• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.46-48
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• 2009

This paper aims to investigate generation conditions necessary for the most efficient generation by measuring electricity power under various irradiation conditions, since the photovoltaic generation system has high costs and low efficiency. In addition, because the irradiation varies hourly, daily, monthly, and yearly, the research on the irradiation necessary for photovoltaic generation was carried out by analyzing the pattern o( Bower under various irradiation conditions. Also, after measuring the daily variations of irradiation and generation power, the monthly accumulated irradiation and monthly accumulate power which had the most generation power were investigated and the pattern of the annual generation power was analyzed. The results of this study are as follows. As for the relationship between the photovoltaic generation system and the irradiation, the generation power increased with the irradiation and when the irradiation was more than 600 $[W/m^2]$ the generation power amounted to more than 100 [Wh] as the resonable result.

• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.180-182
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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-V characteristics according to a irradiation range of 100$\sim$900 $[W/m^2]$, voltage and current were increased with an increase in irradiation. The result is thought of as an increase in output power with increasing irradiation.

• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.177-179
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• 2009

Solar, as an ideal renewable energy, it has inexhaustible, clean and safe characteristics. However, solar energy is an extreme intermittent and inconstant energy source. In order to improve the photovoltaic system efficiency and utilize the solar energy more fully, and the DC current varies with the irradiation, it is necessary to study the characteristics of photovoltaic I-V according to the external factors. This paper presents the analysis of characteristics of photovoltaic I-V according to the irradiation.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.413-416
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• 2009

Since the solar radiation is main input for sizing any solar photovoltaic system and solar thermal power system, it will be necessary to understand and evaluate the insolation data. The Korea Institute of Energy Research(KIER) has begun collecting horizontal global insolation data since May, 1982 and direct normal insolation data since December 1992 at 16 different locations. Because of a poor reliability of existing data, KIER's new data will be extensively used by solar energy system users as well as by research institutes. Among some significant results, the yearly averaged horizontal global insolation was turned out 3.61 kWh/$m^2$/day and the yearly mean 5.38 kWh/$m^2$/day of the direct normal insolation was evaluated for clear days.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.323-325
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• 2008

Solar Array는 일사량 및 온도에 의해 얻을 수 있는 최대전력이 변화한다. 또한 Solar Array의 전압에 따라 출력 전력이 변화한다. 따라서 태양전지의 동작점을 최대 전력점에서 동작하게 하는 최대 전력점을 추적(MPPT:Maximum Power Point Tracking)하는 제어 시스템이 필요하다. 본 논문에서는 Solar Array의 전압과 전력의 상관관계를 이용하여 최대 전력점을 추종하는 제어 시스템을 제안한다. 이 방식은 빠르게 최대 동작점을 찾을 수 있고 높은 전력 변환 효율을 가지며 다른 방식에 비해 구성이 간단하다. 제안된 제어기법의 타당성을 검증하기 위하여 MPPT시뮬레이션과 실험을 수행하였다.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.58-60
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• 2007

국내 신재생에너지의 보급은 정부 보조금 지원을 통해 국내 지역별로 다양한 형태, 발전 용량으로 보급되고 있다. 그 중에서도 태양광 발전의 주택보급과 산간지역의 풍력발전 보급은 발전 규모와 설비가 대형화 되어 가고 있다. 본 논문에서는 이러한 발전 시스템 지원을 위한 지역 기후 현황 분석과 발전 시스템과의 연계를 통해 특성을 분석하고자 하였다.

• New & Renewable Energy
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• v.2 no.1 s.5
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• pp.56-65
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• 2006

The thermal performance of glass evacuated tube solar collectors are numerically and experimentally investigated. Four different shapes of solar collectors are considered and the performances of these solar collectors are compared. Dealing with a single collector tube, the effects of not only the shapes of the absorber tube but also the incidence angle of solar irradiation (beam irradiation) on thermal performance of the collector are studied. However, the solar irradiation consists of the beam irradiation as well as the diffuse irradiation. Also, the interference of solar irradiation and heat transfer interaction between the tubes exist in an actual solar collector, These effects are considered in this study experimentally and numerically. The accuracy of the numerical model is verified by the experimental results. The result shows that the thermal performance of the absorber used a plate fin and U-tube is the best.

• Proceedings of the KIEE Conference
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• summer
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• pp.548-550
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• 2004

This paper suggests a methodology for calculation of photovoltaic(PV) generation system output using probability distribution function, PV way efficiency and PV system design Parameters. Long term irradiance recorded for every hour of the day for 11 years were used. For goodness-fit test, several distribution functions are tested by Kolmogorov- Smirnov(K-S) test. And the calculated generation output is compared with that of CMS(Centered Monitoring System), which can monitoring PV generation output of each PV generation site.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.216-218
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• 2019

태양광발전시스템은 최대의 전력을 생산하기 위하여 PV 패널의 운전을 최대전력점에서 동작하게 하는 MPPT(Maximum Power Point Tracking) 제어가 필요하다. 그중 대표적인 방법인 P&O(Perturb and Observe) 알고리즘은 전류와 전압을 측정하여 계산된 전력의 값이 최대가 되는 전압의 운전점을 찾는다. 그러나 센서의 측정오차로 인하여 발전전력의 계산 및 전압의 제어에 불규칙한 오차가 발생하여 정확한 MPP 운전점을 찾지 못하는 문제가 발생한다. 본 논문에서는 전형적인 맑은 날씨와 흐린 날씨에서 취득한 일사량 데이터와 전류 및 전압 센서의 오차를 고려하여 P&O 알고리즘에 의한 전력 생산량을 시뮬레이션 한다. 시뮬레이션 분석을 통해 실제 날씨 및 센서허용오차 조건에서 MPPT 목표 효율을 극대화할 수 있는 최적의 MPPT 제어주기와 변량전압의 크기를 제시한다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.3
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• pp.277-284
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• 2012

In this study, a heat-transfer performance analysis is carried out for a multi-channel volumetric air receiver for a solar power tower. On the basis of a series of reviews regarding the relevant literature, a calculation process is proposed for the prediction of the wall- and air- temperature distributions of a single channel at given geometric and input conditions. Furthermore, a unique mathematical model of the receiver effectiveness is presented through analysis of the temperature profile. The receiver is made of silicon carbide. A total of 225 square straight channels per module are molded to induce the air flow, and each channel has the dimensions of $2mm(W){\times}2mm(H){\times}0.2mm(t){\times}320mm(L)$. The heat-transfer rate, temperature distribution and effectiveness are presented according to the variation of the channel and module number under uniform irradiation and mass flow rate. The available air outlet temperature applied to the solar power tower should be over $700^{\circ}C$. This numerical model was actually used in the design of a 200 kW-level commercial solar air receiver, and the required number of modules satisfying the thermal performance could be obtained for the specified geometric and input conditions.