• Journal of information and communication convergence engineering
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• v.3 no.2
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• pp.101-104
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• 2005

Recently advanced countries are making every effort to promote the efficiency of electric power production and supply, to deal with the environmental problems, and to develop the new energy. In particular, they are driving forward to develop various technologies for electric power in mid-long term, that are technology for building infrastructure of power transportation, establishing service network for account management using electronic technologies, elevating economic productivity by innovative electronic technologies, control-ling the discharge of global warming gas, using clean efficient energy, and so forth. However, power technology of Korea lagged behind than technology of advanced countries. Also, resources for developing power technology are limited in our country. Therefore, it is necessary to improve the efficiency of R&D investment. For it, our country must compare and analyze with technologies of advanced countries which are taking competitive advantage in the main future energy. Through comparative analysis, limited R&D resources of our country must be concentrated on technologies that can secure competitive advantage from now on.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.7
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• pp.1287-1293
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• 2009

This paper presents an application of Harmony Search (HM) meta-heuristic optimization algorithm for optimal operation of microgrid system. The microgrid system considered in this paper consists of a wind turbine, a diesel generator, and a fuel cell. An one day load profile which divided 20 minute data and wind resource for wind turbine generator were used for the study. In optimization, the HS algorithm is used for solving the problem of microgrid system operation which a various generation resources are available to meet the customer load demand with minimum operating cost. The application of HS algorithm to optimal operation of microgrid proves its effectiveness to determine optimally the generating resources without any differences of load mismatch and having its nature of fast convergency time as compared to other optimization method.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.4
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• pp.346-353
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• 2010

Hydrogen fueled vehicle was evaluated as one of the next-generation technology that will be able to solve the global warming, depletion of fossil fuel and etc. The practical use of hydrogen fueled vehicle, nevertheless, is being delayed more than expected schedule due to various causes. In order to promote the dissemination of hydrogen fueled vehicle, development status and obstacle factors of practical use for hydrogen fueled vehicles were reviewed and the strategy plans for dissemination promotion were proposed. Hydrogen fueled vehicles are included the hydrogen fuel cell, neat and enriched hydrogen fueled engines. The technicalness, economy, safety, cognizance, system, support and etc were considered in the strategy plans.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.12
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• pp.50-55
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• 2012

This paper presents an application of optimization method for efficient operation in micro grid. For operational efficiency, the objective function in a diesel generator consists of the fuel cost function similar to the cost functions used for the conventional fossil-fuel generating plants. The wind turbine generator is modeled by the characteristics of variable output. The cost function of fuel cell plant considers the efficiency of fuel cell. Particle swarm optimization(PSO) and sequential quadratic programming(SQP) are used for solving the problem of microgrid system operation. Also, from the results this paper presents the way to attend power markets which can buy and sell power from upper lever grids by connecting a various generation resources to micro grid.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.3
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• pp.50-64
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• 2011

In this paper, a DC-coupled photovoltaic (PV), fuel cell (FC) and ultracapacitor hybrid power system is studied for building microgrid. In this proposed system, the PV system provides electric energy to the electrolyzer to produce hydrogen for future use and transfer to the load side, if possible. Whenever the PV system cannot completely meet load demands, the FC system provides power to meet the remaining load. The main weak point of the FC system is slow dynamics, because the power slope is limited to prevent fuel starvation problems, improve performance and increase lifetime. A power management and control algorithm is proposed for the hybrid power system by taking into account the characteristics of each power source. The main works of this paper are hybridization of alternate energy sources with FC systems using long and short storage strategies to build an autonomous system with pragmatic design, and a dynamic model proposed for a PV/FC/UC bank hybrid power generation system. A simulation model for the hybrid power system has been developed using Matlab/Simulink, SimPowerSystems and Matlab/Stateflow. The system performance under the different scenarios has been verified by carrying out simulation studies using a practical load demand profile, hybrid power management and control, and real weather data.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.6
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• pp.602-608
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• 2014

Hydrogen energy, a field of low-carbon substitute energy, can be produced by fossile fuel reforming and electrolysis of water etc. We developed 1kW class flat type reformer for PEM Fuel Cells. The PEMFC is highly sensitive to carbon monoxide because CO has detrimental effects on the performance of the fuel cell. Thus, reformed gas supplied to Fuel cell system, which maintained CO concentration below 10ppm. After applying optimum drive condition, reformed gas was measured with gas chromatography and could find out about each experimental condition of $H_2$ and CO concentration. As a results, The 1kW class plate type hydrogen generation system's optimum condition is A/F ratio ${\alpha}=1.3$, STR temperature 1023K, S/C ratio 3, and $PrOx1{\cdot}2$ 30cc/min. It turns out that installation of PrOx 2 stage is more efficient for reducing CO concentration.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.1
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• pp.49-62
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• 2016

In this study, a solid oxide fuel cell (SOFC) system model including balance of plant (BOP) for building electric power generation is developed to study the effect of operating conditions on the system efficiency and power output. SOFC system modeled in this study consists of three heat-exchangers, an external reformer, burner, and two blowers. A detailed computational cell model including internal reforming reaction is developed for a planer SOFC stack which is operated at intermediate temperature (IT). The BOP models including an external reformer, heat-exchangers, a burner, blowers, pipes are developed to predict the gas temperature, pressure drops and flow rate at every component in the system. The SOFC stack model and BOP models are integrate to estimate the effect of operating parameters on the performance of the system. In this study, the design of experiment (DOE) is used to compare the effects of fuel flow rate, air flow rate, air temperature, current density, and recycle ratio of anode off gas on the system efficiency and power output.

• Korean Journal of Hazardous Materials
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• v.6 no.2
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• pp.77-86
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• 2018

Interest in renewable energy is increasing for eco-friendly use of energy, and fuel cells are being used in various ways such as houses and buildings as power generation methods that have low emissions such as $NO_X$ and $CO_2$. As the supply of fuel cells expands, more and more boilers are installed in the existing buildings, but safety management is not being performed properly. Therefore, in this study, a prior study was conducted on the status of fuel cell-boiler complex installation and related criteria, and the risk factors were analyzed according to the installation environment and structure. Based on these standards, the safety performance of the fuel cell-boiler combined installation is assessed by conducting a demonstration using the starting product of the simulated operation to derive the installation criteria (proposal) for the fuel cell-boiler combined installation. The installation criteria (proposal) include the construction and connection method of the piping according to the fuel cell-boiler complex installation.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.6
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• pp.394-399
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• 2008

There are many attempts to use a fuel cell system as a residential power generation system. The purpose of this study is to investigate the optimal design of a water tank for a hot water system when the fuel cell co-generation system is combined with a domestic hot water supply system. The demands of hot water supply per month per home are investigated in Busan for a year. It showed somewhat large differences between the actual demand and the designed demand of hot water, but the actual capacity of hourly averaged hot water demands is analyzed as $60{\ell}/h$ in this study based on the actual demand. The experiments are performed in the various inlet and outlet locations of nozzles, and the hot water consumption rates. The experimental results are showed that the optimal capacity of the water tank is $200{\ell}$ when the thermal efficiency, the storing capacity of hot water and the space for installation are considered.

• Transactions of the Korean hydrogen and new energy society
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• v.11 no.3
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• pp.137-147
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• 2000

Not only study of fuel cell performance but study of fuel cell application is very important, therefore these studies were paralleled together for the commercialization of exciting power generation. The objective of this study is to determine the characteristics of shaft power and efficiency as a function of rpm and to compare natural convection air method to forced air method. From these results, performance of forced air was better than that of natural convection air because it enables to improve mass transportation by increasing air flow rate. With decreasing shaft power, efficiency of fuel cell decreases remarkably because dc motor drives at the low range of efficiency. Fuel cell powered vehicle has to be driven considering efficiency and shaft power. It should be driven at 35-45% of efficiency and 0.55-0.75v/cell.