• Journal of Navigation and Port Research
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• v.34 no.9
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• pp.705-709
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• 2010

Buildings nowadays are increasingly expected to need higher and more economic performance requirements. Energy consumption in buildings accounts for over 30% of total energy use. The Building Energy Management System (BEMS) and renewable energy (RE) technologies are considered as a potential measure to improve energy efficiency and reduce use of grid-power. It is, however, a challenge to utilise the intermittent energy supply of RE in building energy systems. This paper presents an experimental study on a RE-embedded BEMS. A control algorithm for the RE-embedded BEMS was designed to maximise the utilisation of RE and eventually to reduce electrical utility bill. The proposed system is tested at a laboratorial chamber with an air conditioner, fan and heater. The contribution of RE in building energy system is discussed to this end.

• New & Renewable Energy
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• v.10 no.3
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• pp.22-30
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• 2014

The isolated self-generating electricity with diesel engine generator has been used in islands far away from main land. It costs high because of increasing oil price, and unsafe to have supplying oil and its related components by ship due to unexpectable marine conditions. Therefore there is the need for the hybrid system of renewable energy like wind or solar energy systems with oil engine generator, which can reduce oil use and extend oil supplying period. In this study, the feasibility of such hybrid system with smart micro grid on the eight islands of Jeon-nam province is surveyed to find good place for the demonstration test of the hybrid system. In each island, 3 wind turbine systems of 10 kW and photovoltaic of 20 kW are tested with already installed diesel engine. The performance and costs of the hybrid system in each island are compared in the given conditions of solar and wind energy potential. As a result of the study, Jung-ma island is recommended for the optimum place to make real field demonstration test of isolated hybrid generating and smart grid systems.

• Journal of the Korean Institute of Educational Facilities
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• v.20 no.2
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• pp.25-32
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• 2013

The purpose of this study is to analyze the state-of-the-art solar energy system design cases among LEED(Leadership in Energy and Environmental Design) certified school projects and to explore the feasibilities for their applications in domestic school design. Investigating the sold wattages in some kinds of buildings, the wattages per an educational facility is the second-largest after that per an industrial facility. That shows that our attention should be actively directed to the utilization of New and Renewable Energy in school facilities. Therefore photovoltaics systems, lighting systems and solarthermal facilities of solar energy systems were analyzed in the LEED cases. Findings demonstrate that applications of solar energy systems in K-12 educational facilities have been executed more than those in higher educational facilities. However, K-12 educational facilities and higher educational facilities by private funds are not categorized as Green Buildings by Support for Making Green Buildings Act. That fact is needed to be amended. Besides that, design developments are needed for building integrated photovoltaics systems and solarthermal facilities in domestic educational facilities.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.51.2-51.2
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• 2010

Efficient and durable electrical energy storage is one of the major factors limiting the wide-spread adoption of renewable energy. Since lithium-ion batteries (LIBs) were first commercialized in the early 1990s, LIBs have emerged as an important energy storage device for portable electronics. LIBs are very desirable because of their high energy storage per volume and per mass. However, LIBs with high energy and power as well as higher stability are needed for their use in a variety of energy storage applications such as MEMS devices, PDA, plug-in hybrids, all-electric vehicles and large scale utility systems. In this talk, I will discuss present energy perspective, especially energy storage and its role in renewable energy. After that I will discuss the recent advances in nanostructured materials and interface engineering that have led to the achievement of improved Li-ion batteries. Finally I will talk aboutcritical issues that need to be addressed to obtain further improvements in Li-ion batteries.

• Journal of Korean Institute of Industrial Engineers
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• v.40 no.3
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• pp.333-341
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• 2014

The purpose of this study is to forecast the penetration rate of renewable energy and a reasonable scale for the R&D investment plan in Korea based on the relationship between the diffusion and R&D investments drawn by analogy from empirical cases of advanced countries. Among numerous candidate developed countries, the German market was chosen based on the similarity of the diffusion patterns to those of the Korean plan. We then figured out how the investment triggers the growth of technology from the selected benchmark, and applied the technology S-curve relation formula to derive the desirable investment plan for Korea. The present paper is a pioneering attempt to forecast the diffusion process of renewable energy technology in Korea using the comparative analogy from cases of advanced countries.

• Journal of Power Electronics
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• v.15 no.4
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• pp.899-909
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• 2015

A dual-input boost-buck converter with coupled inductors (DIBBC-CI) is proposed as a thermoelectric generator (TEG) power conditioner with a wide input voltage range. The DIBBC-CI is built by cascading two boost cells and a buck cell with shared inverse coupled filter inductors. Low current ripple on both sides of the TEG and the battery are achieved. Reduced size and power losses of the filter inductors are benefited from the DC magnetic flux cancellation in the inductor core, leading to high efficiency and high power density. The operational principle, impact of coupled inductors, and design considerations for the proposed converter are analyzed in detail. Distributed maximum power point tracking, battery charging, and output control are implemented using a competitive logic to ensure seamless switching among operational modes. Both the simulation and experimental results verify the feasibility of the proposed topology and control.

• Journal of the Korean Solar Energy Society
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• v.33 no.2
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• pp.64-69
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• 2013

According to the Fourth Assessment Report of Intergovernmental Panel on Climate Change(IPCC) Working Group III, climate change is already in progress around the world, and it is necessary to execute mitigation in order to minimize adverse impacts. This paper suggests future climate change needs, employing IPCC Special Report on Emissions Scenarios(SRES) to predict temperature rises over the next 100 years. This information can be used to develop sustainable architecture applications for energy efficient buildings and renewable energy. Such climate changes could also affected the present supplies of renewable energy sources. This paper discusses one recent Fourth Assessment Report of IPCC (Mitigation of Climate Change) and the Hadley Centre climate simulation of relevant data series for South Korea. Result of this research may improve consistency and reliability of simulation weather data or climate change in order to take advantage of SRES and PRECIS QUMP. It is expected that these calculated test reference years will be useful to the designers of solar energy systems, as well as those who need daily solar radiation data for South Korea. Also, those results may contribute zero carbon and design of sustainable architecture establishing future typical weather data that should be gone ahead to energy efficient building design using renewable energy systems.

• New & Renewable Energy
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• v.16 no.1
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• pp.41-46
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• 2020

The share of agrophotovoltaics in the "renewable energy 3020", which is the Korean government policy for revitalizing new and renewable energy, is increasing gradually. In this study, the distribution of solar radiation received by crops growing on virtual farmland under a range of conditions, such as module height, module angle, shading ratio, and module type, was quantified and analyzed using an Ecotect program, which allows insolation analysis during the period from spring to fall. As the module angle increases, transmissive modules increase the amount of solar radiation delivered to the lower farmland. In addition, the difference between 3x12 Cell Type and 4x9 Cells Type, which are types of photovoltaic modules used in practice, was found to be small. The analysis results can be used as a design standard for the future establishment of agrophotovoltaic systems.

• Journal of Power Electronics
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• v.14 no.2
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• pp.324-340
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• 2014

Recent developments in power electronics technology have spurred interest in the use of renewable energy sources as distributed generation (DG) generators. The key component in DG generators is a grid-connected inverter that serves as an effective interface between the renewable energy source and the utility grid. The multifunctional inverter (MFI) is special type of grid-connected inverter that has elicited much attention in recent years. MFIs not only generate power for DGs but also provide increased functionality through improved power quality and voltage and reactive power support; thus, the capability of the auxiliary service for the utility grid is improved. This paper presents a comprehensive review of the various MFI system configurations for single-phase (two-wire) and three-phase (three- or four-wire) systems and control strategies for the compensation of different power quality problems. The advances in practical applications and recent research on MFIs are presented through a review of nearly 200 papers.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.10
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• pp.1321-1327
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• 2014

Faulted section identification is one of the most important function in distribution automation systems. Conventional over current detection based fault indicators frequently mal-operate due to the reverse fault current from the renewable energy resources. This paper present a new faulted section identification method based on the fuzzy decision making technique. In order to establish feasibility of the proposed method, case studies using Matlab Simulink has been performed.