• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.134-137
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• 2006

Tidal power can use conventional technology to extract energy from the tides. It is usually best deployed in areas where there i s a high tical range which includes Western and Southern coastal areas in Korea. However, to extract tical energy, a barrage across an estuary or a bay is to be constructed that is now very hard due to severe environmental impact on local estuary. The recent technology of application of tidal stream provides a new window to extract power minimizing the adverse environmental impact Tidal stream technology which directly exploits these currents is relatively new but is presently generating considerable interest Turbine rotors can be used to extract energy from the flows. Prototype devices currently on test in the UK include the 300kW SeaFlow turbine. In this paper, the recent technology and research on ocean tical stream power are addressed

• Proceedings of the KIEE Conference
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• 1992.07a
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• pp.180-182
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• 1992

In spite of recent stagnation, the rate of electric consumption has highly grown in accordance with a high cultural livings, Also, a usage of electric energy is growing with development of multi-information society. To make the matter worse, hard work of highest order is required because distribution system are widely spread and complex. And consummers demand for the electricity of good quality and it is obstracle to be not able to train related technitian for maintenance without an interruption of electric power. It is sure the counterplan of uninterruption of electric power is very necessary. In this paper, considering the working circumstances, we presented the necessity of work method, the effects and the future prospect for uninterruption power supply.

• Journal of Power Electronics
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• v.11 no.4
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• pp.551-560
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• 2011

This paper proposes a grid-tied power conditioning system for the fuel cell power generation, which consists of a 2-stage DC-DC converter and a 3-phase PWM inverter. The 2-stage DC-DC converter boosts the fuel cell stack voltage of 26-48V up to 400V, using a hard-switching boost converter and a high-frequency unregulated LLC resonant converter. The operation of the proposed power conditioning system was verified through simulations with PSCAD/EMTDC software. Based on the simulation results, a laboratory experimental set-up was built with a 1.2kW PEM fuel-cell stack to verify the feasibility of hardware implementation. The developed power conditioning system shows a high efficiency of 91%, which is a very positive result for the commercialization.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.598-599
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• 2007

The electricity supply industry for which high stability and quality of power are the primary aim of power company and the first order of business target. As the facilities of generations, transmissions and substations are increased every year, power system becomes more complex and hard to control. The complexity of the power system causes harmful influence on its security and power facilities. Moreover, difficulty of predicting weather condition in these days with its complexity increases the level of uncertainty of energy demand. Wide area online monitoring of power system offers lots of informations and solutions which clear the causes of insecurity in power system. In this paper, we presents the development of synchrophasor data measurement and transmission system using satellite network for power system online monitoring.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1397-1400
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• 1999

The function of newly developed equipments must be verified in real power system before they put into operation. However, it is hard to test them in real power system due to the possibility of abnormal operation. In this paper, test method for new relays is developed in order to simulate their function in real power system using RTDS (Real Time Digital Simulator) and the simulation results show the capability of method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.8
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• pp.1551-1558
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• 2009

This paper proposes a new power conditioning system for the fuel cell power generation, which consists of a LLC resonant DC-DC converter and 3-phase inverter. The LLC resonant converter boosts the fuel cell voltage of 26-48V up to 400V, using the hard-switching boost converter and the high-frequency ZVS half-bridge converter. The operation of proposed power conditioning system was verified through simulations with PSCAD/EMTDC software. The feasibility of hardware implementation was verified through experimental works with a laboratory prototype, which was built with 1.2kW PEM fuel-cell stack, 1kW LLC resonant converter, and 3kW PWM inverter. The proposed system can be utilized to commercialize a real interconnection system for the fuel-cell power generation.

• Proceedings of the KIEE Conference
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• summer
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• pp.64-66
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• 2004

Due to the involvedness of power system, the analysis of power system is hard to make out. In some cases, visualized analysis results help to understand the power system effectively. In this paper, 3D graphic is used to visualize the power system, and chains of power system's changes are represented using the result of HyperSim, a real-time simulator. We represent states of each bus by changing height and colors of cylinder. The current of transmission lines and the angle of generators are represented by the size of pyramids and the drection of arrows respectively. Results of power system analysis are represented more easily and more intuitably using the visualization.

• KEPCO Journal on Electric Power and Energy
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• v.8 no.1
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• pp.1-4
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• 2022

In this study, a tensile test, one of the mechanical tests, was performed with the collected natural aging ACSR. In order to be used as basic data for predicting the replacement cycle of ACSR, the tensile strength with the normal cables was compared for cables which was caused white rust due to exposure of the hard-drawn aluminum wire surface. Among the ACSR wires collected from various regions, white rust was found on the surface of the small wire, and by checking the tensile strength of them, we would like to suggest the criteria for the ACSR replacement cycle, focusing on changes in mechanical properties.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.84-87
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• 2010

We manufacture an antifuse OTP (One-time programmable) cell for analog trimming which will be used in power management ICs. For the antifuse cell using dual program voltage of VPP (=7V) and VNN (=-5V), the thin gate oxide is broken down by applying a voltage higher than the hard break-down voltage to the terminals of the antifuse. The area of the manufactured antifuse OTP cell using $0.18{\mu}m$ BCD process is $48.01{\mu}m^2$ and is about 44.6 percent of that of an eFuse cell. The post-program resistances of the antifuse are good with the values under several kilo ohms when we measure twenty test patterns.

• Journal of Satellite, Information and Communications
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• v.6 no.2
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• pp.136-140
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• 2011

Satellites industry has been developing with the commercial and military needs. Because power system of satellites is very important to survival operation and hard to test, increasing reliability is very critical. Especially LEO small satellites are very sensitive to power system, effective stabilization control is important. Because of various need of load condition, converter design are complicated. Therefore this paper introduced general modeling of LEO small satellite converter system and analyzed stabilization control design. The performance prediction of LEO small satellites power system is typically critical. Because of verity controller and rectification value, it is hard to computation and test implementation. So, this approach has merit that will reduce cost and make more reliable system. Furthermore, it can be constraint of converter specification and controller design. This paper will examine generation a modeling of LEO small satellites power converting system, and a possible guide line to design reliable controller which optimizing power converters of LEO small satellite.