• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.4
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• pp.90-99
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• 1998

The DC/DC power converter increase switching frequency in order to achieve small size, a low noise, and light weight. However, the power switches have high power losses and switching stresses as the switching frequency is increased. Therefore in this paper, the author propose the Soft-Switching Forward-Flyback PWM DC/DC converter using assistant-circuit, based on forward-flyback operation of a high-frequency transformer. The proposed converter scheme is verified by simulation and experiment.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.409-412
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• 1998

In this paper, an improved soft switching forward dc/dc converter is proposed. The proposed converter is constructed by using non-dissipate snubbers in parallel with the main switch and output diode of the conventional forward converter. Due to use of the non-dissipative snubbers, the proposed converter achieves zero-voltage switching for all switching devices and output diodes without switching losses. The complete operating principles and experimental results will be presented.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.1
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• pp.19-25
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• 1999

To achieve high efficiency in high power and high frequency applications, reduction of switching losses and noise is very important. In this paper, an improved zero voltage switching forward dc/dc converter is proposed. The proposed converter is constructed by using energy recovery snubbers in parallel with the main switches and output diodes of the conventional forward dc/dc converter. Due to the use of the energy recovery snubbers in the primary and secondary side, the proposed converter achieves zero-voltage-switching turn-off without switching losses for switching devices and output rectification diodes. The complete operating principles and experimental results will be presented.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.140-141
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• 2010

최근 저전압 입력에 의한 대용량 DC/DC 컨버터의 수요가 급증함에 따라 대용량 DC/DC 컨버터에서도 효율 및 저가화가 매우 중요한 요소로 자리 잡고 있다. 따라서 본 연구에서는 저전압 대용량용 DC/DC 컨버터 구성에서 고효율 및 저가화를 위해 1개의 능동 스위치 소자에 의한 ZCS를 구현할 수 있는 새로운 타입의 공진형 Forward DC/DC 컨버터 구조를 제안하고, 시뮬레이션을 통해 제안된 방식의 타당성을 검증하였다.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.159-162
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• 2000

In his paper the principle of using coreless printed circuit board (PCB) based transformer in 2.3MHz, 12W class ZVS Forward DC-DC converter has been successfully demonstrated. With no core loss coreless PCB transformer and inductor are found to have favorable characteristics at high frequency operations. The maximum power conversion efficiency is 80% Even for high operating frequency an efficiency greater than 70% can be obtained with under 0.7% regulation error.

• Journal of Power Electronics
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• v.10 no.3
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• pp.245-250
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• 2010

Input-series-output-parallel (ISOP) converters consisting of multiple modular DC/DC converters can enable low voltage rating switches to be used under high voltage input applications. This paper presents a digital control strategy, which can achieve equal sharing of input voltage for a modular ISOP system consisting of two-transistor forward DC/DC converters by forcing the input voltages of neighboring modules to be equal. The proposed scheme is analyzed using small signals analysis based on the state space average method. The performance of the proposed control strategy is verified with an experimental prototype of an ISOP converter made up of three two-switch forward converters.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.9
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• pp.1341-1350
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• 2017

In this paper, a high reliability 30W DC-DC converter is designed considering military standard (MIL-STD) for military applications such as guided weapon and aircraft. The performances and specifications of conventional military grade DC-DC converter are practically analyzed. The requirements for military grade DC-DC converter are established in consideration of MIL-STD and analysis results of conventional product. Two isolated DC-DC converter, forward and fly-back converter, are designed and compared to determine topology. From experimental results under various operating conditions, the forward topology satisfied performances and specifications of MIL-STD for military DC-DC converter.

• Proceedings of the KIPE Conference
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• 2009.11a
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• pp.167-169
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• 2009

본 논문에서는 Forward DC/DC 컨버터 설계에 있어서 출력 커패시터에 따른 제어기 설계를 제안한다. 최근 DC/DC 컨버터의 소형화로 스위칭 주파수가 고주파로 됨에 따라 출력 커패시터는 전해 커패시터에서 Tantal 커패시터와 MLCC로 대체되는 추세이다. 이에 본 논문에서는 Tantal 커패시터와 MLCC의 특성을 분석하고 각각의 출력 커패시터 특성에 따른 안정적인 제어기를 설계하였으며, 시뮬레이션과 실험을 통해서 검증하였다. 본 논문에서는 50W급 Forward DC/DC 컨버터를 제작하여 스텝응답 테스트를 통해서 제시한 설계 기법이 타당함을 검증하였다.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.387-392
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• 1990

In this papers, SPICE which is widely used in analysis of general circuit and simulation in electric and electrical field is applied to DC-DC converter. Be selected Forward which is widely used as SMPS(Switched Mode Power Supply) amang DC-DC converter, and showed the aveformer, we know that the converter is operated in normal. Including the control circuit in converter, by controlling the duty ratio of switch, we know that the output voltages is staple from the transient state of convwrter. Also, comparing SPICE simulation with experiment, the validity of simulate is showed.

• Journal of Power Electronics
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• v.18 no.2
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• pp.356-363
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• 2018

The combination of a buck converter and a forward converter can be considered to accomplish a high step-down non-isolated converter. To decrease the insufficient step-down ratio of a regular buck converter and to distribute switch voltage stress, a forward-integrated buck (FIB) converter is proposed in this paper. The proposed interleaved DC-DC converter provides an additional step-down gain with the help of a forward converter. In addition to its simple structure, the transformer flux reset problem is solved and an additional magnetic core reset winding is not required. The operational principle and an analysis of the proposed FIB converter are presented and verified by experimental results obtained with a 240 W, 150 V/24 V prototype.