JPS603114A - Oil-immersed 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 improvements in oil-immersed capacitors that are widely used for power factor correction, for driving and operating motors, and as ballasts for lighting equipment. be.

Conventional structure and its problems Oil-immersed capacitors, which are made by wrapping electrode paper with vapor-deposited metal layers on both sides and plastic film as a dielectric layer and impregnating them with insulating oil, have traditionally been used in the above fields. Widely used. Increasing the potential gradient of such oil-immersed capacitors not only makes the plastic film thinner, but also reduces the consumption of insulating oil and capacitor containers, as well as lowers the price of capacitors. , a significant effect in terms of resource saving can be expected.

Conventionally, in oil-immersed capacitors using electrode paper, the occurrence of partial discharge has been suppressed due to good impregnation properties, and it also has the self-healing property unique to vapor-deposited metals, so it is possible to use a structure that does not use insulating oil. Compared to some dry capacitors and oil-immersed capacitors using metal foil or metallized film, a higher potential gradient can be set.

In order to further increase the potential gradient of such an oil-immersed capacitor, it has been conventionally proposed to increase the resistance value of the electrode layer on the side where the capacitor is formed to improve self-healing properties.

FIG. 1 is a sectional view of a conventional example proposed for this purpose. On both sides of the electrode paper 10, a vapor-deposited metal electrode layer 2 made of zinc is formed, consisting of a low resistance part of 9 Ω/hole or less and a high resistance part of 20 to 200 Ω/hole, and a plastic film 3
Roll it over and over.

A non-halogenated insulating oil 4 is filled between the layers, and the electrodes are led out using a metal sprayed part 5 for leading out the electrodes.

The reason why the vapor-deposited metal electrode layer 2 has a low resistance on the electrode-leading metal sprayed part 5 side is to reduce the contact resistance between the electrode-leading metal sprayed part 5 and the vapor-deposited metal electrode layer 2.

However, although such a configuration improves self-healing performance, the dielectric loss tangent value increases due to the high resistance on the capacitor formation side, and heat dissipation to the outside through the trenched electrode layer is also suppressed. In particular, a problem arose in that thermal deterioration and thermal breakdown were likely to occur under high temperature and high voltage conditions. Regarding this point, it has been proposed to insert metal foil between the layers and dissipate the heat to the outside through this, but this inevitably increases the volume of the element, and the original purpose of making oil-immersed capacitors smaller and lighter is to reduce the weight. It was not possible to achieve a price reduction.

As is clear from the above explanation, oil-immersed capacitors in which the electrode layer on the capacitance formation side has high resistance still have problems such as thermal deterioration and thermal destruction under high temperature and high voltage, and have good self-contained properties. The current situation was that the characteristic of resilience was not fully utilized.

Purpose of the Invention In view of the above problems of oil-immersed capacitors, the present invention achieves a high potential gradient by improving the dielectric loss tangent value itself under high temperature and high voltage, thereby realizing a smaller and lighter capacitor and a lower cost. The purpose is to

Structure of the Invention As a further structure, the present invention has a vapor-deposited metal electrode layer made of zinc on both sides, and the resistance value of the vapor-deposited metal electrode layer is 9Ω/mouth or less on the side of the metal sprayed part for electrode lead-out. On the capacitor forming part side, a non-halogenated insulating oil containing one or more types of silane coupling agent is applied to the capacitor element, which is made by overlapping and winding electrode paper within the range of 20 to 200 Ω/port and a plastic film as a dielectric material. It is impregnated with
Description of Examples A silane coupling agent is usually represented by the general formula %. Here, X is a hydrolyzable group bonded to a Si atom, and is an alkoxy group.

Representative examples include acyloxy groups and halogens.

Further, Y is an organic functional group, and typical examples thereof include a vinyl group, an amino group, an imino group, a chloro group, an epoxy group, a mercapto group, a peroxy group, and a ureido group. Note that Y is bonded directly or directly to the Si atom via the organic group R. An example of such a silane coupling agent is γ-methacryloxypropyltrimethoxysilane.

γ-glycidoxyglobiltrimethoxysilane.

γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxylan, γ-aminopropyl L
ethoxysilane, N-β(aminoethyl)γ-teminopropyltrimethoxysilane.

N-β (amine ethyl) γ-aminopropylmethyldimethoxysilane, vinyl tris (β-methoxyethoxy)
Silane, vinyltriethoxysilane.

There are vinyltrichlorosilanes, etc., and the object of the present invention can be achieved when one or more of these is added to a non-loginated insulating oil. Furthermore, the amount of the silane coupling agent added is desirably about 0.1 to 10% by weight relative to the insulating oil. This is because if it is less than 0.1%, it is difficult to have a noticeable effect, and if it is mixed in more than 10%, the insulation resistance value will only decrease slightly and there will be no problem with the characteristics, but silane coupling Since agents are generally expensive, this poses a cost problem.

Examples of the non-halogenated insulating oil used in the present invention include aromatic hydrocarbon insulating oil, aliphatic hydrocarbon insulating oil, and mixtures thereof. For example, phthalate ester, maleate ester, fumarate ester,
Alkylbenzene oil.

A typical example is silicone oil, and when one of these oils, a mixed oil, or a mixed oil with other non-halogenated insulating oils is used, remarkable effects can be obtained.

Furthermore, a heat stabilizer,
It is also widely practiced to add up to a few percent of epoxy additives to stabilize the voltage and prevent oxidative deterioration.
Also in this case, the object of the present invention can be achieved by mixing the silane coupling agent into the insulating oil.

In addition, examples of the plastic film used in the present invention include polypropylene film, polyethylene film, polyethylene terephthalate film, polycarbonate film, etc., and remarkable effects can be obtained when one or a mixture of these films is used. can.

As a specific example of the present invention, an oil-immersed capacitor having the structure shown in FIG. The case of a capacitor will be explained below.

FIG. 2 shows the relationship between the applied voltage and the dielectric loss tangent value at 100°C. P is a conventional product with the configuration shown in Figure 1 and using only DOP as the insulating oil, ■, ■,
(2) is an example product of the present invention in which one weight of the silane coupling agent shown in the following table was added to DOp.

In the conventional products shown in the table, the dielectric loss tangent value increases rapidly under high temperature and high voltage, but it can be seen that this is significantly improved in the example products of the present invention.

FIG. 3 shows the capacitor P, 1. I1. I [100 of I
This figure shows the results of a step-pressure breakdown test at ℃. Start charging with a voltage of 300V, and apply 5V every 24 hours.
The voltage was increased by 0V, and the voltage at which the capacitor broke down was defined as the withstand voltage. Clearly, in the example products of the present invention, a high withstand voltage far exceeding that of the conventional products is obtained.

The above explanation was for the case where the silane coupling agents shown in the table were added, but similar results were obtained when other silane coupling agents were added. Similar results were also obtained when insulating oil other than DOp was used. Furthermore, similar results were obtained when polyethylene film, polyethylene terephthalate film, polycarbonate film, etc. were used as the dielectric material in addition to PP film.

Effects of the Invention According to the present invention, by adding a silane coupling agent to the non-loginated insulation of an oil-immersed capacitor, an epoch-making product that can withstand high potential gradients far superior to conventional products and is small and lightweight. This provides an excellent effect that makes it possible to realize a capacitor with high performance.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view of an oil-immersed capacitor, Fig. 2 is a comparative characteristic z diagram showing the relationship between applied voltage and dielectric loss tangent value of an oil-immersed capacitor in an embodiment of the present invention and a conventional example, and Fig. 3 is the same. FIG. 3 is a comparative characteristic diagram showing the results of a step pressure-up breakdown test. 1... Electrode paper, 2... Vapor deposited metal electrode layer, 3
...Plastic film, 4...Non)
10-gen insulating oil, 5...Metal sprayed part for electrode lead-out. Name of agent: Patent attorney Toshio Nakao and 1 other person
Figure 1 Figure 2 A) U Black '1t) i (vλ Figure 3 Lock 24 Hr/lt)/v

Claims (1)

[Claims] It has a vapor-deposited metal electrode layer made of zinc or the like on both sides, and the resistance value of the vapor-deposited metal electrode layer is 9Ω on the metal sprayed part side for electrode derivation.
One or more types of silane coupling agents were added to a capacitor element made by wrapping electrode paper and a plastic film as a dielectric material in a layered manner. Oil-immersed capacitor impregnated with non-halogenated insulating oil.