• Journal of Electrical Engineering and Technology
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• v.4 no.3
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• pp.382-388
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• 2009

Recently, hydrogen energy has been anticipated to change the paradigm of conventional power systems because it can expand sustainable energy utilization and conceptually provide remarkable flexibility to power system operation. Since hydrogen energy can be converted to electric energy through fuel cells, fuel cells are expected to play an important role in the future hydrogen economy. In this paper, a Proton Exchange Membrane Fuel Cell (PEMFC) is modeled as an equivalent circuit and its steady-state characteristics investigated using the model. PEMFCs can be connected to power systems through power conditioning systems, which consist of power electronic circuits, and which are operated as distributed generators. This paper analyzes the effects of the characteristics of the PEMFC internal voltages and investigated the dynamic responses of the PEMFC under fault conditions. The results show that the fault current contribution of the PEMFC is different from those of conventional generators and is closely related to its operating point.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.8 s.251
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• pp.756-763
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• 2006

PEMFC has several technical problems such as water management, long term stability and performance degradation as. PEMFC has been studied not only to solve water management, but also to generate power in stable manner to system by using a hybrid system with auxiliary energy storage device. The purpose of this study is to couple PEMFC with supercapacitor to make a hybrid system and to design and test control strategies for stable power generation in case of changing output power. The polarization curve and dynamic behaviors while changing power were investigated to find out characteristics of PEMFC stack. A DC/DC converter was fabricated in order to increase fuel cell and supercapacitor voltage and to charge supercapacitor. We found that the operation strategy 2 was recommended to the system because of solving water management problem and increasing the dynamic behavior.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.3
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• pp.222-230
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• 2004

In this paper, a 3㎾ fuel cell generation system with an active fuel cell simulator has been proposed. The developed fuel cell simulator generates the actual voltage and current output characteristics of the Polymer Electrolyte Membrane Fuel Cell (PEMFC), so that the overall performance and the dynamics of the proposed system could be effectively examined and tested. In This paper, at first, the system configuration and operational principle of the developed fuel cell simulator has been investigated and the design process of the fuel cell generation system is explained in detail. In addition, the validity of the proposed system has been verified lly the informative simulation and experimental result

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.1
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• pp.9-14
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• 2009

The modelling of PEMFC(Proton Exchange Membrane Fuel Cell) has been studied in many kinds of methods. But there are some limitations in application of the developed models to analyze transient phenomena of power systems. The PSCAD/EMTDC is very popular simulation tool in power system areas. To analyze power systems interconnected to PEMFCs, the PSCAD/EMTDC model of the PEMFCs is needed. In this paper, we developed a PSCAD/EMTDC model of PEMFC based on electro-chemical characteristic equations of PEMFC. Also, we performed simulations using the developed model in the PSCAD/EMTDC program and tested appropriateness of the proposed models. The simulations showed good results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.9
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• pp.1706-1713
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• 2009

In this paper, a parallel operation algorithm for high power PEMFC generation systems is proposed. According to increasing the capacity of fuel cell systems with several fuel cell stacks, the different dynamic characteristics of each fuel cell stack effect on imbalance of load sharing and current distribution, so that a robust parallel operation algorithm is desired. Therefore, a power-sharing technique is developed and explained in order to design an optimal distributed PEMFC generation system. In addition, an optimal controller design procedure for the proposed parallel operation algorithm is introduced, along with informative simulations and experimental results.

• Journal of the Microelectronics and Packaging Society
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• v.13 no.1 s.38
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• pp.57-61
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• 2006

Fuel cells are direct current (DC) power generators. They generate electricity through an electrochemical process that converts the energy stored in a fuel directly into electricity. Fuel cells have many benefits, which produce no particulate matter, nitrogen or sulfur oxides. And they have few moving parts and produce little or no noise. When fueled by hydrogen, they yield only heat and water as byproducts. Their wide application can reduce our dependence on fossil fuels and foreign sources of petroleum. This paper is studied on a high efficiency power conditioning system (PCS) applied to the proton exchange membrane fuel cell (PEMFC) generation system. This paper is designed to a novel PCS circuit topology of high efficiency. Some experimental results of the proposed PCS is confirmed to the validity of the analytical results.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.29-32
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• 2008

Testing was conducted to determine the performance of a residential fuel cell system when subjected to DSS and WSS operation, especially for start-up and shut-down characteristics. In terms of start-up time, it took about 70min to start output power generation and stably to reach 1kW at cold start. Measurement of the characteristics of heat and power generation were carried out at start-up and shut-down time. Fuel gas is used for heating both reformer and stack from start-up to the beginning of power generation. In terms of start-up and shut-down characteristics, it was important to control the reformer temperature precisely. The average output water temperature during the rated output operation(960W) was $63.2^{\circ}C$ constantly. The results of the investigation are being used to develop a new test protocols for residential fuel cell system.

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

• Proceedings of the KIPE Conference
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• 2007.11a
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• pp.193-195
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• 2007

These days, to change the new & renewable energy change the subject because environmental pollution and exhausted fossil power. The most notable Fuel cells by one of the new & renewable energies are one of very useful power conversion sources. Their advantages are low environmental pollution, highly efficient power generation, diversity of fuels (natural gas, LPG, methanol and naphtha), and reusability of exhaust heat, modularity, and faster installation. PEMFC by one of the Fuel Cells is the energy of new technology which is produced by the electric chemical reaction directly. The essential composition elements of PEMFC stack are membrane electrode assembly (MEA), catalyst, Bipolar Plate. Under the this study, know-how is manufacturing single cell of PEMFC and Study design of Low Voltage, Low Electric Power System by PEMFC Single Cell.

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