• 신재생에너지
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• 제8권4호
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• pp.21-29
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• 2012

The extensible supply of New & Renewable energy resources desperately needs to counter the high dependence on imported energy, recent high oil prices and the Climate Change Conference, and the government has operated the 'Renewable Portfolio Standard' (RPS) as one of the renewable energy policy from 2012. By analyzing the operation case of combined heat and power plant using the woodchip biomass, we drew the price of wood chip fuel, plant capacity factor, electricity selling price, heat selling price and LCOE value. After analyzing the economic feasibility of 3MWe combined heat and power plant based on the operating performance, the minimum of economic feasibility has appeared to be secured according to the internal rate of return (IRR) is 6.34% and the net present value (NPV) is 3.6 billion won as of 20 years life time after installation, and after analyzing the cases of the economic feasibility of the price of wood chip, plant capacity factor, electricity and heat selling price are changed, the economic feasibility is valuable when the price of wood chip is over 64,000 won/ton, NPV is minus, and the capacity factor is above 46.9%, the electricity selling price is 116 won/kWh and the heat selling price is above 75,600 won/Gcal. When going over the new installation hereafter, we need the detailed review of the woodchip storage and woodchip feeding system rather than the steam-turbine and boiler which have been inspected many times, the reason why is it's hard to secure the suitable quality (constant size) of woodchip by the lack of understanding about it as a fuel because of the domestic poor condition and the calorific value of woodchip is seriously volatile compared with other fuels.

• 한국인터넷방송통신학회논문지
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• 제20권2호
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• pp.13-20
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• 2020

빅 데이터 관련 주요 논제 중의 하나는 방대한 시간 기반 또는 원격 측정 데이터의 가용성에 관한 문제이다. 현재 저비용 획득 및 저장 장치의 등장은 더 세밀한 분석에 사용될 상세한 시간 데이터를 얻을 수 있어서 배후 시스템에 대해 여러 가지 지식을 갖거나 미래의 이벤트를 더 정확히 예측할 수 있다. 특히, 스마트 미터가 설치된 수많은 가정 및 기업 등을 대상으로 전기 사용에 관한 고객 맞춤형 계약을 정의하는 것은 다른 무엇보다도 중요한 문제이다. 수많은 스마트 미터 데이터를 바탕으로 공통적인 전력 소비 형태를 몇 가지 그룹으로 구분할 필요가 있다. 이에 본 연구에서는 스마트 미터 측정 관련 공개 데이터와 자바 기반 공개 소스인 KNIME 플랫폼을 사용하여 스마트 미터 관련 빅 데이터 변환과 클러스터링을 나타낸다. 빅 데이터 구성 요소는 공개 소스는 아니지만, 시험판으로 사용할 수 있다. 스마트 미터 빅 데이터를 가져오고, 정리하고, 변환한 후 전력 사용량 행위와 관련된 각 미터 ID의 해석과 클러스터링에 적합한 DTW 접근 방식을 통해 전력 사용 행위에 관한 스마트 계약을 정의할 수 있다.

• Journal of Biosystems Engineering
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• 제20권3호
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• pp.275-287
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• 1995

The rice processing complex(RPC) consisted of the rice handling, drying, storage, and milling processes. It has been established at 83 locations domestically by April 1994, and 200 of RPC will be built more throughout the country. Therefore, this study has been performed to achieve two objectives as the followings : 1) Development of mathematical models which can assess the requirement of electricity, fuel, and labor for four model systems of rice processing complex. 2) Development of a computer simulation model which produce the improved designs of RPC by the evaluation results of energy requirements of four RPC models. The results from this study are summarized as follows : 1) Mathematical models were developed on the basis of result of mass balance analysis and required power of machines for each process. 2) A computer simulation model was developed, which can produce the improved designs of RPC by the evaluation results of energy requirements. The computer simulation model language was BORLAND $C^{++}$. 3) The results of simulation showed that total energy requirements were ranged from 75.94㎾h/t to 124.30㎾h/t. 4) From the results of computer analysis of energy requirement classified by drying type, it was found that energy requirement of the drying type A{paddy rice (PR) for storage-natural air drying(15%), PR for milling-heated air drying(16%)} were less than that of the drying type B{1 step-natural air drying(PR for storage : 18%, PR for milling : 20%), 2 step-heated air drying(PR for storage : 15%, PR for milling : 16%)}. 5) The energy efficient drying method is that all the incoming rough rice to RPC should be dried by national air drying systems. If it is more than the capacity of national air drying system, the amount of surplus rough rice is recommended to be dried by the heated air drying method.

• 전기전자학회논문지
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• 제19권3호
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• pp.295-303
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• 2015

지구 온난화 및 탄소배출권 저감을 위한 대안으로 에너지저장장치(ESS, Energy Storage System)의 중요성을 인식하고 ESS 산업육성을 위한 보급사업 및 인센티브 정책을 추진하고 있다. 우리나라는 2020년까지 ESS 누적 용량 2GW 보급을 추진하고 있다. 이러한 보급정책과 기업들의 기술개발에 따라 시장 확대로 인한 ESS의 배터리 가격이 점차 하락할 전망이다. 본 논문에서는 ESS 기술개발에 따른 ESS 가격 하락에 따른 ESS 보급량 추정을 하였으며, 이에 따라 발생하는 비용의 경제성 분석을 실시하였다. 또한 ESS 종류에 따라 발생할 수 있는 비용 및 ESS와 풍력전원의 연계에 따른 투자비용 분석을 하였으며, ESS보급에 따라 발생할 수 있는 전력판매수익 및 신재생에너지공급인증서 판매수익에 대한 경제성 분석을 실시하였다.

• 전기학회논문지
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• 제65권6호
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• pp.923-933
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• 2016

This paper proposes a new method for evaluating Effective Load Carrying Capability(ELCC) and capacity credit(C.C.) of power system including Wind Turbine Generator(WTG) combined with Battery Energy Storage System(BESS). WTG can only generate electricity power when the fuel(wind) is available. Because of fluctuation of wind speed, WTG generates intermittent power. In view point of reliability of power system, intermittent power of WTG is similar with probabilistic characteristics based on power on-off due to mechanical availability of conventional generator. Therefore, high penetration of WTG will occur difficulties in power operation. The high penetration of numerous and large capacity WTG can make risk to power system adequacy, quality and stability. Therefore, the penetration of WTG is limited in the world. In recent, it is expected that BESS installed at wind farms may smooth the wind power fluctuation. This study develops a new method to assess how much is penetration of WTG able to extended when Wind Turbine Generator(WTG) is combined with Battery Energy Storage System(BESS). In this paper, the assessment equation of capacity credit of WTG combined with BESS is formulated newly. The simulation program, is called GNRL_ESS, is developed in this study. This paper demonstrates a various case studies of ELCC and capacity credit(C.C.) of power system containing WTG combined with BESS using model system as similar as Jeju island power system. The case studies demonstrate that not only reasonable BESS capacity for a WTG but also permissible penetration percent of WTG combined with BESS and reasonable WTG capacity for a BESS can be decided.

• 한국수소및신에너지학회논문집
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• 제30권1호
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• pp.14-20
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• 2019

The power to gas (P2G) is one of the energy storage technologies that can increase the storage period and storage capacity compared to the existing battery type. One of P2G technologies produces hydrogen by decomposing water from renewable energy (electricity) and the other produces $CH_4$ by reacting hydrogen with $CO_2$. The objective of this study is the reaction of $CO_2$ methanation which synthesized methane by reacting carbon dioxide and hydrogen. The effect of $CO_2$ conversion and $CH_4$ selectivity on reaction temperature, pressure, and methane contents over 40% Ni catalyst was mainly investigated throughout this study. As a result, the activity of this catalyst appeared to be the highest in $CH_4$ yield at around $400^{\circ}C$ and the selectivity of $CH_4$ increased with increasing reaction pressure. The methane content was not significantly influenced below 3% of all componets. As the space velocity increases from 10,000 to 30,000/hr, the $CO_2$ conversion rate tends to decrease.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2004년도 Proceedings of the 4th Korea-China Joint Workshop on Nuclear Waste Management
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• pp.140-142
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• 2004

Since the April of 1978, Korea has strongly relied on the nuclear energy for electricity generation. As of today, eighteen nuclear power plants are in operation and ten are to be inaugurated by 2015. The installed nuclear capacity is 15, 716 MW as of the end of 2002, representing 29.3% of the nation's total installed capacity. The nuclear share in electricity remains around 38.9 at the end of 2002, reaching at the level of 119 billion kWh's. New power reactors, KSNP's (Korea Standard Nuclear Power Plant) are fully based on the domestic technologies. More advanced reactors such as KNGR (Korea Next Generation Reactor) will be commercialized soon. Even though the front end nuclear cycle enjoys one of the best positions in the world, there have been some chronical problems in the back end fuel cycle. That's the one of the reason why we need more active R&D programs in Korea and active international and regional cooperation in this area. The everlasting NIMBY problem hinders the implementation of the nation's radioactive waste management program. We expect that the storage capacity for the LILW(Low and Intermediate Level radioactive Waste) will be dried out soon. The situation for the spent fuel storage is also not so favorable too. The storage pools for spent fuel are being filled rapidly so that in 2008, some AR pools cannot accommodate any more new spent nuclear fuels. The Korean Government in strong association with utilities and national academic and R&D institutes have tried its best effort to secure the site for a LILW repository and a AFR site. Finally, one local community, Buan in Jeonbook Province, submitted the petition for the site. At the end of the last July, the Government announced that the Wido, a small island in Buan, is suitable for the national complex site. The special force team headed by Dr IS Chang, president of KAERI teamed with Government officials and many prominent scholars and journalists agreed that by the evidences from the preliminary site investigation, they could not find any reason for rejecting the local community's offer.

• 한국수소및신에너지학회논문집
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• 제29권4호
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• pp.363-369
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• 2018

This paper considers the alternative way to mitigate cost for REC instead of Photovoltaic (PV) panels with Energy Storage System (ESS). This study starts from an economic analysis of a 1 megawatt PV system without ESS. Several assumptions have been applied in consideration of the current domestic situation. Based on this result, the economic efficiency of PV with ESS improved. However, the reliance on government subsidies was very high. The alternative way to cover the fluctuation power from renewable energy was reviewed with economical and technical way. In case the natural gas engine applied to PV, the IRR and Levelized Cost of Electricity (LCOE) can be improved without ESS. And if small amount of additional REC, the IRR can be improved up to investment level.

• 전기학회논문지
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• 제65권4호
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• pp.547-554
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• 2016

Analyze the customer daily load patterns, be used to determine the optimal charging and discharging schedule which can minimize the electrical charges through the battery energy storage system(BESS) installed in consumers is an object of this paper. BESS, which analyzes the load characteristics of customer and reduce the peak load, is essential for optimal charging and discharging scheduling to save electricity charges. This thesis proposes optimal charging and discharging scheduling method, using particle swarm optimization (PSO) and penalty function method, of BESS for reducing energy charge. Since PSO is a global optimization algorithm, best charging and discharging scheduling can be found effectively. In addition, penalty function method was combined with PSO in order to handle many constraint conditions. After analysing the load patterns of target BESS, PSO based on penalty function method was applied to get optimal charging and discharging schedule.

• 전기학회논문지
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• 제65권6호
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• pp.979-986
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• 2016

At present, electric power industry around the world are being gradually changed to a new paradigm, such as electrical energy storage system, the wireless power transmission. Demand for ESS, the core technology of the new paradigm, has been growing worldwide. However, it is essential to estimate the optimal capacity of ESS facilities for frequency regulation because the benefit would be saturated in accordance with the investment moment and the increase of total invested capacity of ESS facilities. Hence, in this paper, the annual optimal mathematical investment model is proposed to estimate the optimal capacity and to establish investment plan of ESS facility for frequency regulation. The optimal mathematical investment model is newly established for each season, because the construction period is short and the operation effect for the load by seasons is different unlike previous the mathematical investment model. Additionally, the marginal operating cost is found by new mathematical operation model considering no-load cost and start-up cost as step functions improving the previous mathematical operation model. ESS optimal capacity is established by use value in use iterative methods. In this case, ESS facilities cost is used in terms of the value of the beginning of the year.