• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1997년도 하계학술대회 논문집 F
• /
• pp.1989-1992
• /
• 1997

A new soft switching single stage AC-DC full bridge boost converter with unit input power factor and isolated output is presented. Due to using of the non-dissipative snubber in the primary side, a single stage high-power factor isolated full bridge boost converter has a significant reduction of switching losses in main switching devices and output rectifiers of the primary and secondary side, respectively. The non-dissipative snubber adopted in this study is consisted of a snubber capacitor C. and a snubber inductor $L_r$, a fast recovery snubber diode $D_r$, a commutation diode $D_p$. This paper presents the complete operating principles, theoretical analysis and simulation results.

• 조명전기설비학회논문지
• /
• 제29권9호
• /
• pp.81-88
• /
• 2015

LED has been great attentions in lighting industry because of its long life-time, high efficiency, excellent light output characteristics. However, the life-time of the LED driving system is decreased because of the electrolytic capacitor which is used in the power conversion system for driving LED lighting. Therefore the capacitance reduction methods have been studied to replace an electrolytic capacitor with film or tantalum capacitor. This paper presents the Single stage PFC flyback converter with the simplified third harmonic current injection circuit to reduce output capacitance and the proposed system is theoretically analyzed and verified through the experiment.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 1999년도 전력전자학술대회 논문집
• /
• pp.493-496
• /
• 1999

A new soft switching single stage AC-DC full bridge boost converter with unit input power factor and isolated output is presented in this paper. Due to the use of a non-dissipative snubber on the primary side, a single stage high-power factor isolated full bridge boost converter has a significant reduction of switching losses in the main switching devices. The non-dissipative snubber adopted in this study consists of a snubber capacitor Cr, a snubber inductor Lr, a fast recovery snubber diode Dr, and a commutation diode Dr, and a commutation diode Dp. This paper presents the complete operating principles, theoretical analysis and experimental results.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2000년도 전력전자학술대회 논문집
• /
• pp.145-149
• /
• 2000

A single-stage power factor correction AC/DC converter with a simple link voltage suppressing circuit (LVSC) for the universal line application is proposed. Using this simple circuit a low link voltage can be realized without deadbands at line zero-crossings. The proposed converter is analyzed and a prototype converter with 5C, 12V output is implemented to verify the performance. The experimental results show that the link voltage stress and efficiency are about 447V and 81%, respectively.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 1999년도 전력전자학술대회 논문집
• /
• pp.626-630
• /
• 1999

A new integrated single-stage zero current switched(ZCS) quasi-resonant converter (QRC) for the power factor correction(PFC) converter is introduced in this paper. The power factor correction can be achieved by the discontinuous conduction mode(DCM) operation of an input current. The proposed converter has the characteristics of the good power factor, low line current harmonics, and tight output regulation. Furthermore, the ringing effect due to the output capacitance of the main switch can be eliminated by use of active clamp circuit.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 1998년도 전력전자학술대회 논문집
• /
• pp.438-443
• /
• 1998

A simple single-stage AC/DC forward converter with transformer magnetic energy feedback technique for power factor correction is proposed. The operational principle of the proposed converter is presented. The proposed converter gives the good power factor correction, low line current harmonic distortions, and tight output voltage regulation. The prototype shows high power factor with low line current harmonics.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제54권12호
• /
• pp.601-608
• /
• 2005

This paper presents a novel single-stage high-power-factor electronic ballast for fluorescent lamps operating in critical conduction mode. The proposed topology is based on integration of boost converter as power factor corrector(PFC) and a half-bridge high frequency parallel resonant inverter into a single stage. The input stage of the boost converter is operating in critical conduction mode for positive and negative half cycle voltage respectively at line frequency(60Hz). So that a boost converter makes the line current follow naturally the sinusoidal line voltage waveform. The simulated and experimental results for 100W fluorescent lamps operating at 42kHz switching frequency and 220V line voltage have been obtained. This proposed inverter will be able to be practically used as a power supply in various fields as induction heating applications, fluorescent lamp and DC-DC converter etc.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
• /
• pp.611-616
• /
• 2001

This paper analyzed PFC of active clamp ZVS flyback converter by adding two methods PFC (power Factor Correction) circuit - two-stage and single-stage. The addition of active clamp circuit also provides a mechanism for achieving ZVS of both the primary and auxiliary switches. ZVS also limits the turn off di/dt of the output rectifier, reducing rectifier-switching loss and switching noise, due to diode reverse recovery. As a result, the proposed converters have characteristics of the reduced switching noise and high efficiency in comparison to conventional flyback converter. The simulation and experimental results show that the proposed converter improve the input PF of 300W ZVS flyback converter by adding single-stage, two-stage PFC circuit.

• 융합신호처리학회논문지
• /
• 제3권3호
• /
• pp.70-75
• /
• 2002

본 논문은 새로운 단일 전력단 역률보상 풀 브리지 컨버터를 제안하였다. 제안된 컨버터는 역률보상을 위하여 앞단에 2개의 인덕터, 2개의 다이오드, 2개의 자성결합 변압기를 가진 2VS 풀브리지 DC/DC 컨버터로 구성되어 있다. 이러한 구성방법에 의해 전력은 전원에서 분리되고, 안정된 직류출력전압을 얻을 수 있다. 이 토폴로지에서 주소자의 전압스트레스는 영전압스위칭에 의해서 감소되며, 또한 제안된 컨버터는 능동 역률보정 스위치와 제어 및 게이팅 보드와 같은 보조회로가 필요치 않게되어 규격과 단가를 낮출 수 있을 뿐 아니라 효율을 증가시킬 수 있다.

• Journal of Electrical Engineering and Technology
• /
• 제11권1호
• /
• pp.143-149
• /
• 2016

The two-stage converter is widely used in traditional DC/AC inverter. It has several disadvantages such as complex topology, large volume and high loss. In order to overcome these shortcomings, a novel half load-cycle worked dual SEPIC single-stage inverter, which is based on the analysis of the relationship between input and output voltages of SEPIC converters operating in the discontinuous conduction mode (DCM), is presented in this paper. The traditional single-stage inverter has remarkable advantages in small and medium power applications, but it can’t realize boost DC/AC output directly. Besides one pre-boost DC/DC converter is needed between the DC source and the traditional single-stage inverter. A novel DC/AC inverter without pre-boost DC/DC converter, which is comprised of two SEPIC converters, is studied. The output of dual SEPIC converters is connected with anti-parallel and half load-cycle control is used to realize boost and buck DC/AC output directly and work properly, whatever the DC input voltage is higher or lower than the AC output voltage. The working principle, parameter selection and the control strategy of the inverters are analyzed in this paper. Simulation and experiment results verify the feasibility of the new inverter.