• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.277-280
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• 2005

Air-breathing polymer electrolyte membrane fuel cells (PEMFC) are highly promising particularly for small-power applications up to tens watts class. A distinctive feature of the air-breathing PEMFC is its simple system configuration in which axial fans operate for dual purposes, supplying both oxidant and coolant in a single manner. In the present study, a nominal SOW air-breathing PEMFC system is developed and investigated to determine the optimal operating strategy through parametric studies (i.e., reactant humidity, and fan-blowing flow rate). The cell voltage distributions are examined as a function of time to evaluate the system performance under various operating conditions.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.561-564
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• 2005

Gasification has been regarded as a very important technology to decrease environmental pollution and to obtain higher efficiency. The gasification process converts carbon containing feedstock into a synthesis gas, composed primarily of CO and $H_2$. And the synthesis gas can be used as a source for power generation or chemical material production. Through more than nine years, IAE developed and upgraded several gasification/melting pilot plant system, and obtained a good quality synthesis gas. This paper illustrates the gasification characteristics and operation results of two 3 ton/day synthesis gas production facilities. One is entrained-bed slagging type coal gasifier system which is normally operated in the temperature range of $1,400\~1,450^{\circ}C,\;8\~10$ bar pressure. And the other is fixed-bed type gasification/melting furnace system using MSW and industrial wastes as a feedstock.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.160-163
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• 2005

This paper proposes a simple MPPT control scheme of a Current-Control-Loop Error system Based that can be obtains a lot of advantage to compare with another digital control method, P&O and IncCond algorithm, that is applied mostly a PV system. An existent method is needed an expensive processor such as DSP that calculated to change the measure power of a using current and voltage sensor at the once. Therefore, it is applied a small home power generation system that required many expenses. But, a proposed method is easy to solve the cost reduction and power unbalance problems that it is used by control scheme to limit error of a current control of common sensor. This proposed algorithm had verified through a simulation and an experiment on battery charger using PIC that is the microprocessor of a low price.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.321-323
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• 2008

전력설비에 대한 접지시스템의 근본 목적은 인체에 대한 안정성의 확립과 설비의 기능 향상을 위하여 사고 발생 시 고장 전류를 대지로 안전하고 신속하게 방전시키는데 그 목적이 있다. 풍력발전기 접지설계 시 고려해야 할 중요한 설계 요소는 토양조건, 대지저항률의 측정과 분석, 고장전류, 안전전압 결정 등이 있으며, 이러한 설계 파라미터 가운데 대지저항률은 접지설계 방법 및 물량에 미치는 영향이 결코 작지 않으므로 이에 대한 정확한 측정과 분석을 통하여 효율적인 접지 설계를 시행할 수 있어야 한다.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.626-629
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• 2008

In this study, a geothermal power generation system using the Kalina cycle was investigated by the simulation method. The Kalina cycle system can be used for the utilization of a low-temperature heat sources such as geothermal and industrial waste heat that are not hot enough to produce steam. The sea/river water can be considered as a cooling media. A steady-state simulation model was developed to analyze and optimize its performance. The model contains a turbine, a pump, an expansion valve and heat exchangers. The turbine and pump were modelled by an isentropic efficiency, while a condenser, an evaporator and a regenerative heat exchanger were modeled by UA-LMTD method with a counter-flow assumption. The effect of the ammonia fraction at the separator inlet on the cycle performance is investigated in detail.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.41-44
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• 2009

본 논문에서는 태양광발전이 본격적으로 보급 활성화 되기 전인 1999년 4월에 50 kVA 계통연계형 태양광 발전시스템 개발과제로 구축된 50kWp급 중규모의 계통연계 태양광 발전시스템의 약 10년간의 장기 실증운전을 통하여 취득한 자료를 기반으로 장기운전에 따른 운전특성 변화를 분석하였다. 본 설비는 50kVA급 PCS, 3kVA급 PCS 및 모듈 50kWp의 용량으로 1999년도에 한전 전력연구원 구내에서 실증시험용으로 구축되었으며, 장기운전에 따른 출력감소율은 10년간 전년도 대비 연 2.73% 이며, 발전설비 이용율은 11.04% 로 분석되었다

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.183-186
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• 2009

The crystalline silicon solar cell was one of the first to be developed and it is still the most widely used type. The photovoltaic cells will exhibit long-term degradation if the temperature exceed a certain limit. The purpose of this study is to investigate the possible of improving the performance of a photovoltaic cooling system. According to the results of the experiment, the thermal degradation of 44.63degrees was observed by cooling on the surface of photovoltaic cells. It is a decrease of 22.215percent of generating power. It is shown that photovoltaic cooling system is effected on improving the effectiveness of a photovoltaic out of power.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.660-663
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• 2009

Currently in Korea, the lack of facilities and technical criteria for the performance test of small hydropower degrades the efficiency of the domestic small hydropower turbine, and makes it difficult to objectively evaluate the performance of hydro turbine. Therefore Korean institute of water and environment in K-water planned making a basis of performance test of small hydropower by using our flowmeter calibration system the largest one in Korea. We planned the maximum measurable power of hydro turbine will be 200 kW in our system. Improving the efficiency of small hydropower system can achieve the additional development benefit about 1.5 billion won per year.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.583-587
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• 2009

This paper presents a series of numerical simulations on the thermal performance and sectional efficiency of a closed-loop vertical ground heat exchanger (U-loop) equipped in a geothermal heat pump system (GHP). A 3-D finite volume analysis (Fluent) was used to simulate the operating process of the closed-loop vertical ground heat exchanger by considering the effect of the thickness of HDPE pipe and grout thermal properties, distance between the inflow and outflow pipes, and the effectiveness of the latticed HDPE pipe system. It was observed that the thermal interference between the two strands of U-loop is of importance in determining the efficiency of the ground heat exchanger, and thus it is highly recommendable to modify the cross section configuration of the conventional U-loop system by including a thermally insulating latice between the two strands.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.60.2-60.2
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• 2011

This study is to develop a 1kW-class small wind turbine blade which will be applicable to relatively low speed regions. For this blade, a high efficiency wind turbine blade is designed and a light and low cost composite structure blade is adopted considering fatigue life. In this study, shape design of 1kW-class small wind turbine blade for hybrid power generation system is carried out by BEMT(blade element momentum theory). X-FOIL open software was used to acquire lift and drag coefficients of the 2D airfoils used in power prediction procedure. Moreover, pressure and velocity distributions are investigated according to TSR by CFD analysis.