• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2160-2161
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• 2011

IEC 61936의 저압기기 허용 상용주파 과전압에 대하여 선로의 지락고장시 고장전류의 분류 효과 및 등가회로를 이용하여 수학적 계산식을 도출하고 EMTP를 이용하여 모의를 수행하였다. 또한 시험선로를 이용하여 실증시험을 수행하여 실제 고장현상을 검토하였다. 현재 배전계통의 접지수준은 기준을 충분히 만족하고 있으므로 다양한 사례 연구를 통하여 접지기준의 개정을 검토할 필요가 있는 것으로 판단된다.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.462-464
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• 2005

This paper analyses the transient phenomena against single line to ground fault and lightning surge between Korea and Japan on underground power cable systems. For analysis, find proper earthing resistance of neutral grounding system adopted in Japan. This paper is expected to contribute the establishment of proper protection methods against transients on underground power cable systems.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.9
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• pp.111-119
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• 2008

As the penetration of distributed generation systems is recently high, there have been metering errors, trips of protective devices in KEPCO distribution systems including an occurrence of false fault-indicator in distribution automation system. The cause of malfunctions was the reverse-power-flow phenomenon due to transformer wiring types. By the effect of the reverse-power-flow, each of phase's fundamental currents was added by about 3 times on the neutral line. A new method based on the analysis of the reverse-power-flow is proposed in this paper. Fault currents on each section were analyzed by the proposed method, and the effect of types of transformer wiring was examined experimentally. In order to reduce the malfunctions due to the reverse-power-flow, controlling the zero-sequence impedance of transformer was designed and verified by using PSCAD/EMTDC software.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.284-287
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• 2006

In this paper variety test results were discussed regarding to the ground potential increase. The tests conducted with a joint box simulating leakage point having an insulator fault. Inside the joint box three-phase cables and one neutral line were connected and the insulator at jointed part was peeled from the one of three-phase cables. The potentials around manhole cover were measured with the variation of manhole material, ground resistance and water resistance when the manhole was flooded. The potentials induced by an electric leakage were drastically decreased with increasing the distance from the leakage location and with less ground resistance.