• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.339-344
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• 2005

A PEMFC system model for FCEV was constructed and simulated numerically to examine the heat/water flow of the system and air/fuel humidification process for various operation conditions (ambient pressure /temperature/humidity, operating temperature, power load). We modeled PEMFC stack which can generate maximum electricity of about 80 kW. This stack consists of 400 unit cells and each unit cell has $250cm^2$ reacting area. Uniform current density and uniform operating voltage per each cell was assumed. The results show the flow characteristics of heat and water at each component of PEMFC system in macro-scale. The capacity shortage of the radiator occurred when the ambient was hot $(over\;40^{\circ}C)$ and power level was high (over 50 kW). In spite of some heat release by evaporation of water in stack, heat unbalance reached to 20kW approximately in such a severe operating condition. This heat unbalance could be recovered by auxiliary radiators or high speed cooling fan with additional cost. In cold environment, the capacity of radiator exceeded the net heat generation to be released, which may cause a problem to drop the operating temperature of stack. We dealt with this problem by regulating mass flow rate of coolant and radiator fan speed. Finally, water balance was not easily broken when we retrieved condensed and/or unused water.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.4
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• pp.631-638
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• 2016

Offshore wind power can be an alternative for onshore wind power which suffers from not only civil complaints regarding to landscape damage and noise but also wind power siting due to lack of onshore site candidates. Compared to onshore wind power, offshore wind power is free from these problems considering that generally the sites are far enough from the coast. And more electricity is generated in offshore wind turbines due to abundant offshore wind resources. However high installation costs of offshore turbines could deteriorate the economical efficiency. The main cause of the high installation costs comes from a long-term lease of the heavy marine equipment and the consequential high rental cost. In this paper, the conceptual design of the support structure for offshore wind turbines will be suggested for the installation of them with less heavy marine equipment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.5
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• pp.1005-1012
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• 2016

LED beacons operated on an isolated marine area are mostly employing the solar power supply system, and this system is well known for increasing the cost of management and maintenance. Recently, a number of researches and demonstrations on self-contained LED beacon is actively conducted to solve this issue. In this work, we propose an self-contained LED beacon with Bluetooth Low Energy function for an effective management of LED beacon. Firstly, control program structure is designed by expanding the status protocol of self-contained LED beacon, and then it is implemented into the form which administrator can easily understand. The control system visualizes the status and control data of self-contained LED beacon, and this enables the rapid decision-making of administrator. Also, minimizing electricity consumption of the beacon, it can transfer and update the status or light information of self-contained LED beacons with smart phone.

• Journal of Energy Engineering
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• v.20 no.3
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• pp.231-235
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• 2011

Ligneous biomass such as wood pellet is characterized as carbon neutral which has no carbon dioxide emission ; additionally, it can be used as an alternative fuel by co-firing without additional plant reformation as well as for maintaining stability of fuel supply. We can develop CDM project while co-firing by using biomass into conventional coal fired thermal power plant with AM0085 CDM methodology, and it's possible to prove additionality as fuel cost per kWh is higher than bituminous. The study shows that the electricity by biomass can reduce green house emission by $0.6737tCO_2$ per MWh.

• Proceedings of the Korean Professional Engineer Association Conference
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• 1996.12a
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• pp.76-102
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• 1996

북한은 전력부족난과 전기품질의 저하로 인하여 주요 생산기업에 지장을 주고 있으며, 노후 발전소의 성능저하도 함께 진행되고 있는 것으로 추정된다. 이에 대한 적절한 대책이 없는 한 그 상황은 더욱 악화될 전망이다. 한반도 에너지 개발기구(KEDO)가 추진하고 있는 경수로 원자력 발전기가 6～7년 후에 준공된다고 해도 이처럼 불안정한 전력계통에 병입되어 원활한 운전이 가능할런지 기대하기 곤란하다. 이러한 실정에서 \circled1 전력부족으로 주파수가 저하될 때 우선 순위가 낮은 부하를 제한하는 자동 부하제한 방식을 포함한 자동 주파수 제어 계통개선 \circled2 기존발전소 성능과 이용을 향상을 위한 재가동(Repowering) 등의 리 엔지니어링 \circled3 가스터빈 복합화력과 열병합발전(Co-generation) 등과 같이 건설기간이 짧고 비용이 적게 들며 송전 설비 건설도 불필요한 분산형 전원의 건설 \circled4 수력발전소와 조력발전소의 건설 \circled5 양수발전 등 전력에너지 저장설비의 개발 \circled6 송전전압격상과 배전방식개선 및 종합전력정보시스템 구축 \circled7 남ㆍ북한 전력계통 내지는 동북아시아 전력계통을 연계하는 평화망사업(Peace Network Project)등의 추진이 경수로 사업에 선행되어야 한다. 특히 러시아, 중국, 한국, 일본의 발전 에너지원 분포와 년간 부하곡선을 고려할 때 동북아시아 전력계통의 연계는 관련국 상호간에 에너지 환경과 경제적 측면에서 상당한 이득과 안정성을 강화해 줄 것이며, 기술발전과 평화공존에 크게 기여 할 것이다. 이를 위하여 관련국의 전력계통연계 전문가들이 참여하는 남\ulcorner북한전력 계통연계연합회(Co-Pia ; Co-rea Power Systems Interconnection Association)와 동북아지역전력 계통연합회(Near Pia=North-Eastern Asia Region Power Systems Interconnection Association)의 구성을 제안하는 바이다. 주요용어(Key Words): 자동주파수 제어(AFC), 리엔지니어링(Re-Engineering), 분산형 전원(Dispersed Generation System), 전력저장(Power Storage), 부하조절기(Load Conditioner), 수요관리(DSM) 연계(Interconnection), 인터시스템(Intersystem), 통합자원계획(IRP), 안전성 강화(Security Enhancement), 전력시장개방(Electricity Free Maket), 통일비용(Unification Expense, Unification Cost), 남ㆍ북한전력계통연계연합회(Co-Pia), 동북아지역전력 계통연계연합회(Nea,-Pia).

• Journal of the Korean Solar Energy Society
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• v.30 no.4
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• pp.9-14
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• 2010

The main cause of global warming is carbon dioxide generated from the use of fossil fuels, and active research on the reduction of carbon is in progress to slow down the increasing global warming. Wind turbines generate electricity from kinetic energy of wind and are considered as representative for an energy source that helps to reduce carbon emission. Since the kinetic energy of wind is proportional to the cube of the wind speed, the intensity of wind affects wind farm construction validity the most. Therefore, to organize a wind farm, validity analysis should be conducted first through measurement of the wind resources. To facilitate the approval and permission and reduce installation cost, measuring sensors should be installed at locations below the actual wind turbine hub. Wind conditions change in shape with air density, and air density is most affected by the variable sterrain and surface type. So the magnitude of wind speed depends on the ground altitude. If wind conditions are measured at a location below the wind turbine hub, the wind speed has to be extrapolated to the hub height. This correction of wind speed according to height is done with the Deacon equation used in the statistical analysis of previously observed data. In this study, the optimal Deacon equation parameter was obtained through the analysis of the correction of the wind speed error with the Deacon equation based on the characteristics of terrain.

• Proceedings of the KIEE Conference
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• summer
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• pp.648-651
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• 2004

현재 원가반영발전경쟁시장(CBP : Cost Based Pool)에서는 발전사업자의 변동비용에 기초하여 공급곡선을 형성하게 된다. 그래서 공급 곡선에 있어서 는 비교적 불확실성이 덜하다고 할 수 있다. 그러나 양방향입찰시장에서의 가격결정은 발전사업자와 전력구매자의 입찰데이터(bidding data)로 결정되므로 불확실성의 정도가 매우 심해진다. 즉 가격결정에 있어서 입찰데이터는 매우 중요하며 입찰전략에 따라 사업자의 수익이 달라지기 때문이다. 또한 수직통합체제 때와는 달리 설비용량의 증설도 계통의 부하를 충족시키기 위해서가 아니라 각 발전사업자의 수익성을 고려하여 수행된다. 따라서 중장기적으로는 설비용량계획의 불확실성이 존재하고 단기적으로는 각 발전사업자의 수익 극대화를 위한 입찰 전략에 있어서의 불확실성이 존재하게 된다. 이와 같은 상황에서는 과거의 역사적 데이터를 바탕으로 해당시장에서 발전사업자들의 형태를 분석하는 실증적 분석(empirical analysis)이 가장 설득력이 있지만 현재 우리나라의 전력 시장은 CBP 체제이고 TWBP 시장은 열리지도 않았기 때문에 축적된 데이터는 전무하다. 이러한 현실적 여건 때문에 불확실성의 정도는 더욱 심해지고 TWBP 시장에서의 가격을 예측하는 과정에서도 어려움이 더욱 커지게 된다. 따라서 본 연구에서는 가능한 다양한 해외 연구 사례를 참조하여 시장에서의 발전사업자 중장기적(설비), 단기적(입찰전략) 행위를 어떤식으로 모델링하고 시장가격과 어떤 식으로 연결되는지를 분석해보고자 한다.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.4
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• pp.210-220
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• 2002

We analysised the effect of harmonics on electric machines of substation power system barred on quantitatively measured harmonics and proposed the methods for prevention of harmonics through checking on transformer, rectifier and cable's capacities against harmonics with reference to KEPCO's electricity service standard. In order to analysis harmoninics of silicon rectifier that is power source in DC substation, computer simulations for a substation with TR of high voltage distribution switchboard are performed. Simulation results show that the total harmonic distortion factor becomes smaller for TR primary and receiving points in order rather than silicon rectifier which is harmonic generation source so that the harmonics generated frets each rectifier are outflowed to power supply and high voltage distribution switchboard The result of higher distortion factors of voltage and current for rectifier with 100% load than those with 50 % and 30% indicates that the waveform of voltage and current for the real substation power system at the office-going and the closing hours with heavy loads might be more distorted. As proposed methods for harmonic reduction, the conventional 6 pulse-type for substation is required to be replaced by 12 pulse-type for reduction of 5th and 7th harmonics. The active filter rather than the passive filter is more effective due to severe variance of rectifier loads, but the high cost is price to be paid. In view of installation area and costs, the use of 12 pulse-type transformer is desirable and then the parallel transformer and the rectifier within the substation must be replaced at the same time. Other substations with parallel feeder can use 6 pulse-type transformer.

• Journal of Environmental Policy
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• v.9 no.4
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• pp.77-102
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• 2010

The purpose of this paper is to analyze the Japanese emission trading system and climate change policy thereby contributing to the instituting of similar systems that will be viable for the Korean context. In applying such analyses, it is important to include a careful consideration of cost sharing between stakeholders and firms, an enhancement of the trust worthiness of data concerning greenhouse gases, and an examination of related infrastructure such as emissions authentication agencies and their development. Moreover, it is important to minimize the outflow of domestic resources such as offset credit, green electricity certification system, and ecopoint, making compatible economic growth and carbon reduction thereby encouraging the production and dissemination of 'Environmental Value' as well as connecting 'Environmental Value' to a emission trading system.

• Journal of IKEEE
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• v.19 no.3
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• pp.295-303
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• 2015

Considering to Energy Storage System (ESS) is a global trend In order to reduce global warming and carbon emissions. South Korea has announced various policies to vitalize the development and uptake of renewable energy. South Korea is planning the cumulative capacity of ESS of two million kW in 2020. According to the government support and development of technology companies, the battery of ESS prices are expected to fall gradually. In this paper, we develop a planning model that take into account the supply expansion of technology of ESS and prices. Based on planning model, we analyze the cost of ESS linked with wind power and the revenue for trading electricity and renewable energy certifications.