• 한국태양에너지학회 논문집
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• 제22권4호
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• pp.107-119
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• 2002

A review on the papers published in the Korean Journal of Solar Energy between 2000 and 2002 has been done. Focus has been put on current status of research in the aspect of Insolation. Solar Collector and Storage System, Solar Heating and Cooling System, Solar Cell and Lighting System, Active and Passive Solar Building, Heat Transfer in Solar Energy and Natural Energy. The conclusions are as follows. 1) Many studies on Insolation were conducted to optimize the usage of Solar Energy. 2) A review of the recent studies on solar thermal shows that there were many papers on solar collector and storage system. However, studies on the HVAC system using solar energy were relatively insufficient. 3) To produce high efficient solar cell. various experimental and numerical papers were published. However studies on control system, solar cell and lighting were seemed to be insufficient. 4) Studies on using solar energy in passive solar buildings were widely carried out, however, studies based on synthetic analysis of buildings and BIPV were insufficient. 5) Studies on heat transfer were mainly about heat exchanger, performance of heat pipe and multi air conditioner. 6) Studies on energy resources except for solar energy, such as hydraulic power and wind power etc. were very few.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 추계학술대회 논문집
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• pp.238-243
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• 2003

The solar cells should be operated at the maximum power point because its output characteristics are greatly fluctuated on the variation of insolation, temperature and load. The output power of solar cell is DC, therefore it is necessary to install an inverter among electric power converts. The inverter have to supply a sinusoidal current and voltage to the load and the interactive utility line. In the paper, the proposes a photovoltaic system designed with a step up chopper and single phase PWM voltage source inverter. Synchronous signal and control signal was processed by microprocessor for stable modulation. The step up chopper operates in continuous mode by adjusting the duty ratio so that the photovoltaic system tracks the maximum power point of solar cell without any influence on the variation of insolation and temperature because solar cell has typical dropping character. The single phase PWM voltage source inverter consists of complex type of electric power converter to compensate for the defect, that is, solar cell cannot be developed continuously by connecting with the source of electric power, from 10 to $20\%$. The single phase PWM voltage source inverter operates in situation that its output voltage is in same phase with the utility voltage. The inverter supplies an ac power with high factor and low level of harmonics to the load and the utility power system.

• 태양에너지
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• 제19권4호
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• pp.63-69
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• 1999

The conventional grid connected PV(Photovoltaic) system has a unstable output pattern due to its dependence on the weather condition, although solar-cell array averagely has a regular output characteristics to have a peak output nearly at noon. Therefore assuming the high density grid connection in the future, this unstable output pattern can be one of the main reasons to generate power disturbance such as voltage variation, frequency variation and harmonic voltage generation in low voltage distribution line. However general grid connected solar-cell system do not have functions to cope with these disturbances. Therefore this study proposed a advanced type grid connected PV system with functions to suppress output power fluctuation due to solar-cell array output variation and showed the levelling effect of fluctuation due to instantaneous array output variation.

• 동굴
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• 제89호
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• pp.27-33
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• 2008

Solar energy is most green and clean, unlimited and sustainable energy source on the earth. It is almost 97% of imported consumer energy in Korea. Because of resource poor nation, it is necessary to do their best to make alternative energy to allot their deficiency of the matter in hand of energy resources of petroleum. In a point of view of this problems, the natural solar energy should be improved by any methods as much, possible as we need. Photovoltaic generation with solar tracking system for obtaining optimal power is one of most benefit equipment to improve power of solar-cell panel producing clean electric power efficiently. Solar tracker is a device for orienting a solar photovoltaic panel toward the sun perpendicularly to sunlight, especially in widely separated place. For this reason, we are very interested in developing the equipment system of tracker, specially in solar cell applications, obtaining a high degree of accuracy to ensure that the optimal sunlight could be directed precisely against to the powered device. As a result, it was obtained of 12.46 volts at 90$^\circ$toward solar panel and 9.44 volts at 45$^\circ$, furthermore, improved efficiency more than 30% of average output voltage between tracker system (12.41V) and fixed system (8.55V), respectively. It is also very useful for optimum power system of widely separated cave.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권4호
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• pp.269-275
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• 2004

Photovoltaic(PV) system has been studied and watched with keen interest due to a clean and renewable power source. But, the output power of PV system is not only unstable but uncontrollable, because the maximum power point tracking (MPPT) of PV system is still hard with the tracking failure under the sudden fluctuation of irradiance. Authors suggest that the optimal voltage for MPPT be obtained by only solar cell temperature. Having an eye on that the optimal voltage point of solar cell is in proportion to its panel temperature, with operating the power converter whose operating point keeps its input voltage to the optimal voltage imagined by the surface's temperature of PV panel, the maximum power point becomes tenderly possible to be tracked. In order to confirm the availability of the proposed control scheme. And both control methods are simulated not only on the various angle of sampling time of switching control, but also with the real field weather condition. As the results of that, the conversion efficiency between PV panel and converter of the proposed control scheme was much better than that of the power comparison MPPT control, and what is better, the output voltage of PV panel was extremely in stable when the optimal voltage for MPPT is obtained by only solar cell temperature.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 전력전자학술대회 논문집
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• pp.138-142
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• 1998

This paper has been analyzed, modeled, designed, fabricated, and tested for solar cell simulator which has solar array characteristics. The main purpose is the development of solar cell simulator to test electrical power subsystem for GEO Communication Spacecraft. The maximum power of the simulator is about 5 ㎾, which is consist of 12 independent simulator modules with 420 W power rating. The 12 simulator modules are independently controlled like as real solar array system.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.313-318
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• 2012

In the present study, the preliminary study on a small solar-powered RC airplane are performed for the development of a long-endurance solar-powered UAV. Solar energy enables the solar-powered UAV to fly longer or eternally. The solar-powered UAV transfers the solar energy to electric energy and this energy is used for the flight and the battery charge. To increase the flying time, the efficiency of the solar-cell power system must be increased and the required power for flight must be minimized. Hence, the system integration including solar cell and controller, the power system design, and the aerodynamic and structural designs of the UAV is very important. The present study have performed the design, manufacture, and flight test of the small solar-powered UAV for the preliminary study of the long-endurance solar-powered UAV. From this study, the system integration technology of the solar-powered UAV design is established, and the possibility and the issue points for the development of the long-endurance solar-powered UAV are discussed.

• 전력전자학회논문지
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• 제4권1호
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• pp.57-65
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• 1999

본 논문은 충방전 제어기를 사용한 독립형 태양광 발전시스템을 다루고 있다. 독립형 태양광 발전시스템의 주전원은 일반적으로 태양전지와 배터리이다. 그러므로 독립형 태양광 발전시스템은 배터리와 태양전지와의 결선에 따라서 다양한 형태로 구분할 수 있다. 그중 주로 사용되는 결선은 태양전지와 배터리를 직접 연결하는 것으로 단순하고 간결한 구조를 갖는 이점이 있다. 그러나 그러한 시스템은 배터리와 솔라셀 사이의 전압불균형으로 인한 손실을 갖는다. 그러므로 태양전지를 최대전력점으로 운전할 수 있는 충방전 제어기를 갖는 독립형 태양광 발전시스템을 제안하여 순시치제어기로 설계하였다. 시스템의 동작특성을 실험실의 초기 시작품으로 검증되었다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.72-75
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• 2001

The solar energy is purity and infinity. Solar power converter were used to convert the electrical energy from the solar arrays to a stable and reliable power source. So much country research this solar energy system. The photovoltaic system is construct many solar cell array, In this paper, new implementation solar system was showed buck converter that V-I curve produced. This system can be used to study the short-term and long-term performances of solar cell and efficiency. This system is a far more cost effective and reliable replacement for field and outdoor flight testing. Study of buck converter, analysis and control shun t$\cdot$series connection characteristics of solar cell array.

• 에너지공학
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• 제15권3호
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• pp.181-187
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• 2006

본 논문에서는 소방 비상용으로 이용되는 태양전지 발전시스템을 제안하고, 발전시스템의 효율을 증대시키기 위한 새로운 고효율의 전력변환장치(승압용 초퍼와 인버터)가 설계된다. 직류-직류(DC-DC) 승압용 초퍼와 직류-교류(DC-AC) 인버터는 사용된 제어스위치들의 스위칭 손실을 최소화하기 위해 공진회로를 이용한 새로운 소프트 스위칭 기법이 적용되고 시스템의 효율을 증대시킨다. 또한 본 논문에서는 태양전지(solar cell)의 최대전력 전송에 의한 태양전지의 효율적인 사용을 위한 태양전지 발전전력의 최대점 $P_{max}$을 손쉽게 추종하고 검출하는 새로운 제어기법과 제어회로에 대해 상세히 해석된다. 고효율의 전력변환 장치와 태양전지 최대전력 전송회로는 컴퓨터 시뮬레이션과 실험을 통하여 그 타당성이 입증된다.