• Journal of Construction Engineering and Project Management
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• v.3 no.3
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• pp.23-34
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• 2013

As climate change and environmental pollution become one of the biggest global issues today, new renewable energy, especially solar photovoltaic (PV) system, is getting great attention as a sustainable energy source. However, initial investment cost of PV system is considerable, and thus, it is crucial to predict electricity generation accurately before installation of the system. This study analyzes the loss ratio of solar photovoltaic electricity generation from the actual PV system monitoring data to predict electricity generation more accurately in advance. This study is carried out with the following five steps: (i) Data collection of actual electricity generation from PV system and the related information; (ii) Calculation of simulation-based electricity generation; (iii) Comparative analysis between actual electricity generation and simulation-based electricity generation based on the seasonality; (iv) Stochastic approach by defining probability distribution of loss ratio between actual electricity generation and simulation-based electricity generation ; and (v) Case study by conducting Monte-Carlo Simulation (MCS) based on the probability distribution function of loss ratio. The results of this study could be used (i) to estimate electricity generation from PV system more accurately before installation of the system, (ii) to establish the optimal maintenance strategy for the different application fields and the different season, and (iii) to conduct feasibility study on investment at the level of life cycle.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.375-385
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• 2013

As climate change and environmental pollution become one of the biggest global issues today, new renewable energy, especially solar photovoltaic (PV) system, is getting great attention as a sustainable energy source. However, initial investment cost of PV system is considerable, and thus, it is crucial to predict electricity generation accurately before installation of the system. This study analyzes the loss ratio of solar photovoltaic electricity generation from the actual PV system monitoring data to predict electricity generation more accurately in advance. This study is carried out with the following five steps: (i) Data collection of actual electricity generation from PV system and the related information; (ii) Calculation of simulation-based electricity generation; (iii) Comparative analysis between actual electricity generation and simulation-based electricity generation based on the seasonality; (iv) Stochastic approach by defining probability distribution of loss ratio between actual electricity generation and simulation-based electricity generation ; and (v) Case study by conducting Monte-Carlo Simulation (MCS) based on the probability distribution function of loss ratio. The results of this study could be used (i) to estimate electricity generation from PV system more accurately before installation of the system, (ii) to establish the optimal maintenance strategy for the different application fields and the different season, and (iii) to conduct feasibility study on investment at the level of life cycle.

• Korean Journal of Materials Research
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• v.19 no.5
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• pp.245-252
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• 2009

Changes in the surface morphology and light scattering of textured Al doped ZnO thin films on glass substrates prepared by rf magnetron sputtering were investigated. As-deposited ZnO:Al films show a high transmittance of above 80% in the visible range and a low electrical resistivity of $4.5{\times}10^{-4}{\Omega}{\cdot}cm$. The surface morphology of textured ZnO:Al films are closely dependent on the deposition parameters of heater temperature, working pressure, and etching time in the etching process. The optimized surface morphology with a crater shape is obtained at a heater temperature of $350^{\circ}C$, working pressure of 0.5 mtorr, and etching time of 45 seconds. The optical properties of light transmittance, haze, and angular distribution function (ADF) are significantly affected by the resulting surface morphologies of textured films. The film surfaces, having uniformly size-distributed craters, represent good light scattering properties of high haze and ADF values. Compared with commercial Asahi U ($SnO_2$:F) substrates, the suitability of textured ZnO:Al films as front electrode material for amorphous silicon thin film solar cells is also estimated with respect to electrical and optical properties.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.363-366
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• 2003

In recent years, the Photovoltaic(PV) industries have been increasing steadily by an average of 30$\%$ per you. However, it is necessary to reduce PV module cost and to improve conversion efficiency to be promoted distribution of PV Japan, USA and Europe have been researching cost and efficiency of that. In this paper, we try to review diffusion perspective of PV in these countries. From the results of this paper, we will intend to suggest a suitable future course for domestic PV distribution.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.359-362
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• 2003

In recent years, the Photovoltaic(PV) industries have been Increasing steadily by an average of 30$\%$ per year. However, it is necessary to reduce PV module cost and to improve conversion efficiency to be promoted distribution of PV Japan, USA and Europe have been researching cost and efficiency of that. In this paper, we try to review diffusion status and policy of PV in these countries. From the results, we will intend to suggest a suitable future course for domestic PV distribution.

• Journal of Electrical Engineering and Technology
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• v.11 no.5
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• pp.1077-1083
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• 2016

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.8
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• pp.1485-1491
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• 2011

This paper deals with the technical problems for the protection devices, by simulating test facilities of protection coordination for Photovoltaic systems. In order to analyze the operation characteristics for the protection devices in the case that the Photovoltaic systems with bi-directional power supply are located in the feeder, this paper proposes the test facilities composed of model distribution system, protection device and model Photovoltaic systems. By performing the simulation for operation characteristics for the protection devices based on the test facilities, this paper presents the malfunction mechanism for the protection devices. The test results show that this paper is practical and effective for the technical guideline for the Photovoltaic systems.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.3B no.2
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• pp.103-110
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• 2003

With significant development of power electronics technology, the proliferation of nonlinear loads such as static power converters has deteriorated power quality in power transmission and distribution systems. Notably, voltage harmonics resulting from current harmonics produced by the nonlinear loads have become a serious problem in many countries. Many photovoltaic power generation systems installed in building systems have harmonics that are the worst object for distribution systems as a utility interactive system, and it tends to spread out continuously. Proposed and implemented in this paper is a multi-function inverter control strategy that allows a shunt active filter function to the power inverter of the photovoltaic power generation system established on a building system. The effectiveness of the proposed system is demonstrated through the simulation of a hypothetical power system using PSCAD/EMTDC.

• Journal of the Korean Institute of Educational Facilities
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• v.18 no.6
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• pp.25-32
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• 2011

The building integrated photovoltaic(BIPV) system has a double advantage that it reduces costs for exterior materials and PV panels. It allows the construction of a low-energy building without the need for the additional installation space. At the construction planning stage, however, it requires sufficient evaluation on the efficiency and performance. This study was performed to promote the distribution of photovoltaic power generation system by estimating the potential photovoltaic power generation capacity of the BIPV system installed on the university lecture building and by evaluating the characteristics and performances of window, spandrel and combined attachment types via the simulation of generation capacity per unit area.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.12-13
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• 2007

In this paper, we studied the analysis of environmental effects on maximum output power change of crystalline silicon photovoltaic module. During the test period, there was a 5% reduction of maximum output power on an average. And the degree of output power uniformity became better compared to initial value. Using climate data like rain, snow and dust, we tried to find the reasons for maximum power fluctuation. The surface of PV module was monitored using microscope and infrared camera to study temperature distribution. The further analysis is described in the following paper.