• 전기학회논문지
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• 제63권9호
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• pp.1199-1205
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• 2014

A power system configuration has been increasingly advanced with a number of generating units. In particular, renewable energy resources are widely introduced due to the environmental issues. When applying the renewable energy sources with the ESS (Energy Storage System), the ESS is the role of a potential generating resource in the power system while mitigating the output volatility of renewable energy resources. Thus, for applications of the ESS, the surrounding environment of it should be considered, which means that capacity and energy of the ESS can be affected. Moreover, operation strategy of the ESS should be proposed according to the installation purpose as well as the surrounding environment. In the paper, operation strategy of the ESS is proposed considering load demand and the output of renewable energy resources on a hourly basis. Then, the cost of electrical energy is minimized based on the economic model that consists of capital cost, operation cost, fuel cost, and grid cost for a year. It is sure that peak-shaving effects can be achieved while satisfying the minimum cost of electrical energy.

• 신재생에너지
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• 제17권2호
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• pp.9-23
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• 2021

In Korea, various community investment renewable project models are being implemented to increase community acceptance of renewable energy. An important factor for enhancing local acceptance is that renewable energy projects have a positive effect on revitalizing the local economy such as income increase or job creation for residents and local companies. To maximize the local economic effect of large-scale community investment renewable energy projects, this study developed an evaluation index for local economy activation, whose indicators are the local return on investment, local companies' participation, local job creation, regional cooperation, transparency, and governance. Analysis of existing evaluation indicators and current renewable projects, financial analysis, and expert interviews were used in this research. The pilot evaluation determined that, the local economic effect was high in the following order: a fund investment wind project (Gangwon), benefit-sharing wind project (Jeju), and general wind project. In particular, residents' investment amount, the number of participating residents, and the amount and transparency of the regional cooperation fund were key factors to expand the effect of local economy activation. This evaluation index could be used in public bidding for renewable energy projects such as offshore wind zoning areas of local government.

• 한국수소및신에너지학회논문집
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• 제18권2호
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• pp.216-223
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• 2007

The present carbon-based energy system will not last long due to its environmental and economical drawbacks. Hydrogen energy attracts more attention recently and seems to have large ripple effect on economy providing its technical, environmental and economical problems are solved. This paper analyses the situation changed from fossil to non-fossil energy system and the R&D policies of advanced countries by reviewing the world energy status and the energy policy of foreign countries. Finally, the R&D strategy of hydrogen energy technology was developed through analyzing the present states of energy research policy and programs of major countries.

• Journal of Power Electronics
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• 제15권3호
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• pp.849-859
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• 2015

This paper proposes a novel compound-type hybrid energy storage system (HESS) that inherits the unique advantages of both battery/supercapacitor (SC) and the SC/battery HESSs for electric vehicles (EVs). Eight operation modes are designed to match this system. A mode control strategy is developed for this HESS on the basis of these modes, and five classes of operation modes are established to simplify this strategy. The mode control strategy focuses on high operating efficiency and high power output. Furthermore, the compound-type HESS is designed such that the SC is the main priority in braking energy absorption. Thus, this HESS can operate efficiently and extend battery life. Simulation results also show that the compound-type HESS can not only supply adequate power to the motor inverter but can also determine suitable operation modes in corresponding conditions. Experimental results demonstrate that this HESS can extend battery life as well. The overall efficiency of the compound-type HESS is higher than those of the battery/SC and the SC/battery HESSs.

• 전기학회논문지
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• 제63권6호
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• pp.820-827
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• 2014

Since a microgrid has renewable energy sources, imbalance between power supply and power demand occurs in the islanded mode. In order to solve the imbalance, several energy storage systems (ESSs) such as bettary energy storage system (BESS), EDLC (electric double layer capacitor), flywheel, and SMES (superconducting magnetic energy storage) are generally used. Especially, their electrical characteristics are different. For efficient use of them, a coordinated control scheme is required. In this paper, a coordinated control scheme for using a Lead-acid BESS, a Lithium BESS, and a EDLC is designed to efficient frequency control for a microgrid in the islanded mode. The coordinated frequency control strategy is designed based on their electrical characteristics. The feasibility of the proposed coordinated frequency control strategy is verified through the simulation.

• KIEAE Journal
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• 제10권6호
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• pp.33-39
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• 2010

Visual Environment and productivity are correlated. So we need to create a comfortable visual environment and maintain proper workplane illumination level. We can obtain lighting energy savings and comfortable visual environment using daylight and LED lights. In this study, we characterized the indoor illuminance level according to the sky condition and proposed dimming control strategy of LED lights. Energy savings in On/Off control mode are 40% at clear sky and 28% at intermediate sky. In dimming control mode, energy savings are 77.2% at clear sky and 64.1% at intermediate sky. Then we obtain the appropriate dimming control strategy of LED lights based on data. Dimming rates are 0-14.2-80(min-avg-max, %) for LED 1, 0-19.9-60% for LED 2 and 30-61.4-90% for LED 3. Lighting energy savings are 68.2% for LED dimming system applied this control method.

• 기술혁신연구
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• 제29권1호
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• pp.1-38
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• 2021

본 논문에서는 에너지 섹터의 혁신성 제고를 위한 리빙랩(Living Labs) 활용 전략 수립에 관한 탐색적 분석 연구를 수행하였다. 기존 연구문헌을 통해 이론적 배경이 되는 리빙랩의 개념, 필수 구성요소, 혁신성 특성과 에너지 섹터의 혁신 이슈 유형을 확인할 수 있었다. 이를 토대로 리빙랩 필수 구성요소의 맞춤형 전략 수립과 혁신성 제고와의 연관성, 에너지 섹터에서의 혁신 이슈에 대한 접근으로 리빙랩 활용 가능성에 대해 에너지 리빙랩 사례 연구(해외 8건, 국내 1건)을 통해 분석되었다. 연구 결과, 리빙랩 필수 구성요소의 맞춤형 전략 수립이 혁신성 제고에 동인으로 작용 될 수 있으며, 리빙랩이 에너지 섹터의 혁신 이슈(수요관리, 공급기술, 기술사업화 촉진 및 수용성, 기술정책)에 대한 접근 방법론으로 효과적으로 활용 될 수 있음을 확인되었다. 사례연구 결과 기반으로 혁신성 기여 관점에서 리빙랩 사례별 동인을 도출하고 에너지 혁신이슈별 리빙랩 활용 전략을 수립하였다. 본 연구는 에너지 섹터에서의 혁신이슈에 대한 접근으로 리빙랩 모델의 활용 전략과 그 가치에 대한 탐색적, 기술적 분석 연구로서 종래에 시도되지 않았던 리빙랩 활용 전략 프레임워크를 제공할 수 있고, 에너지 리빙랩 활성화와 네트워크 형성에도 기여될 수 있다는 점에서 학술적·실용적·정책적 함의가 있다고 볼 수 있다.

• Strategy21
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• 통권34호
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• pp.26-57
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• 2014

Revolution of Shale gas literally brings about great changes in many spheres. In the past most academic research had been focused on the influence and innovative change in term of economic perspective. But nowadays we should more concern about the security approach and perspective as its status of the future's core energy resources. Revolution of Shale gas has an great influence on the reshaping of global and regional alliance order. There are many international political implications as follows. Contribution of energy hegemony with leading U.S.; Acting as strategic leverage on the reshaping international order; Deepening competition among major states on the construction of energy security and so on. We'd better make a good solution and systematic policies which are preparing for the Shale gas's revolution period including on the understanding about the change on the global energy structure and making a national policy agenda of energy security issues and so on. The thesis like 'to get the energy resources is to get the hegemonic power in the world' will persist. The same holds good of Shale gas case. To meet the revolution of shale gas era, we have important tasks as like making an opportunity to develope not only regional but also international prosperity.

• Journal of Information Processing Systems
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• 제17권1호
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• pp.63-74
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• 2021

According to the double-phase cluster-head election method (DCE), the final cluster heads (CHs) sometimes are located at the edge of cluster. They have a long distance from the base station (BS). Sensor data is directly transmitted to BS by CHs. This makes some nodes consume much energy for transmitting data and die earlier. To address this problem, energy efficient multi-hop cluster-head election strategy (EEMCE) is proposed in this paper. To avoid taking these nodes far from BS as CH, this strategy first introduces the distance from the sensor nodes to the BS into the tentative CH election. Subsequently, in the same cluster, the energy of tentative CH is compared with those of other nodes, and then the node that has more energy than the tentative CH and being nearest the tentative CH are taken as the final CH. Lastly, if the CH is located at the periphery of the network, the multi-hop method will be employed to reduce the energy that is consumed by CHs. The simulation results suggest that the proposed method exhibits higher energy efficiency, longer stability period and better scalability than other protocols.

• 신재생에너지
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• 제5권1호
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• pp.32-39
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• 2009

Availability of reliable and affordable energy supply is a prerequisite for economic growth. Renewables are the third largest contributor to global electricity production after coal and natural gas and account for a share of 18%. Power generating capacity from renewables has increased to around 900GW by the year 2007. Today biodiesel fuels have been in commercial use in many countries and recently the world-wide biodiesel market has experienced considerable growth, which is partly due to various tax concession programs and other financial incentives. In Korea, biodiesel has already been used for transportation fuel, but not used for power generation fuel yet Korean government has a strategy for renewable energy propagation, especially the goal of power generation amount by renewable energy is 3% of total power production by 2012. This paper focuses on the feasibility study for adaptability and strategy of using biodiesel as power generation fuel. The study also has the plan to replace the fuel of thermal power plant, gas turbine and distributed power system. As the increase of biodiesel fuel, I look forward to environment-friendly power generation and the strategy of Renewable Portfolio Standards(RPS).