Watkins-Johnson 공진형 DC-DC 컨버터의 정상상태 해석과 최적설계

안태영,Ahn, Tae-Young 대한전자공학회 1999 電子工學會論文誌, S Vol.s36 No.8

A new resonant switching Watkins-Johnson converter was proposed, which minimizes the switching loss and is well suited for high-frequency operation. The steady-state analyses revealed that the voltage gain of the proposed converter is solely determined by the switching frequency. Consequently, to regulate the output voltage of the converter for variable load current the switching frequency should be varied accordingly. Based on the results of analyses, an optimum design procedure for the resonant component values is proposed, which minimized the voltage stress of power switch while maintaining the desired property of zero-voltage switching. Finally, accuracy of analyses and validity of an optimum design procedure are verified on an experimental resonant switching Watkins-Johnson converter prototype. 본 논문에서는 스위칭 손실을 저감시키고, 높은 주파수 동작에 적합한 새로운 Watkins - Johnson 공진형 컨버터를 제안하였다. 정상상태 해석에서는 제안 된 공진형 컨버터의 전압이득은 스위칭 주파수에 의존하게 된다는 것을 밝혔다. 따라서 컨버터의 출력전압을 안정시키기 위해서는 부하 전류 변화에 따라 스위칭 주파수도 함께 변화시켜야한다. 또한 해석결과를 토대로, 스위치의 전압 스트레스를 최소화시키고, 영전압 스위칭되는 조건하에서 컨버터의 공진소자 값을 결정할 수 있는 최적의 설계방식을 제시하였다. 끝으로 Watkins-Johnson 공진형 컨버터의 실험회로를 구성하여 최적 설계방식의 타당성을 입증하였다.

WBG 스위치를 적용한 소용량 플라이백 컨버터의 내부손실 특성과 효율 개선에 관한 연구

안태영,유정상,Ahn, Tae Young,Yoo, Jeong Sang 한국반도체디스플레이기술학회 2020 반도체디스플레이기술학회지 Vol.19 No.4

In this paper, efficiency and loss characteristics of GaN FET were reported by applying it into the QR flyback converter. In particular, for the comparison of efficiency characteristics, QR flyback converter experimental circuits with Si FET and with GaN FET were separately produced in 12W class. As a result of the experiment, the experimental circuit of the QR flyback converter using GaN FET reached a high efficiency of 90% or more when the load power was 2W or more, and the maximum efficiency was observed to be about 92%, and the maximum loss power was about 1.1W. Meanwhile, the efficiency of the experimental circuit with Si FET increased as the input voltage increased, and the maximum efficiency was observed to be about 82% when the load power was 9W or higher, and the maximum loss power was about 2.8W. From the results, it is estimated that that in the case of the experimental circuit applying the GaN FET switch, the power conversion efficiency was improved as the switching loss and conduction loss due to on-resistance were reduced, and the internal loss due to the synchronous rectifier was minimized. Consequently, it is concluded that the GaN FET is suitable for under 20W class power supply unit as a high efficiency power switch.

액티브 스너버형 플라이백 컨버터를 적용한 60W급 초소형 어댑터에 관한 연구

안태영,Ahn, Tae-Young 한국전기전자학회 2018 전기전자학회논문지 Vol.22 No.3

본 논문에서는 액티브 스너버형 플라이백 컨버터를 60W급 어댑터에 적용하고 시험 회로를 제작하여 그 시험 결과를 보고하였다. 특히 어댑터의 시험 회로는 입력전압이 110V와 220V 겸용으로 설계하였으며 출력전압은 노트북 컴퓨터 등에서 가장 많이 사용되는 19V 60W급으로 설계하였다. 시험용 60W급 어댑터의 체적은 약 $50cm^3$, 전력밀도는 약 $1.22W/cm^3$로 설계하여 사이즈를 최소화 시켜서 휴대성을 확인 하였다. 시험 회로는 입력전압 변화에 대해 최대부하 60W에서는 최대 90.88%의 고효율을 나타내었다. 입력전압 220V에서 효율은 60W 출력에서 최대 91.04%이었다. 또한 부하 전력에 대한 출력전압 안정도는 약 0.07%이내로 관측되었다. In this paper, an active snubber type flyback converter was applied to a 60W class adapter and its test results are reported by producing a prototype. Especially, the prototype of the adapter was designed for both input voltage of 110V and 220V. The output voltage was designed for 60W with 19V class which is the most commonly used in laptops. The prototype was designed to a volume of about $50cm^3$ and a power density of about $1.22W/cm^3$ to minimize the size and verify portability. The maximum efficiency of the prototype was 90.88% at its maximum load of 60W against input voltage change and 91.04% was observed at 60W under input voltage of 220V. Furthermore, the stability of the output voltage against load power was observed to be within about 0.07%.

대호 저수지의 세균분포에 미치는 환경요인

안태영,곽노태,고유석 ( Tae Young Ahn,No Tae Kwak,You Seak Go ) 한국환경생물학회 1992 환경생물 : 환경생물학회지 Vol.10 No.2

From April 1990 to March 1991, nineteen variables of physico-chemical factors, bacteria and activity were investigated 12 times at the 3 stations in Lake Daeho and the influence of environmental factors on the distribution of bacteria and activity were analysed through stepwise multiple regression. The results of multiple regression were as follows. At station 1, the variation of bacterial populations and activity was controlled by that of available nitrogen, ammonia and nitrate. At station 2, water temperature and BOD were shown as the major factors affecting the variation of microbial populations. The variation of heterotrophic bacteria and spore forming bacteria could be controlled by the variation of BOD and water temperature could explain the variation of proteolytic and lipolytic bacteria. The variation of total coliform bacteria depended on the variation of pH and nitrate by 68%. Fifty five percent of the variation of glucose turn-over rate was affected by phospate and salinity. At station 3, dissolved oxygen was found out as a main factor governing the variation of bacterial populations. The variations of heterotropic, proteolytic and lipolytic bacteria depended on dissolved oxygen by 32%, 32%, 58% and 59% repectively. Lipolytic bacteria was affected by water temperature as same as at station 2. And glucose turnover rate had a close relation to chlorophyll a.

역률개선용 스위칭 정류기의 데이터 수집과 저장에 관한 연구

안태영(Tae-Young Ahn),임범선(Bum-Sun Im) 한국조명·전기설비학회 2016 조명·전기설비학회논문지 Vol.30 No.2

In this paper, a prototype of power supply with a power factor correction is proposed. As a unique feature the proposed power supply, a status monitoring circuit is embedded on the switching power supply. The status monitoring circuit analyzes the functionality of the system and saves the key components of the power supply in the case of malfunctions. The results of various fault tests are reported to verify the operation and performance of the proposed method. This paper discusses the experimental results of the monitoring module and provides the technical information to monitor, predict, and troubleshoot the system against the potential failure of power supplies for real applications.

6배압 정류기를 이용한 고전압 전원장치에 관한 연구

안태영(Tae-Young Ahn),길용만(Yongl-Man Gil) 한국조명·전기설비학회 2015 조명·전기설비학회논문지 Vol.29 No.2

This paper presents design, fabrication, and performance evaluation of a high voltage power supply for Carbon Nano Tube-based planar light sources. The proposed power supply employs an LLC resonant half-bridge converter and a sixfold voltage-multiplying rectifier. Steady-state characteristics of the voltage-multiplying rectifier are analyzed and used to derive the input-to-output voltage conversion ratio of the power supply. The input-to-output frequency response characteristics of the LLC tank circuit are analyzed and utilized in designing a proto-type power supply which produces a 15 KV output using a 400 V input source. The high-voltage transformer is fabricated using a sectional bobbin structure with an epoxy impregnation, in order to provide sufficient insulation for high voltage operations. The performance of the proposed power supply is confirmed with stable and reliable operations at the 15 KV output from no load to nominal load conditions. The proposed power supply is well suited as an electric ballast required stable operations of Carbon Nano Tube-based planar light sources.

불연속 변형해석에서의 새로운 선-선 접촉 해석 적용

안태영(Tae-Young Ahn),이정인(Chung-In Lee),문영삼(Young-Sam Moon),최용근(Yong-Keun Choi) 한국암반공학회 2005 터널과지하공간 Vol.15 No.4

불연속 변형해석은 에너지 최소화원리를 이용하여 전체 행렬을 구성하는 유한요소법과 개별블록의 대변 위를 모사할 수 있는 개별요소법의 장점을 모두 가지고 있는 해석법이다. 이 연구에서는 불연속 변형해석에서 해석결과에 문제점이 있는 접촉문제를 개선하는 시도로써 불연속 변형해석에서 정의하는 접촉 중 선-선 접촉을 해석하는 새로운 기법을 적용하였다. 이를 위해 접촉쌍의 개념을 이용하여 새로운 7 가지의 선-선 접촉의 상태를 정의하고 이에 따른 새로운 전단거동 결정 방법과 개폐수렴반복해석에서의 수렴조건, 접촉찾기 등의 세부알고리듬을 제시하였다. 또한 블록간의 접촉에 의해 작용하는 마찰력을 기존의 점하중 형태에서 선하중의 형태로 개선하는 식을 유도하여 새 알고리듬에 적용하였다. DDA (Discontinuous Deformation Anlaysis) is one of the latest numerical analysis which has merits of both FEM and DEM. In this research, a new edge-to-edge contact algorithm was applied on DDA. With adoption of new edge-to-edge contact state definition, sub-algorithm was improved about open-close iteration, contact state judge, contact detecting, and friction forces acting on joints. Newly applied DDA was verified based on two different cases. The DDA results show good agreement with numerically predicted one.

새로운 플라스틱 자성 코어를 가진 변압기를 이용한 AC/DC Adaptor

安泰榮(Ahn Tae Young) 대한전기학회 2002 전기학회논문지 B Vol.51 No.7

사례를 통해 본 대규모 지하공간의 방재대책에 관한 연구

안태영(Ahn, Tae-Young),성준식(Sung, June-Shik) 한국화재소방학회 2010 한국화재소방학회 학술대회 논문집 Vol.2010 No.춘계

대규모 지하공간은 지상공간에 비하여 화재취약요소가 많으며, 재해 발생 시 폐쇄적인 공간 특성으로 인하여 중대재해로 이어져 막대한 인명피해 및 재산손실을 가져올 수 있다. 본 연구는 대규모 지하공간의 방재 특성 분석 및 일본 "샤레오" 방재계획과 국내 C Mall의 방재계획 사례 연구를 통하여 지하공간의 화재 안전상 고려되어야 할 대책들에 대하여 고찰하였다.

배전류 정류회로를 이용한 능동클램프형 포워드 컨버터의 특성해석

安泰榮(Tae-Young Ahn),魚性濬(Sung-Jun Eur),崔載昊(Jae-Ho Choi) 대한전기학회 1998 전기학회논문지 Vol.47 No.7