• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.7
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• pp.578-583
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• 2001

The bushing for high voltage and large and power should endure weight of itself and force of pushing from contact with circuit breaker. Like this, epoxy mold bushing has to be strong without fault. However, the external circumstances and internal factors was caused by partial discharge, flashover and dielectric breakdown. Therefore, to remove external factor of defect and to prevent the internal cracks and cavity generated from the contraction on interface of Cu-Epoxy, we should form semi-conductive layer on Cu bar by carbon. Then, the PD properties and the insulation qualities of epoxy mold type bushing was able to improved by roles of cushions for the direction of diameter and by effects fo natural sliding like as separated from conductor for the direction of length. So, in this work, we could prove the method of semi-conductive layer in making the long conductor.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.10
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• pp.902-908
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• 2005

Various stresses (such as electrical stress, mechanical stress, environmental and electrochemical stress, and defects of structure) result in insulation degradation of epoxy mold type insulators. Since the insulation degradation of BCT(Bushing Current Transformer) and bushing proceeds during fabrication process or operation time due to these causes, various methods to reduce the degradation in their insulation ability have been suggested. In this paper, we investigated surface temperature increment of these insulators due to PD(partial discharge). After the voltage applied into the insulator to generate the artificial PD, the surface temperature of the insulator was measured with non-contact thermometer using infrared rays. It was confirmed through the analysis based on PD experiments that the procession in the insulation degradation of the insulator could be estimated through the measurement of the surface temperature in the insulator.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.787-790
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• 2001

Polymer bushing used for overhead line switch was designed and investigated. Requirements of electrical ratings such as partial discharge, ac withstand voltage, impulse voltage and material properties were proposed in accordance with IEEE 386 and pre-standard (PS) 151-146∼147, 170∼180 of KEPCO. The polymer bushing consists of an internal epoxy bushing and external housing made of EPDM rubber. The rubber housing was molded with mold cone. Therefore, the polymer bushing offers several advantages like light weight, good sealing properties, easy installation and excellent performance in contamination. Electric field analysis was also introduced in order to verify the reliability of the design.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.9-12
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• 2000

Insulators for high-voltage and large-power should be endured mechanically the weight of mold bushing itself and the force of pushed from contact with circuit breaker and conductor. But dielectric breakdown could be occurred result from the external circumstances and internal factors such as chemical reaction, partial discharge, change of temperature and the relation of temperature-time in process of casting. Therefore, to get rid of external and internal factors of dielectric breakdown. Furthermore, to prevent the internal cracks, void, cavity which resulted from the contraction originated on the interface between copper and epoxy resin, formed semi-conductive layer with partially carbon painted on copper bar. The PD properties and the insulation qualities of epoxy molded insulators were improved by roles of cushions for the direction of diameter and natural sliding effects as like separated from conductor for the direction of length.