• Journal of Power Electronics
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• v.9 no.4
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• pp.604-611
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• 2009

A dP/dV feedback-controlled MPPT (Maximum Power Point Tracking) method for photovoltaic power systems using II-SEPIC (Isolated Inverse-SEPIC; Single Ended Primary Inductance Converter) is presented and a current-mode dP/dV feedback-controlled MPPT method is devised to apply for the PV power converter system. A control strategy for the current-mode dP/dV feedback control system is developed in this paper and the proposed MPPT shows relatively satisfactory dynamics against rapidly changing insolation conditions. In order to verify the validity and effectiveness of the proposed method, simulations and experiments of the PV power system using II-SEPlC converter are performed. These simulation and experiment results show that the proposed method enables the PV power system to extract maximum power from the photovoltaic module against the solar insolation variation.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.12
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• pp.1175-1183
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• 2009

In photovoltaic(PV) generator systems, DC-DC converters are significantly considered for control system performance in power quality point of view. This paper presents a novel adaptive control method for DC-DC converters applied in PV generator systems. First, we derive a state-space average model of the converter system and then propose a reset control methodology to enhance transient response performance for time-varying PV systems. For estimating parameters of a reset control, a gradient descent optimization is utilized and an adjustment rule of them are derived respectively. An objective of the optimization is that characteristic equation of an augmented system model which is formed with an converter system model and an reset control is to trace a predefined polynomial given as a reference characteristic model. Next, we accomplish stability analysis by means of a well-known Lyapunov theory for nonlinear converter systems including time-varying voltage excitation from a PV generator. Numerical simulation demonstrates reliability of our control methodology and its superiority by comparison to a traditional control strategy.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.356-360
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• 2009

Recent global environmental pollution and contamination and depletion of limited fossil energy prices surge as an energy source to replace it depending on wind, fuel cells and solar power and other renewable and pollution free renewable energy is of interest in increase. The photovoltaic systems are pollution-free, unlimited energy source, and easy to install because it is rated as the most valuable renewable energy sector and the prevalence is spreading throughout the world. Photovoltaic systems at one end of the stable development of the role that solar power inverter applications can be the most important. No matter how much power the solar arrays, even if the inverter output in the normally if he's no use. These photovoltaic inverters to evaluate the performance of the inverter efficiency measures that can be called directly. This way of measuring the efficiency of solar inverters in Europe efficiency and CEC efficiency is currently being used. In this paper, until now about how to measure the efficiency of solar power inverter technology and the new Korean Meteorological Solar Insolation data analysis to derive weights based on this inverter efficiency for Korea is to offer.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.303-308
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• 2009

In 2008, the global photovoltaic(PV) market reached 5.6GW and the cumulative PV power installed totalled almost 15GW compared to 9GW in 2007. Due to a favourable feed-in-tariff, Korea emerged in 2008 as the 4th largest PV market worldwide. PV power installation rose 495.5 percent to 268MW in 2008 compare to 45MW in 2007. However many PV systems are not installed in suitable part which is concerned about geometrical factor. It is generally recognized that the actual output of PV system in field is a function of orientation, tilt angle, irradiance, temperature, soiling and various system-related losses. Thus this paper shows that a experimental result of PV modules(A group) with uniform azimuth angle and PV modules(B group) with non-uniform azimuth angle. As a result, the electrical output of B group is decreased 48.8% as compared with electrical output of A group.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.631-634
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• 2001

This paper presents a maximum power point tracking without a current sensor for a small scale photovoltaic power system. The small scale photovoltaic power systems are used in parallel, and so the cost and the reliability are strongly demanded. In the proposed inverter, the current is controlled with open loop, and then the power of photovoltaic array is calculated by the equation using the voltage of the photovoltaic array. Therefore, the system can obtain the power by detecting only the voltage of the photovoltaic array. As a result, we may obtain the performance of the MPPT with a current sensor as well as with a current sensor.

• KIEAE Journal
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• v.12 no.6
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• pp.129-134
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• 2012

The lightshelf system, a daylighting device, has been applied to improve the visual environment by optimal light distributions and intense illumination levels of a interior. Also, The photovoltaic is one of the most important sustainable technologies appliable to architectures. This study aims to evaluate the performance of photovoltaic integrated lightshelf system. For the study, the 1/5 scaled office models were made and the field tests were experimented under clear sky conditions. The power ratio has been analyzed to evaluate the performance of photovoltaic integrated lightshelf system. As results, the power performance was high on photovoltaic lightshelf installation angle $0^{\circ}$. And the performance was reduced on 23(%) by installation angle $15^{\circ}$ and 63(%) by installation angle $30^{\circ}$.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.11B no.4
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• pp.169-174
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• 2001

A novel simulation scheme of transient phenomenon for the photovoltaic (PV) generation system under the real weather conditions has been proposed in this paper. A grid connected PV array is simulated using PSCAD/EMTDC. The transient changes of the output current of PV array under the real weather conditions is described and the output current of DC/AC converter flowing through the utility power network is also analyzed with the PWM switching width. Moreover, the MPPT control of PV generation system is combined to the system during the simulation for the comparison purposes of the control schemes. The outcome of the simulation demonstrates the effectiveness of the proposed simulation scheme. The result shows that the cost effective verifying for the efficiency or availability and stability of PV generation systems and the comparison research of various control schemes like MPPT under the same real whether conditions are eventually possible.

• Journal of Power Electronics
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• v.14 no.1
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• pp.156-164
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• 2014

The power-voltage (P-V) characteristic of a photovoltaic (PV) array is nonlinear and time varying with the change in atmospheric conditions. As a result, the maximum power point tracking (MPPT) technique must be applied in PV systems to maximize the generated energy. The incremental conductance (INC) algorithm, one of the MPPT strategies, is widely used for its high tracking accuracy, good adaptability to rapidly changing atmospheric conditions, and easy implementation. This paper presents a modified asymmetrical variable step size INC MPPT method that is based on the asymmetrical feature of the P-V curve. Compared with conventional fixed or variable step size method, the proposed method can effectively improve tracking accuracy and speed. The theoretical foundation and design principle of the proposed approach are validated by the simulation and experimental results.

• Journal of the Korean Solar Energy Society
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• v.26 no.3
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• pp.79-87
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• 2006

This study aims to presents the applicability of apartment building for renewable energy systems using method of uncomplicated calculation and computer simulation. According to the weather conditions (NASA Surface meteorology and Solar Energy) analysis, it has been found that photovoltaic and wind power system can be applied to apartment buildings application. In case study considering layout and block plan, adaptation of solar water heating, photovoltaic and wind energy system to apartment buildings was proved to produce a profit. And the application strategies of renewable energy systems can be used not only for the investment decisions for economic analysis but also for the comparative analysis of uncomplicated calculation and computer simulation.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.408-411
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• 2008

In this paper, a new DC ground fault detection system is proposed, which is suitable for photovoltaic power generation systems. The proposed ground fault systems is superposition of divide resistance and detection circuit. The proposed system has the characteristics of a simplified structure, reduced cost and volume compared with those of the conventional ground fault system for DC source. The operation principle of the proposed systems is described and verified by simulation result.