• Design & Manufacturing
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• v.15 no.3
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• pp.50-55
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• 2021

Solar power generation, which is one of the methods of using solar energy, has a high possibility of practical implementation compared to other renewable energy power generation, and it has the characteristic that it can generate as much power as needed in necessary places. In addition, maintenance is easy, unmanned operation is possible, and power management can be performed more efficiently if operated in a hybrid method with existing electric energy. Therefore, in this study, numerical analysis using a computer program was performed to analyze the efficient operation and performance improvement of solar energy of the rotating condensing type solar LED street lamp. As a result, the two-axis tracking type could obtain 15.23 % more electricity per year than the fixed type, and additional auxiliary power generation was required for the fixed type by 19 % per year than the tracking type. As a result of computational fluid dynamics(CFD) simulation for PV module surface temperature prediction, the The surface temperature of the Photovoltaics(PV) module incident surface was predicted to be about 10℃ higher than that of the fixed type.

• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.1
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• pp.38-45
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• 2021

The photovoltaic module has the characteristic of changing its output characteristics depending on the amount of radiation and temperature, where the arrays that connect them in series and parallel also have the same characteristics. These characteristics require the MPPT technique to find the maximum power point. Existing P&O and IncCond cannot find the global maximum power point (GMPP) for partial shading. Moreover, in the case of Improved-GMPPT and Enhanced Search-Skip-Judge-GMPPT, GMPP due to partial shading can be found, but the variation in the open voltage during temperature fluctuations will affect the operation of the Skip and will not be able to perform accurate MPPT operation. In this study, we analyzed the correlation between voltage, current, and power under solar module and array conditions. We also proposed a technique to find the maximum power point even for temperature fluctuations using not only the amount of radiation but also the temperature coefficient. The proposed control technique was verified through simulations and experiments by constructing a 2.5 kW single-phase solar power generation system.

• New & Renewable Energy
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• v.18 no.4
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• pp.64-69
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• 2022

Double-sided photovoltaic (PV) modules have received significant attention in recent years as a technology that can achieve higher annual energy production rates than single-sided modules. The shingled technology is a promising method for manufacturing high-density and high-power modules. These modules are divided by laser and joined with electrically conductive adhesives. The output efficiency of the divided cells depends on the division pattern and the electrode pattern, making it important to understand the output characteristics. In this study, the output characteristics of large-area double-sided light-receiving shingled cells with different split patterns and electrode patterns were investigated. The M6 size, with 6 divisions in the electrode pattern, had the highest efficiency when using 142 front fingers and 146 rear fingers. The M10 size, with 7 divisions, had the highest output when using 150 fingers equally in the front and rear. The M12 size, also with 7 divisions, showed the highest output characteristics when using 192 front fingers and 208 rear fingers.

• Current Photovoltaic Research
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• v.11 no.4
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• pp.108-113
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• 2023

Pressure to reduce costs in the current solar market is driving the development and implementation of new module designs and prompting the use of new materials and components. In order to utilize the variability of each material that makes up the module, it is essential to understand the basic characteristics of the material. In this article, we evaluate light degradation after UV irradiation as an encapsulation material. Measure and analyze the results of various characteristic tests for discoloration, optical and electrical property degradation before and after UV accelerated testing. To evaluate weathering stability, UV tests were performed comparing existing EVA and UVT-EVA, POE and improved low-cost POE. Even in the weather resistance test with a total UV exposure of 60 kW/m², the properties of the encapsulants were mostly stable. EVA and POE-based encapsulants showed slight differences, and these slight differences are believed to pose a threat to long-term stability. This study is a basic analysis of encapsulation research for PV modules and will be helpful in understanding future development and encapsulant properties.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.3
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• pp.182-187
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• 2018

In this study, 20.8% of a p-type Si bifacial solar cell was used to develop a photovoltaic (PV) module to obtain the maximum power under a limited installation area. The transparent back sheet material was replaced during fabrication with a white one, which is opaque in commercial products. This is very beneficial for the generation of more electricity, owing to the additional power generation via absorption of light from the rear side. A new model is suggested herein to predict the power of the bifacial PV module by considering the backside reflections from the roof and/or environment. This model considers not only the frontside reflection, but also the nonuniformity of the backside light sources. Theoretical predictions were compared to experimental data to prove the validity of this model, the error range for which ranged from 0.32% to 8.49%. Especially, under $700W/m^2$, the error rate was as low as 2.25%. This work could provide theoretical and experimental bases for application to a distributed and microgrid network.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.2
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• pp.186-193
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• 2018

Generally, it is difficult to operate moveable-weir due to the expensive cost of the facility management and manpower consumption. Also, when it is installed in a remote area, there is a problem that the cost of connection for power system increases as well as the operating cost. Therefore, this paper proposes an optimal design algorithm to replace an existing power system with an Eco-friendly power supply system for movable-weir using PCS, PV module and lithium-ion battery. Also, this paper proposes a modeling method of environment-friendly power supply system for a movable-weir based on the PSCAD/EMTDC S/W and implements 5[kW] prototype environment-friendly power supply system. As a result of the performance test using the S/W modeling and the prototype system, it is confirmed that the proposed system has stable characteristics in the independent operation mode and the interconnection mode.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.278-281
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• 2011

This system can predict the maximum output about all illumination levels so that the PV system designer can design the system having the best efficiency. For the output prediction exact about the solar cell, that is the device the basis most in the PV system, the basis has to be in order to try this way. The solution based on Lambert W-function are presented to express the transcendental current-voltage characteristic containing parasitic power consuming parameters like series and shunt resistances. A simple and efficient method for the extraction of a single current-voltage (I-V) curve under the constant illumination level is proposed. With the help of the Lambert W function, the explicit analytic expression for I is obtained. And the explicit analytic expression for V is obtained. This analytic expression is directly used to fit the experimental data and extract the device parameters. The I-V curve of the solar cell was expressed through the modeling using Lambert W-function and the numerical formula where there is the difficulty could be logarithmically expressed This method expresses with the I-V curve through the modeling using Lambert W-function which adds other loss ingredients to the equation2 as to the research afterward. And the solar cell goes as small and this I-V curve can predict the power penalty in the system unit.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4447-4454
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• 2013

In October 2011, a commercialized 100kW class floating photovoltaic system positive plant was installed at Hapcheon dam a multi-purpose reservoir the first time ever in the nation. Floating photovoltaic system differs in water float, mooring device and underwater cable process from land photovoltaic system. As for land and building photovoltaic power generation equipments, many installation cases and skilled experiences are available, and thus installation is not difficult. However, commercial power generation floating photovoltaic system, which is attempted for the first time in the nation, requires to be designed and installed through a series of processes like technical review and verification of data by process in comparison with similar cases. The structure of floating photovoltaic system, an equipment for float photovoltaic module and other electrical equipment, is required to withstand weather environments like wind or typhoon etc and yet not affect water quality negatively, and for implementation of this system, construction efficiency and economy etc should be considered comprehensively. In this paper, the techniques of installing floating photovoltaic structure, mooring device, underwater cable, electrical equipment and remote monitoring control system are explained. The 100kW floating PV system is operating with 15% average capacity factor.

• Korean Journal of Materials Research
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• v.29 no.11
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• pp.720-726
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• 2019

Recently, research on cost reduction and efficiency improvement of crystalline silicon(c-Si) photovoltaic(PV) module has been conducted. In order to reduce costs, the thickness of solar cell wafers is becoming thinner. If the thickness of the wafer is reduced, cracking of wafer may occur in high temperature processes during the c-Si PV module manufacturing process. To solve this problem, a low temperature process has been proposed. Conductive paste(CP) is used for low temperature processing; it contains Sn57.6Bi0.4Ag component and can be electrically combined with solar cells and ribbons at a melting point of $150^{\circ}C$. Use of CP in the PV module manufacturing process can minimize cracks of solar cells. When CP is applied to solar cells, the output varies with the amount of CP, and so the optimum amount of CP must be found. In this paper, in order to find the optimal CP application amount, we manufactured several c-Si PV modules with different CP amounts. The amount control of CP is fixed at air pressure (500 kPa) and nozzle diameter 22G(outer diameter 0.72Ø, inner 0.42Ø) of dispenser; only speed is controlled. The c-Si PV module output is measured to analyze the difference according to the amount of CP and analyzed by optical microscope and Alpha-step. As the result, the optimum amount of CP is 0.452 ~ 0.544 g on solar cells.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.7
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• pp.4463-4468
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• 2014

To increase the efficiency of a solar module, the development of solar concentrator using a lens or reflection plate is being proceeded actively and the concentrator pursues the a concentration using a lens or an optical device of a concentration rate and designing as a solar tracking system. On the other hand, as the energy density being dissipated as a heat according to the concentration rate increases, the cares should be taken to cool the solar concentrator to prevent the lowering of efficiency of solar cell by the increasing temperature of the solar cell. This study, researched and developed an economical concentrator module system using a low priced reflection optical device. A concentrator was used as a general module to increase the generation efficiency of the solar module and heat generated was emitted by the concentration through the cooling system. To increase the efficiency of the solar concentrator, the cooling system was designed and manufactured. The features of the micro cooling system (MCS) are a natural circulation method by the capillary force, which does not require external power. By using the potential heat in the case of changing the fluid, it is available to realize high performance cooling. The 117W solar modules installed on the reflective plate and the cooling device in the cooling module and the module unit was not compared. The cooling device was installed in the module resulted in a 28% increase in power output.