• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1064_1065
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• 2009

PV (Photovoltaic) power generation system has been widely studied as a clean and renewable power source. Tracking the MPP (maximum power point) of a PV array is usually an essential part of a PV system. This paper describes POS (Photovoltaic Output Sensorless) MPPT method and optimization technique of its operational characteristics for grid-connected PV generation system. A DC-DC converter has been used to step-up the PV voltage and DC-AC converter has been used for connecting the system to the grid. Optimization technique has been implemented to optimize the current and voltage controller gain parameters and duty ratio increment of DC-DC converter. Simulation results reveal that the proposed control has better response.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.61-63
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• 2005

Utility interactive photovoltaic systems is one of the most premising applications of photovoltaic systems. These systems are employed in applications where utility service is already available. In this case, there is no need for battery storage because utility power may be used to supplement photovoltaic systems when the load exceeds available PV generation. The load receives electricity from both the photovoltaic array and the utility inter-tied. In this paper, Principle and operating characteristic of Utility Interconnected Photovoltaic System is presented. For the purpose of optimal utility Inter-tied photovoltaic system design and installation. It is that demonstrate throughout the installed 3 PV system respectively, 3kW utility interconnected residential system.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.226-227
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• 2007

The purpose of this study for photovoltaic (PV) generation system is to keep the output power of photovoltaic cells maximized under any weather conditions. In a conventional MPPT (Maximum Power Point Tracking) control method, both voltage and current coming out from PV array have to be fedback. Thus, the system has a complex structure, and may fail to track MPP of PV array when unexpected weather conditions happen. This paper proposes a novel PV Output Senseless (POS) control method to solve the mentioned problem. The main advantage of this method is that the current flowing into load is the only one considerable factor. In case of a huge PV generation system, it can be operated much more safely than the conventional system. To verify this theory, results that compare and analyze the simulated data with experimental data under real weather condition of the manufactured PV generation system are shown in this paper. Authors vividly states that this theory uses constant resistors and variable resistors of DC-DC converter in PV system. Authors emphasize that it is a very useful method to maximize power from PV cells to load with only the feedback of load current. Authors also emphasize that this theory is applicable in case of the PCS in PV power generation system.

• New & Renewable Energy
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• v.8 no.1
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• pp.8-17
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• 2012

The Korean government pushed ahead various policies to disseminate photovoltaic (PV), wind power, small hydro, bio-fuel, etc. Renewable energy system (RES) budget of the Korean government increased from 118 billion won of 2003 to 876.6 billion won of 2010. The R&D budgetary supports for RES increased by 6.8 times in the period 2003-2010. It is necessary to confirm RES budget expenditure that renewable energy promotion policy makes good performance evaluated in quantity level. This paper made Input-Output Table 2009 contains photovoltaic power generation equipment industry as a dependent sector and analyzed induced production effect by demand of photovoltaic power generation equipment industry. From the empirical analysis result, additional demand in photovoltaic power generation equipment induced 1.932 times of induced production in Korea. Each of industry sector has positive induced production from the additional demand in photovoltaic power generation equipment. Renewable energy promotion in photovoltaic power generation is considered together with industry policy as the option to sustain economic growth.

• KIEAE Journal
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• v.15 no.1
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• pp.89-95
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• 2015

The centralized power supply system and rainwater treatment system, which are major infrastructure in modern cities, are showing their limitations in accommodating environment load due to climate changes that has aggravated recently. As a result, complex issues such as shortage of reserve power and urban flooding have emerged. As a single solution, decentralized systems such as a model integrating photovoltaic system and rooftop greening system are suggested. When these two systems are integrated and applied together, the synergy effect is expected as the rooftop greening has an effect of preventing urban flooding by controlling peak outflow and also reduces ambient temperature and thus the surface temperature of solar cells is lowered and power generation efficiency is improved. This study aims to compare and analyze the monitoring results of four algorithms that define correlations between micro-climate variables around rooftop greening and the surface temperature of solar cells and generate their significance. By doing so, this study seeks to present an effective algorithm that can estimate the surface temperature of solar cell that has direct impact on the efficiency of photovoltaic power generation by observing climate variables.

• Journal of the Korean Solar Energy Society
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• v.34 no.4
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• pp.1-7
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• 2014

The microgrid system is the combination of photovoltaic(PV) array, load, and battery energy storage system. The control strategies were defined as multi-modes of operation, including rest operation without use of battery, power charging, and power discharging, which enables grid connected mode or islanded mode. Photovoltaic power is a problem of the uniformity of power quality because the power generated from solar light is very sensitive to variation of insolation and duration of sunshine. As a solution to the above problem, energy storage system(ESS) is considered generally. There fore, in this study, we did basic research activities about optimization method of the amount of energy used, using a smart microgrid test-bed constructed in building. First, we analyzed the daily, monthly and period energy pattern amount of power energy used, and analyzed PV power generation level which is built on the roof. Utilizing building energy pattern analysis data, we was studied an efficient method of employing the ESS about building power consumption pattern and PV generation.

• Journal of the Korean Solar Energy Society
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• v.39 no.4
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• pp.69-77
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• 2019

Among the main functions of the grid-connected photovoltaic (PV) system, the anti-islanding operation function is a very important problem. Recently, due to the improvement in power generation efficiency and the maintenance advantages in PV system, the use of string inverter has increased so that the possibility of islanding operation has been raised. Generally, when a power system faults, the PV inverter must be disconnected from power system within 10 cycles by the anti-islanding operation function. However, in the real-time of power system, the output power of the PV system within 10cycles is effected. In this paper, we analyzed the effect of grid-connected PV system on power quality in a short time within 10 cycles on fault case of power system using the Matlab Simulink program.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.296-300
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• 2001

Novel concept of shunt active filter (AF) function added in Photovoltaic (PV) generation system is described in this paper. So far, for the PV generation system has been treated as one of harmonic sources to the power distribution systems, not only a PV system combined with AF but also AF systems using PV module as their power source have never been discussed. The basic structure and control strategy of the PV-AF system are, for the first time, introduced in this work. In order to stabilize the output current of voltage source inverter (VSI), the reference voltage MPPT control is applied. Simulation analysis shows that it is possible to combine AF function to the three-phase grid-connected PV generation system without any physical difficulties, and the performance of the proposed PV-AF system is acceptable and stable as well.

• ETRI Journal
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• v.33 no.6
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• pp.880-886
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• 2011

With the introduction of high-current 8-inch solar cells, conventional Schottky bypass diodes, usually adopted in photovoltaic (PV) panels to prevent the hot spot phenomenon, are becoming ineffective as they cause relatively high voltage drops with associated undue power consumption. In this paper, we present the architecture of an active circuit that reduces the aforementioned power dissipation by profitably replacing the bypass diode through a power MOS switch with its embedded driving circuitry. Experimental prototypes were fabricated and tested, showing that the proposed solution allows a reduction of the power dissipation by more than 70% compared to conventional Schottky diodes. The whole circuit does not require a dedicated DC power and is fully compatible with standard CMOS technologies. This enables its integration, even directly on the panel, thereby opening new scenarios for next generation PV systems.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.10
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• pp.353-360
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• 2016

Recently, solar photovoltaic(PV) power generation which generates electrical power from solar panels composed of multiple solar cells, showed the most prominent growth in the renewable energy sector worldwide. However, in spite of increased demand and need for a photovoltaic power generation, it is difficult to early detect defects of solar panels and equipments due to wide and irregular distribution of power generation. In this paper, we choose an optimal machine learning algorithm for estimating the generation amount of solar power by considering several panel information and climate information and develop a defect detection system by using the chosen algorithm generation. Also we apply the algorithm to a domestic solar photovoltaic power plant as a case study.