• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.232-238
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• 2016

This paper presents protection techniques against electric shock in low voltage DC(direct current) grounding systems depending on the analysis of earth fault current paths. Firstly, the comparison between alternating current and direct current on human was conducted, and current threshold values for each current path and for long duration were analyzed. Secondly, the analyses of the earth fault current flows were performed depending on the grounding types and earth fault conditions. Lastly, based on these analyses, adequate protection measures of electric shock depending on low voltage DC grounding types were provided.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.227-231
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• 2016

Electrical disasters have not been greatly reduced despite continuous prevention efforts until now. However, the smart distribution board which can be measured information about general electrical condition such as current, voltage, power, power factor etc. and electrical safety condition such as over-current, leakage current, arc etc. and communicated analysis information about electrical condition with server will be helpful for the prevention of electrical disasters through real-time surveillance and data analysis under smart grids based on the two-way communication. In this paper, the proposal standard of smart distribution board for electrical safety is suggested about the structure, functional requirements of compositions, communication, security and so on.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.1
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• pp.188-195
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• 2015

This paper presents measurement error reduction technique of touch and step voltage of grounding system based on numerical analysis. When measuring touch and step voltage of grounding system, auxiliary current probes should be located at suitable places. However, the auxiliary probes can not be located at suitable places in such cases as there are buildings and pavements. Therefore, in this paper, we provided measurement error reduction technique of touch and step voltage of grounding system according to the positions of auxiliary probes and angle between auxiliary probes. Also, measurement error analyses of touch and step voltage of grounding system have been conducted using more than one current probe. Based on these analyses, recommended positions of auxiliary probes within allowable measurement errors were presented.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.6
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• pp.995-1000
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• 2017

In this paper, we present an electrical arc detection algorithm using the mash-up analysis technique which is the core technology for the autonomous electrical safety management system(AESMS) of the multi-unit dwellings. The mash-up analysis technique analyzes the voltage, load current, zero phase current data simultaneously to judge arc faults. In order to develop the arc fault detection algorithm, the characteristics of series arc and parallel arc were analyzed. Also, we propose the mash-up analysis technique that analyzes waveforms of voltage, load current, and zero phase current at the same time. The arc fault detection algorithm was developed using the mash-up analysis technique. The developed algorithm can prevent electrical disasters in an effective way through accident prediction, and it will be used as a basic technology to introduce an autonomous electrical safety management system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.576-577
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• 2005

In this paper, the oxidization characteristics were analyzed according to the shapes of Residual Current Protective Device(RCD) contacts. RCD is an electrical safety device specially designed to immediately switch the electricity off when electric leakage is detected at a level harmful to a person using electrical equipment. The shapes of RCD contacts are a little bit different according to the models. When RCD is turned on, stationary and moving contact do not fit together. So, it can cause the increase of contact resistance. To discover the deterioration characteristics of RCD contacts by switching repetition, the contacts were analyzed by stereo microscope, Scanning Electron Microscope(SEM) and Energy Dispersive X-ray Spectrometer(EDS).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.234-235
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• 2006

In this study, we experimented deterioration characteristics of PVC insulation wires for electrical apparatus by series arcing and analyzed the heat generation at the contacts of wires, glowing/growing process of copper oxide, waveforms of contact voltage, current, power dissipation, and so on. We found out that how glowing contacts and surface arcing can decompose PVC insulation and that subsequent series arc can lead to ignition. We expect that these results are useful for improving fire protection technology by providing a better understanding of how electrical fires can initiate.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.554-555
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• 2013

본 연구는 스마트 e버스 시스템 중 배터리 교환로봇을 이용한 배터리 교체시설과 배터리 급속충전 시설인 자동 배터리 교환시설의 전기안전성 안전진단을 통하여 현 시설물의 문제점 분석과 개선사항 도출을 통하여 안전한 사용을 위한 스마트 e 버스 시스템의 전기 시설 기준(안)을 개발하는데 도움이 되고자 한다

• Journal of Korean Society for Quality Management
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• v.46 no.3
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• pp.497-508
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• 2018

Purpose: The purpose of this study is to research the revision efficiency of the referenced specifications/standards for raw and subsidiary materials in the field of national defense. Methods: Firstly, it was carried out to investigate the all of the Korean military drawings and establish the database for specifications/standards referenced in the field of national defense. Secondly, it was reviewed the validity of referenced specifications/standards of raw and subsidiary materials. Finally, proposal documents were made for invalid referenced specifications/standards of raw and subsidiary materials in order to suggest alternative specifications/standards. Results: All of the specifications/standards referenced in the Korean military drawings were 11,924 kinds and raw and subsidiary specifications/standards were 2,711 kinds. The proposal documents for revision of invalid referenced specifications/standards were suggested and approved by the military procurement standardization committee of DAPA (Defense Acquisition Program Administration). Therefore, the revision process of 472 kinds of referenced specifications/standards and 160,177 papers of the Korean military drawings were finished. Conclusion: Based on the results of this investigation, it could be significantly reduce to administrative costs and efforts through revision of referenced specifications/standards instead of conventional engineering change.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2208-2209
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• 2008

최근 국제 표준 및 규격의 국내 도입에 따라 다양한 접지 방식에 대한 안전성과 신뢰성이 요구되고 있으나, 현재 국내 규정은 국제 규격과 부합되지 않는 측면이 있다. 따라서, 국내 건축물의 접지시스템에 대한 정확한 현장 실태를 바탕으로 국내 실정에 맞는 접지시스템의 개발이 요구되고 있다. 본 논문에서는 아파트, 공장, 상가, 학교 등의 신축 건물에 시설된 접지방식 및 등전위 본딩 실태 등을 현장 조사를 중심으로 분석하였다. 접지실태조사는 접지방식, 접지단자의 접속방식, 공결방식, 접지요소간의 접속방식 등을 분석하였으며, 등전위 본딩 실태조사는 IEC 60364에 규정된 방법을 근거로 계통외 도전성 부분과 기기외함의 연속성을 평가하였다.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2046-2048
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• 2005

This paper deals with ground potential rise of structure grounding electrode when a test current flows through grounding electrode. In order to analyze the potential gradient of ground surface on structure grounding electrode, the reduced scale model has been used. The structures were designed through reducing real buildings and fabricated with four types on a scale of one-one hundred sixty. The supporter was made to put up with weight of structure and could move into vertical, horizontal, rotary direction. When a test current flowed through structure grounding electrodes, ground potential rise was the lowest value at electric cage type(type B). According to resistivity and absorption percentage in concrete attached to structure, the potential distribution of ground surface appeared differently.