 are C1-C8 alkoxy, 01
-C8 acyloxy or 06-C18 substituted or unsubstituted aryloxy) or furthermore the following general formula % (wherein R1 and R3 and R5 are C1-C8 alkylene or C1-C8 alkoxy, R2 is hydrogen,
C1-C8 alkyl, C1-C8 alkoxy, 06-C
I8 substituted or unsubstituted Ryl, C1-C8 acyloxy or 06-018 substituted or unsubstituted aryloxy, R4 and R6 are hydrogen, C1-C8 alkoxy, 01% C8 acyloxy or 06-C18 substituted or unsubstituted (selected from aryloxy) alone or in combination.

Among them, preferred silane coupling agents are as follows.

(b) γ-methacrylate xyglobiltrimethoxy 7
Run H3 CH2=C-C-0-C3H6Si(OCH3)3I (b) T-glycidoxyglobiltrimeth, xysilane GHz-CHCHzOC+HGSi(OCH3)3\1 HN-β(aminoethyl)T-aminopropyltrimethoxy Silane H2N (zH4NHC3H6Si(OCH3) 3)
N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane H2NC2H4NHC3H6s1 (OCH3゜H3 mr-aminopropyltriethoxysilane (to) γ-
Mercaptoglobil trimethoxysilane H3 (3H6s
i(OCH3)3 (g) γ-chloropropyltrimethoxy 7-ran CdC
3H6Si(OCH3)3 (t) Vinyltris(β-methoxyethoxy)silane CH2=CH81(OCzHsOCH3)3 The silane coupling agent mentioned here has two or more functional groups in the molecule, and usually the functional 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 Si atoms, such as alkoxy groups, acyloxy groups (especially acetoxy groups), halogens (especially chlorine)
Y represents various organic functional groups, such as vinyl group, amino group, imino group, etc.
Chlor group, epoxy group, mercapto group, peroxy group,
A typical example is an organic functional group containing a ureido group, which is bonded to the S1 atom via the organic group R or directly. At least one type of silane coupling agent is added in an effective amount to the main insulating oil, and the effective amount is 0.02 wt% or more, preferably Q1 wt% or more, based on the main insulating oil. Up to awt% (d), the initial dielectric properties of electrical equipment at high temperatures improve as the amount added increases, but beyond 3 wt%, the initial dielectric properties did not improve even if the amount added was increased.

However, it exhibits all initial properties that are far superior to those without additives, and exhibits excellent electrical dielectric properties even at an additive amount of about 10 wt%. Furthermore, if the amount added is increased to 20-3wt%, the initial properties will temporarily deteriorate, but the properties will dramatically improve after voltage aging treatment. However, the current silane coupling agent is extremely expensive. Therefore, the cost of the oil-immersed capacitor is extremely high, so at present, the preferred addition amount range is from 0.1 wt.% to 10 wt.%.

The dielectric material used as the electrodes constituting the capacitor is Zn or A4.
Electrodes made by vapor-depositing and directly metallizing, or A7 foil are used as electrodes. Furthermore, if a round etched electrode is used to alleviate the electric field concentration at the end of the fully folded electrode of the A5 foil, corona discharge can be suppressed.

As the dielectric material constituting the capacitor, synthetic resin, aluminum, or paper is used. In particular, when using a roughened synthetic resin film (for example, a roughened polypropylene film) that improves impregnability, the film itself has low dielectric loss and good impregnation, resulting in a high corona development voltage and excellent high-temperature, high-voltage properties. A concrete example of the present invention will be described below. FIG. 2 shows an oil-immersed capacitor according to the present invention.

It represents the initial tan δ at °C, and the capacitor element configuration is the same as in FIG. The characteristics in this case are that 11 wt% of epoxidized soybean oil is added to dioctyl adipate, and γ
-methacryloxyglobil trimethoxysilane f, 1
Capacitor C impregnated with insulating oil added with 1 wt% and epoxidized soybean oil f 1 wt% in dioctyl adipate.
and γ-mercaptoglobil trimethoxysilane 11wt
These are the characteristics of capacitor D impregnated with insulating oil containing 11 wt % of epoxidized soybean oil and 11 wt % of epoxidized soybean oil added to dioctyl adipate and capacitor E impregnated with insulating oil containing 11 wt % of γ-chlorobutη pyrutrimethoxysilane. As can be seen from Figure 2, the oil-immersed capacitor of the present invention exhibits lower softness/tan δ characteristics than the conventional oil-immersed capacitor; therefore, the oil-immersed capacitor of the present invention can be used at high temperatures and with a sufficiently higher potential gradient than the conventional oil-filled capacitor. be able to.

Effects of the Invention As described above, according to the present invention, there is no sudden increase in tan δ in the high temperature and high potential gradient region seen in conventional oil-immersed capacitors, making it impossible to use conventional capacitors. It is possible to provide an excellent oil-immersed capacitor that can be used even at high temperatures and high potential gradients.

[Brief explanation of the drawing]

FIG. 1 is an initial tan δ-potential gradient characteristic diagram of a conventional oil-immersed capacitor, and FIG. 2 is an initial tan δ-potential gradient characteristic diagram of an oil-filled capacitor according to an embodiment of the present invention. Name of agent: Patent attorney Toshio Nakao and one other person. Fig. 1 40 60 Bo foo f20 Sense I stand Ishi Page Cliff (V//lL) Fig. 2 40 60 80 100 120

Claims (1)

[Claims] An oil-immersed capacitor impregnated with insulating oil made by adding at least one type of silane coupling agent to dioctyl adipate.