• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.1235-1236
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• 2006

In this paper, we designed high performance, high quality and high density switch mode power supply for precision electronics, and communication equipments. For this, we used two parallel DC-DC converters, which have opposite phases, to support proper high performance and high quality power. To reduce switching losses and make high switching frequency, active-clamp and ZVS technique were employed in each converter.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1695-1696
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• 2006

In this paper, we designed high performance, high quality and high density switch mode power supply for precision electronics, and communication equipments. For this, we used two parallel DC-DC converters, which have opposite phases, to support proper high performance and high quality power. To reduce switching losses and make high switching frequency, active-clamp and ZVS technique were employed in each converter.

• Current Optics and Photonics
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• 제1권3호
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• pp.239-246
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• 2017

A compact plasmonic switching scheme, based on the phase change of a thin-film chalcogenide material ($Ge_2Sb_2Te_5$), is proposed and numerically investigated at optical-communication wavelengths. Surface plasmon polariton modal analysis is conducted for various thicknesses of dielectric and phase-change material layers, and the optimized condition is induced by finding the region of interest that shows a high extinction ratio of surface plasmon polariton modes before and after the phase transition. Full electromagnetic simulations show that multiple reflections inside the active region may conditionally increase the overall efficiency of the on/off ratio at a specific length of the active region. However, it is shown that the optimized geometrical condition, which shows generally large on/off ratio for any length of active region, can be distinguished by observing the multiple-reflection characteristic inside the active region. The proposed scheme shows an on/off switching ratio greater than 30 dB for a length of a few micrometers, which can be potentially applied to integrated active plasmonic systems.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권8호
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• pp.517-524
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• 2004

In this paper, a novel zero-voltage-switching(ZVS) resonant DC-DC converter is proposed. It is composed of two symmetrical active-clamped circuits, the converter can be achieve ZVS in each switches. Also, active clamp capacitor ratios($\alpha$) of proposed circuit can be reduce a peak stress of switching voltage for each main switch. Simulation results using Pspice 9.2 ver and $C^{++}$ characteristic analysis show a provement for the validity of theoretical analysis. The analysis of the proposed Current-Fed Push Pull type DC-DC converter is generally described by using normalized parameter, and achieved an evaluated characteristic values which is needed to design a circuit. We confirm a rightfulness theoretical analysis by comparing a theoretical values and experimental values obtained from experiment using MOSFET as switching devices.

• Journal of Power Electronics
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• 제10권4호
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• pp.388-395
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• 2010

An active boost converter for a single phase SRM using series-parallel connected capacitors is proposed in this paper. The proposed active boost converter has two diodes and one power switch with an anti-parallel diode and one additional boost capacitor. The additional boost capacitor could be series or parallel connected to the dc-link capacitor to produce proper excitation and demagnetization voltage. The proposed active boost converter can easily achieve a fast excitation and demagnetization from the capacitor connection. In this paper, series and parallel connected converters are reviewed, and the detailed operating modes as well as the voltage characteristics of the proposed converter are analyzed. The simulation and experimental results shows the effectiveness of the proposed active boost converter.

• 전자공학회논문지
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• 제50권1호
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• pp.180-184
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• 2013

이 논문에서는 (SOI) CMOS 공정을 이용한 저전력 안테나 스위치 컨트롤러 IC가 설계되었다. 제안 된 컨트롤러는 전력 수용능력과 고조파 왜곡 성능을 향상시키기 위하여 입력 신호에 따라 안테나 스위치를 구성하는 FET소자의 게이트 단자와 바디 단자에 +VDD, GND 그리고 -VDD에 해당하는 3 가지 상태의 로직 레벨을 제공한다. 또한, 입력-결합 전류제한 링 발진기와 하드웨어 효율적인 레벨 시프터를 적용함으로서 전력소모와 하드웨어 복잡도를 크게 감소시켰다. 제안 된 회로는 +2.5 V 전원을 공급받으며 송신 모드에서 135 ${\mu}A$를 소모하며 10 ${\mu}s$의 빠른 start-up 시간을 달성하였고, 전체 면적은 $1.3mm{\times}0.5mm$로 설계되었다.

• 조명전기설비학회논문지
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• 제22권12호
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• pp.36-46
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• 2008

본 논문은 대전력시험설비를 이용한 특고압 가스 절연 부하 개폐기의 대전력 시험회로의 구성과 통합형 시험 방법에 관하여 연구하였다. 대전력시험설비는 전기기기의 전기적 및 기계적인 성능을 검증하는 설비로서 단락발전기, 보호차단기, 투입스위치, 임피던스, 고압변압기, 저압변압기, 측정 및 보호시스템 등으로 구성되며, 이 시스템을 이용하여 단시간전류시험, 전류개폐용량시험, 단락투입 및 차단시험 등을 실시한다. 특고압 가스 절연 부하 개폐기의 규격으로는 국내 배전계통에 적용되는 ES(한국전력공사 표준규격) 5925-0002가 있으며, 국제 규격으로는 IEC 60265-1, 62271-1 및 IEEE C 37.74 등이 있다. 본 논문에서는 여러 규격에 각각 규정되어 있는 시험 절차, 시험회로 구성 및 시험 방법 등을 통합하여 600[MVA]급 대전력 시험설비에 적용하였다.

• 한국전자파학회논문지
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• 제21권4호
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• pp.381-391
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• 2010

본 논문에서는 상용 초고주파 MEMS 스위치를 이용하여 세 개의 주파수 대역에서 재구성 동작이 가능한 주파수 재구성 능동 배열 안테나 시스템(Reconfigurable Active Array Antenna System: RAA System)을 제안하였다. MEMS 스위치는 삽입 손실 및 선형성 특성이 우수하고 격리도가 높아 주파수 재구성 시스템 구현 시, 재구성을 위한 스위치로 인한 성능 열화가 거의 없다는 장점이 있다. 제안된 주파수 재구성 능동 배열 안테나 시스템은 간단한 구조의 임피던스 매칭 회로(Reconfigurable impedance Matching Circuit: RMC)를 갖는 주파수 재구성 증폭기(Reconfigurable Front-end Amplifier: RFA)가 집적화 되어 있으며, 안테나 방사체(Reconfigurable Antenna Element: RAE)와 재구성 제어 보드(Reconfiguration Control Board: RCB)로 구성되어 있다. 본 논문에서 제안한 RAA 시스템은 850 MHz, 1.9 GHz, 3.4 GHz의 세 개 주파수로 재구성되어 동작하며, 안테나 방사체는 $2{\times}2$ 배열을 가지고 각각의 방사체는 광대역 다이폴 형태를 갖는다. 제작된 RAA 시스템은 실험을 통하여 그 타당성을 확인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 정기총회 및 추계학술대회 논문집 학회본부
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• pp.110-113
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• 1993

The MOSFET synchronous rectification in the Active-Clamp Forward converter is presented. The Active-Clamp Forward converter has little dead time during the off time of the main switch and it is suitable for the MOSFET synchronous rectification comparing to the other Forward converter topologics. Using the MOSFET synchronous rectification on the Active-Clamp Forward converter with 3.3[V] output and 500[kHz] switching frequency, the improvement of efficiency is achieved comparing with the conventional Schottky barrier diode rectification.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 춘계학술대회 논문집 에너지변화시스템부문
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• pp.156-160
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• 2009

This paper presents the interleaved active-clamping ZVS(Zero Voltage Switching) forward converter, which is mainly composed of two active-clamping forward converters. Only two switches are required, and each one is the auxiliary switch for the other. The circuit complexity and cost are thus reduced. The leakage inductance of the transformer or an additional resonant inductance is employed to achieve ZVS during the dead times. The duty cycles are not limited to be equal and within 50%. The complementary switching and the resulted interleaved output inductor currents diminish the current ripple in output capacitors. Accordingly, the smaller output chokes and capacitors lower the converter volume and increase the power density. Detailed analysis and design of this new interleaved active-clamping forward converter are described.