• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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• pp.400-402
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• 1994

The voltage drop in distribution path of battery-reserved DC power system can affect the total of battery, cable and electricity costs. To determine an optimum voltage drop in distribution path for minimizing the total cost, battery, cable and electricity costs are represented as a function of the voltage drop, respectively, and are summed up to the total cost. An optimum voltage drop is selected as the value giving the minimum total cost. In this paper, a design technique of optimum voltage drop in distribution path of DC power system is proposed to minimize the total of battery, cable and electricity costs. The design procedure is described and design curve for selecting optimum voltage drop is also presented as a function of distribution distance.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.15-20
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• 2008

The objectives of this study are to analyze the energy independence plan and to propose a suitable sewage treatment plant in Korea. The total amount of electricity consumption for public sewage treatment plant was estimated as 1,182 GWh in 2007. It was estimated that total 16 sewage treatment plants with renewable energy systems produced electricity of 15.2 GWh per year, which could replaced 0.8% of total electricity used for sewage treatment. It was found that domestic sewage treatment plants with power generation plants by digestion gas were installed in 7 places and produced electricity of 13 GWh per year. It was also found that the power generation plants by digestion gas were the most cost-effective for sewage treatment out of the renewable energy systems based on the benefit-cost analysis.

• 한국수자원학회논문집
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• 제42권9호
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• pp.759-771
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• 2009

장거리 용수공급 시스템에서 전력비용은 전체 운영비용의 큰 부분을 차지한다. 본 연구는 시간단위의 펌프와 배수지 시스템의 최적 운영계획을 평가하기 위해 동적계획기법에 기초한 방법론을 제시하고 있다. 해석방법은 운영비용 최소화 관점에서 펌프용량 확대를 전제로 현재 가용 펌프의 효율적 운전과 전력요금체계, 시간별 용수수요 추이 그리고 배수지 특성과 송수관로의 제약조건 등을 고려하였다. 이를 위해 적용 가능한 시스템 운영목적과 제약조건이 제시되었고 개발된 방법은 수도권 광역상수도 양주계통의 2개 가압장과 5개 배수지를 대상으로 적용하였다. 적용결과는 펌프 확장의 경우 상당한 수준의 운전비용을 절감할 수 있는 것으로 나타났으며, 이와 같은 방법은 기존 시스템의 최적운영은 물론 생애주기 비용 최소화 측면에서 신규 용수공급 체계의 설계 등에 적절히 활용될 수 있다.

• 한국수소및신에너지학회논문집
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• 제33권6호
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• pp.643-659
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• 2022

For the economic analysis of fuel cells, levelized cost of electricity was calculated according to the type, capacity, and annual production of the fuel cells. The cost of every component was calculated through the system component breakdown. The direct cost of the system included stack cost, component cost, assembly, test, and conditioning cost, and profit markup cost were added. The effect of capacity and annual production was analyzed by fuel cell type. Sensitivity analysis was performed according to stack life, capital cost, project period, and fuel cost. As a result, it was derived how much the economic efficiency of the fuel cell improves as the capacity increases and the annual production increases.

• 자원ㆍ환경경제연구
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• 제23권1호
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• pp.43-65
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• 2014

본 논문에서는 국내 제조업 가운데 전력 사용량이 상대적으로 많은 화합물 및 화학제품 산업을 대상으로 암묵 (shadow) 비용함수를 사용하여 전력 등의 투입요소 간 효율적 배분 여부를 검증하고 전력의 적정수준 대비 과잉 투입 규모를 조사한다. 기업의 비용최소화 달성을 전제로 각 투입요소에 대한 수요의 가격탄력성을 추정하여 전력요금 인상에 대한 각 요소 수요의 파급효과를 모의실험을 통하여 분석한다. 또한 공급관계식을 비용함수의 방정식체계에 추가하여 동시 추정함으로써 전력요금 10% 인상 시 물가지수에 미치는 영향을 분석한다. 실증분석 결과, 1982-2006년 기간 동안 '투입요소 간 효율적 배분 달성'의 귀무가설은 기각되었으며, 전력은 적정수준 대비 평균적으로 매년 약 98% 과잉 사용되고 있는 것으로 나타났다. 다른 요인들이 불변하다면 전력요금이 10% 인상될 경우 전력 수요는 약 11.4% 감소하였으며, 공급가격은 평균적으로 0.08% 하락하는 것으로 나타났다.

• 대한전기학회논문지:전력기술부문A
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• 제53권2호
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• pp.97-103
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• 2004

CHP system supplies electricity and heating together with high efficiency. Current utility's CHP system uses electric power by itself and sells thermal energy to KDHC(Korea District Heating Corporation). CHP's operation cost except sales revenue of heating was covered by the sale revenue of electricity. Thus Electric generation cost in district Heating CHP system has close relationship with the level of heating price. However, after the restructuring of electricity industry, the operation cost could not be covered by sales revenue of heating and electricity. This loss was compensated by energy subsidy program in the electric power industry infrastructure fund. This paper suggests reasonable evaluation and improvement methods of the loss calculation of CHP system utilizing the infrastructure fund efficiency In terms of the direction of support by the fund, it provides the methods to prevent inefficient operation through setting up the upper limit of subsidy and to improve the loss calculation. Moreover, it suggest fixed rate support by heating supply level and reducing subsidy gradually for an efficient operation of CHP system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권12호
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• pp.5712-5728
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• 2017

Recently, there are many studies, that considering green wireless cellular networks, have taken the energy consumption of the base station (BS) into consideration. In this work, we first introduce an energy consumption model of multi-mode sharing BS powered by multiple energy sources including renewable energy, local storage and power grid. Then communication load requests of the BS are transformed to energy demand queues, and battery energy level and worst-case delay constraints are considered into the virtual queue to ensure the network QoS when our objective is to minimize the long term electricity cost of BSs. Lyapunov optimization method is applied to work out the optimization objective without knowing the future information of the communication load, real-time electricity market price and renewable energy availability. Finally, linear programming is used, and the corresponding energy efficient scheduling policy is obtained. The performance analysis of our proposed online algorithm based on real-world traces demonstrates that it can greatly reduce one day's electricity cost of individual BS.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.550-552
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• 2001

The vertically integrated power industry was divided into six generation companies and one market operator, where electricity trading was launched at power exchange. In this environment, the profits of each generation companies are guaranteed according to utilization of their own generation equipments. Especially, the electricity demand shows seasonal and weekly regular pattern, which the some capacity should be provided into ancillary service based on the past demand forecasting error and operating results of electricity market. Namely, if generation cost function is applied to SMP and BLMP as announced the previous day, the available generation capacity of the following day could be optimally distributed, and therefore contract capacity of ancillary service applied to CBP(Cost Based Pool) and TWBP(Two-Way Bidding Pool) is determined. Consequently, it is Possible to use the retained equipments optimally. This paper represents on efficient bidding strategies for generation equipments through the calculation of the contract and the application of each generator cost function based on the past demand forecasting error and market operating data.

• 전기학회논문지
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• 제63권7호
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• pp.889-895
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• 2014

Korea electric power industry had been under vertical monopoly but is typically getting restructured for free competition. An ideal pricing system under the competitive market system is 'unbundled pricing system' and 'marginal pricing system', but the current pricing system still adheres to the traditional bundled system and the average cost pricing system. Especially, progressive electricity rates for residential use reflect governmental policy-making which is focused on income redistribution & welfare, industrial supports and energy saving. This study proposes new and reasonable residential electricity pricing systems which are Time-Of-Use (TOU) and Real-Time Pricing (RTP) to reflect variations in the wholesale price of electricity. It also presents examples of various tariffs for residential electricity pricing systems.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1202-1207
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• 2011

This article introduces the benchmarking methodologies, the results of comparative analysis on the railway electricity maintenance management - preventive maintenance, corrective maintenance, upgrade maintenance. This article also compares the Korean railway electricity maintenance management with the results mentioned above and analyses the situations of each country - France, Germany, Japan. Lastly this article tries to find the comparative position of the Korean railway infrastructure costs and discusses the direction of cost reduction in railway electricity maintenance management.