• 전기학회논문지P
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• 제58권2호
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• pp.101-107
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• 2009

This paper deal with development of on-line type voltage sag compensation system using supercapacitor EDLC to solve the voltage sag problems which are considered to be dominant disturbances affecting the power quality. With the wide use of semiconductor devices in electrical equipment, modem-type loads are becoming increasingly sensitive to the voltage sags and the disturbances prove to be costly to industries. Supercapacitor EDLC is employed to compensate dynamically for the voltage sag of system with sensitive loads. This capacitor has higher energy density than the electrolytic capacitor. Also, this capacitor has a lot of advantage such as no maintenance, longer life cycle and faster charge-discharge time than the battery system. Therefore, in this paper, the energy design scheme of supercapacitor and the configuration technique of on-line type voltage sag compensation systems are newly introduced. According to the results of experimental of prototype 5[kVA] system, it is verified that the developed system has effectiveness of voltage sag compensation by using a supercapacitor EDLC.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.151-153
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• 2008

DC 마이크로그리드는 태양광과 연료전지와 같은 DC 출력의 분산전원, 풍력이나 가스엔진과 같은 AC 출력의 분산전원이 이차전지나 수퍼커패시터와 같은 에너지 저장장치와 직류로 결합되어 있는 구조로, 최근 급증하고 있는 디지털부하에 고품질, 고신뢰도 전력을 공급하는 새로운 직류배전시스템이다. 본 연구에서는, 먼저 DC 마이크로그리드의 한 시스템 구성을 가정하고, 이들 분산전원과 에너지저장의 컨버터를 제어하는 기법을 제안하였다. 또한 PSCAD/EMTDC 소프트웨어를 사용하여 각각의 분산전원의 세부모델을 구현하고, 이를 DC 마이크로그리드로 구성한 후 분산전원의 생산량, 에너지저장의 저장량, 부하의 소모량, 연계 계통의 공급량을 타당한 시나리오로 가정하여 전체 마이크로그리드의 동작을 분석하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.606-609
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• 2000

We describe the preparation of a manganese oxide polymorph in which the solid-pore architecture of the material is controllably varied. All MnO$_2$ gels derived from a KMnO$\_$4/-based sol-gel synthesis. The mesoporous structure of the initial gel is maintained by removingore fluid under conditions where the capillary forces that result fro extraction are either low or no existent. are either low or noexistent. Controlling both the pore and solid architecture on the nanoscale offers a strategy for the design of supercapacitor.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.573-576
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• 2001

In the research fields of energy storage, and more specifically of supplying high powers, electrochemical supercapacitor have been among the most studied systems for many years. One of the possible applications is in electric vehicles. We have been working on electronically conducting polymers for use as active materials for electrodes in supercapacitors. These polymers have the ability of doping and undoping with rather fast kinetics and have an excellent capacity for energy storage. polythiophene (Pth) and polyparafluorophenylthiophene (PFPT) have been chemically synthesized for use as active materials in supercapacitor electrodes. Electrochemical characterization has been performed by cyclic voltammetry and an electrode study has been achieved to get the maximun capacity out of the polymers and give good cyclability. specific capacity values of 7mAh/g and 40mAh/g were obtained for PFPT and polythiophene, respectively. Supercapacitors have been built to characterize this type of system. Energy storage levels of 260F/g were obtained with Pth and 110F/g with PFPT

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.160-161
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• 2007

This paper describes the development of a single-phase DVR(Dynamic voltage Restorer), which is composed of H-bridge inverter and super-capacitors. The operational feasibility was verified through computer simulations with PSCAD/EMTDC software, and experimental works with 3kVA prototype. The developed system can compensates the input voltage sag and interruption within 2ms, in which the maximum allowable duration of voltage interruption is 1.5 seconds. It can be effectively used to compensate the voltage interruption in the sensitive load, such as computer, communication equipment, automation equipment, and medical equipment. The developed system has a simple structure to be easily implemented with commercially available components and to be highly reliable in operation.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2012년도 전력전자학술대회 논문집
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• pp.262-263
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• 2012

3상 새그 보상기는 계통 새그나 사고 발생 시 빠르게 이상상태를 검출하여 계통을 분리하고 수퍼커패시터에 충전된 에너지를 부하에 안정하고 연속적인 정격 전압을 공급하는 장치이다. 그러나 비선형 부하일 때, 3상 새그 보상기의 출력전압에 저차 고조파가 포함된 왜곡이 발생한다. 본 논문에서는 비선형 부하에서도 안정적인 정현파 전압을 공급하기 위해 선택적 고조파 제거 방식을 도입한 전압제어기를 제안 하였다. 새그 보상기 시작품을 제작하였으며, 제안한 선택적 고조파 제거 전압제어기의 타당성을 실험을 통하여 THD가 12.7%에서 4.3%로 개선되는 것을 확인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기물성,응용부문
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• pp.164-166
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• 2002

Over the past two decades, the electrochemical supercapaictors are receiving growing attention due to their possible applications as power backup in electronic equipment and electrical vehicles. Both of amorphous cobalt oxide and manganese dioxide were prepared by sol-gel process reported in our previous work. Nano-structured supramolecular oligomer of 1,5-diamino anthraquinone(DAAQ) coated metal oxides were successfully prepared by electrochemical oxidation from an acidic non-aqueous medium. We established process parameters of the technique for the formation of nano-structured materials. Furthermore, improved the capacitive properties of the nano structured metal oxide electrodes using controlled solution chemistry. $CoO_2$ and $MnO_2$-based composite electrode showed relatively good electrochemical behaviors in acidic electrolyte system with respect to specific capacity and scan rate dependency

• 전기화학회지
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• 제16권2호
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• pp.91-97
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• 2013

이온성 액체 전해질염 1-ethyl-3-methylimidazolium tetrafluoroborate ($EMIBF_4$)과 용매 acrylonitrile (ACN) 및 propylene carbonate (PC)와 각각 혼합한 용액에 poly(ethylene glycol)diacrylate (PEGDA)를 45-60 wt.% 첨가하고 자외선 조사를 통해 경화시켜 고체 고분자 전해질 필름을 제조하였다. 이 고체 고분자 전해질 필름을 분리막으로 채택하고 활성탄 전극을 사용하는 수퍼커패시터를 제조하여 그 전기화학적 특성을 사이클릭 볼타메트리와 임피던스 방법으로 조사하였다. 결과적으로 PEGDA를 45 wt.% 첨가하여 제조한 고체 고분자 전해질 필름을 채택한 경우가 스캔속도 $20mVs^{-1}$에서 $46Fg^{-1}$의 가장 우수한 축전용량을 나타내는데, 이것은 PEGDA의 저함량 때문에 상대적으로 자외선 경화가 약하게 진행되어 고분자 전해질 필름의 유연성이 충분히 확보되므로 필름 내 이온전도가 가장 활발히 진행될 수 있었기 때문이다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.163.2-163.2
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• 2010

We developed a simple method to synthesis a nitrogen doped graphene, nitrogen plasma treated graphene (NPG) sheets thought nitrogen plasma etching of graphene oxide (GO). X-ray photo electron spectroscopy (XPS) study of NPG sheets treated at various plasma conditions reveal that N-doping is classified to 3 kinds of binding configurations. The nitrogen doping concentration is at least 1.5 at % and up to 3 at% with changing of ratio of nitrogen configuration in NPG. Our group demonstrate ultracapacitor with high capacity and extremely durable using a NPG sheets that are comparable to pristine graphene supercapacitor, and pseudocapacitor using polymer and metal oxide with redox reaction, capacitance that are three-times higher, and a cycle life that are extremely stable. We also realized flexible capacitor by using the paper electrode that are coated by NPG sheets. NPG paper capacitor presented almost same performance compare with NPG on a metal substrate, and durability is much more enhanced than that. To additionally explain that how different kind of atoms in graphene layers can act as the ion absorption sites, we simulated the binding energy between nitrogen in graphene layer and ions in electrolyte. Increasing the energy density and long cycle life of ultracapacitor will enable them to compete with batteries and conventional capacitors in number of applications.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.573-576
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• 2001

In the research fields of energy storage, and more specifically of supplying high powers, electrochemical supercapacitor have been among the most studied systems for many years. One of the possible applications is in electric vehicles. We have been working on electronically conducting polymers for use as active materials for electrodes in supercapacitors. These polymers have the ability of doping and undoping with rather fast kinetics and have an excellent capacity for energy storage. polythiophene (Pth) and polyparafluorophenylthiophene (PFPT) have been chemically synthesized for use as active materials in supercapacitor electrodes. Electrochemical characterization has been performed by cyclic voltammetry and an electrode study has been achieved to get the maximun capacity out of the polymers and give good cyclability. specific capacity values of 7mAh/g and 40mAh/g were obtained for PFPT and poly thiophene, respectively. Supercapacitors have been built to characterize this type of system. Energy storage levels of 260F/g were obtained with Pth and 110F/g with PFPT.