• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.12
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• pp.2190-2195
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• 2011

Due to enhanced demands on quality, security and reliability of the electric power energy system, a microgrid has become a subject of special interest. In this paper, output characteristics of energy storage system (ESS) with an electric double layer capacitor (EDLC) and battery energy storage system (BESS) of a renewable energy based microgrid were analyzed under grid-connected and islanded operation modes. The microgrid which consists of photovoltaic and wind power turbine generators, diesel generator, ESS with an EDLC, BESS and loads was modeled using real time digital simulator. The results present the effective control patterns of the microgrid system.

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.2148-2154
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• 2013

Three push-pull organic semiconductors, TPA-$Th_3$-MMN (1), TPA-ThTT-MMN (2), and TPA-ThDTT-MMN (3), comprising a triphenylamine donor and a methylene malononitrile acceptor linked by various ${\pi}$-conjugated thiophene units were synthesized, and the effects of the ${\pi}$-conjugated bridging unit on the photovoltaic characteristics of solution-processed small-molecule organic solar cells based on these semiconductors were investigated. Planar bridging units with extended ${\pi}$-conjugation effectively facilitated intermolecular ${\pi}-{\pi}$ packing interactions in the solid state, resulting in enhanced $J_{sc}$ values of the SMOSCs fabricated with bulk heterojunction films.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.287.2-287.2
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• 2016

Silicon has considerably good characteristics on electron, hole mobility and its price. With 2-D sinlge-layer Graphene/n-Si heterojunction solar cell shows that in one sun condition exhibit power conversion efficiency(PCE) of 10.1%. This photovoltaic effect was achieved by applying gate voltage to the Schottky junction of the heterostructure solar cell. Energy band diagram shows that Schottky barrier between Si and graphene can be adjust by the external electric field. because of the fermi level of the graphene can be changed by external gate voltage, we can control the Schottkky barrier of the heterostructure solar cell. The ratio between generated power of solar cell and consumption electrical power is remarkable. Since we use the graphene as the top gate electrode, most of the sun light can penetrate into the active area.

• KIEAE Journal
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• v.15 no.1
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• pp.83-88
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• 2015

This study aims to develope the light-weight PV blinds with windows and to investigate the shading analysis by the control conditions. For the study, the polycarbonate characteristics and coating methods are analyzed and the PV blind design for a small office is suggested. Also, the mock-up model of a suggesting system was made. The field tests were controled based on a solar altitude under clear sky conditions. As results, it is necessary to use a polycarbonate instead of a tempered glass for a light-weight PV. The shading effects of blind systems are high in slat angle $30^{\circ}$ and low in $0^{\circ}$. Also, the shading ratio is more affected by solar latitude than solar altitude. The shading change rate is relevantly constant on the solar altitude.

• Journal of the Korean Solar Energy Society
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• v.26 no.3
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• pp.53-62
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• 2006

Since the direct normal radiation and clear day are a main factor for designing any solar thermal and photovoltaic concentrating system, it is necessary to evaluate its characteristics all over the country. The work presented here are the investigation of direct normal radiation and clear day in Korea. The data utilized in the investigation consist of direct normal radiation collected for 14 years('90. 12${\sim}$2004. 12) and clear-day collected for 23 years($1982{\sim}2004$) at measuring stations across the country. The analysis shows that the annual-average daily direct normal radiation is 5.4 kWh/m2 and the annual-average total clear-day is 92.7 days in Korea. We also constructed the contour map of direct normal radiation and clear-day in Korea by interpolating actually measured data across the country.

• Proceedings of the KIEE Conference
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• 2008.04c
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• pp.202-204
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• 2008

본 논문에서는 고정형 30KW태양광발전시스템 운전특성을 해석하고 이론을 바탕으로 실 시스템을 적용 운용시 시스템의 운전특성 및 발전량을 비교 분석하였다. 장기적인 일사량 측정 데이터 수집을 통하여 그래프화, 모니터링 시스템에 관한 연구를 살펴보았다.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2262-2264
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• 1997

In this paper, Maximum Power Point Tracking Method using Fuzzy controller is proposed to improve energy conversion efficiency. The solar cell has an optimum operating point to be able to get maximum power. To obtain maximum power from photovoltatic any, photovoltatic power system usually requires maximum power point tracking controller. The output characteristics of solar cell are nonlinear. To obtain maximum power from photsvoltatic array, the fuzzy controller only uses the output power. Therefore this control method is easy to implement to real system.

• Journal of the Korean Electrochemical Society
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• v.13 no.1
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• pp.10-18
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• 2010

Nanostructured metal oxides have been widely used in the research fields of photoelectrochemistry, photochemistry and opto-electronics. Dye-sensitized solar cell is a typical example because it is based on nanostructured $TiO_2$. Since the discovery of dye-sensitized solar cell in 1991, it has been considered as a promising photovoltaic solar cell because of low-cost, colorful and semitransparent characteristics. Unlike p-n junction type solar cell, dye-sensitized solar cell is photoelectrochemical type and is usually composed of the dye-adsorbed nanocrystalline metal oxide, the iodide/tri-iodide redox electrolyte and the Pt and/or carbon counter electrode. Among the studied issues to improve efficiency of dye-sensitized solar cell, nanoengineering technologies of metal oxide particle and film have been reviewed in terms of improving optical property, electron transport and electron life time.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.99-102
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• 2008

In terms of operation profiles and building characteristics, Schools, as public facilities, are one of the most suitable buildings for small scale Renewable energy systems since they have its energy demand on daytime mostly and large open area, roof surface available for the installation of Renewable energy systems such as solar collectors or Photovoltaic pannels. This paper presents a methodology of the feasibility test for Renewable energy systems to be intalled at schools. The methodology is based on the analysis of the demand/supply profiles dynamic matching. a case study is also presented to test the applicability of the proposed assessment methodology.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.2
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• pp.1-9
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• 2011

Daylight provides residents with good visual environment. And available daylight in inside provides positive influence on psychological and physiological aspects. Also, sunlight can be converted directly into electricity using PV(photovoltaic) power generation. This study was to analyze characteristics of daylight distributions, calculate an amount of solar radiation and a PV power generation on the building facade using Radiance and Ecotect simulation programs. Ultimately, the purpose of this study is to verify the applicability of Blind PV systems.