• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.9
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• pp.1577-1582
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• 2016

Now we are facing severe environmental issues such as global warming. Due to these, the concerns about eco-friendly energy have been increased. Kyoto protocol and Copenhagen climate change conference are circumstantial evidence of it. With these trends, the interests for the Electric Vehicles(EVs) which do not emit any harmful gases have gradually been raised. Unfortunately, however, massive connection of EVs to the power system could cause negative impacts such as voltage variations, frequency variations and increase of demand power. To prevent the mentioned issues, KEPCO adopts Time-of-Use(ToU) price for EVs charging. Nevertheless, it is important to verify the propriety of the charging system. In this paper, therefore, we used pre-introduced price elasticity concept to predict possible Demand Response(DR) on charging of EVs. And analyzed possible demand power increase according to various price elasticities. Simulation results show that given ToU based charging system would not enough to control the increase of demand power by EVs on the power system. It is concluded, therefore, additional methods and/or algorithms are required.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.5
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• pp.60-70
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• 2011

Vehicle location detection and wireless communication method have be designed along the same lines as GPS, CDMA and WLAN, which is based upon the selecting factors such as state-of-art technology trend, accuracy, stability, and economic feasibility, in order to select the optimum method of information communication networks for integrated "Transportation-Power-Facilities" on the electric bus. In addition, the key features of each alternative for an efficient linkage have been review and the integration methodology for linking among Transportation Charging Center, Transportation(ITS, BIS) Center and smart Grid Center has been drawn up based on a technical level of difficulty of each alternative, political and administrative difficulties, and expense justification.

• Transactions on Electrical and Electronic Materials
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• v.8 no.3
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• pp.143-146
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• 2007

Polymer insulators are used widely in variable fields for high voltage insulation and separating people from high voltage charging parts for safety and also supporting overhead power line in electric railway. But it may be broken down by tracking path resulting from continuous surface discharge. This paper has investigated synthetically both the characteristics of electrical aging using precision CT(current transformer) and the thermal aging using thermography method. Electrical aging was analyzed for time-frequency region and thermal aging was illustrated by image processing method. This synthetic method may be an appropriate one to evaluate the surface degradation of polymer insulator.

• Journal of Digital Convergence
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• v.12 no.11
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• pp.289-298
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• 2014

Recently, the traditional paradigm in railroad technology is changing as more efficient and cost-effective electric vehicle (EV) technologies have emerged. The original concept of PRT (Personal Rapid Transit) proposed in the past has come to be regarded as unrealistic, but its feasibility is improving through the utilization of an EV platform. In particular, battery-powered vehicles pose difficult technical challenges in attempts to achieve reliable and efficient operation. However, based on the inductive power transfer (IPT) technology, the fast charging of supercapacitors with high energy density can contribute to overcoming this technical challenge and promote the transition to electric-powered ground transportation by improving the appearance of cities. This study discusses the development process of a power supply system for PRT, including concept design, numerical analysis, and device manufacturing, along with performance predictions and evaluations. In terms of results, the system was found to meet the performance requirements for power supply modules on a test-bed.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.147-148
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• 2011

최근 지구 온난화 등의 환경문제와 $CO_2$ 배출량 규제 강화, 화석 연료 고갈 및 고유가 등의 사회적 문제에 대한 해결 방안으로서 전기자동차의 개발과 보급이 활발하다. 2009년 7월 제주시 구좌읍에 Smart Grid(스마트 그리드) 실증 단지가 구축되면서 친환경 전기자동차 및 우전 인프라 실증이 더욱 가속화 되고 있다. 우리나라를 비롯하여 세계 각국의 자동차 연비 및 배기 가스 규제가 강화될 수록 전기자동차 기술과 관련한 Smart Transportation 기술의 상용화는 더욱더 빨라질 것이며, 이에 따라 전기자동차의 보급과 개발이 확산되고, 이를 지능적으로 관리 및 운영하는 충전인프라 기술이 요구될 것이다. 본고에서는 이러한 전기자동차 충전을 위한 운영시스템 설계에 대하여 충전운영시스템 구성과 기능 및 아키텍쳐 설계에 관하여 기술한다.

• Proceedings of the KIPE Conference
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• 2010.11a
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• pp.220-221
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• 2010

스마트 그리드(Smart Grid) 사업 분야에 속해있는 스마트 트랜스포테이션(Smart Transportation)사업은 전기자동차 운영에 주 초점을 맞추고 있는 실정이다. 전기자동차를 운영하기 위해서는 전기자동차 충전 인프라 구축이 필수적으로 필요하며 전기자동차 충전 인프라는 크게 전력망, 충전소, 급 완속 충전기, 과금 및 정산, 운영 시스템 등으로 구성되어 있다. 본 논문에서는 이러한 스마트 트랜스포테이션 사업의 충전 인프라 구축을 수행함에 있어 주차장이나 아파트 등에서 사용할 완속 충전 스탠드와 그에 따른 충전 시스템 구성을 소개하고자 한다.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.556-557
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• 2012

국내에서 활발히 진행중인 스마트 그리드(Smart Grid) 사업분야에 속해 있는 스마트 트랜스포테이션(Smart Transportation) 사업에서는 전기차를 이용한 운영에 중점을 두고 진행이 되고 있다. 그러나 실제적으로 전기차를 운영하기 위해서는 운영에 충분한 충전 인프라가 구축되어야 하며 충전 인프라를 구축하기 위해서는 그에 맞는 충전 시스템을 갖추어야 한다. 충전 시스템에는 현재, 완속 충전기와 급속 충전기가 주를 이루고 있으며 본 논문에서는 완속 충전기의 표준화의 일환으로 미국자동차기술학회에서 제시하는 SAE-J1772 규격에 맞추어 개발한 자사의 완속 충전기에 관하여 소개하고자 한다.

• Journal of Korean Society of Transportation
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• v.27 no.2
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• pp.145-155
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• 2009

This paper compares the relative performances of area and cordon tolls as opposed to the first-best congestion tolls with respect to alleviation of traffic congestion and social welfare. The comparison is done in the monocentric city where all the jobs are located at the city center. The study shows that the size of charging zones is similar in the two second-bests, but that the optimal toll level is higher in area pricing than in cordon pricing. Area pricing schemes turn out to perform better than cordon pricing schemes as measured by average speeds and daily average travel time. Accordingly, the former is shown to increase the social welfare more than the latter. In the case of the cordon tolls, the residents at the charging zones are exempted from the tolls. In this way, cordon tolls invite people into the most congested areas over the optimal level while partially negating the whole spirit of the congestion tolls.

• Clean Technology
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• v.27 no.4
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• pp.277-290
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• 2021

A supercapacitor, also called an ultracapacitor or an electrochemical capacitor, stores electrochemical energy by the adsorption/desorption of electrolytic ions or a fast and reversible redox reaction at the electrode surface, which is distinct from the chemical reaction of a battery. A supercapacitor features high specific power, high capacitance, almost infinite cyclability (~ 100,000 cycle), short charging time, good stability, low maintenance cost, and fast frequency response. Supercapacitors have been used in electronic devices to meet the requirements of rapid charging/discharging, such as for memory back-up, and uninterruptible power supply (UPS). Also, their use is being extended to transportation and large industry applications that require high power/energy density, such as for electric vehicles and power quality systems of smart grids. In power generation using intermittent power sources such as solar and wind, a supercapacitor is configured in the energy storage system together with a battery to compensate for the relatively slow charging/discharging time of the battery, to contribute to extending the lifecycle of the battery, and to improve the system power quality. This article provides a concise overview of the principles, mechanisms, and classification of energy storage of supercapacitors in accordance with the electrode materials. Also, it provides a review of the status of recent research and patent, product, and market trends in supercapacitor technology. There are many challenges to be solved to meet industrial demands such as for high voltage module technologies, high efficiency charging, safety, performance improvement, and competitive prices.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.83-84
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• 2013

최근 국내에서 진행중인 스마트 그리드(Smart Grid) 사업 분야에 속해 있는 스마트 운송(Smart Transportation) 사업의 하나로 전기차 운영이 핵심이 되어 진행이 되고 있다. 그러나 실제적으로 전기차를 원활히 운영하기 위해서는 극복해야 할 여러 문제가 있으며 대표적으로 주행 거리를 좌우하는 배터리 용량 문제와 고객이 어디서든 전기차를 사용하고 충전하는데 불편이 없을 만큼 충분한 충전 인프라 구축 문제가 있다. 충전 인프라는 현재, 완속 충전기와 급속 충전기로 구성되어 있으나 본 논문에서는 완속 충전기에 한정하여 서술하였고 인프라 구축에 있어 표준화 일환으로 미국자동차기술학회에서 제시하는 SAE-J1772 규격에 맞추어 개발한 자사의 완속 충전기에 2012년 독일과 미국의 자동차 업체 주도로 발표된 국제표준(ISO/IEC 15118, Vehicle-to-Grid Communication Interface) 기술 규격이며 향후 충전 인프라에 적용 예상이 되는 PLC 통신 방식을 적용한 완속 충전기 개발에 관하여 소개하도록 하였다.