http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
전압 리플을 이용해 영전류스위칭하는 두개의 트랜스포머를 가지는 위상천이 풀-브릿지 컨버터
윤현기(Hyun-Ki Yoon),문건우(Gun-Woo Moon),윤명중(Myung-Joong Youn) 전력전자학회 2005 전력전자학술대회 논문집 Vol.- No.-
This paper presents a Zero-Current Switching(ZCS) two-transformer phase-shift full-bridge(TTFB) converter using voltage ripple. The proposed converter provides Zero-Voltage Switching(ZVS) of leading leg switches and ZCS of lagging leg switches using voltage ripple. Especially, circulating current is reduced by ZCS operation and there are no additional components required for the soft switching of power switches. Furthermore, in case of light load, ZVS operation of lagging leg can be achieved. The operations, analysis and design consideration of proposed converter are presented. To verify the validity of the proposed converter, experimental results for a 410W (205V, 2A) prototype are presented.
BiFe0.65MoP0.1 촉매 상에서 1-부텐의 산화탈수소화 반응: 인 전구체의 영향
박정현 ( Jung Hyun Park ),윤현기 ( Hyun Ki Youn ),신채호 ( Chae Ho Shin ) 한국화학공학회 2015 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.53 No.6
The influence of phosphorous precursors, NH4H2PO4, (NH4)2HPO4, H3PO4, (C2H5)3PO4, and P2O5, on the catalytic performance of the BiFe0.65MoP0.1 catalysts in the oxidative dehydrogenation of 1-butene to 1,3-butadiene was studied. The catalysts were characterized by XRD, N2-sorption, ICP, SEM and TPRO analyses. It was not observed big difference on the physical properties of catalysts in accordance with used different phosphorous precursors, however, the catalytic performance was largely depended on the nature of the phosphorous precursors. Of various precursors, the BiFe0.65MoP0.1 oxide catalyst, which was prepared from a phosphoric acid precursor, showed the best catalytic performance. Conversion and yield to butadiene of the catalyst showed 79.5% and 67.7%, respectively, after 14 h on stream. The cation of phosphorous precursors was speculated to affect the lattice structure of the catalysts during catalyst preparation and this difference was influenced on the re-oxidation ability of the catalysts. Based on the results of TPRO, it was proposed that the catalytic performance could be correlated with re-oxidation ability of the catalysts.
LCD 백라이트용 트랜스포머 없는 냉음극관(CCFL) 구동 회로
최은석(Eun-Seok Choi),윤현기(Hyun-Ki Yoon),문건우(Gun-Woo Moon),윤명중(Myung-Joong Youn),강문식(Moon-Shik Kang) 전력전자학회 2006 전력전자학술대회 논문집 Vol.- No.-
The conventional cold cathode fluorescent lamp (CCFL) driver for LCD TV has a transformer for each lamp to step up the high sinusoidal waveform from the low input voltage. The transformer used in the conventional topology causes the driver to have bulky size and high cost. This paper proposes a new transformer-less CCFL driver for LCD backlight that is based on the parallel-loaded resonant inverter topology. This resonant topology enables the circuit to supply enough high voltage for CCFL without a transformer. Also, with current-balancing technique, this transformer-less inverter drives 16 CCFL lamps.
0.5보다 큰 시비율로 동작하는 전류원 하프-브릿지 컨버터의 무손실 스너버 설계
강정일(Jeong-il Kang),한상규(Sang-Kyoo Han),윤현기(Hyun-Ki Youn),김정은(Chong-Eun Kim),윤명중(Myung-Joong Youn),김윤호(Youn- Ho Kim) 전력전자학회 2002 전력전자학술대회 논문집 Vol.- No.-
전류원 컨버터는 전압원 컨버터에 비해 스위치 차단 시 발생하는 서지에 연루되는 에너지가 커, 무손실 스너버가 필수적인데, 이 스너버는 그 동작원리가 복잡하고 동작조건이 바뀜에 따라 성능의 변동이 심하여 설계가 어렵고, 적용되는 회로에 따라서도 설계식이 달라진다. 본 논문에서는 0.5 이상의 시비율로 동작하는 전류원 하프-브릿지 컨버터를 위한 무손실 스너버의 동작을 완전히 분석하고 설계사항에 대해 고찰한 뒤 실험을 통해 검증한다.