• Journal of Electrical Engineering and Technology
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• 제13권6호
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• pp.2245-2253
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• 2018

With the increase of electrical consumption and the unbalance of power demand and supply, power reserve rate is getting smaller and also the reliability of the power supply is getting deteriorated. Under this circumstance, the electrical energy storage (EES) System is considered as one of essential countermeasure for demand side management. This paper proposes efficient evaluation algorithms of multiple functions for EES systems, especially the secondary battery energy storage systems, in the case where they are interconnected with the power distribution systems. It is important to perform the economic evaluation for the new energy storage systems in a quantitative manner, because they are very costly right now. In this paper, the multiple functions of EES systems such as load levelling, effective utilization of power distribution systems and uninterruptible power supply are classified, and then the quantitative evaluation methods for their functions are proposed. From the case studies, it is verified that EES systems installed at distribution systems in a dispersed manner have multiple functions involved with direct and indirect benefits and also they can be expected to introduce to distribution systems with respects to economical point of view.

• 디지털융복합연구
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• 제15권7호
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• pp.41-53
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• 2017

본 연구에서는 2011년 3월 발생한 동일본대지진 이후 스마트그리드에 대한 관심이 높아지고 있는 가운데 일본의 스마트그리드 정책 추진현황 및 문제점에 초점을 맞춰 살펴보았다. 분석 결과, 일본에서는 2011년 동일본대지진으로 인한 전력수급 문제를 계기로 신재생에너지의 고정가격매수제도가 도입되고, 나아가 신재생에너지로 생산된 전력을 거래하는 분산형 그린 전력매매 시장을 설립하는 등 에너지 위기와 환경문제를 동시 해결하는 하나의 솔루션으로서 스마트그리드 관련 프로젝트가 본격적으로 실행되었다. 그 결과 피크전력 억제 및 CO2 삭감효과, 신재생에너지원을 이용한 에너지 수급의 안정적 확보 등 가시적인 성과를 거두었다. 한편, 현행 일본의 스마트그리드 정책 운영상의 개선과제로는 전력계통 안정화 장치의 도입(송배전망의 광역적 운용이나 대형 축전지 도입 등), 스마트그리드 관련 자국기술의 국제표준, 추진 스마트 그리드의 보안성 강화 지원 등을 제시하였다.

• 디지털융복합연구
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• 제17권10호
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• pp.103-113
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• 2019

본 논문은 한국에서의 석탄산업이 신기후체제의 출범 이후에도 여전히 중요하며, 일정한 물량의 석탄 비축을 통해 에너지원의 수급을 조절할 수 있는 능력을 지닐 필요성에 대한 근거를 제시하는데 있다. 최근 신재생에너지의 비중 증가는 석탄이나 석유와 같은 화석연료의 의존도를 낮출 것으로 전망된다. 그리고 이에 따라 석탄의 사용도 감소할 것으로 전망되지만, 아직 에너지원별 수요의 면에서나 전력 공급의 면에서 석탄이 에너지원으로서의 지위가 여전히 큰 것이 확인되었다. 석탄의 최적 비축 규모는 기존 연구의 연간 수요를 기준으로 추정하였다. 이러한 점에서 지속가능한 성장을 위한 산업적 정책으로서 석탄산업의 유지와 연간 최적 비축 규모의 결정은 매우 중요한 문제이다.

• 자원ㆍ환경경제연구
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• 제28권2호
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• pp.177-200
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• 2019

전력수급계획의 근간이 되는 전력수요 전망은 GDP와 기상변수 등 다양한 요인에 의해 영향을 받기 때문에 확률 프로세스로 이해할 수 있다. 이 전망치를 바탕으로 전력설비의 구성 방안이 수립되는데, 실제 의사결정 과정은 주어진 확률분포에 대한 정보가 온전하다고 가정한다는 한계를 가진다. 그러나 현실적으로는 확률분포 자체의 중첩 불확실성이 존재하기 때문에 강건한 최적계획(robust optimization)의 수립이 필요하다. 본 논문은 중첩 불확실성을 포함한 발전설비 조정의 최적의사결정을 연구한다. 구체적으로 원자력의 감축투자 관련 실물옵션 모형을 수립하고 우리나라 전력수급기본계획의 특성을 고려한 중첩 불확실성하에서 원전감축 투자를 분석한다. 분석 결과, 현재의 원전축소 정책은 전력수요 증가율이 낮다는 것을 전제로 한 정책으로서 전력수요 증가에 대응할 수 있는 정책 강건성을 갖추지는 못한다는 것을 보여준다.

• 에너지공학
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• 제26권2호
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• pp.80-92
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• 2017

본 연구는 1998년부터 2015년까지의 16개 시도별 경유수요량, 경유제품 판매가격(유통단계), 및 총 부가가치생산의 패널데이터를 이용하여, 패널GLS, 고정효과(Fixed Effect), 확률효과(Random Effect) 및 동적패널(Dynamic Panel) 모형을 통해 국내 경유수요함수를 추정하고, 이를 통해 가격탄력성과 소득탄력성을 추정하였다. 단기 가격탄력성은 -0.2146(패널GLS), -0.2886(고정효과), -0.2854(확률효과), -0.1905(동적패널)로 추정되었고, 단기 소득탄력성은 0.7379(패널GLS), 0.4119(고정효과), 0.7260(확률효과), 0.4166(동적패널)로 추정되었는데, 모두 비탄력적인 것으로 나타났다. 장기 가격탄력성과 장기 소득탄력성은 동적패널을 통해 추정하였고, 각각 -0.4784, 1.0461로 유의하게 나타났다. 경유 수요는 소득에 증감에 대해 단기적으로는 비탄력적이나, 장기적으로는 탄력적으로 나타나고 있다. 추가로 서울지역을 기준으로 지역변수를 더미변수(Dummy Variables)로 하여 각 지역의 경유수요로의 효과를 검정하였는데, 10개 지역에서 상대적으로 유의하게 추정되었다.

• International Journal of Railway
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• 제6권2호
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• pp.33-44
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• 2013

In recent years, energy consumption in the transportation sector by expanding motorization continues to increase in almost every country in the world. Moreover, the growth rate of the transportation energy consumption is significantly higher than those of the civilian and industrial sectors. Therefore, every country strives to reduce its dependence on private transport, which is the main contributor to the transportation energy consumption. In many countries, concepts such as Transit Oriented Development (TOD) or New Urbanism, which controls road traffic by increasing the proportion of the public transportation significantly, have been implemented to encourage a modal shift to public transport. However, the level of change required for eliminating environmental problems is a challenging task. Minimizing transportation energy consumption by controlling the increase of the traffic demand and maintaining the level of urban mobility simultaneously is a pressing dilemma for each city. Grasping the impact of the diversity of the urban transport and infrastructure is very important to improve transportation energy efficiency. However, the potential for reducing urban transportation energy consumption has often been ineffectively demonstrated by the diversity of cities. Therefore, the accuracy of evaluating the current efficiency rate of the urban energy consumption is necessary. Nevertheless, quantitative analyses related to the efficiency of transportation energy consumption are scarce, and the research on the current condition of consumption efficiency based on international quantitative analysis is almost nonexistent. On the basis of this background problem definitions, this research first built a database of the transportation energy consumption of private modes in 119 cities, with an attempt to reflect individual travel behaviors calculated by Person Trip data. Subsequently, Data Envelopment Analysis (DEA) was used as an assessment method to evaluate the efficiency of transportation energy consumption by considering the diversity of the urban traffic features in the world cities. Finally, we clarified the current condition of consumption efficiency by attempting to propose a target values for improving transportation energy consumption.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2017년도 학술발표회
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• pp.184-184
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• 2017

A nation-wide water-energy-food (WEF) nexus simulation model has been developed by the authors and successfully applied to South Korea to predict the sustainability of those three resources in the next 30 years. The model was also capable of simulating future scenarios of resources allocation based on priority rules aiming to maximize resources sustainability. However, the process was still relying on several assumptions and trial-and-error approach, which sometimes resulted in non-optimal solutions of resources allocation. In this study, an optimization module was introduced to enhance the model in generating optimal resources management rules. The objective of the optimization was to maximize the reliability index of resources by determining the resources' allocation and/or priority rules for each demand type that accordingly reflect the resources management policies. Implementation of the optimization module would result in balanced allocation and management of limited resources and assist the stakeholders in deciding resources' management plans, either by fulfilling the domestic production or by global trading.

• 에너지공학
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• 제23권2호
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• pp.57-61
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• 2014

자동차산업이 해결해야 할 과제로서 석유에너지의 소비증가와, $CO_2$ 배출에의한 지구온난화, 배기가스 배출에 의한 도시부 대기오염 등에 대한 대처가 필요한 시점이다. 이들의 해법으로 시장에서 높은 평가를 받고 있는 전기자동차의 필요성이 대두되고 있다. 본 연구에서는 전기자동차 모터, 배터 리 및 구동모터를 포함한 고전압 핵심부품들의 효율적인 열관리 기술, 배터리 및 구동모터의 열관리 기술 및 개발동향을 알아보고자 한다.

• 한국물환경학회지
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• 제36권1호
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• pp.55-68
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• 2020

Because of the intensified environmental problems such as climate change and resource depletion, sewage treatment technology focused on energy management has recently attracted attention. The conversion of primary sludge from the primary sedimentation tank and excessive sludge from the secondary sedimentation tank into biogas is the key to energy-positive sewage treatment. In particular, the primary sedimentation tanks recover enriched biodegradable organic matter and anaerobic digestion process produces methane from the organic wastes for energy production. Such technologies for minimizing oxygen demand are leading the innovation regarding sewage treatment plants. However, sewage treatment facilities in Korea lack core technology and operational know-how. Actually, the energy potential of sewage is higher than sewage treatment energy consumption in the sewage treatment, but current processes are not adequately efficient in energy recovery. To improve this, it is possible to apply chemically enhanced primary treatment (CEPT), high-rate activated sludge (HRAS), and anaerobic membrane bioreactor (AnMBR) to the primary sedimentation tank. To maximize the methane production of sewage treatment plants, organic wastes such as food waste and livestock manure can be digested. Additionally, mechanical pretreatment, thermal hydrolysis, and chemical pretreatment would enhance the methane conversion of organic waste. Power generation systems based on internal combustion engines are susceptible to heat source losses, requiring breakthrough energy conversion systems such as fuel cells. To realize the energy positive sewage treatment plant, primary organic matter recovery from sewage, biogas pretreatment, and co-digestion should be optimized in the energy management system based on the knowledge-based operation.

• 전기학회논문지
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• 제56권11호
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• pp.1903-1909
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• 2007

As the electric power industry has been revolutionarily transformed such that the distributed energy resources have been interconnected with power systems and a variety of energy service providers have been appeared, the need of Consumer Energy Portal as a core of two-way communication and service infrastructure between power suppliers and consumers has been gradually increased. Consumer Energy Portal can be thought of as a combination of hardware and software enabling two-way communication between energy service providers and equipment within the consumers' premises or a physical and logical link between consumers' in-building networks and wide-area access networks. In other words, Consumer Energy Portal can make the way the power industry has been traditionally operated the web-based way, enabling two-way interactions between energy service providers and consumers and mutual networking between end users' equipment. Thus, Consumer Energy Portal can be a kind of Service portal that provides new value-added services and efficient power operations that in the past. In this paper, for ESPs' integrated resources management, demand side management and value-added service provision, we have established the two-way access network that can gather real-time metering data using ZigBee technology and control physically networked equipment.