• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 추계학술대회
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• pp.675-676
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• 2014

Photovoltaic (PV) systems bosed on solar energy offer an environmentally friendly source of electricity. A key feature of such PV sysem is the efficiency of conversion at which the power converter stage can extract the energy from the PV arrays and deliver to the load. The Maximum power point tracking (MPPT) of the PV output for all sunshine conditions allows reduction of the cost installation and maximizes the power output from the PV panel. The proposed algorithm is to control the width of the pulse for battery charging based on the open voltage of the PV panel. As a lab results, the proposed system was implemented functions to adapt to the changes of the PV open voltage, and improved the charging efficiency.

• 한국태양에너지학회 논문집
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• 제27권4호
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• pp.105-111
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• 2007

Hybrid PV/Thermal systems consisting of photovoltaic module and thermal collector can produce the electricity and thermal energy. The solar radiation increases the temperature of PV modules, resulting in the decrease of their electrical efficiency. Accordingly hot air can be extracted from the space between the PV panel and roof, so the efficiency of the PV module increases. The extracted thermal energy can be used in several ways, increasing the total energy output of the system. This study describes a basic type of PV/T collector using water. In order to analyze the performance of the collector, the experiment was conducted. The result showed that the thermal efficiency was 17% average and the electrical efficiency of the PV module was about $10.2%{\sim}11.5%$, both depending on solar radiation, inlet water temperature and ambient temperature.

• 한국농촌건축학회논문집
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• 제20권4호
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• pp.1-8
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• 2018

In this study, we survey the 2 buildings at the Central 1 and 8 buildings at the Central 2, which are divided by each climate region in the rural regions. Major heat loss factors are 47% loss of the outer shell including outer wall, roof, and bottom, 30% loss through window, and 23% loss through crevice wind. We analyze the energy simulation of ECO2 program to construct a zero energy building regarding village hall located in Jung Juk 4-le at Centeral 2. We simulate the primary energy requirement regarding village hall and the simulated results show the $265.3kWh/m^2{\cdot}a$ and it may estimate '2' energy efficiency grade. The energy requirement regarding village hall is the $183.2kWh/m^2{\cdot}a$ when the passive technology are applied in village hall. We research total amount of energy requirement in village hall when the passive and active technologies such as solar cell with 3kW and solar thermal with $20m^2$, geothermal power with 17.5kW. The simulated results show the improved energy efficiency certification grade with $1^{{+}{+}{+}}$ due to the reduced primary energy requirement with 73% when passive technology including 3kW of solar panel is applied and the energy independence rate is 54%, which is estimated to be 4th grade of zero energy buildings. The order of energy consumption are solar panel, solar thermal, and geothermal power under applied passive technology in the building. In order to expand the zero energy building, it is necessary to introduce the zero energy evaluation system in the rural region.

• 한국항공우주학회지
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• 제43권4호
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• pp.318-325
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• 2015

극초소형 위성은 극히 제한적인 크기로 인하여 태양전지판 장착을 위한 표면적이 제한적이다. 또한 자세제어 방식에 따라서는 태양전지판에 대한 태양 입사각이 계속적으로 변화하며 이는 전력생성에 있어 주요 변수이다. 본 논문에서는 태양전지판에 대한 태양입사각이 전력생성에 불리한 조건에도 프레넬렌즈를 이용해 전력생성효율 향상이 가능한 극초소형 위성용 집광형 태양전력시스템을 제안하였다. 제안된 집광형 태양전력시스템의 전력생성효율 극대화 가능성 입증을 위하여 태양광 모사기와 상용 프레넬렌즈를 이용한 전력측정시험을 수행하였으며, 시험결과를 기반으로 상용 S/W인 STK를 활용해 영구자석 안정화 자세제어 방식이 적용된 극초소형 위성의 궤도 전력생성효율 분석을 수행하였다.

• 한국태양에너지학회 논문집
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• 제37권6호
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• pp.69-77
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• 2017

The amount of solar irradiation obtained by a photovoltaic (PV) solar panel is the major factor determining the power generated by a PV system, and the array tilt angle is critical for maximizing panel radiation acquisition. There are three types of PV systems based on the manner of setting the array tilt angle: fixed, semi-fixed, and tracking systems. A fixed system cannot respond to seasonal solar altitude angle changes, and therefore cannot absorb the maximum available solar radiation. The tracking system continually adjusts the tilt angle to absorb the maximum available radiation, but requires additional cost for equipment, installation, operation, and maintenance. The semi-fixed system is only adjusted periodically (usually seasonally) to obtain more energy than a fixed system at an overall cost that is less than a tracking system. To maximize semi-fixed system efficiency, determining the optimal tilt angle adjustment schedule are required. In this research, we conducted a simulation to derive an optimal operation schedule for a semi-fixed system in Seoul, Korea (latitude $37.5^{\circ}$). We implemented a solar radiation acquisition model and PV genereation model on MATLAB. The optimal operation schedule was derived by changing the number of tilt angle adjustments throughout a year using a Dynamic Algorithm. The results show that adjusting the tilt angle 4 times a year was the most appropriate. and then, generation amount of PV system increased 2.80% compared with the fixed system. This corresponds to 99% compared to daily adjustment model. This increase would be quite valid as the PV system installation area increased.

• 제어로봇시스템학회논문지
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• 제20권5호
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• pp.557-562
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• 2014

It is well known that solar tracking systems can increase the efficiency of exiting solar panels significantly. In this paper, a hybrid solar tracking system has been developed by using both astronomical estimates from a GPS and the image processing results of a camera vision system. A decision making process is also proposed to distinguish current weather conditions using camera images. Based on the decision making results, the proposed hybrid tracking system switches two tracking control methods. The one control method is based on astronomical estimates of the current solar position. And the other control method is based on the solar image processing result. The developed hybrid solar tracking system is implemented on an experimental platform and the performance of the developed control methods are verified.

• 태양에너지
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• 제12권3호
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• pp.84-93
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• 1992

본 연구에서는 꽃저장용 냉장시스템 등에 태양열을 이용할 수 있는 난방시스템을 조합하여 충분한 양의 고온을 확득하여 주택의 난방을 가능케 하는 시스템을 설계, 제작했다. 압축기는 기존의 압축기 냉각방식을 공냉식에서 수냉식으로 전환시켜 적절한 냉각효과의 증대는 물론 냉열을 회수하여 고온의 온수를 빠른 시간 내에 획득할 수 있는 시스템을 개발했다.

• Journal of the Optical Society of Korea
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• 제17권5호
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• pp.371-375
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• 2013

To improve the utilization efficiency of solar energy, a new solar optical concentrating system composed of a parabolic reflector with a square cross-section, a hyperbolic reflector with a square cross-section and two converging convex lenses has been designed. The proposed method can simultaneously focus and shape sun light into a square pattern on the solar panel. In addition, the total reflection property of photonic crystal within the range of the visible sunlight spectrum has been analyzed. Finally, the relationship between solar concentrating multiples and the diameter of the primary mirror has been discussed.

• 한국산학기술학회논문지
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• 제12권2호
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• pp.847-851
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• 2011

태양광 발전 시스템은 친환경성을 바탕으로 설치용량이 증가하고 있으며 효율 개선을 위한 연구가 활발하다. 고 효율 시스템 설계를 위해서는 태양전지 패널의 출력특성을 정확히 파악하는 것이 중요하다. 태양전지 패널은 단일 다이오드 모델로 물리적 특성을 표현할 수 있으나, 정확한 파라미터를 얻는 것은 여러 단계의 측정과 수치해석 등의 복잡한 과정을 거쳐야 한다. 본 논문에서는 패널 제조사의 데이터 시트에 제공되는 태양전지 패널의 I-V 특성곡선을 기반으로 패널의 단일 다이오드 모델의 특성 파라미터를 추출하는 방법을 제시하였다. 제시한 방법의 검증을 위하여, Simulink의 Solar Cell 블록에 추출한 파라미터를 입력하여 출력을 측정하고, 데이터 시트와 오차를 계산하였다.

• 한국태양에너지학회 논문집
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• 제27권1호
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• pp.91-98
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• 2007

Perimeter zone is one of the weakest area in buildings and it makes an increase of heating and cooling loads, in addition to condensation or discomfort with cold-draft to residents in winter. Because of this, it needs to be reinforced by active systems. However, they use fossil fuel, and ultimately greenhouse effect is urged. Thus, we proposed BIPV system functioned as solar collector which can substitute active system. As an fundamental stage, heat balance equation in steady-state by Fortran was used not only, in winter for pre-heating effect and electric power capacity during the day, but also in summer, for the latter during the day and sky radiation effect during the night. Especially, we should have considered shading on PV by IES Suncast, since even a little bit of it makes the efficiency too low for the PV modules to work. As a result, in summer day, the PV panel should be tiled in 70 degrees to gain the most electric power. Moreover, we could verify that this model makes higher temperature and heat flux under 0.02 m/s. On the other hand, the PV had the high efficiency with high velocity because of cooling effect behind the PV. Therefore, we should regard the air current distribution later on.