• Journal of the Speleological Society of Korea
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• no.89
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• pp.27-33
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• 2008

Solar energy is most green and clean, unlimited and sustainable energy source on the earth. It is almost 97% of imported consumer energy in Korea. Because of resource poor nation, it is necessary to do their best to make alternative energy to allot their deficiency of the matter in hand of energy resources of petroleum. In a point of view of this problems, the natural solar energy should be improved by any methods as much, possible as we need. Photovoltaic generation with solar tracking system for obtaining optimal power is one of most benefit equipment to improve power of solar-cell panel producing clean electric power efficiently. Solar tracker is a device for orienting a solar photovoltaic panel toward the sun perpendicularly to sunlight, especially in widely separated place. For this reason, we are very interested in developing the equipment system of tracker, specially in solar cell applications, obtaining a high degree of accuracy to ensure that the optimal sunlight could be directed precisely against to the powered device. As a result, it was obtained of 12.46 volts at 90$^\circ$toward solar panel and 9.44 volts at 45$^\circ$, furthermore, improved efficiency more than 30% of average output voltage between tracker system (12.41V) and fixed system (8.55V), respectively. It is also very useful for optimum power system of widely separated cave.

• New & Renewable Energy
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• v.17 no.3
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• pp.16-23
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• 2021

Recently, the Korean government announced a plan to activate renewable energies, with focus on clean energy sources such as solar and wind power as the core and the goal of achieving carbon neutrality by 2050. Unlike other photovoltaic (PV) systems, offshore PV installations are advantageous for large-scale expansion because of the ease of securing sites; they also enable lowering the power generation costs based on construction of large-scale power facilities of megawatt class or higher owing to low noise and landscape damage. However, any power generation should proceed with consideration of the special environmental conditions of the ocean. Above all, when installing large-scale facilities, it is important to reduce fluctuations of the structure and secure stability to actively respond to waves. This study is concerned with the development of a floating body technology that actively responds to waves so as to enable commercialization of offshore solar power. A unit platform for research and development on offshore PV generation was installed in the Saemangeum sea, and the structural fluctuations and stability were analyzed to ensure conformity with the major performance indicators.

• Advances in Energy Research
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• v.5 no.1
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• pp.31-55
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• 2017

In the present study, PV/T collector was modeled via analysis of governing equations and physics of the problem. Specifications of solar radiation were computed based on geographical characteristics of the location and the corresponding time. Temperature of the collector plate was calculated as a function of time using the energy equations and temperature behavior of the photovoltaic cell was incorporated in the model with the aid of curve fitting. Subsequently, operational range for reaching to maximal efficiency was studied using Genetic Algorithm (GA) technique. Optimization was performed by defining an objective function based on equivalent value of electrical and thermal energies. Optimal values for equipment components were determined. The optimal value of water flow rate was approximately 1 gallon per minute (gpm). The collector angle was around 50 degrees, respectively. By selecting the optimal values of parameters, efficiency of photovoltaic collector was improved about 17% at initial moments of collector operation. Efficiency increase was around 5% at steady condition. It was demonstrated that utilization of photovoltaic collector can improve efficiency of solar energy-based systems.

• Current Photovoltaic Research
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• v.7 no.2
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• pp.38-45
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• 2019

In this paper, we analyzed the present status of the safety manager and safety assurance aspects through a complex analysis on the operational aspects, marketability and electrical safety aspects of photovoltaic power generation facilities. In the analysis of the equipment status, we analyzed the status and operated status of the installed PV system in Korea and the correlation between the safety manager and the accident. In addition, we analyzed the direction of the ESS through the analysis of the installation status of the ESS, and applied it to the interpretation part of the ESS associated with the solar power generation. The status of the electric safety manager can be used to analyze the data for selecting the electric safety manager by capacity by analyzing the accident status, the electric safety manager operation status, the safety management time by capacity, and the electric safety manager market.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.3
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• pp.479-484
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• 2018

This paper describes domestic technical standard of Photovoltaic(PV) PCS(Power Conditioning Systems)-Characteristics of the utility interface. This standard tests utility compatibility and personnel safety and equipment protection of PV inverter performance functions. Especially utility compatibility part includes test items of 1)voltage, current and frequency, 2)normal voltage operating range, 3)DC injection, 4)normal frequency operating range, 5)harmonics and 6)waveform distortion, 7)power factor of PV inverter. Therefore in this paper each test item of domestic technical standard is studied and analyzed and finally full tested by PV inverter performance function.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.144-146
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• 2004

This paper presents experimental operation with utility invertactive 3kW photovoltaic generation system. And that describe configuration of utility interactive photovoltaic system which power supply for Demonstration experiment. The status of photovoltaic generation system comp-onents and interconnection and safety equipment will be summarized. This paper discusses property operation state which system endure division of power for demonstration experiment.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.205-207
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• 2004

This paper presents experimental operation with utility invertactive 3kW photovoltaic generation system. And that describe configuration of utility interactive photovoltaic system which power supply for Demonstration experiment. The status of photovoltaic generation system components and interconnection and safety equipment will be summarized. This paper discusses property operation state which system endure division of power for demonstration experiment.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.564-566
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• 2006

This paper presents experimental operation with utility interactive 50kW photovoltaic generation system. And that describe configuration of utility interactive photovoltaic system which power supply for dormitory. The status of photovoltaic generation system components and interconnection and safety equipment will be summarized. This paper discusses property operation state which system endure division of power for dormitory.

• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.244-246
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• 2003

This paper presents experimental operation with utility invertactive 3kW photovoltaic generation system. And that describe configuration of utility interactive photovoltaic system which power supply for Demonstration Complex. The status of photovoltaic generation system components and interconnection and safety equipment will be summarized. This paper discusses property operation state which system endure division of power for Demonstration Complex.

• Proceedings of the KIPE Conference
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• 2003.07b
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• pp.761-764
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• 2003

Islanding phenomenon of a grid-connected photovoltaic (PV) power conditioning system (PCS) is said to occur if the PCS continues to power a section of the utility system after that section has been disconnected from the utility source. Since islanding creates hazards for personnel and equipment, PCSs are required to detect and prevent Et. In this paper, several islanding detection methods (IDMs) and reactive power variation method are described. Islanding test results for 9kW PCS are presented for verification.