• Journal of the Korea Institute of Military Science and Technology
• /
• v.14 no.4
• /
• pp.732-739
• /
• 2011

A fuel cell/secondary battery hybrid power generation system could extend well beyond the efficiency and interoperability of the conventional diesel generator. The suggested power source system consists of 2.3 kW class PEMFC, 100 Ah lithium polymer battery, and two DC/DC converters by serial connection type. It was known that interoperability of sub-systems is the key factor for stable and optimal control of the hybrid power generation system. The modeling and simulation methods have been proposed to reduce the number of configurations and performance tests for components selection and select the optimized control condition of the power generation system. The control model for power source system is implemented based on the empirical formulation and carried out in the Matlab/Simulink environment. The results show that the simulation can be used to establish the algorism of prototype and increase the durability of the power source system.

• Transactions of the Korean hydrogen and new energy society
• /
• v.28 no.1
• /
• pp.30-39
• /
• 2017

Interests in fuel cell based power generation systems are on the steady rise owing to various advantages such as high efficiency, ultra low emission, and potential to achieve a very high efficiency by a synergistic combination with conventional heat engines. In this study, the performance of a hybrid system which combined a molten carbonate fuel cell (MCFC) and an indirectly fired micro gas turbine adopting carbon dioxide capture technologies was predicted. Commercialized 2.5 MW class MCFC system was used as the based system so that the result of this study could reflect practicality. Three types of ambient pressure hybrid systems were devised: one adopting post-combustion capture and two adopting oxy-combustion capture. One of the oxy-combustion based system is configured as a semi-closed type, while the other is an open cycle type. The post-combustion based system exhibited higher net power output and efficiency than the oxy-combustion based systems. However, the semi-closed system using oxy-combustion has the advantage of capturing almost all carbon dioxide.

• 한국신재생에너지학회:학술대회논문집
• /
• 2009.06a
• /
• pp.341-344
• /
• 2009

In this paper, protective function evaluation was conducted to determine the performance and safety of a power conditioning system(PCS) for 1kW residential fuel cell system. It is essential to have a power quality, grid-connection and safety of PCS. Even though it is under 500ms by KGS-A410 standard, it is shown a rapid response time of 25ms from input under-voltage test. In terms of output over/under-voltage test, it is shown 29.15 and 79.4ms. Especially using anti-islanding test, it is shown all times under 100ms for combination cases of real and reactive power. We confirmed a rapid response characteristics and safety of PCS. The results of this evaluation are being used to develop a new test protocols of PCS.

• Transactions of the Korean hydrogen and new energy society
• /
• v.22 no.6
• /
• pp.852-858
• /
• 2011

This paper is aiming to estimate the mutual influence of the stack cooling performances with the operation modes of the thermal management system for the hydrogen fuel cell vehicles. The heat capacity of the thermal management system was measured by varying the operating modes such as stack cooling heat exchanger only (Mode 1), stack cooling and electric devices cooling heat exchangers (Mode 2), and stack cooling and electric devices cooling heat exchangers with an operation of the condenser (Mode 3).As the results, Performance of the thermal management system (TMS) at Mode 3 decreased up to 34.0%, compared with the result of the Mode 1. In addition, in order to optimize the performance of TMS, the entropy change of stack cooling heat exchanger using irreversibility analysis technique was analyzed with the relationship between entropy generation and entering air velocity of the thermal management system.

• Journal of Microbiology and Biotechnology
• /
• v.29 no.12
• /
• pp.1861-1872
• /
• 2019

In the present work, we isolated and identified Aspergillus sydowii NYKA 510 as the most potent laccase producer. Its medium constituents were optimized to produce the highest possible amount of laccase, which was after 7 days at 31℃ and pH 5.2. Banana peel and peptone excelled in inducing laccase production at concentrations of 15.1 and 2.60 g/l, respectively. Addition of copper sulfate elevated enzyme yield to 145%. The fungus was employed in a microbial fuel cell (MFC). The best performance was obtained at 2000 Ω achieving 0.76 V, 380 mAm^-2, 160 mWm^-2, and 0.4 W. A project to design a self-sufficient lighting unit was implemented by employing a system of 2 sets of 4 MFCs each, connected in series, for electricity generation. A scanning electron microscopy image of A. sydowii NYKA 510 was utilized in algorithmic form generation equations for the design. The mixed patterning and patterned customized mass approach were developed by the authors and chosen for application in the design.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.8 no.6
• /
• pp.551-560
• /
• 2003

This paper summarizes development of a 10KW stand-alone power processing unit for 5KW SOFC-low voltage battery hybrid fuel cell power generation system. The power processing unit Includes three parts a high frequency DC-DC converter boosts low fuel cell voltage, a DC-AC inverter converts a dc voltage into a regulated ac voltage and a bidirectional DC-DC converter charges or discharges the battery. The converter topology, design, control method, and experimental result arc presented to meet the specifications such as efficiency of 90% and cost of $40/KW laid down for the "2003 Future Energy Challenge Competition" organized by the U.S. Department of Energy and IEEE. and IEEE.

• Proceedings of the KIPE Conference
• /
• 2003.07a
• /
• pp.231-234
• /
• 2003

This paper presents a novel high frequency transformer linked full-bridge type soft-switching phase-shift PWM control scheme DC-DC power converter, which can be used as power conditioner fur small-scale fuel cell power generation system. Using full-bridge soft-switching DC-DC converter topology makes possible to use low voltage high performance MOSFETs to achieve high efficiency of the power conditioner. A tapped inductor filter is implemented in the proposed soft-switching converter topology to achieve soft-switching PWM constant high frequency operation for a wide load variation range. to minimize circulating and idling currents without using additional resonant circuit and auxiliary power switching devices. The practical effectiveness of the proposed soft-switching DC-DC converter is verified in laboratory level experiment with 1 kW 100kHz breadboard setup using power MOSFETs. Actual efficiency of 94-96$\%$ is obtained for the wide load range

• Proceedings of the KIPE Conference
• /
• 2007.07a
• /
• pp.530-532
• /
• 2007

This paper presents the design, development and performance of a power conditioning system (PCS) for application to a 250kW Molten Carbonate Fuel Cell (MCFC) generation system. A DSP controller was used to control the dc-dc and dc-ac converter operation for grid connection and power injection to the grid. The controller must also supervise the total PCS operation while communicating with the fuel cell system controller. A control method for parallel operation of dc-dc converters was proposed and verified. A 250kW prototype was successfully built and tested. Experimental performances are compared to minimum target requirements of the PCS for MCFC.

• Transactions of Materials Processing
• /
• v.21 no.8
• /
• pp.499-505
• /
• 2012

The fuel cell is a very promising power generation system combining the benefits of extremely low emissions, high efficiency, ease of maintenance and durability. In order to promote the commercialization of fuel cells, a flexible forming process, in which a hyper-elastic rubber is adopted as a medium to transmit forming pressure, is suggested as an efficient and cost effective manufacturing method for fuel cell bipolar plates. In this study, the ability of this flexible forming process to produce the micro channel arrays on metallic bipolar plates was first demonstrated experimentally. Then, a finite element (FE) model was built and validated through comparisons between simulated and experimental results. The effects of key process parameters on the forming performance such as applied load and punch velocity were investigated. As a result, appropriate process parameter values allowing high dimensional accuracy without failure were suggested.

• 한국신재생에너지학회:학술대회논문집
• /
• 2010.11a
• /
• pp.82.2-82.2
• /
• 2010

The development of bipolar plate having high efficiency and chemical properties has a major impact on fuel cell applications commercialization. Even though graphite bipolar plate has high electric conductivity and chemical resistance, it has demerits about mass production and brittle property for commercialization. Hence, metallic bipolar plate can be substitute for fuel cell bipolar plate. Although its inadequate corrosion behavior under PEMFC environment lead to a deterioration of membrane by dissolved metal ions, metallic bipolar plate for PEMFC is more suitable for automotive and residential power generation system because of its high mechanical strength, low gas permeability and applicability to mass production. Therefore, several types of coating has been applied to prevent corrosion and oxide film growth and to achieve more high durability. This work presents durability of coated metal bipolar plate for low temperature PEMFC which made for fuel cell vehicle. This results showed surface treatment increase long-term durability, even electric conductivity and corrosion resistance.