• Journal of Electrical Engineering and Technology
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• v.5 no.2
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• pp.319-328
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• 2010

In this paper, an optimal selection methodology for the number of phases will be proposed for an interleaved boost converter (IBC). Also, the analysis of the input current ripple according to CCM and DCM is carried out. The proposed design methodology will be theoretically analyzed, and its validity verified by simulation as well as with experimental results. Moreover, a comparison of cost and efficiency based on a 600W laboratory prototype using the Ballard NEXA 1.2kW PEMFC system is demonstrated.

• 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.

• Proceedings of the KIPE Conference
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• 2008.10a
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• pp.187-189
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• 2008

화석연료의 고갈과 에너지 공급의 불안정성을 극복하기 위하여 화석연료를 대체할 수 있는 신 재생에너지의 개발이 시급하다. 특히 우리나라는 화석에너지의 수입 의존도가 97% 이상을 상회하고 선진국 대비 4배 이상의 에너지소비증가율을 보이는 우리나라에서는 장기적인 에너지 수급정책의 수립과 신 재생에너지 개발이 절실히 필요하다. 본 연구에서는 신 재생에너지중 세계에서 가장 각광받고있는 연료전지 시스템 중 PEMFC 즉 고분자 연료전지의 직접 설치 구동과 구동특성을 파악하는데 목적을 두고 연구를 진행하였다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.183-186
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• 2011

In this paper, we present some results of power analyses, and weight estimation on electric propulsion systems for Personal Air Vehicles(PAV) applications. When hybrid electric propulsion is adopted, its power performance using fuel cells and batteries is inferior to that of internal combustion engines for 1,000 kg PAV. However, hybrid electric propulsion systems may replace IC engines when energy density and power density is over $0.75kW{\cdot}hr/kg$and 2.5 kW/kg, respectively.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.5
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• pp.473-480
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• 2011

The proton exchange membrane (PEM) fuel cell system is critically dependent on the humidity, which should be properly maintained over the entire operating range. A membrane humidifier is used for the water management in the PEMFC because of the membrane humidifier's reliable performance and zero parasitic power loss. In the PEMFC system, the membrane humidifier is required to provide appropriate humidity for the design point of the fuel cell. Although the performance of the fuel cell depends on the performance of the humidifier, few studies have provided a systematic analysis of the humidifier. We carry out an experimental analysis of the membrane humidifier using a vapor condensation bottle. The dry air pressure, water flow temperature, and air flow rate were chosen as the operating parameters. The results show that the time constant for the dynamic response of the membrane humidifier is relatively short, but additional analysis should be carried out.

• Transactions of the Korean hydrogen and new energy society
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• v.18 no.1
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• pp.60-66
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• 2007

In terms of the vehicle efficiency, a fuel cell hybrid system has advantages compared to a conventional internal combustion engine and a fuel cell alone-powered system. The efficiency of the fuel cell hybrid vehicle mainly depends on the maximum power of the fuel cell and therefore it is important to decide the design value of the fuel cell maximum power. In this paper, to estimate the performance of the fuel cell hybrid mini-bus in the design phase the simulator based on the models for the fuel cell stack, the electric battery, the fuel cell balance of plant, the controller, and the vehicle itself is proposed. Additionally, the hybrid mini-bus efficiencies with several different fuel cell powers are simulated for a city driving schedule and are compared on another. Consequently, the proposed simulation scheme is useful to determine the best design value of the fuel cell hybrid vehicles.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.5
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• pp.359-366
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• 2008

A two-dimensional thermal model of proton exchange membrane fuel cell with large active area is developed to investigate the performance of fuel cell with large active area over various thermal management conditions. The core sub-models of the two-dimensional thermal model are one-dimensional agglomerate structure electrochemical reaction model, one-dimensional water transport model, and a two-dimensional heat transfer model. Prior to carrying out the simulation, this study is contributed to set up the operating temperature of the fuel cell with large active area which is a maximum temperature inside the fuel cell considering durability of membrane electrolyte. The simulation results show that the operating temperature of the fuel cell and temperature distribution inside the fuel cell can affect significantly the total net power at extreme conditions. Results also show that the parasitic losses of balance of plant component should be precisely controlled to produce the maximum system power with minimum parasitic loss of thermal management system.

• Journal of Electrical Engineering and Technology
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• v.8 no.4
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• pp.760-765
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• 2013

An Interline Power Flow Controller (IPFC) is a converter based controller which compensates and balance the power flow among multi-lines within the same corridor of the multi-line subsystem. The Interline Power Flow Controller consists of a voltage source converter based Flexible AC Transmission System (FACTS) controller for series compensation. The reactive voltage injected by individual Voltage Source Converter (VSC) can be controlled to regulate active power flow in the respective line in which one VSC regulates the DC voltage, the other one controls the reactive power flows in the lines by injecting series active voltage. In this paper, a circuit model for IPFC is developed and simulation of interline power flow controller is done using the proposed circuit model. Simulation is done using MATLAB Simulink and PSPICE. The results obtained by MATLAB are compared with the results obtained by PSPICE and compared with theoretical values.

• Journal of the Korean Solar Energy Society
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• v.34 no.4
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• pp.17-22
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• 2014

The design of a fuel cells stack is important to get optimal output power. This study focuses on the evaluation of fuel cell system for unmaned aerial vehicles (UAVs). Low temperature proton exchange membrane (LTPEM) fuel cells are the most promising energy source for the robot applications because of their unique advantages such as high energy density, cold startup, and quick response during operation. In this paper, a 600 W open cathode LTPEM fuel cell was tested to evaluate the performance and to determine optimal operating conditions. The open cathode design reduces the overall size of the system to meet the requirement for robotic application. The cruise power requirement of 600 W was supported entirely by the fuel cell while the additional power requirements during takeoff was extended using a battery. A peak of power of 900 W is possible for 10 mins with a lithium polymer (LiPo) battery. The system was evaluated under various load cycles as well as start-stop cycles. The system response from no load to full load meets the robot platform requirement. The total weigh of the stack was 2 kg, while the overall system, including the fuel processing system and battery, was 4 kg.

• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.1
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• pp.75-85
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• 2010

In this paper, a Z-source hybrid active power filter is proposed to compensate the harmonics and reactive power in power distribution system. The proposed system is composed of a 7th harmonics-tuned passive filter and an active power filter with a Z-source inverter topology, while voltage source PWM inverter or current source PWM inverter are applied as the power converter topology of conventional active power filters. The Z-source impedance network along with shoot through capability would ensure a constant DC voltage across the DC link. A polymer electrolyte membrane fuel cell is employed as an compensation DC energy source of the proposed system and its equivalent R-L-C circuit is modeled for simulation. As the compensation and control algorithm of the proposed system, the current synchronous detection algorithm is applied. The simulation analysis by PSIM is performed under the three-phase 220V/60Hz voltage source and 25A nonlinear diode loads. The effectiveness of the proposed the system is verified in the steady and transient states.