• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.320-322
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• 2007

A new binder-free $TiO_{2}$ paste was prepared by common ion applying effect, enabling low temperature fabrication required for flexible solar cells. The binder-free and high viscosity $TiO_{2}$ coating solution was produced by adding 7.5% aniline in $TiO_{2}$ colloid solution obtained from the high pressure water-heat response method. The resulting pastes had high level of viscosities proper for optimal coating and thus revealed excellent performances in terms of thickness uniformity and I-V characteristics.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.323-325
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• 2007

$TiO_{2}$ electrode electrospun directly onto the substrate was developed for energy conversion device. To enhance energy conversion efficiency of dye-sensitized solar cell, electrodes should have higher surface area to absorb more dyes and higher conductivity to reduce recombination of generated electrons. $TiO_{2}$ nanofibers with higher surface areas were fabricated by annealing electrospun $TiO_{2}/PVP$ nanofibers at $500^{\circ}C$ for 3 hrs in air. it was revealed that $TiO_{2}$ nanofiber electrodes is hybrid with MWNT showed higher conductivity than $TiO_{2}$ semiconductor electrode possibly due to band gap change.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.343-345
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• 2007

Temperature difference between two plates occurs when a current is passed though two semi-conductors that are connected each other at two junctions. The current drives a transfer of heat from one junction to the other. In this study, the thermoelectric module based on th "Peltier effect" was made by combing fullerene and polyaniline. Continuous temperature measurements on both surfaces were performed at room temperature($25.4^{\circ}C$) by an infrared non-contact thermometer. The results showed that cool ing effect of $2.2^{\circ}C$ was attained by 30 seconds, after which the effect was continuously vanished mainly due to electro decomposition.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2003.11a
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• pp.1311-1318
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• 2003

최근 흡한 속건성은 사이언스 소재로 가장 보편적으로 이용되고 있는 소재 성능이다. 하지만 아직 제대로 된 측정 평가법이 존재하고 있지 않고, 몇몇 의류업체에서는 단순히 객관적 속성만을 측정하고 있다. 본 연구에서는 객관적 속성인지들의 연속적이 값들이 실제 인체에서는 얼마만큼의 변별력으로 인식되는지 정신물리학적 측정법으로 최소 자극치(PSE)를 구하여 등급을 나누어 보았다. 시료는 흡한속건성 직물로 가장 많이 이용되고 있는 Coolmax(R), Coolever(R), 친수성 이중직물의 3개 그룹으로 나누었고, 측정 인자로 객관적 속성인자는 cling force, drying time을, 이와 대응하는 주관적 속성인자는 clinginess, dampness를 측정하고 각각의 PSE값을 구하였다. 그룹에 따라 객관적 속성인자 값들이 이라고 느끼는 PSE 구간까지 도달하는 시간과 속력을 측정하여 그룹마다의 흡한속건 등급을 정하였다. 또한 설계된 소재의 성능을 간접적으로 알 수 있는 transmissibility라는 인자도 도입하여 수분 전달성도 객관적으로 살펴볼 수 있었다. Clinginess, Dampness, Transmissibility 각 인자들을 평가해본 결과 Coolmax(R) 가 가장 우수함을 알 수 있었다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.8
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• pp.1472-1478
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• 2009

The domestic power distribution system is operating in an open loop mode; however, it already has a loop structure. Power distribution systems must be changed for bi-directions power supply for smart networks due to a changing of paradigm in electric power industry. The simplest bi-directions distribution networks can make it closing of normally open switch. However, bi-directions power supply is very difficulty to be operated and there are many parts which it must study. This paper presented various models that are able to change a radial system for loop structures. Further, we compared the reliability index for each model by evaluating the amount of improvement reliability required in radial power distribution system. In addition, we calculated CIC(Customer Interruption Cost) for each model by comparing and analyzing.

• Proceedings of the KIEE Conference
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• 2008.05a
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• pp.141-142
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• 2008

국내 배전선로에서는 1999년부터 폴리머피뢰기를 설치하여 운영하고 있으나, 이들의 열화특성에 관한 데이터와 적합한 평가방법이 부족하여 장기적인 운영계획 수립이 어려운 상태이다. 이에 따라 본 논문에서는 폴리머피뢰기의 현장 열화인자를 인가할 수 있는 복합가속열화 시험장치를 제작하고 국내 환경조건을 모의할 수 있는 시험주기를 개발하여 폴리머피뢰기 완제품에 대한 장기신뢰성 평가법을 제안하였다. 그리고 가속열화시험 및 현장설치에 의한 전기적, 화학적 특성변화를 분석하여 폴리머피뢰기의 열화정도를 평가함으로써 본 연구에서 제안한 평가기법의 실효성을 검증하고 국산 폴리머피뢰기의 유지보수에 필요한 특성 데이터를 제시하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.7
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• pp.55-62
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• 2011

PCS(Power Conditioning System) is the necessary component in Microgrid, composed of multiple distributed generators and energy storage system. In this paper, the functions of PCS are defined and 10[kW] PCS for PV and BESS are developed. To apply PCSs to Microgrid, this paper presents a 3-phase inverter with the decoupling current controller, voltage controller and DPLL control system. PCSs were applied to 120[kW] pilot plant and its performance tests were carried out. Test results of PCS at each operation mode show stable in Microgrid.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.210-213
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• 2007

In this study accelerated aging test cycle and equipment was developed for aging test of polymer housed surge arresters under domestic weather condition In order to investigate aging characteristics of polymer surge arresters electrical and chemical analysis of the arresters which are used for accelerated aging test and outdoor exposure test were conducted. Through the analysis the capability of the proposed method was verified and characteristics data were presented for maintenance of domestic arresters. Based on these results long term reliability assessment method was proposed for polymer housed distribution surge arresters.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.88-91
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• 2001

Our knowledge about their long-term performance in an outdoor environment is still very limited. The electrical stress caused the surface of these insulators to become degradation. In order to evaluate leakage current patterns caused by surface aging on polymeric insulators, we utilized the combined aging test facility and leakage current monitoring system. And we get the continuous leakage current values from each sample. After completing the 3000h combined aging cycle test, leakage current measurement were conducted for these samples and carried out harmonics analysis for its data.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.886-889
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• 2002

This paper describes the characteristic analyses and a new design of the bushing for the pole transformers. The mechanical breakdown of the upper part of the bushing was frequently occurred. This caused the leakage of mineral oil, resulted in the interruption of electric power. Therefore, the bushings were investigated by the material analytical method and Finite Element Method. The analyses were performed by the Induced Coupled Plasma(ICP), X-ray diffraction(XRD), Scanning Electron Microscopy(SEM), and Dielectric Thermal Analyzer(DETA). Also, the Von-Mises stress of the top part of bushing was determined by using ANSYS program. The Von-Mises stress of the newly designed bushing was reduced about 50%. Therefore, if we apply the newly designed bushing, the number of mechanical breakdown may be decreased.