• Proceedings of the KIEE Conference
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1215-1217
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• 2007

This paper is proposed a novel method to approximate the maximum power for a photovoltaic inverter system. It is designed for power systems application and utilities. The proposed Maximum Power Point Tracking(MPPT) control has the advantage to provide a new simple way to approximate the optimal or rated voltage, the optimal or rated current and maximum power rating produced by a solar panel and the photovoltaic inverter. And this straightforward method will be named linear reoriented coordinates method(LRCM) with the advantage that Pmax and $V_{op}$ can be approximated using the same variable as the dynamic model without using complicate approximations or Taylor series. This paper is proposed MPPT using LRMC method using weather condition of domestic moderate program technique. This paper is proposed the experimental results to verify the effectiveness of the new methods.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국정보통신학회 2014년도 추계학술대회
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• pp.561-564
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• 2014

In this paper a photovoltaic energy harvesting charger with battery management circuit is proposed. The proposed circuit harvests maximum power from a solar cell by employing MPPT(Maximum Power Point Tracking) control and charges an external capacitor battery with the harvested energy. The charging state of the battery is controlled according to the signals from the battery management circuit. The proposed circuit is designed in a 0.35um CMOS process technology and its functionality has been verified through extensive simulations. The maximum efficiency of the designed entire system is 84.8%, and the chip area including pads is $1350um{\times}1200um$.

• Journal of the Korean Solar Energy Society
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• 제26권2호
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• pp.69-77
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• 2006

Photovoltaic is an attractive technology to remote power applications, because of its reliability, low maintenance, and zero fuel requirements. In this paper represents residential PV system based on BESS(battery energy storage system) for managing the electric power, a pattern of daily operation considering the load characteristics of the house, the generation characteristics of PV power, and utility power leveling. For apply to control algorithm, we consider the load on monthly power consumption trend and daily usage pattern. As for the control of the proposed system, to increase the conversion efficiency of the PV power, bidirectional converter is used for MPPT and SPWM inverter. An experimental system is implemented, and some experimental results are provided to demonstrate the effectiveness of the proposed system.

• Proceedings of the KIEE Conference
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• 대한전기학회 2008년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.221-223
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• 2008

This paper presents a maximum power point tracking(MPPT) of Photovoltaic system with chopping ratio of DC-DC converter considered load. A variation of solar irradiation is most important factor in the MPPT of PV system. That is nonlinear, aperiodic and complicated. The paper consists of solar radiation source, DC-DC converter, DC motor and load(cf, pump). NN algorithm apply to DC-DC converter through an adaptive control of neural network, calculates converter-chopping ratio using an adaptive control of NN. The results of an adaptive control of NN compared with the results of converter-chopping ratio which are calculated mathematical modeling and evaluate the proposed algorithm. The experimental data show that an adequacy of the algorithm was established through the compared data.

• The Transactions of The Korean Institute of Electrical Engineers
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• 제59권12호
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• pp.2212-2217
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• 2010

Previous studies have been focused on the voltage of Bypass diode and Isc(Short Circuit Current) of the influenced solar cell. The Bypass diode starts working when it gets the reverse applied voltage. Previous studies have only concentrated on Isc of the influenced solar cell and Imp of PV module to explain the bypassing performance. PV module is usually working together with inverter having MPPT(Maximum Power Point Tracking) function for best performance. bypassing point is regulated by MPPT function of inverter. In this paper, simulation results of Bypass diode in PV module have been analyzed to represent the relationship of the bypassing point with the composition of PV module. From the results, the more cells are connected with each string, the earlier bypassing performance happens under the fixed number of strings. As diode groups increase or irradiation decreases, the bypassing performance starts fast.

• Journal of the Korean Society for Aviation and Aeronautics
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• 제23권3호
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• pp.1-7
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• 2015

In the present study, we conducted the research on the high efficiency propulsion system for the development of long-endurance UAV with an electric propulsion system. For the long endurance UAV, fair aerodynamic characteristics with the high efficiency of the propulsion system is required because the flight power and the duration time of the long-endurance UAV vary greatly depending on the efficiency of the propulsion system. Therefore, in this study, the tracking program which records the performance of motor, propeller was developed because of their wide variation in the efficiency depending on the using condition, and records from the existing flight test program were utilized to check the accuracy of the program we had developed. For the development of future long-endurance solar UAV, we confirmed the applied voltage of motor, the optimal rotation of propeller and the gear ratio of reduction gear in order to get the highest efficiency on the propulsion system at the optimal flying condition.

• Journal of the Korean Solar Energy Society
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• 제24권2호
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• pp.9-15
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• 2004

3kW grid connected PV(photovoltaic) systems have been constructed for evaluating and analyzing performance of PV system at FDTC(field demonstration test center) in Korea, PV systems installed in FDTC have been operating and monitored since November 2002. As climatic and irradiation conditions have been varied through long-term field test, data acquisition system has been constructed for measuring performance of PV system to observe the overall effect of environmental conditions on their operation characteristics. The performance of PV systems has been evaluated and analyzed for component perspective(PV array and power conditioning system) and global perspective(system efficiency, capacity factor, and electrical power energy) by field test. By the results, it is very important to develop optimal design technology of grid connected PV system.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.153-159
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• 2012

In photovoltaic system, the characteristic of photovoltaic module such as open circuit voltage and short circuit current will be changed because of cell temperature and solar radiation. Therefore, a boost converter of the PV system connects between the output of photovoltaic system and DC link capacitor of grid connected inverter as controlling duty ratio for maximum power point tracking(MPPT). This paper shows the dynamic characteristic of the boost converter by comparing single-loop control algorithm and two-loop control algorithm using both analog and digital control. The proposed both compensation method has been verified with computer simulation and simulation results obtained demonstrate the validity of the proposed control schemes.

• Journal of the Korean Solar Energy Society
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• 제29권6호
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• pp.14-21
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• 2009

The demand and installation for photovoltaic system(namely, PV) has grown steadily in Korea. However, the PV system has a various economic viability according to the PV system characteristic variables such as inverter efficiency, miscellaneous power conditioning losses, azimuth and slope of PV array, PV tracking mode, and so on. The other variables are the monthly consumed electric energy and economic related factor such as initial cost, government subsidy, maintenance cost, inflation rate, energy cost escalation rate, discount rate, etc. Therefore, this study is to present economic evaluation of PV system with those concerned factors by calculating internal rate of return, year-to-positive cash flow and net present value indices.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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• pp.407-410
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• 2008

This paper presents a maximum power point tracking(MPPT) of photovoltaic system with duty ratio of DC-DC converter considered load. A variation of solar irradiation is most important factor in the MPPT of PV system That is nonlinear, aperiodic and complicated. NN was widely used due to easily solving a complex math problem. The paper consists of solar radiation source, DC-DC converter, DC motor and load(cf, pump). NN algorithm apply to DC-DC converter through an adaptive control of neural network, calculates converter-duty ratio using an adaptive control of NN. The results of an adaptive control of NN compared with the results of converter-duty ratio which are calculated mathematical modeling and evaluate the proposed algorithm. The experimental data show that an adequacy of the algorithm was established through the compared data.