• 한국수소및신에너지학회논문집
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• 제32권5호
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• pp.324-330
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• 2021

In recent years, polymer electrolyte membrane fuel cell (PEMFC) based cogeneration system has received more and more attention from energy researchers because beside electricity, the system also meets the residential thermal demand. However, the low-quality heat exited from PEMFC should be increased temperature before direct use or storage. This study proposes a method to utilize the heat exhausted from a 10 kW PEMFC by coupling a heat pump. Two different configuration using heat pump and a reference layout with heater are analyzed in term of thermal and total efficiency. The system coefficient of performance (COP) increases from 0.87 in layout with heaters to 1.26 and 1.29 in configuration with heat pump and cascade heat pump, respectively. Lastly, based on system performance result, another study in economics point of view is proposed.

• 전기학회논문지
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• 제58권9호
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• pp.1720-1727
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• 2009

This paper presents that generation and propagation mechanism of low frequency current ripples generated by a rectification effect of an inverter in fuel cell generation system is analyzed. The ripple reduction methode using hardware components such as capacitors and inductors is examined to reduce low frequency current ripples. A new fast and robust low frequency current ripple elimination algorithm is then proposed to incorporate a single loop current controller, which directly controls fuel cell current, without any extra hardware. The proposed algorithm can completely eliminate this current ripple as well as an overshoot or undershoot is significantly reduced. And the de link voltage and output current are well regulated by inverter controller. The validity of proposed algorithm is verified both computer simulation using PSIM 6.0 and experiment with a 1kW laboratory prototype.

• 한국미생물·생명공학회지
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• 제50권1호
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• pp.122-125
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• 2022

The cellulose-fed microbial fuel cell (MFC) is a biotechnological process that directly converts lignocellulosic materials to electricity without combustion. In this study, the cellulose-fed, MFC-integrated thermophilic bacterium, Bacillus sp. WK21, with endoglucanase and exoglucanase activities of 1.25 ± 0.08 U/ml and 0.95 ± 0.02 U/ml, respectively, was used to generate electricity at high temperatures. Maximal current densities of 485, 420, and 472 mA/m² were achieved when carboxymethyl cellulose, avicel cellulose, and cellulose powder, respectively, were used as substrates. Their respective maximal power was 94.09, 70.56, and 89.30 mW/m³. This study demonstrates the value of the novel use of a cellulase-producing thermophilic bacterium as a biocatalyst for electricity generation in a cellulose-fed MFC.

• 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.

• 한국수소및신에너지학회논문집
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• 제14권2호
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• pp.114-121
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• 2003

Hydrogen generation system using aqueous $NaBH_4$ solution was developed for feeding small polymer electrolyte membrane fuel cells (PEMFCs). Ru was selected as a catalyst with its high activity for the hydrogen generation reaction. Hydrogen generation rate was measured with changing the solution temperature, amount of catalyst loading, $NaBH_4$ concentration, and NaOH (a base-stabilizer) concentration. A passive air-breathing 2 W PEMFC stack was operated on hydrogen generated using $20wt%\;NaBH_4+5wt%$ NaOH solution and Ru catalyst.

• 조명전기설비학회논문지
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• 제22권5호
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• pp.21-30
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• 2008

전력 에너지 소비의 급격한 증가와 환경오염, 화석연료의 고갈, 그리고 고유가에 대한 에너지 자원의 대처방안으로 신재생 에너지원에 대한 연구가 진행되고 있다. 다양한 대체 에너지들 중에서 연료전지 발전은 지속적인 원료공급시 연속적으로 화학반응 에너지를 직접 전기에너지로 변환시키는 기술로서 연료비 부담이 없으며, 에너지 변환효율이 높고, 대기오염이나 폐기물 발생이 없다. 또한 소규모 구성과 복합 구성이 가능하고, 전형적인 발전시스템과 달리 기계적인 진동과 소음이 낮다. 이처럼 연료전지를 이용한 발전시스템 분야의 연구와 실용화가 진행되고 있는 실정이다. 본 논문에서는 PSCAB/EMTDC를 사용하여 삼상 380[V], 50[kW]급 연료전지 발전시스템의 모델링 및 구성된 연료전지 발전시스템의 전력신호를 웨이블릿 기법으로 분석하고, 분석된 결과를 전력품질의 관점으로 평가하여 해당 시스템의 모의 성능을 평가하고자 한다. 이를 통하여 보다 상세한 연료전지 발전 모델과 운전에 따른 문제점을 도출할 수 있으며, 특히 계통연계 시 발생하는 다양한 전력품질 및 신호 특성을 선행하여 연구할 수 있다.

• 한국수소및신에너지학회논문집
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• 제34권6호
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• pp.728-733
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• 2023

Efforts are continuing to change from fossil fuels used to hydrogen energy society. In order to become a hydrogen society, stable production and real-life applicability are important. As a result, hydrogen generation system linked to fuel cell are being developed. Through this, it is expected that production to power generation will be possible where desired by utilizing the existing urban gas piping network. Hydrogen generation system and hydrogen fuel cell have been subjected to risk assessment and have already been commercialized, but no risk assessment has been conducted on the integrated system linking them. Therefore, it is intended to secure its safety by conducting a risk analysis on the integrated system.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권4호
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• pp.399-404
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• 2005

In this paper, a hybrid photovoltaic fuel-cell generation system employing an electrolyzer for hydrogen generation and battery for storage purpose is designed and simulated. The system is applicable for remote areas or isolated DC loads. Control strategy has been considered to achieve permanent power supply to the load via the photovoltaic/battery or the fuel cell based on the power available from the sun. MATLAB and SIMULINK have been used for the simulation work. A sensitivity analysis is conducted for various load level based on availability of solar radiation.

• Journal of Power Electronics
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• 제11권4호
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• pp.551-560
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• 2011

This paper proposes a grid-tied power conditioning system for the fuel cell power generation, which consists of a 2-stage DC-DC converter and a 3-phase PWM inverter. The 2-stage DC-DC converter boosts the fuel cell stack voltage of 26-48V up to 400V, using a hard-switching boost converter and a high-frequency unregulated LLC resonant converter. The operation of the proposed power conditioning system was verified through simulations with PSCAD/EMTDC software. Based on the simulation results, a laboratory experimental set-up was built with a 1.2kW PEM fuel-cell stack to verify the feasibility of hardware implementation. The developed power conditioning system shows a high efficiency of 91%, which is a very positive result for the commercialization.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 제17회 워크샵 및 추계학술대회
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• pp.648-654
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• 2005

The performance prediction of a planar-type solid oxide fuel ceil is conducted by a computational analysis. The transport processes are formulated with the help of a simplified treatment of heat generation by the electrochemical reaction. From the result of the computational analysis, it is shown that the electrochemical reaction is closely related to the transport phenomena inside a solid oxide fuel cell. Transport phenomena including heat and mass transfer have influence on the distribution of local current density and as a result, on the performance characteristics of the fuel cell. Computational analysis is also extended to the parametric study to investigate the performance behavior of the fuel cell with different amount of supplied fuel flow rates. It is also demonstrated that the mathematical formulation and computational procedures proposed in this study can be applied to prove the importance of the specific TPB(Three-Phase-Boundary) area in the manufacturing process of electrodes in a solid oxide fuel cell.