• 천문학회보
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• 제38권1호
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• pp.69.2-69.2
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• 2013

The direct detection of gravitational wave has a very important meaning as a basis for verification of the theory of relativity. Several laser interferometer detectors have attempted to detect GW directly (e.g. LIGO, VIRGO), but positional accuracy of GW detector is too wide (about 10~100sq deg) to find which objects emit GW. One of the main sources of GW is gamma-ray burst which can be detected even in electromagnetic wave. Then to verify Gamma-ray burst object as a GW source, we proceed EM follow-up observation with wide field of view. A first program initiating EM follow-ups to possible transients GW events has been developed and exercised by LIGO and VIRGO community in association with several partners. Using QUEST optical data, we tested the method of cross-convolution recommended by EM follow-up community. We will describe the results of that test.

• 대한전기학회논문지
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• 제45권1호
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• pp.67-73
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• 1996

Subsynchronous resonance(SSR) causes a torsional shaft torque on the generator. Damages resulting from the uncontrolled SSR have resulted in the breakdown in the shaft and costs for replacement power. This paper is to determine the feasibility of controlling SSR by the fast modulation of series compensation capacitors. The presence of subsynchronous currents in the system was detected by a subsynchronous relay which was modeled by the transient analysis of control systems(TACS) in electromagnetic transients program (EMTP). The capacitor segments were switched by bi-directional thyristor switches. These were modeled into EMTP. The strategy to switch the capacitors were modeled as a closed loop system. The paper proves that effective control of SSR can be obtained only by the detuning of the system and the removal or blocking of subsynchronous energy from the system. (author). refs., figs., tabs.

• 대한전기학회논문지:전력기술부문A
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• 제48권12호
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• pp.1507-1513
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• 1999

This paper describes simulation and experimental results to analyze the dynamic characteristics of STATCOM, which is connected to the ac system for compensation the power factor and improving the voltage stability. The simulation and experimental results confirm that the scaled model for STATCOM can properly compesate the power factor of the load and regulate the bus voltage at the common connection point.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.871-874
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• 1998

A new transmission line parameter extraction method of iC interconnects on silicon substrate is presented. To extract the acurate parameters, the silicon substrate effects were taken into account. Since the electromagnetic fields under the silicon substrate are propagated with slow wave mode, effective dielectric constant and different ground plane with the multi-layer dielectric structures were employed for inductance and capacitance matrix determination. Then accurate signal transients simulation were performed with HSPICE by using the parameters. It was shown that the simulation resutls has an excellent agreement with TDR/TDT measurements.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전력기술부문
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• pp.120-122
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• 2001

PSCAD/EMTDC is a well-known simulation program for electromagnetic transients phenomena. This paper deals with the development of highly varying load models using PSCAD/EMTDC, and the simulation results illustrate the model's capabilities.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.417-421
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• 1991

In electromagnetic transient analysis, complex transmission system should be modelled in detail. But in large system, this full representation of power transmission system has a big burden in many sides such as computation time, modelling efforts, etc. It is very required, therefore, in electromagnetic transients studies to represent parts of a complete system in a reduced or an equivalent form. This paper develops the method from which system equivalents may be derived. The suggested method is of an essentially transient form, and allows travelling wave interaction between the equivalent and explicit transmission network to be modelled.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1822-1824
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• 1996

Damage and upset of control and communication equipment due to transient overvoltages which occur due primarily to internal switching surge and external lightning surge are an important problems in electromagnetic compatibility(EMC). In this paper, we analyzed operation characteristic of metal oxide varistor widely used low voltage AC line using the electromagnetic transients program(EMTP) and compare it with experimental results and also, we modeled combination generator producing $1.2/50{\mu}s$ open circuit voltage and $8/20{\mu}s$ short circuit current as a source which is critical in calculating operation characteristic. Simulation results showed that most of Transient energy consumes at MOV located in service entrance side than load side, and it showed similar to experimental results. Therefore, entrance side MOV should be selected more energy capacity than that of load side MOV.

• 한국철도학회논문집
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• 제19권4호
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• pp.436-444
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• 2016

철도차량용 주변압기 고압권선은 고압인통선에 유기되는 이상전압과 내부공진을 발생 시킬 수 있는 다양한 주파수 대역의 고유주파수를 가진다. 공장시험은 다양한 파형과 지속시간을 지닌 이상전압의 여자가능성을 판단하는데 한계가 있다. 본 연구는 전자계과도해석프로그램(이하 EMTP)을 이용하여 고압권선 모델을 설계하고 초기 전압분포와 전압-주파수 관계 측면에서 내부공진특성을 모의분석한다. 턴 단위의 집중매개변수는 변압기 형상정보부터 계산되며, 각 레이어 단위로 합산된 서브모델은 네트워크 모델로 결합되어 EMTP의 라이브러리를 통해 구현한다. 사례연구는 주파수 변동에 따른 레이어 단위의 전압-주파수 관계 특성과 시계열 영역에서 전압 확대 및 분포 양상을 보여준다.

• 전기전자학회논문지
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• 제23권1호
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• pp.289-294
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• 2019

현재 국내 소규모 섬들은 주로 디젤발전기를 이용하여 전력을 공급하고 있다. 그러나 디젤발전기는 부하변동에 대한 속응성이 느리기 때문에 계통을 불안정하게 할 수 있고, 화석연료 사용에 의한 탄소가스 배출로 환경문제를 야기한다. 이러한 문제를 극복하기 위하여 본 논문에서는 주전원을 디젤발전기를 통하여 전력을 공급받고 있는 추자도에 태양광발전, 풍력발전, 에너지저장장치를 도입하여 최적의 마이크로그리드를 구축하는 방안을 제안한다. 이때 각 분산형 전원의 경제적 최적용량은 HOMER(Hybrid Optimization Model for Multiple Energy Resources) 프로그램을 이용하여 산정하였고, 이를 계통의 안정성을 분석할 수 있는 PSCAD/EMTDC(Power Systems Computer Aided Design/ Electromagnetic Transients including DC) 프로그램을 활용하여 제안한 마이크로그리드의 타당성을 입증한다.

• 한국전자파학회논문지
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• 제29권8호
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• pp.583-593
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• 2018

자연 대기에서 발생하는 낙뢰는 항공기에 용융, 소손 및 아크 등의 물리적인 손상을 발생시킬 뿐만 아니라, 낙뢰의 관통 과정에서 발생하는 기체 외부의 자기장은 기체 내부의 전자장비 및 배선에 전압 및 전류 과도현상을 발생시킨다. 이러한 효과는 항공기 내부의 항공전자시스템에 유도낙뢰를 발생시켜 안전한 비행을 불가능하게 한다. 본 논문에서는 표준감항인증 요구도를 만족하는 보호회로 설계 기법과 공인인증된 시험 결과를 소개하였다.