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%.

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.

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.

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.

LLC 공진형 하프브릿지 컨버터의 동기정류기 구동회로에 관한 연구

안태영(Tae-Young Ahn),임범선(Bum-Sun Im) 한국조명·전기설비학회 2016 조명·전기설비학회논문지 Vol.30 No.1

In this paper, we propose a current-driven synchronous rectifier driver circuit for LLC resonant half-bridge converters. The proposed driver circuit detects a relatively low current in the primary side of the transformer although a large current is flowing in the secondary side. Due to this feature, the driver circuit has a simple circuit structure and stabilizes the switching operation with a logic-level switching voltages for the synchronous rectifier. The operation and performance of the proposed driver circuit are confirmed with a prototype of 1kW class LLC resonant half-bridge converter. The experimental results proved that the proposed synchronous rectifier driver method improves the power conversion efficiency by around 1% and reduces the internal power loss by 17W.

선천성 수직 거골에서 수술적 치료의 결과

안태영(Tae Young Ahn),강정한(Jeong Han Kang),임극필(Kuk Pil Lim),김휘택(Hui Taek Kim) 대한정형외과학회 2015 대한정형외과학회지 Vol.50 No.5

목적: 선천성 수직 거골 환자의 수술적 치료에 대한 임상 및 방사선적 결과를 분석하였다. 대상 및 방법: 9명의 환자(양측성 6명, 단측성 3명) 총 15예를 대상으로 하였다. 수술 당시 평균 연령은 10.9개월이었다. 모든 환자에서 Cincinnati 절개술 시행 후 Kumar 술식을 사용하여 단 단계 수술적 정복술을 시행하였다. 부가적으로 4명의 환자(양측성 3명, 단측성 1명) 총 7예에서 전 경골건 1/2을 거골 경부로 이전하였다. 수술 결과는 술 전, 술 후, 최종 관찰 시 체중부하 전후면 및 측면방사선 사진에서 거종골 각, 거골과 제1중족골 간의 각, 경골과 거골 간의 각, 경골과 종골 간의 각을 측정하각여 변화를 평가하였고, Laaveg-Ponseti score를 통해 환자의 만족, 기능, 통증의 정도를 평가하였다. 결과: 모든 환자에서 거골은 제위치에 정복되었고, 방사선적 계측치는 최종 추시 시 유의한 호전을 보였다. Laaveg-Ponseti score는 만족도와 기능에서 각각 16점, 통증은 24점이었다. 수술 이후 재발의 소견은 없었으며, 1예에서 전 경골건 이전 시 거골 경부에 골절이 발생하였다. 결론: 선천성 수직 거골의 단 단계 수술적 치료로 방사선적, 기능적으로 모두 만족스러운 결과를 보여주었다. Purpose: We performed clinical and radiological evaluation of surgical outcomes of congenital vertical talus. Materials and Methods: Fifteen surgically treated feet in 9 patients (6 bilateral and 3 unilateral) which were followed-up for at least 2 years were included. Mean patient age at the time of surgery was 10.9 months. The surgical technique was a one-stage correction using the Kumar technique with a Cincinnati skin incision. In 7 feet we also transferred half of the tibialis anterior to the talar neck (the Grice technique). Radiologic parameters (talo-calcaneal angle, talo-first metatarsal angle, tibio-talar angle, tibio-calcaneal angle) were analyzed pre- and postoperatively and at the last follow-up, and clinical outcomes by the Laaveg-Ponseti score. Results: Talus orientation was improved in all patients. All radiologic parameters showed statistically significant improvement by the last follow-up. The mean Laaveg-Ponseti score at the last follow-up was 16 for patient satisfaction, 16 for function, and 24 for pain. There was no recurrence, however one case of talar neck fracture occurred during the tibialis anterior transfer. Conclusion: One-stage surgical correction for congenital vertical talus at an early age provides satisfactory functional and cosmetic results.

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.

복합 인덕터를 적용한 인터리브 브릿지리스 스위칭 정류기에 관한 연구

안태영(Tae-Young Ahn) 한국조명·전기설비학회 2018 조명·전기설비학회논문지 Vol.32 No.1

A magnetic coupled inductor which can be applied on interleaved bridgeless switching rectifier was suggested, and steady-state characteristics were analyzed through periodic equivalent circuits. A 1kW class prototype was produced to verify the operational steady-state characteristics and practicality of the suggested magnetic coupled inductor applied switching rectifier and the coupled inductor itself. As a result of the experiment, the suggested interleaved bridgeless switching rectifier using magnetic coupled inductor performed 98.25% in power transition efficiency, under 0.1% in output voltage stability and 99.8% in power factor. It was confirmed that highly performing rectifier can be designed with the suggested method.

크롬 노출에 따른 숭어, Mugil cephalus의 혈액성분 변화

안태영 ( Tae Young Ahn ),정달상 ( Jeong Dal Sang ),김준환 ( Jun Hwan Kim ),강주찬 ( Ju Chan Kang ) 한국어병학회 2013 한국어병학회지 Vol.26 No.2

크롬은 여러 산업으로 배출되어 수 환경을 오염시키는 주요 중금속 중 하나이며, 특히 Cr(Ⅵ)은 수용액 내에서 주로 크롬산 이온으로 존재하며, 생체막을 쉽게 통과하여 산화 스트레스 및 생체 축적을 일으킨다. 따라서 본 연구는 숭어를 대상으로 그들의 혈액성분의 변동에 미치는 크롬의 영향을 검토하였다. RBC count 및 Ht 값은 50 ㎍/L Cr 농도에서 유의적인 감소를 나타냈으나, Hb 농도의 유의한 변동은 관찰되지 않았다. 혈청 칼슘농도는 50 ㎍/L Cr의 농도에서 유의적인 감소를 보였고, 마그네슘농도는 100 ㎍/L Cr의 농도에서 유의적인 증가를 보였다. Glucose 및 total protein 농도는 가장 높은 크롬농도인 200㎍/L Cr에서 유의적인 증가를 보였으나, 중성지방인 triglyceride 농도는 노출기간 동안 유의한 변화가 관찰되지 않았다. GOT 및 GPT 활성은 100 ㎍/L Cr 이상의 농도에서 유의적인 증가를 보였고, ALP활성은 가장 높은 크롬농도인 200 ㎍/L Cr에서 유의적인 증가를 보였다. 이상의 결과는 숭어의 혈액성상과 혈청 무기성분은 크롬 농도 50 ㎍/L 이상, 혈청유기성 분과 효소성분은 크롬농도 100 ㎍/L이상에서 변동이 나타나는 것으로 결론 내릴 수 있다. The study was carried out to investigate the changes of hematological parameters induced by waterborne exposure of chromium (Cr) in the mullet, Mugil cephalus. The mullet was exposed to sub-chronic concentrations of chromium (0, 25, 50, 100, 200 ㎍/L Cr) for 4 weeks. The major hematological findings were significant decreases in the red blood cell (RBC) count and hematocrit value in mullet exposed to ≥50 ㎍/L Cr. Although serum calcium concentration was significantly reduced at ≥50 ㎍/L Cr, magnesium concentration was found to be significantly increased at ≥100 ㎍/L Cr. The serum glucose and total protein concentrations were significantly increased at 200 ㎍/L Cr. However, serum triglyceride concentration did not show any noticeable changes in the range of 25∼200 ㎍/L Cr of chromium compared to control group during the experimental period. A significant increment of GOT (glutamic oxalate transminase) and GPT (glutamic pyruvate transminase) activities was noticed at ≥100 ㎍/L Cr. These results indicate that hematological and serum biochemical changes in the mullet by waterborne exposure to chromium are affected at more than 50 ㎍/L Cr.