• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1214-1216
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• 2004

Conventional Switched Mode Power Supplies(SMPS) with diode-capacitor rectifier have distorted input current waveform with high harmonic contents. Typically, these SMPS have a power factor lower than 0,65. To improve with this problem the power factor correction(PFC) circuit of power supplies has to be introduced. PFC circuit have tendency to be applied in new power supply designs. The input active power factor correction circuits can be implemented using either the two-stage or the single-stage approach. In this paper, the comparative analysis of power factor correction circuit using feedforward control with average current mode single-stage flyback method converter and two-stage converter which is combination of boost and flyback converter. The two prototypes of 50W were designed and tested a laboratory experimental. Also, the comparative analysis is confirmed by simulation and experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 F
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• pp.2562-2564
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• 1999

We have development the electronic ballast for metal halide discharge (MHD) lamp. The ballast consists of the boost pre-converter for power factor correction (PFC), a flyback a converter, half-bridge inverter and ignitor. To reject acoustic resonance phenomena, we have designed electronic ballast driving with the low frequency square wave. As results of this study, the ballast had not flicker phenomena and promoted corrected the factor (PF) highly

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 V
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• pp.2939-2942
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• 2003

A new contactless Li-ion battery charging system was proposed. The conventional methods for charging Li-ion battery have some weak points. For example, there can be a contact failure, a poor waterproof, and a difficulty to standardize the battery charging systems. The new proposed system can overcome these weak points. The new charging system is composed of power transfer part and data transfer part. This paper focuses on the power transfer part for contactless battery charging. The power stage is mainly composed of PPRC(Push-pull Parallel Resonant Converter) and flyback converter. The new method of chaging Li-ion battery was proposed and PPRC + flyback-boost topology was analyzed. The proposed toplogy was tested under the constant voltage control and the constant current control which are adequate for charging Li-ion battery.

• Journal of Power Electronics
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• 제8권1호
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• pp.51-59
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• 2008

This paper addresses several issues concerning the analysis, design, modeling, simulation and development of single-phase, single-switch, power factor corrected AC-DC high frequency switching converter topologies with transformer isolation. A detailed analysis and design is presented for single-switch topologies, namely forward buck, flyback, Cuk, Sepic and Zeta buck-boost converters, with high frequency isolation for discontinuous conduction modes (DCM) of operation. With an awareness of modem design trends towards improved performance, these switching converters are designed for low power rating and low output voltage, typically 20.25W with 13.5V in DCM operation. Laboratory prototypes of the proposed single-switch converters in DCM operation are developed and test results are presented to validate the proposed design and developed model of the system.

• Journal of Power Electronics
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• 제13권2호
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• pp.256-263
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• 2013

This paper presents an IHQRR (Integrated High Quality Rectifier Regulator) BIFRED (Boost Integrated Flyback Rectifier Energy Storage DC-DC) converter fed BLDC (Brushless DC) motor drive. A reduced sensor topology is derived by utilizing a BIFRED converter to operate in a dual DCM (Discontinuous Conduction Mode) thus utilizing a voltage follower approach for the PFC (Power Factor Correction) and voltage control. A new approach for speed control is proposed using a single voltage sensor. The speed of the BLDC motor drive is controlled by varying the DC link voltage of the front end converter. Moreover, fundamental frequency switching of the VSI's (Voltage Source Inverter) switches is used for the electronic commutation of the BLDC motor which reduces the switching losses in the VSI. The proposed drive is designed for a wide range of speed control with an improved power quality at the AC mains which falls within the recommended limits imposed by international power quality standards such as IEC 61000-3-2.

• Journal of Electrical Engineering and Technology
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• 제10권6호
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• pp.2288-2296
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• 2015

This paper proposes a novel systematic modeling approach for an integrated single-stage power converter in order to predict its dynamic characteristics. The basic strategy of the proposed modeling is substituting the internal converters with an equivalent current source, and then deriving the dynamic equations under a standalone operation using the state-space averaging technique. The proposed approach provides an intuitive modeling solution and simplified mathematical process with accurate dynamic prediction. The simulation and experimental results by using an integrated boost-flyback converter prototype provide verification consistent with theoretical expectations.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2015년도 전력전자학술대회 논문집
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• pp.183-184
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• 2015

본 논문에서는 차지펌프를 적용한 부스트 플라이백 컨버터를 사용하여 연속 모드로 동작하는 전하 균등화 방법을 제안한다. 이 컨버터는 전압균형 상태일 때 부스트만 동작하므로 높은 효율을 가지며 전압불균형 상태일 때 플라이백이 동작하여 전압을 균등화시키는 특징을 지닌다. 이 때 차지 펌프를 적용한 플라이백을 사용하기 때문에 도통율에 따른 전압의 이득이 부스트와 동일하므로, 부스트 입출력 전압 변화에 자동으로 대응하며 가격과 효율 측면에서 우수하다. 제안된 회로의 동작 원리를 설명하고 400W급 하드웨어로 설계를 하여 검증하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2015년도 전력전자학술대회 논문집
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• pp.153-154
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• 2015

본 논문에서는 보조 스너버 회로가 없는 고효율의 1단 부스트-플라이백 역률개선 컨버터를 제안한다. 제안된 컨버터는 높은 역률을 위한 부스트 역률개선 셀과 전기적 절연을 위한 플라이백 DC-DC 모듈로 구성된다. 입력전력의 일부분은 출력단으로 직접 전달되기 때문에 효율이 증가한다. 그리고 누설인덕터의 에너지가 DC링크 캐패시터에 흡수되기 때문에 별도의 스너버 회로가 필요하지 않다. 제안된 컨버터는 이론적 해석과 100[W]하드웨어 시작품을 제작하여 검증하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 추계학술대회
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• pp.24-25
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• 2010

본 논문은 저전압 대전류의 신재생 에너지원을 고전압 저전류 계통에 연계하기 위하여 필요한 고압의 직류전압으로 변환하기 위하여 기존의 포워드 플라이백 컨버터의 출력단을 직렬로 연결한 새로운 방식의 컨버터를 제안한다. 제안된 컨버터는 절연의 장점을 가지고 있고 변압기 이용률이 높으며 효율이 우수한 장점을 가지고 있다. 제안된 회로의 동작원리를 설명하고 시뮬레이션으로 확인한 후 100[W]급 하드웨어 프로토 타입을 이용하여 검증하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 추계학술대회 논문집
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• pp.85-89
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• 2003

Many single-stage PFC(power-facto.-correction) ACHC converters suffer from the high link voltage at high input voltage and light load condition. In this paper, to suppress the link voltage, a novel high power factor high efficiency PFC AC/DC converter is proposed using the single controller which generates two gate signals so that one of them is used far gate signal of the flyback DC/DC converter switch and the other is applied to the Boost PFC stage. A 130w prototype for LCD monitor adapter with universal input $(90-265V_{rms})$ and 19.5V 6.7A output is implemented to verify the operational principles and performances. The experimental results show that the maximum link voltage stress is about 450V at 270Vac input voltage. Moreover, efficiency and power factor are over $84\%$ and 0.95, respectively, under the full load condition.