• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.533-534
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• 2012

전 세계적으로 지구 온난화 문제가 빠른 속도로 확산되고 있는 가운데 태양전지 또는 풍력발전기를 이용한 발전 시스템이 심화 되어 지구환경 문제와 에너지 문제를 해결하는 수단으로 큰 기대를 받고 있다. 본 논문에서는 Zigbee와 Bluetooth 기반의 센서 네트워크 기술을 복합 발전기 모니터링 분야에 적용하여 무선 통신 네트워크를 구성하는 것을 목표로 한다.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.683-686
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• 2001

This paper presents a novel prototype of the utility­interactive voltage source type sinewave pulse modulated power inverter using a high-frequency flyback transformer link. The proposed power conditioner circuit for the solar photovoltaic generation and small scale fuel cell has an isolation function due to the safety of the power processing system, which is more cost effective and acceptable for the small-scale distributed renewal energy conditioning and processing systems. The discontinuous current mode(DCM) of this power processing conversion circuit is applied to implement a simple circuit topology and pulse modulated control scheme. Its operation principle is described on the basis of simulation evaluations and theoretical considerations. The simulation results obtained herein prove that the proposed inverter outputs with sinusoidal waveforms and unity power factor currents are synchronized to the main voltage in utility power source grid. In this paper, the soft switching topology of high­frequency linked sinewave pulse modulation inverter is proposed and discussed.

• 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 Illuminating and Electrical Installation Engineers
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• v.27 no.11
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• pp.57-68
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• 2013

The market for distributed power generation based on renewable energy is increasing, particularly for standalone mini-grid applications in developing countries with limited energy resources. Stand-alone power systems (SAPS) are of special interest combined with renewable energy design in areas not connected to the electric grid. Traditionally, such systems have been powered by diesel engine generator sets (DEGS), but also hybrid systems with photovoltaic and/or wind energy conversion systems (WECS) are becoming quite common nowadays. Hybrid energy systems can now be used to generate energy consumed in remote areas and stand-alone microgrids. This paper describes the design, simulation and feasibility study of a hybrid energy system for a stand-alone power system. A simulated model is developed to investigate the design and performance of stand-alone hydrogen renewable energy systems. The analysis presented here is based on transient system simulation program (TRNSYS) with realistic ventilation load of a large store. Design of a hybrid energy system is site specific and depends on the resources available and the load demand.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.229-235
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• 2019

A floating photovoltaic generation system is a new concept that combines existing photovoltaic generation technology with floating technology. This is installed in the water not on conventional land and a building. The system is designed as a unit module type that can be connected to other modules according to the power generation capacity, thereby forming a large-scale power generation facility. As a renewable energy source, it is composed of a floating structure, mooring device, photovoltaic power generation facility, and underwater cable. Because this system is installed outdoors, the effect of the wind load on the structure is very large. In this study, the wind loads most affected on the floating photovoltaic generation structure were obtained by computational fluid dynamic analysis. The flow characteristics and wind loads were analyzed for a range of wind orientations and angles of inclination. The analysis showed the position and magnitude of the maximum wind load to the wind direction and the flow characteristics around the solar panel and floating system. The wind load increased with increasing angle of inclination of the panel to the ground.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_1
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• pp.1001-1010
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• 2023

To solve the problem that photovoltaic panels can not harvest electrical energy at a cloudy day and night, a floating solar thermoelectric generator (FSTEG, hereafter) is studied. The FSTEG is consisted of a dome shaped Fresnel lens to condense solar energy, a thermoelectric module connected with a heat sink to keep temperature difference, a floating system simulating a wavy ocean and an electrical circuit for energy storage. The dome shaped Fresnel lens was designed to have 29 prisms and its optical performance was evaluated outdoors under natural sunlight. Four thermoelectric modules were electrically connected and its performance was evaluated. The generated energy w as stored in a Li-ion battery by using a DC-DC step-up converter. For the application of ocean environment, the FSTEG was covered by the dome shaped Fresnel lens and sealed to float in a water-filled reservoir. The harvested energy shows a potential and a method that the FSTEG is suitable for the energy generation in the ocean environment.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.109-112
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• 2004

Photovoltaic energy and wind energy are very in constant depending on the season, time and extremely intermittent energy sources. Because of these reasons, in view of the reliability the solar and the wind generation system have many problems(energy conversion, energy storage, load control etc.) comparing with a conventional power plant. So, in order to solve these existing problems, hybrid generation system of photovoltaic(500W) and wind power(400W), which combines wind power energy and solar energy to have effect of supporting each other, was suggested. But hybrid generation system cannot always generate stable output with weather condition, the auxiliary power compensation apparatus that uses elastic energy of spiral spring to hybrid generation system was also added for the present study. And it may confirm that power was continuously provided to load by storing energy obtained from generating rotary energy of spiral spring generates in small scale generator.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.6
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• pp.753-758
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• 2006

We present the development of the digital fuzzy controller for maximum power regulation. A hybrid system that comprises wind and photovoltaic generation subsystems, and battery bank is developed in this paper. We use Takaki-Sugeno (T-S) fuzzy model to deal with the power regulation problem, since each power generator has complex nonlinear terms. The problem for regulation control can be simplified into a stabilization one. Also, in order to utilize the advanced digital device, we perform the intelligent digital redesign method. Finally, the performance of the proposed controller is extensively assessed through computer simulation.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.51 no.4
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• pp.169-174
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• 2002

The developments of the solar and the wind power energy are neccessary since the future alternative energies that have no pollution and no limitation are restricted. Currently power generation system of existing problems, combined generation system of photovoltaic(400W) and wind power generation system(400W) was suggested. It combines wind power and solar energy to have the supporting effect from each other. However, weather condition, power compensation device that uses elastic energy of spiral spring to combined generation system was also added for the present study. In an experiment, when output of system gets lower than 12V(charging voltage), power was continuously supplied to load through the inverter by charging energy obtained from generating rotary energy of spiral spring operates in small scale generator.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.12
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• pp.2190-2195
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• 2011

Due to enhanced demands on quality, security and reliability of the electric power energy system, a microgrid has become a subject of special interest. In this paper, output characteristics of energy storage system (ESS) with an electric double layer capacitor (EDLC) and battery energy storage system (BESS) of a renewable energy based microgrid were analyzed under grid-connected and islanded operation modes. The microgrid which consists of photovoltaic and wind power turbine generators, diesel generator, ESS with an EDLC, BESS and loads was modeled using real time digital simulator. The results present the effective control patterns of the microgrid system.