JPS61171005A - 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 Field of Industrial Application The present invention relates to a capacitor in which a capacitor element made of a polypropylene film as an electrode material and a dielectric is wound, and in particular to a capacitor in which the above-mentioned capacitor is impregnated with insulating oil. Use film or insulating paper! l! In a capacitor that is used as an electric body and is made by winding together with electrode material and impregnated with insulating oil, the electrical and thermal energy causes deterioration of the insulating oil during a long period of use. Therefore, such capacitors have the disadvantage of not being able to maintain their initial electrical characteristics during long-term use.One way to overcome this disadvantage is to add antioxidants to the insulating oil. Alternatively, it has been proposed to mix a stabilizer such as a deterioration inhibitor, such as an epoxy stabilizer, a phenol stabilizer, or a phosphite stabilizer.

Regarding these, Tokuko No. 52-13623, Tokuko No. 5
2-24239, JP-A-53-35999, and JP-A-54-15158.

The use of such a stabilizer suppresses the decomposition of the insulating oil of the capacitor due to electrical and thermal energy during long-term use, and further suppresses the occurrence of a chain reaction of oil decomposition caused by the decomposition products. However, the dielectric loss value (tana value) of the insulating oil-impregnated capacitor itself cannot be improved.

The above-mentioned stabilizer itself is used for the purpose of hm the deterioration products of the insulating oil mentioned above, and for this purpose, the stabilizer has various functional groups, and the insulating oil with increased contamination is impregnated with the stabilizer. The improved capacitor has a higher capture rate of deterioration products generated during long-term use, thus improving the reliability of the capacitor. However, in this case, the tan δ value of the insulating oil-impregnated capacitor becomes worse.

Therefore, each stabilizer is added in a suitable amount to the insulating oil, but this does not improve the tan δ value of the insulating oil-impregnated capacitor, and the tan δ value of the insulating oil-impregnated capacitor is still poor, especially in the high temperature and high voltage range. It has some drawbacks.

Problems to be Solved by the Invention The above-mentioned insulating oil-impregnated capacitors are subject to restrictions in high potential gradient design because when tan δ increases at high temperatures and high voltages, the capacitors generate heat and may cause thermal breakdown. There was a problem.

Therefore, the purpose of the present invention is to improve the tan δ value characteristics and sound characteristics of an insulating oil-impregnated capacitor at high temperatures and high voltages, and to suppress damage caused by heat when high voltage is applied, thereby making it possible to design the capacitor with a high potential gradient. It's about doing.

Means for Solving the Problems The present invention provides a capacitor formed by winding a capacitor element consisting of a polypropylene film as an electrode material and a dielectric material, which is impregnated with an insulating oil mixed with a titanate coupling agent and epoxidized linseed oil. It's in the capacitor.

In the present invention, a polypropylene film is used as an insulator because its tan δ is small and superior to other plastic films.

Further, as the electrode material, any conventionally used material can be used.

In addition, the insulating oil used in the present invention is
acid ester, fatty acid ester, maleate ester 1
7 Ester such as malic acid ester M Edge m.

Hydrocarbon compound insulating oil such as alkylbenzene, diallylethane, triallyldiethane, dibenzyltoluene, dialkyldiphenyl, 1 alkylnaphthalene, 1 mineral oil, vegetable oil, liquid paraffin, polybutene, etc., or an insulating oil that is a mixture of two or more of these insulating oils. The vine titanate coupling agents used in the present invention include, for example, isopropyl triisostearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tris titanate, tetraisopropyl bis titanate, and tetrabis phosphite titanate 1.
Examples include bisoxyacetate titanate and isopropyltrioctanoyl titanate. Particularly preferred is isopropyl triisostearoyl titanate.

The mixing ratio of the titanate coupling agent and epoxidized linseed oil in the insulating oil is at least 0.02% by weight relative to the insulating oil.

However, if it is used in an amount of 10% or more, the specific resistance value of the insulating oil only slightly decreases and there is no particular problem, but it is not preferable from an economical point of view.

Impregnation of the capacitor with the insulating oil mixed with the titanate coupling agent and epoxidized linseed oil may be carried out by a known method.

Note that the insulating oil used in the present invention may contain various conventionally used stabilizers.

Function: In the insulating oil-impregnated capacitor according to the present invention, the t&nδ value can be significantly reduced, especially under high temperature and high voltage.
The heat generation of the insulating oil-impregnated capacitor due to energy loss, which is correlated with the tarna value, is significantly reduced, the occurrence of thermal breakdown can be suppressed, and a high potential gradient design becomes possible. Further, it is even better if various well-known stabilizers are added.

Example The present invention will be explained below with reference to Examples.

Example 1 Using a capacitor element in which zinc metal was vapor-deposited as an electrode on both sides of a 6 μm thick polypropylene film and wound,
This was impregnated with insulating oil mixed with dioctyl heptalate insulating oil at a ratio of 0.2% of various titanate coupling agents shown below and 1% of epoxidized linseed oil to insulate the electrostatic capacitance of μF. Oil-impregnated capacitors A to 0 were prepared in a conventional manner. A: Isoprobyl triisostearoyl titanate B:
Bisoxyacetate titanate 0: Tetrabisphosphite titanate For comparison, as a conventional example, dioctyl phthalate insulating oil was mixed with only epoxy stabilizer without titanate coupling agent or epoxidized linseed oil. Comparative capacitor D is a capacitor impregnated with
Comparative capacitor E was a capacitor impregnated with l/dioctyl acid insulation alone.

These 5 types of insulating oil impregnated capacitors A-1 100″
The results of measuring the relationship between the tan δ value and the voltage in C are shown in FIG. From FIG. 1, it can be seen that in capacitor X impregnated only with dioctyl heptatalate and conventional capacitor D impregnated with dioctyl phthalate containing a conventional epoxy stabilizer, as the tan δ value increases or the voltage increases, the performance deteriorates rapidly. However, it can be seen that capacitor D is slightly improved over capacitor E. Because of the voltage dependence of the tan δ values of these capacitors D and E, when designing a high potential gradient with these capacitors, it is difficult to avoid tan δ loss when applying voltage. A large amount of heat is generated1, which makes it difficult to design an economical high potential gradient.

In contrast, the insulating oil-impregnated capacitor A~0 according to the present invention
It can be seen that the tana value in the high voltage range can be significantly reduced compared to the capacitors D and E described above. Therefore, capacitors A to 0 can withstand high voltage use, and can be designed with a higher potential gradient than conventional capacitors D and E.

In addition, Table 1 below shows the capacitor A-I [i
Table 1 shows the results of a withstand voltage test conducted on each of J at 100° C. while increasing the voltage stepwise.

Table 1 It can be seen from Table 1 that the insulating oil impregnated capacitors A to 0 according to the present invention are superior in dielectric strength characteristics to the comparative condensers 9'D and E. This is because, as shown in FIG. 1, the insulating oil impregnated capacitors A~0 according to the present invention have a small tana value in a high voltage range and generate less heat. Therefore, it can be seen that the capacitor according to the present invention allows a higher potential gradient gauze than the conventional comparative capacitor.

Effects of the Invention The insulating oil-impregnated capacitor according to the present invention has a
It has the excellent effect of improving the an δ value and providing a capacitor that can be designed with high withstand voltage and high potential gradient.

[Brief explanation of the drawing]

Claims (1)

[Claims] 1. A capacitor formed by winding a capacitor element made of a polypropylene film as an electrode material and a dielectric, characterized in that it contains an insulating oil mixed with a titanate coupling agent and epoxidized linseed oil.