• 디지털콘텐츠학회 논문지
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• 제8권3호
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• pp.393-401
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• 2007

P2P systems have gained a lot of research interests and popularity over the years and have the capability to unleash and distribute awesome amounts of computing power, storage and bandwidths currently languishing - often underutilized - within corporate enterprises and every Internet connected home in the world. Since there is no central control over resources or devices and no before hand information about the resources or devices, device discovery remains a substantial problem in P2P environment. In this paper, we cover some of the current solutions to this problem and then propose our feed forward neural network (FFNN) based solution for device discovery in mobile P2P environment. We implements feed forward neural network (FFNN) trained with back propagation (BP) algorithm for device discovery and show, how large computation task can be distributed among such devices using agent technology. It also shows the possibility to use our architecture in home networking where devices have less storage capacity.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1998년도 춘계학술발표회논문집(1)
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• pp.291-296
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• 1998

The DAta management and Communication NETworks (DACONET), Which it is designed as a subsystem for Man-Machine Interface System of Korea Advanced LIquid MEtal Reactor(KALIMER MMIS) and advanced design concept is approached, is described. The DACONET has its roles of providing the real-time data transmission and communication paths between MMIS systems, providing the quality data for protection, monitoring and control of KALIMER and logging the static and dynamic behavioral data during KALIMER operation. The DACONET is characterised as the distributed real-time system architecture with high performance, Future direction, in which advanced technology is being continually applied to Man-Machine interface System Development of Nuclear Power Plants, will be considered for designing data management and communication networks of KALIMER MMIS

• Journal of Electrical Engineering and Technology
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• 제7권3호
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• pp.297-303
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• 2012

This paper presents the simulation results for the analysis of a lightning surge, switching transients and very fast transients within a thermal plant. The modeling of gas insulated substations (GIS) makes use of electrical equivalent circuits that are composed of lumped elements and distributed parameter lines. The system model also includes some generators, transformers, and low voltage circuits such as 24V DC rectifiers and control circuits. This paper shows the simulation results, via EMTP (Electro-Magnetic Transients Program), for three overvoltage types, such as transient overvoltages, switching transients, very fast transients and a lightning surge.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 전력전자학술대회
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• pp.174-176
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• 2018

도서 및 산간지역에 필요한 독립형 마이크로그리드는 디젤발전, 태양광발전 및 에너지저장장치 등으로 구성된다. 독립형 마이크로그리드내의 급격한 부하 변동, 분산형전원의 발전량 변동과 같은 문제로 인해 교류계통의 전압과 주파수가 변동한다. 특히, 독립형 마이크로그리드간에 전력을 주고받는 상황에서는 상호간의 교류전압과 주파수를 적절히 조절해야 할 필요가 있다. 본 논문에서는 독립형 마이크로그리드 간에 전력을 주고받을 시, 에너지 라우터(Energy Router)라는 기기를 이용하여 통신을 사용하지 않고 자율 분산 제어방법을 통해 계통 전압과 주파수를 제어하는 방법을 제안한다. 에너지 라우터는 AC/AC 컨버터를 사용하여 전력을 상호 간에 전달한다. 시뮬레이션 프로그램을 이용하여 부하 변동 및 분산형전원의 발전량 변동 등을 모의하고 에너지 라우터의 유효성을 검증한다.

• 전기의세계
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• 제15권5호
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• pp.32-39
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• 1966

This voltage Regulator, which regulates voltage in different way from the conventional regulator, is constructed by circular-plate core type stators and controllers (are similar to rotor of conventional). The principle of this Voltage Regulator is based on the rotating magnetic field theory including peculiar homopolar and heteropolar concept. Comparing with the conventional induction regulator, this regulator need not to have short windings and can cancel armature reaction. Moreover, it is able to decrease the machine noise and control the phase of it freely. And it's efficiency can become more than 95% which almost the same as that of transformer's. By increasing numbers of cores of the same size, the output power can be increased, the insulation can be decreased and high Voltage can directly be connected because applied voltage is distributed to each core. This Voltage Regulator can be also used as a current regulator, a starter a induction motor and a phase transformer etc.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2017년도 전력전자학술대회
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• pp.142-143
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• 2017

본 논문에서는 역방향 매트릭스 컨버터를 이용한 분산 발전시스템의 입력 전압 불평형 발생 시, 전류 왜곡 저감을 위한 제어 전략을 제안한다. 분산 발전 시스템을 위한 역방향 매트릭스 컨버터는 발전기의 전력을 계통으로 전달하기 위해 사용된다. 발전기에서 불평형 전압이 발생되는 경우, 역방향 매트릭스 컨버터의 입출력 전류에 왜곡이 발생한다. 정상분 및 역상분 전압, 전류를 이용한 제안하는 제어 전략을 통해 역방향 매트릭스 컨버터의 입출력 전류의 왜곡을 저감할 수 있다. 시뮬레이션을 통해 제안하는 제어 전략의 타당성을 검증한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 전력전자학술대회 논문집
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• pp.457-458
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• 2014

본 논문에서는 분산전원의 출력여부와 상관없이 계통연계지점의 (PCC : Point of Common Coupling) 전압제어를 위한 새로운 알고리즘을 제안한다. 또한, PCC전압이 불평형을 포함했을 때에도 분산전원이 PCC 전압유지를 위한 보상을 할 수 있음을 제안한다. 이를 구현하기 위해 분산전원은 전압유지를 위해서는 무효분 전류를, 불평형 보상을 위해서는 역상분 전류를 이용한다. PSIM 시뮬레이션을 통해 이를 증명하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2012년도 전력전자학술대회 논문집
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• pp.240-241
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• 2012

본 연구에서는 분산전원과 에너지저장으로 구성된 독립형 DC 마이크로그리드의 신뢰도를 향상시키기 위한 협조적 Droop 제어기법을 제안하고 그 성능과 동작을 분석한 내용에 대해 기술하고 있다. 제안하는 시스템의 동작 타당성을 체계적으로 분석하기 위해 PSCAD/EMTDC 소프트웨어를 이용한 시뮬레이션 모델을 개발하였으며 이를 기반으로 하드웨어 시스템을 제작하여 제안하는 시스템의 동작특성을 분석하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2015년도 전력전자학술대회 논문집
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• pp.371-372
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• 2015

Dc microgrid has the advantage of high efficiency as compared to the ac system. Droop method has been realized to suppress the current mismatching among the distributed sources. However, this method involves distribution loss due to the line impedance. In this paper, a novel droop method is proposed to minimize the distribution loss as well as the voltage deviation by adjusting the droop coefficient. The proposed droop method is verified by using the simulation based on PSCAD/EMTDC.

• Journal of Magnetics
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• 제18권3호
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• pp.268-275
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• 2013

This paper shows the characteristics of performance for interior permanent magnet machine (IPM) considering driving conditions such as maximum torque per ampere (MTPA) and flux-weakening control especially in terms of harmonic loss. In particular, based on finite element analysis (FEA), permanent magnet (PM) eddycurrent loss and the harmonic iron loss have been computed where the models have been intentionally designed to identify the effects of pole-slot combinations on the loss while maintaining the required power for electric vehicle. From the analysis results, it was shown that the rotor iron loss and PM eddy-current loss of machine employing fractional slot winding are extremely large at load condition. Furthermore, it was revealed that the harmonic iron loss at high-speed operation is mainly distributed over stator teeth and rotor surface, which may aggravate cooling system of the rotor structure in the vehicle.