• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.4
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• pp.335-339
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• 2016

Output power in photovoltaic systems changes steeply with the change of the sun intensity. The change of output power has influence on the electric power quality of the system. This paper proposes a residential distributed generation system using photovoltaic power generation and polymer electrolyte fuel cells(hybrid systems). In order to level the output power which changes steeply the polymer electrolyte fuel cells are connected to the photovoltaic power generation system in parallel. Thus the generated power of all the system can be leveled. However, the steep generated power in the photovoltaic power generation system can not be leveled. Therefore, the electric double layer capacitor(EDLC) is connected in parallel with the hybrid systems. It is confirmed by the simulation that the proposed distributed generation system is available for a residential supply.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.673-676
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• 2001

The photovoltaic power generation system has a great future as clean energy instead of fossil fuel, which has many environmental problems such as exhausted gas or air pollution. In a utility interactive photovoltaic generation system, a three phase inverter is used for the connection between the photovoltaic array and the utility. This paper presents a three phase inverter for photovoltaic power system with current controller, voltage controller, PLL control system and the phase detector of interactive voltage by using dq transformation. The proposed inverter system provides a sinusoidal ac current for domestic loads and the utility line with unity power factor.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11b
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• pp.33-37
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• 2004

Photovoltaic energy and wind energy are highly dependent on the season, time and extremely intermittent energy sources. Because of these reasons, in view of the reliability the photovoltaic and the wind power generation system have many problems(energy conversion, energy storage, load control etc.) comparing with conventional power plant. In order to solve these existing problems, hybrid generation system composed of photovoltaic(500W) and wind power system(400W) was suggested But, hybrid generation system cannot always generate stable output due to the varying weather condition So, the auxiliary power compensation unit that uses elastic energy of spiral spring was added to hybrid generation system for the present study. It was partly confirmed that hybrid generation system was generated a stable outputs by spiral spring was continuously provided to load.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.2
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• pp.181-186
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• 2019

The floating photovoltaic system is a new concept in the renewable energy technology. That is similar to land based photovoltaic technology except floating system. So the system needs buoyant objects, mooring, ect, besides modules and supports, and that is able to withstand in water level changes and wind strength. Therefore the floating photovoltaic system is much different from land photovoltaic system. Unlike land-based photovoltaics developed on the rooftop and in the mountains of buildings, The floating photovoltaic power generation is a new concept in power generation technology in which photovoltaic modules are installed using buoyancy on the surfaces of dams and reservoirs. It is abundant enough to construct a power plant with a power generation potential of about 5% and a power generation capacity of 4,170MW, so that the land can be efficiently used without destroying the environment. In this paper, the technical standard for evaluating safety in addition to the water-state photovoltaic power generation system is not established yet, and the items to be considered for standardization of the water-state photovoltaic power generation system are summarized in this paper.

• 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.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.39-40
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• 2005

Photovoltaic Power Generation system occupies an important position as an alternative energy source, converting directly sunlight into electricity,using a photovoltaic cell. The Purpose of this research is to present and confirm the effectiveness of concentration and tracking of sun in photovoltaic power generation. Comparative experiments were carried outwith two rating 75 watt solar modules in $25^{\circ}$ under condition of various times concentration, tracking and plain normal measuring generated voltages, currents and temperatures of back sheet of modules by internet monitoring system to find out which is best in economic sense. The experiments show that output power of concentration and tracking photovoltaic power generation is over 180% more then that of plain normal system.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.61 no.4
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• pp.192-198
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• 2012

Switch losses directly affect the efficiency of power conversion systems and those have big differences according to the power consumed by load systems and the structures of power conversion circuits. In this paper, analyses for switch losses in DC link converter are performed based on the circuit structures of the DC/DC converter in photovoltaic generation system whose output power is varied according to the amount of solar radiation, temperature and partial shade on the solar modules. Boost converter is adopted as a DC link converter topology of the photovoltaic generation system and the loss analyses for the switches used in the boost converters are performed according to the circuit structures. Analyses like the things performed in this paper will be a prerequisite to designing the photovoltaic generation system whose output power is changed according to the environmental variations.

• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.46-48
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• 2009

This paper aims to investigate generation conditions necessary for the most efficient generation by measuring electricity power under various irradiation conditions, since the photovoltaic generation system has high costs and low efficiency. In addition, because the irradiation varies hourly, daily, monthly, and yearly, the research on the irradiation necessary for photovoltaic generation was carried out by analyzing the pattern o( Bower under various irradiation conditions. Also, after measuring the daily variations of irradiation and generation power, the monthly accumulated irradiation and monthly accumulate power which had the most generation power were investigated and the pattern of the annual generation power was analyzed. The results of this study are as follows. As for the relationship between the photovoltaic generation system and the irradiation, the generation power increased with the irradiation and when the irradiation was more than 600 $[W/m^2]$ the generation power amounted to more than 100 [Wh] as the resonable result.

• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.381-383
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• 2000

The photovoltaic power generation system has a great future as clean energy instead of fossil fuel which has many environmental problems such as exhausted gas or air pollution. In a utility interactive photovoltaic generation system, a three-phase inverter is used for the connection between the photovoltaic array and the utility. This paper presents a three phase inverter for photovoltaic power system with current controller, voltage controller, PLL control system and the phase detector of interactive voltage by using da transformation. The proposed inverter system provides a sinusoidal ac current for domestic loads and the utility line with unity power factor. The results of the operated from January to October show the system characteristics.

• New & Renewable Energy
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• v.7 no.2
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• pp.28-35
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• 2011

Recently, photovoltaic systems have been devolved into much larger systems up to MW-scale. Photovoltaic industry participants give their focus on power generation capability of photovoltaic modules because their benefits can be decided from the amount of generation. The information on long-term performance change of photovoltaic modules helps to estimate the amount of power generation and evaluate the economic cost-benefits. Long-term performance of a PV system has been analyzed with operation data for 12 years from 1999 to 2010. In the first year, the amount of yearly power generation was 57.7 MWh with 13.2% capacity factor. In 2007, the amount of yearly generation was 44.3 MWh with 10.14% capacity factor, and in 2010, the amount was decreased down to 38.1 MWh with 8.7% capacity factor. The result means that long-term capacity factor has been 4.5% decreased for 12 years and that the amount of generation has been decreased 34.0% for 12 years which is 2.8 % per year. The latter capacity factor has been decreased faster than 0.20%, the average rate for 10 years. The performance decrease of the PV system is meant to be accelerated. The decrease of performance and utilization is due to aged deterioration of photovoltaic modules and lowering conversion efficiency of PCS.