• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.406-410
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• 1995

A superconducting cable is one of the promising methods of undground transmission of high electric power in the future. It is very important that composite insulation system of $LN_2$ and polymer films takes into consideration for application high $T_c$ superconductor. This study is about both the partial discharge and properties V-t in $LN_2$. As result, applied voltage doesn't depend on the radius of non-eroded area but eroded area. And eroded area is observed the formation such as the ring of a tree.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.258-261
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• 2001

In this paper, aging characteristics of silicone rubber used for outdoor insulation have been investigated with regards to salt fog condition and heat aging effect. We look over the change of properties of silicone rubber in salt fog chamber with average leakage current monitoring for observing the transformation of surface degradation properties of silicone rubber with different ATH(alumina trihydrate, $Al_2O_3{\cdot}3H_2O$) filler contents. Surface resistivity, SEM(Scanning Electro Microscope) were measured.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.3
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• pp.122-126
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• 2006

In this study, composite materials were put to dry interfacial treatment by use of plasma technology It has been presented that the optimum parameters for the best wettability of the samples at the time of generation of plasma were oxygen atmosphere, 0.1 Torr of system pressure, 100 W of discharge power, and 3 minutes of discharge time. The decrease in surface potential of charged samples by corona discharge indicates that the amount of accumulated electrical charges reduces and the charges that have been injected lessen rapidly when the duration of UV irradiation increases. The surface resistivity and the tensile strength of plasma treated samples, a longer UV irradiation time resulted in decreased insulation.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.413-416
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• 2011

대용량 기기의 효율적인 전력 공급을 위해 부스닥트의 수요가 급증하고 있으며, 특히 컴팩트형 부스닥트는 케이블에 비해 무게와 부피가 가볍고 전력 효율도 25% 이상 우수하며, 기술의 핵심은 에폭시분체도료의 절연 특성 향상과 제작공정의 최적화와 안정화이다. 따라서 본 연구에서는 유동침적방식(Fluidized Bed Process)에 대한 최적화와 에폭시 분체도료의 절연설계 및 열화특성에 대해 실험 검토 하였다. 또한 전기화재의 주된 원인인 아크방전특성과 절연파괴 특성에 대한 분석과 더불어 다양한 상용제품들의 특성을 비교하였다.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2305-2307
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• 1999

Partial discharge measurement using a ultrasonic technique allows us to detect degradation of the electrical insulation in a power transformer. However, The ultrasonic measurement studies don't offer a good solution in operating conditions. In this paper, we investigated characteristics of ultrasonic noise caused by a 345kV power transformer under operating conditions. The ultrasonic noises generated by corona in air, vibration of core, pump and fan, etc. An ultrasonic frequency caused by corona in air was appeared 9 and 18[MHz] at the outside wall of the transformer. And a spectra of core vibration was detected below 2.5[kHz]. These spectrum were compared with 20 $\sim$ 200[kHz] of the internal partial discharge in the model transformer.

• Proceedings of the KIEE Conference
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• 1997.07e
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• pp.1696-1701
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• 1997

본 연구에서 사용된 절연유 열화센서는 주 매질이 기공 세라믹(Porous Ceramic)으로 구성되어 있어 열화생성된 유불용성분(油不溶 成分)이 일정 크기의 기공 속을 통과할 때 절연유의 열화정도에 따라 인위적인 도전 통로가 형성되는 데, 이러한 회로를 이용하여 전기적인 분석으로 측정된 센서의 누설전류치와 기존 실시되고 있는 절연유 분석법인 전산가, 내압치와 상호 비교 분석한 결과, 지금까지 샘플링에 의한 화학적인 분석법에 앞서 전기적인 분석법으로 절연유 열화 상태를 간단하게 분석할 수 있다는 가능성을 제시하였다.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1507-1509
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• 1997

Property of insulation of electric machine is severely affected by process of electrical tree growing. Partial discharges(PD) have been used to determine degradation of insulations. In this paper, PD quantities detected and analyzed are PD magnitudes, repetition rates, phase angle distribution of PD pulses, and wavelet transformation. The wavelet transformation is an extended method of fourier transformation. The fourier transformation is a powerful tool for signal analysis, but it can't include informations for time. However the wavelet transformation analysis can include on the informations of time and frequencies at the same time. This paper discusses correlation between process of electrical tree growing and characteristics of PD in LDPE specimens.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.516-517
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• 2008

The ethylene-propylene (EP) rubbers mixed with one to one ratio is used as an insulation material in the nuclear power plant. It was investigated the effect of the amount of reinforcing agent. moisture absorption and heat treatment on the Ethylene-Propylene(EP) rubbers. The level of degradation was measured by the amount of discharging and. charging currents. When $\gamma$ rays were radiated on the EP rubbers with more charging material, the amount of discharging and charging currents was depended on the amount of reinforcing agent It was verified that the discharging and charging currents irradiated by $\gamma$ rays were higher than those that was not irradiated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.214-217
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• 1999

Polymeric composite insulators have been in use for outdoor insulation. However, our knowledge about their long-term performance in a outdoor environment is still very limited. Especially, these insulator are subjected to the environmental stress such as ultraviolet radiation. Hence, in this paper. the influence of UV radiation on the aging of the shed materials was evaluated. For the aging evaluation, these insulators studied by experiment methods such as contact angle measurement. oxidation induced time. SEM/EDX, FTRI-ATR, tracking test for the different insulator samples. With the increased UV exposure time, samples are shown to exhibit degradation comparable to those of new ones

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2531-2534
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• 2000

본 연구는 전동기의 부분방전에 의해 발생되는 전자파를 측정하여 전동기의 열화상태를 진단할 수 있는 전동기 절연열화진단시스템을 설계하는 방법을 제안하고자 한다. 따라서 부분방전에 의한 전자파를 측정하는 시스템을 구성하고, 측정된 데이터를 분석하여 정량화된 특징 데이터를 추출하고 생성된 데이터를 이용한 뉴로-퍼지 진단모델설계 방법을 제시한다. 그리고 제안된 방법에 의해 설계된 진단모델을 실측데이터를 통해 진단하여 그 타당성을 입증하고자 한다. 1단계 연구로, 본 연구에서는 현장 전동기의 전자파를 On-Line으로 계측하는 시스템을 구성하여 전동기의 절연체내에서 발생하는 부분방전에 의한 전자파를 계측하여 데이터로부터 전동기의 절연열화상태를 해석하여 절연 열화와의 관계를 분석하였다.