JPH0955136A - Bushing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bushing having a condenser core which is not only fit for use in high-humidity air or in water-mixed oil but also has no difficulty in outdoor use. SOLUTION: An outer coating 3 comprizing a material, such as silicone rubber or EP rubber, which is excellent in tracking resistance and water resistance, is formed on a surface of a non-hygroscopic condenser core 2 which is made of a base material of a non-hygroscopic fiber such as PET wound up together with an electrode for adjusting electric field and is impregnated with a resin such as an epoxy resin and cured. Umbrella is provided integrally with the outer coating 3, and therefore outdoor use is allowed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a bushing used for electric power equipment such as a substation.

[0002]

2. Description of the Related Art A conventional dry bushing used in electric power equipment usually has a capacitor core wound around an electric field adjusting electrode with an insulating paper as a base material around a central conductor. However, in such a conventional bushing, since the insulating paper has a slight hygroscopic property, there is a possibility that the insulating property is gradually lowered by absorbing moisture in the atmosphere during long-term use.

Therefore, the present inventor is developing a non-hygroscopic capacitor core that does not use insulating paper. This non-hygroscopic capacitor core is under the condition (80%) that a conventional insulating paper-based capacitor core deteriorates its characteristics in several months.
In a heating and humidifying test at 90 ° C and 90% RH, no abnormality was found in the characteristics even after 1200 days had passed. This test condition is equivalent to 100 years of use under normal temperature and humidity conditions, and it has been confirmed that it can withstand use in humid air and oil mixed with water.

However, while this non-hygroscopic capacitor core has excellent characteristics as described above, it is difficult to provide the outer surface with tracking resistance and weather resistance, so that sunlight, rainwater, ozone, etc. There was a weakness that it was not suitable for outdoor use exposed to.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems and can not only withstand use in high humidity air or oil mixed with water, but also outdoors. It was made to provide a bushing having a capacitor core that does not hinder the use of the.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a non-hygroscopic fiber base material is wound up together with an electric field adjusting electrode on the surface of a capacitor core impregnated and cured with a resin. The outer cover is formed of a material having excellent tracking resistance and weather resistance. The non-hygroscopic fiber base material may be a PET fiber non-woven fabric. The resin with which the base material is impregnated / cured can be an epoxy resin. Further, the jacket can be silicone rubber or EP rubber.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a bushing of the present invention, and FIG. 2 is an enlarged sectional view of its head. The bushing shown is of a type that does not use a conventional insulator tube. In FIG. 1, 1 is a central conductor, 2 is a capacitor core, and 3 is a jacket integrally bonded to the outer surface of the capacitor core 2. The capacitor core 2 has a non-hygroscopic fiber such as a non-woven fabric of PET fiber as a base material, and a large number of aluminum foils or the like are inserted as electric field adjusting electrodes at intervals of 1 to 2 mm and wound up, and impregnated and cured with epoxy resin or the like. It is a thing.

The outer cover 3 is firmly adhered to the outer surface of such a capacitor core 2 so as to prevent voids and peeling, and is preferably made of silicone rubber or EP rubber. However, in order to vulcanize the EP rubber, conditions of high temperature and high pressure are required, which may affect the capacitor core 2 in some cases. Therefore, silicone rubber that can be vulcanized at a relatively low temperature and atmospheric pressure is used. It is more preferable to do.

In order to form the silicone rubber jacket 3 on the outer surface of the capacitor core 2, a jacket forming die is attached to the outer surface of the capacitor core 2 to seal it, and after vacuuming, 60 to 80 ° C. Inject the heated liquid silicone rubber.
Then, the rubber is vulcanized and cured to form a jacket.
In addition, it is preferable that the outer surface of the capacitor core 2 is preliminarily subjected to a primer treatment so that a gap or peeling does not occur between the outer cover 3 and the outer surface of the capacitor core 2.

As shown in FIG. 1, the cap 4 can be integrally formed on the jacket 3. Since the cap 4 can be thinly formed by the outer cover forming die, it is possible to secure a sufficient surface leakage distance without lengthening the entire length of the bushing, and it is possible to significantly improve the stain characteristic of the bushing. Become.

As shown in FIG. 2, not only the upper end surface of the capacitor core 2 is protected by the outer cover 3 being adhered, but also the gasket 5 is pressed by the reaction force of the spring 6 to seal the shaft, so that water is prevented. It is preferable to prevent intrusion from between the jacket 3 and the capacitor core 2. FIG.
In the above structure, the spring 6 is provided between the spring retainer 7 and the spring receiver 8, and the shaft retainer 7 is tightened with the nut 9 screwed to the center conductor 1 to perform shaft sealing.

Reference numeral 10 shown in FIG. 1 is a flange fitting, which is bonded to the lower end of the outer cover 3. This bushing can be attached to a power device by the flange fitting 10 for use.

[0013]

The bushing of the present invention described above is
It is a non-hygroscopic capacitor core with an outer coating made of a material with excellent tracking resistance and weather resistance, so it can withstand use in humid air or oil mixed with water. Besides, it has many advantages as follows. Unlike the conventional bushing, it does not require a porcelain tube or insulating oil to protect the capacitor core, so it can be made significantly lighter than conventional products. For example, rated voltage 8
With a 0.5kV bushing, the weight can be reduced to 1/4 that of the conventional product. Due to such weight reduction, it is also excellent in earthquake resistance and vibration resistance. Since it is a dry bushing without insulating oil, there is no risk of fire. Since the shade can be made thin together with the jacket,
The fouling property can be improved. Since the power equipment on the side to which the bushing is attached does not need a porcelain tube or a jacket, the length can be shortened and the diameter can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a bushing of the present invention.

FIG. 2 is an enlarged sectional view of a head.

[Explanation of symbols]

1 center conductor, 2 capacitor core, 3 jacket, 4
Caps, 5 gaskets, 6 springs, 7 spring retainers, 8 spring holders, 9 nuts, 10 flange fittings

Claims (4)

[Claims] 1. A non-hygroscopic fiber base material is wound up together with an electric field adjusting electrode, and an outer cover made of a material excellent in tracking resistance and weather resistance is formed on the surface of a capacitor core impregnated and cured with a resin. Bushing characterized by that. 2. The bushing according to claim 1, wherein the non-hygroscopic fiber base material is a nonwoven fabric of PET (polyethylene terephthalate) fiber. 3. The bushing according to claim 1, wherein the resin with which the base material is impregnated and cured is an epoxy resin. 4. The bushing according to claim 1, wherein the outer cover is silicone rubber or EP rubber.