• 반도체디스플레이기술학회지
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• 제17권3호
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• pp.21-26
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• 2018

In this paper, the switching characteristics of the active clamp type flyback converter, which is deemed suitable for the miniaturization of the external power supply for home appliance, were analyzed and the process of reducing the switching loss was explained. The active clamp type flyback converter operating in the DCM has confirmed that the surge voltage of the main switch does not occur and the turn-off / on loss of the switch do not occur in principle. Also, in the case of the switch for synchronous rectifier, it was showed that the switch current showed half-wave rectified sinusoidal characteristic, and the switching loss was reduced. The switching characteristics of the experimental results gathered from 120 W class prototype were compared with the theoretical waveform in the steady-state and it was confirmed that the power conversion efficiency of the active clamp type flyback converter was maintained high due to the reduction of the switching loss.

• Journal of Power Electronics
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• 제15권6호
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• pp.1468-1479
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• 2015

Renewable energy resources such as wind and photovoltaic power generation systems demand a high step-up DC-DC converters to convert the low voltage to commercial grid voltage. However, the high step-up converter using a transformer has limitations of high voltage stresses of switches and diodes when the transformer winding ratio increases. Accordingly, conventional studies have been applied to series-connect multioutput converters such as forward-flyback and switched-capacitor flyback to reduce the transformer winding ratio. This paper proposes new single-ended converter topologies of an isolation type and a non-isolation type to improve power efficiency, cost-effectiveness, and output ripple. The first proposal is an isolation-type charge-pump switched-capacitor flyback converter that includes an extreme-ratio isolation switched-capacitor cell with a chargepump circuit. It reduces the transformer winding number and the output ripple, and further improves power efficiency without any cost increase. The next proposal is a non-isolation charge-pump switched-capacitor-flyback tapped-inductor boost converter, which adds a charge-pump-connected flyback circuit to the conventional switched-capacitor boost converter to improve the power efficiency and to reduce the efficiency degradation from the input variation. In this paper, the operation principle of the proposed scheme is presented with the experimental results of the 100 W DC-DC converter for verification.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2005년도 춘계학술대회논문집
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• pp.467-472
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• 2005

In this paper, design and control of the novel SEPIC-Flyback converter(SF converter) is developed as a possible converter for fuel cell system. This output characteristic of SF converter is similar to Buck-Boost converter in that it can step-up or step-down the voltage. With the small signal equivalent circuit modeling of SF converter, control-to-output transfer function is obtained. SF converter couples up the inductive type converter to capacitive type converter with one transformer, which has less ripple current than its respective one does. To verify the validity of the proposed converter, 500W, 100kHz converter is designed and tested. ZVS switching and active clamping are also tested in practice.

• 전기학회논문지P
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• 제65권3호
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• pp.158-164
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• 2016

In this paper, a high frequency flyback type zero voltage soft switching PWM DC-DC converter using IGBTs is proposed. Effective applications for this power converter can be found in auxiliary power supplies of rolling stock transportation and electric vehicles. This power converter is basically composed of active power switches and a flyback high frequency transformer. In addition to these, passive lossless snubbers with power regeneration loops for energy recovery, consisting of a three winding auxiliary high frequency transformer, auxiliary capacitors and diodes are introduced to achieve zero voltage soft switching from light to full load conditions. Furthermore, this power converter has some advantages such as low cost circuit configuration, simple control scheme and high efficiency. Its operating principle is described and to determine circuit parameters, some practical design considerations are discussed. The effectiveness of the proposed power converter is evaluated and compared with the hard switching PWM DC-DC converter from an experimental point of view and the comparative electromagnetic conduction and radiation noise characteristics of both DC-DC power converter circuits are also depicted.

• 전기전자학회논문지
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• 제26권3호
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• pp.445-455
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• 2022

본 논문에서는 90W급 LED-TV용 DC-DC Flyback 컨버터에 사용되고 있는 소형화 및 권선 자동화에 적합한 사출형 평면 동판 권선 방식의 Flyback 변압기 최적화 설계에 대해서 나타낸다. 또한 본 논문에서는 수동권선방식의 기존 양산 Flyback 변압기에 비해 권선 자동화, Trans 체적 저감 및 전기적 특성 동질성 향상이 가능한 사출형 평면 동판 권선 방식의 Flyback 변압기를 제안한다. 특히 본 논문에서 제안한 사출형 평면 동판 권선 변압기는 권선 자동화를 위하여 수직형 권선 방식으로 구성한다. 본 논문 제안한 사출형 평면 동판 권선 방식의 Flyback 변압기의 1차측과 2차측 권선은 각각 기존 권선, 3중 절연 권선 및 사출형 평면 동판권선을 사용하였다. 최종적으로 Maxwell 2D 및 3D Tool을 이용한 시뮬레이션 결과를 토대로 본 논문에서 제안한 소형화 및 권선 자동화에 적합한 사출형 평면 동판 권선 방식의 Flyback 변압기 최적화 설계를 수행하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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• pp.330-334
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• 2004

A new SEPIC-Flyback converter is proposed. The proposed converter is the integration of SEPIC and Flyback converter. Not only SEPIC output but also Flyback output could be fully regulated by constant frequency PWM control. Merged SEPIC and Flyback topology can share the transformer and power MOSFET. When the switch turns on, one topology operates via capacitive energy transfer. The other topology acts as inductive energy transfer while the switch is off. So, it can increase power density per one cycle. The experimental result is presented and verified.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.314-320
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• 2001

A novel mode of parallel operation of a modular 3-phase AC-DC flyback converter for power factor correction along with tight regulation was recently analyzed and presented. The advantage of the proposed converter does not require expensive high voltage and high current devices that are normally needed in popular boost type 3-phase converter. In this paper the detailed small signal analysis of the modular 3-phase AC-DC flyback converter is provided for control purposes and also experimental results are included to confirm the validity of the analysis.

• 전력전자학회논문지
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• 제4권2호
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• pp.159-165
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• 1999

본 논문에서는 우수한 출력전압 조절 기능과 높은 역률을 갖는 3상 AC-DC flyback 컨버터를 제안한다. 제안한 컨버터의 장점은 보통 부스트 형의 3상 컨버터에서 쓰이는 가격이 비싼 고전압, 대전류의 소자를 필요로 하지 않는다. 본 논문에서는 제어 목적으로 3상 AC-DC flyback 컨버터에 대해서 소신호 해석을 하였고 실험결과는 분석의 타당성을 확증한다.

• Journal of Power Electronics
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• 제2권3호
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• pp.212-219
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• 2002

A novel mode of parallel operation of a modular 3-phase AC-DC flyback converter for power factor correction along with tight regulation was recently analyzed and presented. The advantage of the proposed converter does not require expensive high voltage and high current devices that are normally needed in popular boost type 3-phase converter. In this paper tile detailed small signal analysis of the modular 3-phase AC-DC flyback converter is provided for control purpose and also experimental results are included to confirm the validity of the analysis.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
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• pp.109-111
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• 1998

A novel mode of parallel operation of 3-phase AC-DC flyback converter for power factor correction along with tight regulation was recently analyzed and presented. The advantage of the proposed converter does not require expensive high voltage and high current devices that are normally needed in popular boost type 3-phase AC-DC flyback converter is provided for control purposes and also experimental results are included to confirm the validity of the analysis.