• 전기학회논문지
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• 제58권1호
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• pp.35-41
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• 2009

This paper proposes a stand alone type single-phase fuel cells micro-source with a voltage sag compensator for compensating the ac output voltage variations (sag or swell) of micro-source. The proposed micro-source is consist of a PEM(polymer electrolyte membrane) fuel cells simulator, a full bridge de converter, a 60Hz PWM(pulse width modulation) VSI(voltage source inverter), and a voltage sag compensator. Voltage sag compensator is similar to the configuration of hybrid series active power filter, and it is directly connected to micro-source through the injection transformer. Compensation algorithm of a voltage sag compensator adopts a single phase p-q theory. Effectiveness of the proposed the system is verified by the PSIM(power electronics simulation tool) simulation in the steady state and transient state which the proposed system is able to simultaneously compensate the harmonic current and source voltage sag or swell.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.551-552
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• 2006

The miniature fuel cells have emerged as a promising power source for applications such as cellular phones, small digital devices, and autonomous sensors to embedded monitors or to micro-electro mechanical system (MEMS) devices. Several chemicals run candidate at a fuel in those systems, such as hydrogen. methanol, ethanol, acetic acid, and di-methyl ether (DME). Among them, hydrogen shows most efficient fuel performance. However, there are some difficulties in practical application for portable power sources. Therefore, more recently, there have been many efforts for development of micro-reformer to operate highly efficient micro fuel cells with liquid fuels such as methanol, ethanol, and DME In our experiments, we have integrated a micro-fuel processor system using low temperature co-fired ceramics (LTCC) materials. Our integrated micro-fuel processor system is containing embedded heaters, cavities, and 3D structures of micro- channels within LTCC layers for embedding catalysts (cf. Figs. 1 and 2). In the micro-channels of LTCC, we have loaded $CuO/ZnO/Al_2O_3$ catalysts using several different coating methods such as powder packing or spraying, dipping, and washing of catalyst slurry.

• Transactions on Electrical and Electronic Materials
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• 제12권1호
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• pp.1-6
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• 2011

This paper summarized concept, manufacture and results of the micro-tubular solid oxide fuel cells (SOFCs). The cells were fabricated by co-sintering of extruded micro-tubular anode support and electrolyte coating layer, and then additional cathode coating. The cells showed quick voltage rising within 1 minute, and the electrochemical performances were closely related to the balance of fuel utilization and performance loss. And a thermal-fluid simulation model was also reported in combination with the electrochemical evaluation results on the GDC-based micro-tubular SOFCs.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2009년도 제33회 추계학술대회논문집
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• pp.289-292
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• 2009

본 연구에서는 감광유리를 이용한 PEM 마이크로 연료전지 바이폴라 플레이트의 제작 공정을 확립하고 성능 측정을 수행하였다. 감광유리는 무게가 가볍고 내화학성이 뛰어나며 제작이 용이하다. 비등방성 식각, 열 및 UV 접합, 그리고 금속 층 적층을 통한 MEMS 제작 공정이 확립되었다. 성능 측정 결과 활성화 영역에 은이 적층된 마이크로 연료전지의 성능이 그렇지 않은 것보다 우수하였으며 두 경우에서 측정된 마이크로 연료전지의 성능은 모두 국내외 마이크로 연료전지 연구 수준과 동등한 수준이었다.

• 한국세라믹학회지
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• 제43권12호
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• pp.751-757
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• 2006

Recently, a new type of solid oxide fuel cells has been developed employing extremely thin oxide electrolyte. These fuel cells are expected to operate at significantly reduced temperature compared to conventional solid oxide fuel cells. Accordingly, they may resolve the stability and material selection issues of high temperature fuel cells. Furthermore, they may eliminate the limitations of polymer membrane fuel cells whose operation temperature is under $100^{\circ}C$. In this paper, we review the electrolytes for intermediate temperature operation. Then, we discuss the current development of thin film solid oxide fuel cells that possibly operated at low temperatures.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 추계학술대회 논문집
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• pp.473-474
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• 2007

• Korean Membrane Journal
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• 제5권1호
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• pp.1-9
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• 2003

Due to the increasing intelligence, the increasing connectivity, and always-on characteristics energy needs for the portable electronics cannot be managed by the state-of-art battery technology. Micro fuel cell fuelled by aqueous methanol is gaining lots of interest from the new energy storage developers since it has the potential to offer the longer operation time to the portable electronic devices. Although the technical barriers to the commercialization exit, it is expected that the micro fuel cell technology bring huge benefits to the current energy storage market once it matures. In the article, benefits, challenges and market players of the direct methanol fuel cell arena is briefly reviewed.

• Bulletin of the Korean Chemical Society
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• 제34권9호
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• pp.2822-2824
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• 2013

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.611-612
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• 2005

Fuel cells is proved that potential energy is greater than the existing power generation. In this paper, we describe a principle of fuel cell which is used for next generation portable battery and brief characteristic of direct methanol fuel cells (DMFCs) that used for portable appliances by miniaturization of polymer electrolyte fuel cell. Lastly we describe about research investment for fuel cells.

• 소성∙가공
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• 제17권8호
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• pp.594-599
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• 2008

This paper presents a micro air pump based on the synthetic jet to supply reactant at the cathode side for micro fuel cells. The synthetic jet is a zero mass flux device that converts electrical energy into the momentum. The synthetic jet actuation is usually generated by a traditional PZT-driven actuator, which consists of a small cylindrical cavity, orifices and PZT diaphragms. Therefore, it is very important that the design parameters are optimized because of the simple configuration. To design the synthetic jet micro air pump, a numerical analysis has been conducted for flow characteristics with respect to various geometries. From results of numerical analysis, the micro air pump has been fabricated by the PDMS replication process. The most important design factors of the micro air pump in micro fuel cells are the small size and low power consumption. To satisfy the design targets, we used SP4423 micro chip that is high voltage output DC-AC converter to control the PZT. The SP4423 micro chips can operate from $2.2{\sim}6V$ power supply(or battery) and is capable of supplying up to 200V signals. So it is possible to make small size controller and low power consumption under 0.1W. The size of micro air pump was $16{\times}13{\times}3mm^3$ and the performance test was conducted. With a voltage of 3V at 800Hz, the air pump's flow rate was 2.4cc/min and its power consumption was only 0.15W.