• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.138-144
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• 2017

With the increase in power consumption due to the surge in the demand for power, it is necessary to improve the quality or design of the power (supply) for the purpose of reducing the energy consumption and so reduce the power loss. The switchboard is a mechanical device that receives electricity from the electricity generation facilities of KEPCO and divides it into the facilities required for each building. Switchboards generally consist of enclosures, switches, power conductors, and control components. This study deals with energized power conductors, which constitute the main element in the switchboard. Through the measurement of the effective ac resistance, it was confirmed that the vertical array structure of the conventional type plate conductor is inefficient. If the effective AC resistance increases significantly, the sectional area of the conductor becomes relatively large due to the skin effect. In this study, we studied the energy and material savings that could be obtained using the asterisk (*) array structure, which minimizes the effective ac resistance by reducing the skin effect. The core technology principle of this study is the energy saving switchgear based on conductor resistance reduction technology utilizing the asterisk array structure. The present invention involves a plate-shaped conductor arrangement structure capable of canceling out the magnetic field generated on each of the plate conductors (rst or abc) of the AC power supply in the power distribution panel by mutual action. The effect of this structure is to reduce the amount of inductive reactance due to the increase in the cross-sectional area and reduction of the effective AC resistance.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.6
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• pp.52-58
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• 2005

The concept of the Micro-Grid comprising Micro-Sources supplying both heat and power ranging from several [KW] to 1[MW] to local customers is proposed by CERTS(Consortium for Electric Reliability Technology Solutions). Micro-Sources adopt environmentally friendly and reliable power sources such as Fuel-Cell and Micro-Turbines. Micro-Sources adopt voltage source inverter with AC grid system in order to provide independent real and reactive power control for premium power quality. Thus Micro-Source needs series inductance for interfacing with AC grid system. With this reason, we propose a technique that can decide the optimal size of the inductor for effective transfer of the power into the grid.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1008-1013
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• 2009

The theoretical simulation to predict the variation of supplying heat according to control methods of DHS(District Heating System) have been done by TRNSYS(A Transient System Simulation Program) 16. The physical system for DHS consists of primary and secondary supplying heating loop which is divided by based on heat exchanger for heating demand of building. The simulation results showed that control of secondary supplying heat had influenced more than primary supplying heat control to total energy consumption of DHS. And the outside temperature reset control of primary supplying heating loop could be reduced until about 4% overheating of each zone.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.371-372
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• 2013

태양광 발전 시스템(photo-voltaic system)은 시간별 발전량이 상이하고 발전중 과전류가 발생하거나 쇼트상태가 되면 태양광 발전 모듈인 태양광 판넬(Solar panels)이 파괴되거나 송전 선로에 이상이 생길 수 있다. 또한 태양광 발전시설의 설비는 고가이며 태양광 패널 하나의 손상이 전체 발전시설의 효율을 현저하게 떨어지게 되거나 생산이 중단된다. 그리고 생산효율이 낮아지거나 발전이 중단되면 금전적으로 심각한 손해가 발생한다. 이러한 경우를 대비하여 태양광 발전 시스템의 이상 유무를 판단하고 관리할 수 있는 시스템이 필요하며, 나아가서는 태양광 판넬에서 생산된 DC전력을 모니터링 할 수 있는 기능과인버터를 통해 사용자에게 공급되는 AC전력을 모니터링 할 수 있는 종합적인 전기 에너지 모니터링 시스템을 필요로 하고 있다. 본 논문은 태양광 발전 시스템을 관리하기 위한 전력 생산량 정보, 과전류 정보, 판넬의 온도를 원격으로 스마트폰 상에 모니터링 하며, 관리자가 원격으로 시설의 전력 생산량을 모니터링 할 수 있도록 구현하여 전력생산설비의 효율적으로 관리 할 수 있음을 제시하고자한다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.5
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• pp.199-205
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• 2014

The integration of FC (Fuel Cell) and GSHP (Ground Source Heat Pump) hybrid system could produce a synergistic advantage in thermal and electric way. This study intends to analyse the economical aspect of a FC integrated GSHP hybrid system compared to the conventional system which is consisted with a boiler and a chiller. Based on the hourly simulation, the study indicated that GSHP system and FC+GSHP hybrid system could reduce the energy consumption on a building. The method of the economic assessment has been based on IEA ECBCS Annex 54 Subtask C SPB(Simple Payback) method. The SPB was calculated using the economic balanced year of the alternative system over the conventional (reference) system. The SPB of the alternative systems (GSHP and FC+GSHP) with 50% initial incentive was 4.06 and 26.73 year respectively while the SPB without initial incentive of systems was 10.71 and 57.76 year.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1719-1721
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• 2005

현재 지구 환경 오염에 관한 관심이 증가하면서, 공해가 없는 자연 에너지원에 대한 연구가 많이 진행되고 있다. 그 중에서도 태양전지 분야중 염료감응형 태양전지(DSC)는 Si계 태양전지와 비교하여 낮은 제조비용등 여러 가지 이유로 최근 많은 연구가 진행되고 있다. 따라서 DSC 발전 시스템의 효율 향상이 요구된다. 본 연구에서는 태양전지 분야 중에서 독립적인 발전설비가 필요한 도서 및 산간 지역에 전력을 안정적으로 공급할 수 있는 소형발전용의 설비로 "전압 및 전류의 피드백을 통한 DSC Cell의 독립전원의 안정화"에 관해 연구하였다. DSC Cell측의 DC입력을 받아 Boost Converter로 승압 후 Full Bridge 인버터를 사용하여 단상 220V 60Hz의 상용전원으로 변환하였다. 여기서는 32Bit 마이크로프로세서인 DSP TMS320F2812의 A/D변환기능을 이용하여 Boost Converter의 스위칭과 Full Bridge 인버터의 스위칭을 제어하였다. 특히 TMS320F2812의 RTC(Real Time Clock)를 이용하여 출력전압의 안정성 향상에 주목적을 두었다. 실험결과 출력단에서는 220V 변동범위 0.2% 주파수 60Hz의 상용전원을 얻었으며, 프로그램의 개선을 통하여 출력전압의 변동범위를 감소시켜야 될 것이다.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.2
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• pp.357-368
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• 2018

For well over 100 years, oil has enabled remote communities to generate electricity and enjoy the benefits of a consistent electrical supply. Relying solely on oil for electricity generation has left island and remote communities exposed to several risks and drawbacks. Oil-based electricity generation is often more expensive and subject to price volatility, which can result in the use of risky fuel hedging strategies. The residents of islands and remote communities express concern over the future impacts of climate change or insist on their opinions for the corresponding action with reduction of carbon emissions. These risks and drawbacks can be overcomed with continuing cost reductions in solar, wind, and energy storage technologies by maker. Reducing costs is not always a straightforward process, relying on more diversely and renewably arranged renewable energy sources led to reduced local construction cost in every situation reviewed in this study. In this paper, a convenient and simple design solution which will facilitate the optimum location and transmission route of renewable energy facility using GIS(Geographic Information System) is proposed. The suggested solutions exercised to the case of geomoon island using GIS and identified by local site survey.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.5
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• pp.21-30
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• 2008

The fuel cell generation convert fuel source, and gas directly to electricity in an electro-chemical process. Unlike traditional and conventional turbine engines, the process of fuel cell generation do not burn the fuel and run pistons or shafts, and it has not revolutionary machine, so have fewer efficiency losses, low emissions and no noisy moving parts. A high power density allows fuel cells to be relatively compact source of electric power, beneficial in application with space constraints. In this system, the fuel cell itself is nearly small-sized by other components of the system such as the fuel reformer and power inverter. So, the fuel cell energy's stationary fuel cells produce reliable electrical power for commercial and industrial companies as well as utilities. In this paper, a fuel cell system has been modeled using PSCAD/EMTDC to analyze its electric signals and characteristics. Also the power quality of the fuel cell system has been evaluated and the problems which can be occurred during its operation have been studied by modeling it more detailed. Particularly, we have placed great importance on its power quality and signal characteristics when it is connected with a power grid.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.48-48
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• 2011

2010년 약 19.5 GWp 의 규모로 성장한 태양광 시장의 주요 소재는 실리콘을 이용한 태양전지이며, 고성능 및 고효율 태양전지 시장이 급성장 하였다. 이러한 고품질 태양전지에 사용되는 주요 원료인 9N 급 폴리실리콘은 2008년 4월 $265/kg 까지 상승하였으나, 점차 하향안정세에 있으며, 급속한 가격 경쟁을 통해 당분간 장기공급가가 50$/kg 이하로 하락할 것으로 전망된다. 이러한 실리콘 제조기술 중 가장 많이 사용되는 기술은 Trichloro-silane (TCS) 또는 Mono-silane (MS)를 사용하는 기상법인 일명 Siemens 공정이다. 이러한 기상법의 경우 12N 이상의 초고품질 실리콘 제조가 가능하나, 대규모의 설비투자(1억원/폴리실리콘 1톤)와 높은 에너지(120 kWh/kg)가 요구된다. 이에 최근 기상법이 아닌 야금학적인 정련법에 대한 기술이 개발되고 있으며, 이는 금속 실리콘을 슬래그 처리, 편석 분리, 응고 급랭, 전자빔, 플라즈마 등을 이용하여 정련하는 공정을 말한다. 야금학적 정련법은 순도 면에서 기상법에 비하여 낮은 단점이 있음에도 불구하고, 여러 장점들로 인해 활발히 연구되며 점차 실용화 되고 있는 매우 유용한 기술이다. 야금학적 정련법의 주요 장점은 기상법에 비해 약 25% 정도의 설비 투자비로 가능하고, 금속 실리콘을 직접 사용하며, 에너지 payback이 짧다. 또한, 산 및 염화실렌을 사용하지 않으므로 환경 문제를 적게 야기하고, 생산설비의 확장성도 매우 높다. 본 연구에서는 국내 규석광을 이용하여 일련의 정련 공정을 거쳐 고순도SG(Solar Grade)급 실리콘을 제조하고자 하였다. 실리콘 용융 환원로를 개발하고 순도를 높이기 위해 슬래그정련법을 이용하였으며, 생산된 3N 급의 금속 실리콘을 비기상법정련 방식인 일방향 응고와 플라즈마 정련 및 전자기유도 용해법을 이용하여 고순도의 실리콘을 제조하였다. 본 연구에서는 상업생산을 개시한 외국의 E사와 비교하여 산침출공정을 거치지 않으므로 실리콘회수율 및 환경부하 절감의 장점을 갖고 있으며 최종 순도 실리콘 6N 이상, 보론 함유량 0.2 ppm 이하를 달성하였으며, 기존 기상법 대비 약 20%의 전력 감소와 약 13%의 금속실리콘 원료 절감 효과가 있었다. 저가/고순도 SG급실리콘의 제조기술 개발은 향후 세계 태양광 시장에 대한 경쟁력을 확보하고, 시장 점유율 상승에 기여할 수 있으며, 산업 확대를 통한 주변 산업으로의 파급 효과가 매우 클 것으로 예상된다.

• Journal of Energy Engineering
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• v.28 no.4
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• pp.48-60
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• 2019

After the Paris Agreement in 2015, the government has been promoting various policies such as 'Hydrogen-Economy Roadmap(2019)' to supply hydrogen. As part of this, the government announced the goal of building 310 hydrogen refueling stations(HRS) until 2022. To this end, special case standard for the introduction of complex, packaged, and mobile hydrogen refueling stations(MHRS) have been enacted and promulgated. The MHRS has the advantage of being able to supply hydrogen to multiple regions. However, due to the movement and close distance between facilities, it is necessary to secure proper installation standards and operational safety through safety analysis. In this study, the possibility of introduction was investigated by designing a standard model and quantitative risk assessment(QRA). As a result of QRA, personal and social risk were acceptable, and the empirical test direction and implications were derived.