• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.326-329
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• 2005

Proton exchange membrane (PEM) should be sufficiently hydrated with proper water management to maintain a good ionic conductivity and performance of a PEM fuel cell. However. cathode flooding resulting from excess water can impede the transport of reactants and hence deteriorate the fuel cell performance. For the PEM fuel cell to be commercially viable as vehicle or portable applications, the flooding on the cathode side should be minimized during the fuel cell operation. In this study, visualization technique was applied to understand the cathode flooding phenomena on the cathode side of a PEM fuel cell. To this end. a transparent PEM unit fuel cell wi th an act ive area of $25cm^2$ was designed and manufactured to allow for the visualization of cathode channel with performance characteristics. Two-phase flow resulting from the electro-chemical reaction of fuel cell was investigated experimentally. The images photographed by CCD camera with cell operating temperatures $(30\~50^{\circ}C)$ were presented. Results indicated that the flooding on the cathode side first occurs near the exit of cathode channel. As the operating temperature of fuel cell increases. it was found that liquid water droplets tend to evaporate easily and it can have an influence on lowering the flooding level. It is expected that this study can effectively contribute to the detailed researches on modeling water transport of an operating PEM fuel cell including two-phase flow phenomena.

• 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.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1629-1633
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• 2004

In this paper, we first implement the simulation environment to investigate the efficient control method of a Fuel Cell Electric Vehicle (FCEV) system with battery. The subsystems of a FCEV including the fuel cell system, the electric motor (including the power electronics) and the tansmission (reduction gear), and the auxiliary power source (battery) are mathematically fomulated and coded using the Matlab/Simulink software. Some examples are given to show the capabilities of the modeled system and d a basic control strategy is examined for the economic energy distribution between the fuel cell and the auxiliary power source. It is illustrated by simulations that the actual vehicle velocity follows the given desired velocity pattern while both SOC control and power distribution control are being performed.

• 한국수소및신에너지학회논문집
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• 제15권3호
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• pp.175-186
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• 2004

In this paper, we developed the dynamic model of a fuel cell system suitable for controller design and system operation. The transient phenomena captured in the model include the flow characteristics and inertia dynamics of the compressor, the intake manifold filling dynamics, oxygen partial pressures and membrane humidity on the fuel cell voltage. In the simulations, we paid attention to the transient behavior of stack voltage and compressor pressure, stoichiometric ratio. Simulation results are presented to demonstrate the model capability. For load current following, stack voltage dynamic characteristics are plotted to understand the Electro-chemistry involved with the fuel cell system. Compressor pressure and stoichiometric ratio are strongly coupled, and independent parameters may interfere with each other, dynamic response, undershoot and overshoot.

• Journal of Electrical Engineering and Technology
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• 제3권2호
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• pp.143-151
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• 2008

This paper presents the operation of Fuel Cell Distributed Generation(FCDG) systems in distribution systems. Hence, modeling, controller design, and simulation study of a Solid Oxide Fuel Cell(SOFC) distributed generation(DG) system are investigated. The physical model of the fuel cell stack and dynamic models of power conditioning units are described. Then, suitable control architecture based on fuzzy logic and the neural network for the overall system is presented in order to activate power control and power quality improvement. A MATLAB/Simulink simulation model is developed for the SOFC DG system by combining the individual component models and the controllers designed for the power conditioning units. Simulation results are given to show the overall system performance including active power control and voltage regulation capability of the distribution system.

• 한국가스학회지
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• 제10권2호
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• pp.55-60
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• 2006

Detailed modeling of PEMFCs has been getting considerable interest for predicting the fuel cell performance and also for use in various systems engineering activities. While CFD-based equipment models provide detailed analyses of the performance, they are very time-consuming to develop and run. The computations become quite complex when such models have to be embedded into the flowsheet-level optimization of fuel cell systems. In this paper, we present results about building and using NN-based reduced order models for quickly and repetitively predicting the flow of reactants in a PEMFC manifold.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.98.1-98.1
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• 2011

We present here an isothermal, one-dimensional, steady-state model for a solid alkaline fuel cell (SAFC) with an anion exchange membrane. The conducting ions now move from the cathode to the anode in SAFC. The water is produced at the anode and is also a stoichiometric reactant at the cathode as well as hydrogen and oxygen. In the present model, a net-water-per-proton flux ratio can be predicted and the water transport in the SAFC is explained for various operating conditions.

• 한국수소및신에너지학회논문집
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• 제26권2호
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• pp.156-163
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• 2015

The fuel cells have been investigated in the applications of marine as the high efficient and eco-friendly power generating systems. In this study, modeling of IR Type molten carbonate fuel cell (Internal Reforming Type molten carbonate fuel cell) has been developed to analyze the feasibility of thermal energy utilization. The model is developed under Aspen plus and used for the study of system performances over regarding fuel types. The simulation results show that the efficiency of MCFC system based on NG fuel is the highest. Also, it is also verified that the steam reforming is suitable as pre-reforming for diesel fuel.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.99-102
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• 2006

Optimal flow-field design of bipolar-plates for a commercial class PEM(polymer electrolyte membrane) fuel cell stack was carried out on the basis of three-dimensional computational fluid dynamics(CFD) simulation. A three-dimensional CFD model originally developed by Shimpalee et al., has been utilized for performing large-scale simulation of a single fuel cell consisting of bipolar-plates gas diffusion layers, and a membrane-electrode-assembly(MEA). The CFD model is able to predict the current density, pressure drops, gas velocities, vapor and liquid water contents, temperature distributions, etc. inside a single fuel cell. Depending on simulation results from the CFD modeling of a PEM fuel cell, several flow-fields of bipolar-plates were designed and verified. The final design of the bipolar-plate has been chosen from the simulations and experimental tests and showed the best performance as expected from the simulation results under a normal operating condition. Thus, the CFD simulation approach to design the optimal flow-field of the bipolar-plates was successful. The final design was adopted as the best flow-field to build a commercial scale PEM fuel cell stack, the performance of which shows about 42% higher than that of the older bipolar-plate design.

• 드라이브 ㆍ 컨트롤
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• 제16권2호
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• pp.80-90
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• 2019

Fuel cell hybrid electric vehicle is an attractive solution to reduce pollutants, such as noise and carbon dioxide emission. This study presents an approach for energy management and control algorithm based on energetic macroscopic representation for a fuel cell hybrid electric vehicle that is powered by proton exchange membrane fuel cell, battery and supercapacitor. First, the detailed model of the fuel cell hybrid electric vehicle, including fuel cell, battery, supercapacitor, DC-DC converters and powertrain system, are built on the energetic macroscopic representation. Next, the power management strategy was applied to manage the energy among the three power sources. Moreover, the control scheme that was based on back-stepping sliding mode control and inversed-model control techniques were deduced. Simulation tests that used a worldwide harmonized light vehicle test procedure standard driving cycle showed the effectiveness of the proposed control method.