• ETRI Journal
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• 제33권6호
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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.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 추계 학술논문 발표대회
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• pp.79-80
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• 2015

With the government's support for new and renewable energy, photovoltaic equipment has rapidly been supplied. However, compared to supply rate, maintenance has not supported enough and relevant research has not much conducted. Therefore, the purpose of this study is to analyze maintenance effectiveness of photovoltaic equipment. What is the most important in maintenance effectiveness is a rise in power generation. It was estimated that if photovoltaic equipment for detached houses is maintained well, power generation increases by 4.0% at least, and by 6.5% on average. As a result, it was analyzed that it is necessary to maximize the effectiveness of the government's budget investment through well maintenance of photovoltaic equipment for detached houses.

• 전기학회논문지
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• 제61권7호
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• pp.1007-1013
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• 2012

Modeling of photovoltaic power systems is significant to analytically predict its dynamics in practical applications. This paper presents a novel modeling algorithm of such system by using probability and statistic theories. We first establish a linear model basically composed of Fourier parameter sets for mapping the input/output variable of photovoltaic systems. The proposed model includes solar irradiation and ambient temperature of photovoltaic modules as an input vector and the inverter power output is estimated sequentially. We deal with these measurements as random variables and derive a parameter learning algorithm of the model in terms of statistics. Our learning algorithm requires computation of an expectation and joint expectation against solar irradiation and ambient temperature, which are analytically solved from the integral calculus. For testing the proposed modeling algorithm, we utilize realistic measurement data sets obtained from the Seokwang Solar power plant in Youngcheon, Korea. We demonstrate reliability and superiority of the proposed photovoltaic system model by observing error signals between a practical system output and its estimation.

• 한국전기전자재료학회논문지
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• 제28권11호
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• pp.743-747
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• 2015

In this paper, the power generation efficiency of the 4 [kW] fixed-concentrated type photovoltaic power generation system and that of the 4 [kW] single axis trace type photovoltaic power generation system were compared. For that purpose, the two types of photovoltaic power generation systems have been in operation for 1 year on an experimental basis. The amounts of power generated by the two types during the months of January through December and the characteristics of their operating times during the same period have been compared and analyzed. For the study, the type with higher efficiency was selected and the following conclusions have been reached. It was shown that the amount of power generated and the average operation times during the spring months of March through May are higher that those of the summer months of June through August when more sunlight is available. The reason for this phenomenon is thought to be that as the temperatures of the solar panel surface and the surrounding environment go up, the electric current decreases.

• 한국태양에너지학회 논문집
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• 제27권3호
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• pp.1-6
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• 2007

In this study, we analyze the maximum power generation of photovoltaic(PV) module depending on constituent materials and incidence angle dependence of light. To verify characteristics of constituent materials, we made photovoltaic modules with 4 kinds of solar cells and textured glass according to fabrication method. To find the degree of the maximum power generation dependence on intensity of light, Solar Simulator is applied by changing angle of module and light intensity. Through this experiment, to obtain maximum power generation from limited PV modules, it is needed to fully understand constituent materials, fabrication method and dependence of incident light characteristics.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제3B권2호
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• pp.103-110
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• 2003

With significant development of power electronics technology, the proliferation of nonlinear loads such as static power converters has deteriorated power quality in power transmission and distribution systems. Notably, voltage harmonics resulting from current harmonics produced by the nonlinear loads have become a serious problem in many countries. Many photovoltaic power generation systems installed in building systems have harmonics that are the worst object for distribution systems as a utility interactive system, and it tends to spread out continuously. Proposed and implemented in this paper is a multi-function inverter control strategy that allows a shunt active filter function to the power inverter of the photovoltaic power generation system established on a building system. The effectiveness of the proposed system is demonstrated through the simulation of a hypothetical power system using PSCAD/EMTDC.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1126-1127
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• 2008

A photovoltaic panel is a device that, through the photovoltaic effect, converts luminous energy into electric energy. Photovoltaic generation system used infinity of solar energy, cost of fuel is needless and there in no air pollution or waste occurrence. This paper summarizes the results of these efforts by offering a photovoltaic system structure in 30[kW] large scale applications installed in Mokpo National University dormitory roof. The status of photovoltaic system components, are inter-connection and safety equipment monitoring system will be summarized as this article. This describes configuration of utility interactive photovoltaic system which generated power supply for dormitory. In this paper represent 30[kW] utility photovoltaic system examination result.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 춘계학술대회 논문집 전기설비전문위원
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• pp.183-185
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• 2009

In this thesis, output voltage, current and power of solar module were classified by irradiation and module temperature from data of overall operating characteristics collected for one year in order to manage efficient photovoltaic generation system and deliver maximum power. In addition, from these data, correlations between irradiation, module temperature of photovoltaic cell and amount of power given by photovoltaic cell was quantitatively examined to deduce optimization of the design and construction of photovoltaic generation system. The results of this thesis can be summarized as follows. As I-Y characteristics according to a temperature range of 10$\sim$50[], the area of I-V characteristics were increased with an increase in temperature. Since this area corresponds to the power, output power is thought to have increased with temperature.

• 전기학회논문지P
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• 제61권4호
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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.

• 한국화재조사학회지
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• 제10권1호
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• pp.87-95
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• 2007

This paper is proposed a novel method to approximate the maximum power for a photovoltaic inverter system and tracking method. 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. Furthermore tracking method is improved over 50% photovoltaic efficiency. This paper is proposed MPPT using LRMC and tracking method using weather condition of domestic moderate program technique. This paper is proposed the experimental results to verify the effectiveness of the new methods.