• Journal of the Korean Solar Energy Society
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• v.22 no.1
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• pp.67-72
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• 2002

Solar Air Systems (SAS) have unique advantages for space heating and tempering ventilation air. Air, unlike water, needs no protection against freezing nor are leaks damaging to the building structure or its contents. In contrast to glazed collector, unglazed steel solar collector may have higher efficiencies over glazed flat collector due to the absence of the glass. Therefore, the monitoring of SAS is so important to evaluate actual performance of SAS for right applications. This study is to provide a testing method with a movable test cell developed in KIER to evaluate the thermal performance of SAS based on international standard method ASHRAE 93-86, "Method of Testing to Determine the Thermal Performance of Solar Collectors". The monitoring tool used advanced technique LabVIEW 6i with portable notebook computer. Sample results have been obtained to access the performance of a reference and a target SAS module. The process and tool introduced here could be used to provide a performance verification data for future implementation study applications.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.12
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• pp.2212-2217
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• 2010

Previous studies have been focused on the voltage of Bypass diode and Isc(Short Circuit Current) of the influenced solar cell. The Bypass diode starts working when it gets the reverse applied voltage. Previous studies have only concentrated on Isc of the influenced solar cell and Imp of PV module to explain the bypassing performance. PV module is usually working together with inverter having MPPT(Maximum Power Point Tracking) function for best performance. bypassing point is regulated by MPPT function of inverter. In this paper, simulation results of Bypass diode in PV module have been analyzed to represent the relationship of the bypassing point with the composition of PV module. From the results, the more cells are connected with each string, the earlier bypassing performance happens under the fixed number of strings. As diode groups increase or irradiation decreases, the bypassing performance starts fast.

• 한국태양에너지학회:학술대회논문집
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• 2008.04a
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• pp.247-251
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• 2008

In this paper. we analyze electrical characteristics of photovoltaic module according to mechanical load test. Using the equipment for giving load on the surface of module, dark current-voltage is measured. By varying load from 0kg to 206kg, slight different I-V curve is detected. From this, reduced shunt resistance is roughly calculated and micro crack is assumed to be happened. system Through this experiment, periodic external force on PV module might give an negative effect. The detailed analysis is described in the following paper.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.72-75
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• 2001

The solar energy is purity and infinity. Solar power converter were used to convert the electrical energy from the solar arrays to a stable and reliable power source. So much country research this solar energy system. The photovoltaic system is construct many solar cell array, In this paper, new implementation solar system was showed buck converter that V-I curve produced. This system can be used to study the short-term and long-term performances of solar cell and efficiency. This system is a far more cost effective and reliable replacement for field and outdoor flight testing. Study of buck converter, analysis and control shun t$\cdot$series connection characteristics of solar cell array.

• Current Photovoltaic Research
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• v.7 no.4
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• pp.111-120
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• 2019

The output power of a crystalline silicon (c-Si) photovoltaic (PV) module is not directly the sum of the powers of its unit cells. There are several losses and gain mechanisms that reduce the total output power when solar cells are encapsulated into solar modules. Theses factors are getting high attention as the high cell efficiency achievement become more complex and expensive. More research works are involved to minimize the "cell-to-module" (CTM) loss. Our paper is aimed to focus on electrical losses due to interconnection and mismatch loss at PV modules. Research study shows that among all reasons of PV module failure 40.7% fails at interconnection. The mismatch loss in modern PV modules is very low (nearly 0.1%) but still lacks in the approach that determines all the contributing factors in mismatch loss. This review paper is related to study of interconnection loss technologies and key factors contributing to mismatch loss during module fabrication. Also, the improved interconnection technologies, understanding the approaches to mitigate the mismatch loss factors are precisely described here. This research study will give the approach of mitigating the loss and enable improvement in reliability of PV modules.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.3
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• pp.539-546
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• 2018

Recently, as the solar power generation market is rapidly increasing, interest is focused on research for minimizing the output of the solar cell module. The role of the power optimizer is important when inconsistencies occur in photovoltaic power generation. In the conventional system, centralized inverter method and microinverter method are mainly used. In this paper, we analyze the problem of power generation efficiency loss due to the incompatibility of existing system configuration methods. We also proposed a module - type power compensation method that can improve the mismatch caused by shading. The proposed module - based power optimizer is implemented and compared with the existing operation method. From the simulation result, it was confirmed that the efficiency of the proposed operation method is improved compared to the existing method.

• Current Photovoltaic Research
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• v.1 no.1
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• pp.17-26
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• 2013

In contrast to conventional crystalline cells, back-contact solar cells feature high efficiencies, simpler module assembly, and better aesthetics. The highest commercialized cell and module efficiency was recorded by n-type back-contact solar cells. However, the mainstream PV industry uses a p-type substrate instead of n-type due to the high costs and complexity of the manufacturing processes in the case of the latter. P-type back-contact solar cells such as metal wrap-through and emitter wrap-through, which are inexpensive and compatible with the current PV industry, have consequently been developed. In this paper the characteristics of EWT (emitter wrap-through) solar cells and their status and prospects for development are discussed.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.3
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• pp.293-297
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• 2010

Next generation concentrating photovoltaic technologies could have a large-scale impact on world electricity production once they will become economically attractive and grid parity will be reached. Multi-junction solar cells will be characterised by a high value of the cell economical performance index if the cells were able to operate at high concentration level. Concentrating the sunlight by optical devices like lenses or mirrors reduces the area of expensive solar cells or modules, and, moreover, increases their efficiency. Accurate and reliable tracking is an important issue to maintain high the CPV system output power. Further, for high concentration CPV systems, the actual tracker cost is about 20% of the total CPV system cost. In this paper high-concentration is defined as systems using concentration ratios well above 100 times the one sun intensity and trackerlss CPV system studied. Using sphericalness lens and parallel MJ cell connection method were suggested and achieved experiment on a clear day in summer. Development of these high performance multi-junction CPV module promises to accelerate growth in photovoltaic power generation.

• Journal of Electrochemical Science and Technology
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• v.3 no.4
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• pp.149-153
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• 2012

Among the various solar-hydrogen production techniques a combination of a photovoltaic (PV) and an electrolytic cell into one single system, a monolithic PV-electrolytic cell, has been suggested as a promising one in terms of efficiency and stability. In this mini-review, we describe our recent efforts on the fabrication of the monolithic PV-electrolytic cell. Particularly, we focus on the electrocatalysts for water oxidation and its fabrication method suitable for a monolithic PV-electrolytic cell. We also introduce proto-type devices with a dye-sensitized solar cell module and an InGaP/GaAs photoelectrodes.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.5
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• pp.312-317
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• 2017

In this paper, the effects of environmental variables on the output of the floating photovoltaic water systems, which were installed at the Hapcheon dam in South Korea, were investigated, and the correlations between them were analyzed. The system output was linearly proportional to the solar radiation or irradiance. The output was large in spring and autumn because of high irradiance, but low in the summer when the solar module temperature was high. The influence of the module temperature on the system output was limited in the summer, during which the module temperature change affected the system output more than the change of the irradiance did. In addition, in winter and summer, the module temperature tended to decrease with increasing windspeed, but windspeed did not affect module temperature significantly in the spring and autumn. On the other hand, in winter and spring, the irradiance decreased as the windspeed increased because of movement (or circulation) of the photovoltaic modules.