• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.98-103
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• 2009

In this paper, we test the electrical resistance of flat wire in the PV module. normally solar cell has two kind of flat wire(inter connection ribbon and bus bar ribbon). we found the phenomenon that has a unbalance with resistance when we make a wiling between of string. So, we measurement the resistance of flat wire each other. and analysis of missmatch with resistance between flat wires on PV module. next to survey of IR picture on missmatch flat wire samples for analyze of missmatch with current in the wire. and we perform IR test with solar cell that has a connection with flat wire for test the effect of missmatch resistance on solar cell. Finally we perform the Dark I-V test for survey of effect by the unbalance of resistance. By the result of Dark I-V test, the series resistance of existing connection sample is large more then innovated connection sample.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.4
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• pp.267-271
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• 2019

A shingled PV module is manufactured by dividing and bonding. In this method, the solar cell is divided by lasers and bonded using electrically conductive adhesives (ECAs). Consequently, the manufacturing cost increases because a process step is added. Therefore, we aim to reduce the production cost by reducing the amount of Ag paste used in the solar cell front. Various electrode structures were designed and simulated. The number of fingers was optimized by designing thinner fingers, and the number of fingers with the maximum power conversion efficiency was confirmed. The simulation confirmed the maximum efficiency in the 4-divided electrode pattern. The amount of Ag paste used for each electrode pattern was calculated and analyzed. The number of fingers was optimized by decreasing the width of the finger; this will not only reduce the amount of Ag paste required but also the increase the efficiency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.7
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• pp.4065-4071
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• 2014

The analysis results of the temperature distribution and deformation at the PV cell with a thickness of $200{\mu}m$ according to hot-air temperature at the soldering process of a PV cell and ribbon tend to agree somewhat with the experimental measured values. The best result of the electrical efficiency appears in the module soldered at a hot-air temperature of $390^{\circ}C$. An analysis of the soldering PV cell with a thickness of $150{\mu}m$ at a hot-air temperature of $350^{\circ}C$ confirmed that the maximum deformation was approximately 5.9mm. As the temperature of hot air is set to decrease, the deformation is reduced and it is predicted that the electrical efficiency can be improved.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.282-286
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• 2011

The artificial increase in the solar intensity incident on solar cells using lenses or mirrors can allow solar cells to generate equivalent power with a lower cost. In application areas of Fresnel lenses as solar concentrators, several variations of design were devised and tested. Some PV systems still use commercially available flat Fresnel lenses as concentrators. In this study, we designed and optimized flat Fresnel lens and the 'light pipe' to develop 500X concentrated solar PV system. We performed rigorous ray tracing simulation of the flat Fresnel lens and light-pipe. The light-pipe can play imporatant roles of redistributing solar energy at the solar cell and increase the mechanical tolerance so that it can increase the lifetime of the high-concentration solar PV system and decrease the cost of manufacturing. To investigate the sensitivity of the solar power generated by the concentrated solar PV according to the performance of lens and light pipe, we performed raytracing and executed a simulation of electrical performance of the solar cell when it is exposed to the non-uniform illumination. We could conclude that we can generate 95 % or more energy compared with the energy that can be generated by perfectly uniform illumination once the total energy is given the same.

• Molecules and Cells
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• v.37 no.3
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• pp.220-225
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• 2014

Suppression of bone morphogenetic protein (BMP) signaling induces neural induction in the ectoderm of developing embryos. BMP signaling inhibits neural induction via the expression of various neural suppressors. Previous research has demonstrated that the ectopic expression of dominant negative BMP receptors (DNBR) reduces the expression of target genes down-stream of BMP and leads to neural induction. Additionally, gain-of-function experiments have shown that BMP downstream target genes such as MSX1, GATA1b and Vent are involved in the suppression of neural induction. For example, the Vent1/2 genes are involved in the suppression of Geminin and Sox3 expression in the neural ectodermal region of embryos. In this paper, we investigated whether PV.1, a BMP downstream target gene, negatively regulates the expression of FoxD5b, which plays a role in maintaining a neural progenitor population. A promoter assay and a cyclohexamide experiment demonstrated that PV.1 negatively regulates FoxD5b expression.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.5
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• pp.303-306
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• 2016

Floating PV system is installed on the water such as artificial lake, reservoir, river for the purposes of zero energy town and/or large scale of PV station. There are electrical gains from cooling effect by water and reflection of water surface. Particularly, floating PV power station with high efficiency solar cell modules receives a lot of attention recently. Floating PV system is installed on the water, which means grounding method to the frame of solar cell and electrical box such as connector band and distribution panelboard should be applied in different way from grounding method of PV system on land. The grounding resistance should be 10[${\Omega}$] in case the voltage is over 400[V] in accordance with Korean Standard. The applicable parameters are the resistivity of water in various circumstances, depth of water, and length of electrode in order to meet 10[${\Omega}$] of grounding resistance. We calculated appropriate length of the electrode on the basis of theoretical equation of grounding resistance and analyzed the relation between each parameters through MATLAB simulation. This paper explains grounding system of floating PV power station and presents considerations on grounding design according to the resistivity of water.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.3
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• pp.83-88
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• 1998

This paper presents an overview of environmental evaluation for a photovoltaic-fuel cell hybrid power plant through the Ideal Point approach, which is one of multiobjective decision support systems. Its evaluation is carried out in terms of such tow criteria as land requirement for plant construction and lifetime CO2 emissions, and ten compared with conventional fossil fuel power plants. Fuel cell power system has been proven a viable technology to back up severe PV power fluctuations under inclement weather conditions. Fuel cell power generation, containing small land use, is able to alleviate the heavy burden of large surface requirement of PV power plants. In addition, the PV-fuel cell hybrid power system shows a very little potential for lifetime CO2 emissions.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.3
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• pp.50-64
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• 2011

In this paper, a DC-coupled photovoltaic (PV), fuel cell (FC) and ultracapacitor hybrid power system is studied for building microgrid. In this proposed system, the PV system provides electric energy to the electrolyzer to produce hydrogen for future use and transfer to the load side, if possible. Whenever the PV system cannot completely meet load demands, the FC system provides power to meet the remaining load. The main weak point of the FC system is slow dynamics, because the power slope is limited to prevent fuel starvation problems, improve performance and increase lifetime. A power management and control algorithm is proposed for the hybrid power system by taking into account the characteristics of each power source. The main works of this paper are hybridization of alternate energy sources with FC systems using long and short storage strategies to build an autonomous system with pragmatic design, and a dynamic model proposed for a PV/FC/UC bank hybrid power generation system. A simulation model for the hybrid power system has been developed using Matlab/Simulink, SimPowerSystems and Matlab/Stateflow. The system performance under the different scenarios has been verified by carrying out simulation studies using a practical load demand profile, hybrid power management and control, and real weather data.

• 한국태양에너지학회:학술대회논문집
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• 2008.11a
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• pp.232-237
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• 2008

The integration of PV modules into building facades or roof could raise their temperature that results in the reduction of PV system's electrical power generation. Hot air can be extracted from the space between PV modules and building envelope, and used for heating in buildings. The extraction of hot air from the space will enhance the performance of BIPV systems. The solar collector utilizing these two aspects is called PV/T(photovoltaic/thermal) solar collector. This research is about the development of solar roof system with PV/T collector to apply into buildings. A test cell experiment was performed with the PVT roof installed: It found that the hot air supply from the PVT air collector contributed to increase the heating efficiency by 2 times and the electrical efficiency by about 8%.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.11
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• pp.17-25
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• 2014

This paper proposes a novel maximum power point tracking (MPPT) system using a fuzzy logic control (FLC) algorithm for robust in-environment changing. The power available at the output of a photovoltaic (PV) cell continues to change with radiation and temperature because a solar cell exhibits nonlinear current-voltage characteristics. Therefore, the maximum power point (MPP) of PV cells varies with radiation and temperature. The MPPT methods are used in PV systems to make full utilization of the PV array output power, which depends on radiation and temperature. The conventional MPPT control methods such as constant voltage (CV), perturbation and observation (PO) and incremental conductance (IC) have been studied but these methods are problematic in that they fail to take into account the changing environment. The proposed FLC controller is based on the fuzzy control algorithm and facilitates robust control with the environmental changes. Also, the PV systems applied FLC controller is modeled by PSIM and the response characteristics of the FLC method according to environmental variations are analyzed through comparison with the performance of conventional methods. The validity of this controller is shown through response results.