• 한국건축시공학회지
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• 제13권6호
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• pp.579-584
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• 2013

유사시 군 지휘시설에서는 시설 외부로부터의 수자원 및 에너지자원 공급이 차단 혹은 제한된다. 따라서 방호시설 내부에는 작전기간 중 필요한 충분한 양의 수자원 및 에너지자원을 확보하고 있어야 한다. 하지만, 전쟁양상의 변화는 시설내부에서 최소 2주 이상의 작전지속성을 요구하고 있다. 이러한 요구로 인하여 유사시에도 시설 외부로부터 내부로의 수자원 및 에너지자원 공급이 불가피하게 되었다. 이에 본 연구에서는 유전체 자체의 EMP 차폐 성능에 착안하여, 작전지속성 보장을 위한 충분한 급수/급유가 가능한 도파관 설치를 위하여 도파관 직경 및 유전체 종류에 따른 EMP 방호성능을 실험적으로 분석하였다. 실험을 통해 다중 도파관을 통해 효과적인 EMP 차폐와 동시에 군 지휘시설 내부로의 안정적인 급수/급유가 가능함을 확인할 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.1114-1116
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• 2002

The characteristics of voltage drop and THD for parallel operating 11 PCRs (Phase Controlled Rectifiers) are analysed. The PCRs are used to drive high current (1.6 kA ${\sim}$ 3.7 kADC) electromagnetic coils for electromagnets. All the PCRs operate simultaneously in pulsed mode, and the pulse shot occurs every 150 seconds. During the pulse operation the PCR output current ramps up for 4 seconds, and then keeps flat top state for 2 seconds, and finally ramps down for 4 seconds. For the flat top mode a severe voltage drop and distortion appear in the power system because transformers for the PCRs are designed considering pulsed mode operation. It is expected that the analysis method can be applied to improve the system performance including power factor and design of high power pulsed mode operating power supply systems.

• Journal of Power Electronics
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• 제16권4호
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• pp.1316-1323
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• 2016

Multilevel inverters (MLIs) have been preferred over conventional two-level inverters due to their inherent properties such as reduced harmonic distortion, lower electromagnetic interference, minimal common mode voltage, ability to synthesize medium/high voltage from low voltage sources, etc. On the other hand, they suffer from an increased number of switching devices, complex gate pulse generation, etc. This paper develops an ingenious symmetrical MLI topology, which consumes lesser component count. The proposed level dependent sources concoction multilevel inverter (LDSCMLI) is basically a multilevel dc link MLI (MLDCMLI), which first synthesizes a stepped dc link voltage using a sources concoction module and then realizes the ac waveform through a conventional H-bridge. Seven level and eleven level versions of the proposed topology are simulated in MATLAB r2010b and prototypes are constructed to validate the performance. The proposed topology requires lesser components compared to recent component reduced MLI topologies and the classical topologies. In addition, it requires fewer carrier signals and gate driver circuits.

• 한국전기전자재료학회논문지
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• 제17권1호
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• pp.101-106
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• 2004

The phenomenon of PD(Partial Discharge) is accompanied by electromagnetic wave which can be detected by UHF(Ultra High Frequency) antenna. The signals obtaining from UHF antenna are very high rapid pulse and have wide band frequency responses. The distribution of PRPD(Phase Resolved Partial Discharge) which consisted of those pulse train can show distinct characteristics of PD sources. But it is not sufficient to discriminate among PD sources. This paper suggests that the stochastic parameters formed by preprocessing of STFT(Short Time Fourier Transform) are good tools for differentiate from PD sources. The stochastic parameters are CC(Cross Correlation) mean value, CC standard deviation, CC skewness, CC kurtosis.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권4호
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• pp.174-180
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• 2005

Linear pulse motor (LPM) has the vibration during the operation because of magnetic characteristic which is caused by the mechanical configuration and the electromagnetic property. This paper proposes the calculation of thrust on the base of magnetic equivalent circuit for the purpose of the vibration minimization of LPM. The permeance of LPM is calculated and simulated from the construction tooth. The thrust is compared with the analytical method, the 3D finite element method (FEM) and the experimental values. The vibration of LPM is measured and estimated to select the input current wave for an optimal operation condition.

• 전기학회논문지
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• 제61권7호
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• pp.1061-1068
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• 2012

In this paper, The Next Generation High Speed Railway inverter system using Hybrid Random Pulse Width Modulation (Hybrid RPWM) is proposed to reduce electromagnetic noise. To verify the validity of study, simulation results of the Next Generation High Speed Railway Inverter system using the proposed method was compared with the system using conventional method. A simulation program is developed using Matlab/Simulink. The results show that the voltage and current harmonics of the Next Generation High Speed Railway Inverter system using Hybrid RPWM significantly decrease and spread into wide band area.

• 전력전자학회논문지
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• 제26권2호
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• pp.135-140
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• 2021

This study introduces a new pulse width modulation (PWM) method to reduce common-mode voltages (CMVs) and then compares its performance with other reduced CMV-PWM (RCMV-PWM) methods. CMVs should be reduced to ensure the electromagnetic compatibility and safety of grid-connected inverters. RCMV-PWM methods attempt to synthesize voltage references without zero vectors, which cause high CMV peaks. In these methods, the peak-to-peak magnitude of CMVs can be reduced by one-third of the conventional space-vector PWM. The introduced method splits every reference vector into two vectors to avoid the use of zero vectors. The performances of the RCMV-PWM methods are analyzed in accordance with the modulation index through simulation and experiment.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 추계학술대회
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• pp.45-47
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• 2018

본 논문은 High Altitude Electromagnetic Pulse (HEMP) 응용 분야에 적용되는 리튬 이온 베터리를 이용한 커패시터 충전전원 장치에 관하여 다룬다. 기존에 제안하였던 5.4 kJ/s 고전압 커패시터 충전기를 9 kJ/s 로 용량을 늘렸고, 고전압 커패시터 충전기 후단에 공진 충전 회로를 도입하여 2단 충전 구조로 펄스 방전 시 발생할 수 있는 역전압과 reflecting pulses로 부터 커패시터 충전 전원 장치를 보호한다. 제안하는 충전기의 성능은 시뮬레이션 및 기초 부하 실험을 통해 확인되었다.

• 한국전자파학회지:전자파기술
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• 제6권4호
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• pp.11-19
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• 1995

본 논문에서는 시간영역 유한차분법(Finite Difference Time Domain : FDTD) 에 의해서 동축선로의 전달계수와 차폐효과에 대하여 해석하고 그 결과를 모멘트법과 비교하였다. 기존의 여기방법인 TE 나 TM 모드를 대신하여 반사파의 빠른 시간내의 완전흡수를 위하여 TEM 모드로 가정한 Gaussian 펄스를 인가하는 방법을 사용하였다. 또한, 동축선로의 차폐효과를 FDTD를 이용하여 계산 결과와 모멘트법을 이요하여 얻은 결괄와 매우 유사한 결과를 얻었다.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2005년도 종합학술발표회 논문집 Vol.15 No.1
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• pp.197-202
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• 2005

In this paper, we analyzed the signal distortion incorporating meander-shaped transmission line on PCB in broadband frequency range, up to 50GHz. This broadband characteristic provides reasonable analysis of digital pulse having very short rising time. Simulation results reveal suppression characteristic at multiband which is dependent on only the width of meander arm. This width of arm also can be adjusted using different permittivity because it provides different effective wave-length. It is found that the suppression characteristic shows sharpness with as a function of the number of arms. However, these characteristics shown limitation for microstrip line structure rather than for stripline structure, so we can avoid these unwanted phenomena using stripline structure.