• 신재생에너지
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• 제2권2호
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• pp.16-22
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• 2006

This paper present the performance evaluation of PV systems installed at Tibet area of China in order to identity the key factors that determines system operation at a severe climate conditions and promote the cooperation of PV technology between Korea and China. The installed systems consist of 100kW on-grid connected PV systems, BOS(balance of systems), data acquisition and transmission equipments. The Korea side supplied the solar cell, BOS like as inverter, control box and monitoring system. And the Chinese side assembled solar module, constructed site and built control house. It has been shown that the average radiation per monthly from Tibet is 1.5 times larger than that from Mokpo. Also, radiation time from Tibet is 2hour higher than that from Korea.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.125-129
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• 2006

This paper presents the isolation and performance evaluation of PV systems installed at Tibet area of China in order to identity the key factors that determines system operation at a severe climate conditions and promote the cooperation of PV technology between Korea and China. The installed systems consist of 100kW on-grid connected PV systems, BOS(balance of systems), data acquisition and transmission equipments. The Korea side supplied the solar cell, BOS like as inverter, control box and monitoring system. And the Chinese side assembled solar module by using Koreans solar cells, constructed site and built control house.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.244-244
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• 2007

• 전력전자학회논문지
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• 제13권6호
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• pp.469-475
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• 2008

본 논문에서는 소형 PEM(Proton Exchange Membrane) 연료전지 스택의 마이크로프로세서를 이용한 제어에 관하여 소개한다. 연료전지 제어의 핵심 기술인 스택 내부의 수분 관리는 부하에 의해 요구되는 연료와 온도에 따른 냉각용 공기의 유량을 적절하게 조절하고, 잉여수분을 스택으로부터 배출시킴으로써 성취된다. 이러한 주변장치(BOS: Balance of Stack)의 제어는 시스템의 안정적인 운전을 좌우하는 중요한 요소이기 때문에 이를 정확하게 제어하는 것이 매우 중요하다. 본 연구에서는 최적 운전조건에서 공기유량과 퍼지주기를 측정하고 이를 바탕으로 BOS를 제어함으로써 BOS의 소비전력을 최소화하여 연료 효율을 향상시킬 수 있었으며, 이를 실험을 통해 검증하였다. 마이크로프로세서를 이용하여 개발된 제어기는 시스템의 운전 안정성을 향상시켜 소형 연료전지 스택의 제어에 널리 사용될 것으로 기대된다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.284-287
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• 2007

This paper presents the performance evaluation of PV systems installed at Tibet area of China in order to identity the key factors that determines system operation at a severe climate conditions and promote the cooperation of PV technology between Korea and China. The installed systems consist of 100kW on-grid connected PV systems, BOS(balance of systems), data acquisition and transmission equipments. The Korea side supplied the solar cell, BOS like as inverter, control box and monitoring system. And the Chinese side assembled solar module, constructed site and built control house. It has been shown that the average radiation per monthly from Tibet is 1.5 times larger than that from Mokpo. Also, radiation time from Tibet is 2hour higher than that from Korea. The economical analysis has shown that with the current prices, investment in a grid connected PV systems is generally profitable

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.65.2-65.2
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• 2010

Currently the variety of governmental business support and research for supplying solar energy have been actively progressed. As of now, however, There are no practical testing infrastructures of grid-connected photovoltaic system which test performance of solar power facility in domestic. Therefore, in KEPRI, there is in progress construction of practical testing ground of 500 kW class grid-connected PV System for developing the evaluation of the performance technology including the Module, PCS, and etc, that is the important instrument of the PV System, in Gochang area. It analyzed the site creation work for constructing the practical testing ground and new construction of control room and the unit standards, specifications and capacity of required equipment. For the system detailed design, configuration, instrument-specific parameters established, power generation predictions of Array Type and the components of testing ground are needed to build.

• 제어로봇시스템학회논문지
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• 제16권9호
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• pp.823-826
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• 2010

In this study, the control method of assistive robot was developed for the elderly. The control method of gait-assistant-robot was proposed considering the change of COP (Center of Pelves), BOS (Base of Support) and comparative analysis of the moving velocity for the elderly. We analyzed the movement of COP of the body and its velocity of the elderly equipped with manual walker and gait-assistant-robot. As a result, change in COP was greater from left to right than from anterior to posterior; also, the average velocity of the movement of COP and manual walker for manual walker gait was 0.7(m/s). Therefore, it is necessary to concern more on the left-right balance and synchronization of the velocity of COP.

• Asian-Australasian Journal of Animal Sciences
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• 제32권4호
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• pp.548-555
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• 2019

Objective: The main objective of this study was to evaluate the effect of different feeding levels of a total mixed ration silage-based diet on feed intake, total tract digestion, enteric methane emissions, and energy partitioning in two beef cattle genotypes. Methods: Six mature bulls (three Thai natives, and three Thai natives - Charolais crossbreeds) were assigned in a replicated $3{\times}3$ Latin square design, with cattle breed genotype in separate squares, three periods of 21 days, and three energy feeding above maintenance levels (1.1, 1.5, and 2.0 MEm, where MEm is metabolizable energy requirement for maintenance). Bulls were placed in a metabolic cage equipped with a ventilated head box respiration system to evaluate digestibility, record respiration gases, and determine energy balance. Results: Increasing the feeding level had no significant effect on digestibility but drastically reduced the enteric methane emission rate (p<0.05). Increasing the feeding level also significantly increased the energy retention and utilization efficiency (p<0.01). The Thai native cattle had greater enteric methane emission rate, digestibility, and energy utilization efficiency than the Charolais crossbred cattle (p<0.05). The daily metabolizable energy requirement for maintenance in Thai native cattle ($388kJ/kg\;BW^{0.75}$, where $BW^{0.75}$ is metabolic body weight) was 15% less than that in Charolais crossbred cattle ($444kJ/kg\;BW^{0.75}$). Conclusion: Our results suggested that the greater feeding level in zebu beef cattle fed above maintenance levels resulted in improved energy retention and utilization efficiency because of the reduction in enteric methane energy loss. The results also indicated higher efficiency of metabolisable energy utilization for growth and a lower energy requirement for maintenance in Bos indicus than in Bos taurus.

• Current Photovoltaic Research
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• 제6권3호
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• pp.69-73
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• 2018

PV system is consisted with PV module, inverter and BOS(balance of system). To have robustic operation more than 20 years, the expected and guaranteed durability and reliability of products should be met. Almost components of PV system are qualified through IEC standards at test laboratory. But the qualification certificate of product does not ensure long-term nondefective operation. PV module's expected life time is nowadays more than 20 years and annual maximum power degradation ratio would be less than -1%. But the power degradation ratio is basically based on real data more than several years' record. Developing test method for ensuring annual maximum power degradation ratio is very need because there are many new products every month with new materials. In this paper, we have suggested new test method under continuous artificial light irradiation test condition for analyze expected maximum power drop ratio.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.107.2-107.2
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• 2011

태양광발전 시스템의 성능 평가는 신뢰할 수 있는 데이터의 취득 및 분석을 통하여 발전성능을 제시할 수 있다. 발전성능에 영향을 미치는 요인으로는 일사량과 온도 등의 환경적인 요인, 시스템 구성에 따른 기술적인 요인에 의해 결정될 수 있다. 특히, 시스템 구성에 의해 결정되는 기술적인 요인은 태양전지 모듈의 어레이 손실 및 BOS의 자체 손실 등을 분석하여 전체 시스템의 발전성능을 분석하여 그 성능을 평가할 수 있다. 본 논문에서는 기 설치된 태양광발전 시스템에서 취득된 데이터를 통하여 용량별, 지역별에 따른 태양광발전 시스템의 성능 분석과 손실 원인을 분석하였다. 분석결과 시스템의 성능은 환경적인 요인과 기술적인 요인에 의해 발전성능이 달라진다는 것을 확인할 수 있었다. 본 논문의 결과는 향후 태양광 발전 시스템의 성능의 기준을 제시하는 연구를 위한 사전연구로써 유용한 자료가 되리라 믿는다.