• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.256-260
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• 1997

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 soft switching forward converter is proposed. The proposed converter is constructed by using non-dissipative snubbers in parallel with the main switch and output diode of the conventional forward converter. Due to the use of the non-dissipative snubbers in the primary and secondary, the proposed converter achieves zero-voltage and zero-current switching for all switching devices without switching losses and output diode recovery losses. The complete operating principles, theoritical analysis, experimental results will be presented.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.137-140
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• 2000

This paper proposes an improved soft switching two-transistor forward converter which uses a novel lossless snubber circuit to effectively control the turn-off dv/dt rate of the main transistors. In the proposed soft switching implementation the turn-off voltage traces across the main two transistors are almost the same contributing to reduce the total capacitive turn-on loss and the snubber current is divided into the two transistors resulting in distributed thermal stresses

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.150-154
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• 2000

This paper proposes PFC boost converter with soft switching for harmonics decrement and analyzes characteristics of PFC boost converter. In this technique power factor correction(PFC) is usually obtained by operating the PFC stage in the discontinuous current mode(DCM) Switching devices are operated for reducing current stress and electronical noise. As a result eliminate 3rd harmonic component and high power factor(PF) of the input line are verified by characteristics analysis and experimental results.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.907_908
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• 2009

현재 학계에서는 Soft Switching 방식에 대한 다양한 토폴로지 연구가 활발히 이루어지고 있다. 본 논문에서는 Soft Switching을 이용한 새로운 절연형 DC/DC 컨버터 토폴로지를 제안하였다. 제안된 토폴로지는 입력전압의 거의 모든 영역에 대하여 97% 이상의 효율을 가짐을 검증하였다.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.989_990
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• 2009

최근 신재생에너지원의 사용 및 전기자동차의 이용이 확대되고 있는 실정에서 고승압의 전력변환기의 관심이 높아지고 있다. 이에 본 논문에서는 입출력 절연을 통하여 안전성 향상 및 고승압이 가능하며, 효율이 우수한 Push-Pull 절연형 DC/DC 컨버터를 제안한다. 제안된 컨버터는 출력단에 콘덴서를 이용한 배압 회로를 사용하여 고승압을 실현 하였으며, Soft Switching 방식을 적용하여 고효율화가 가능함을 검증 하였다.

• Bulletin of the Korean Space Science Society
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• 2004.04a
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• pp.85-85
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• 2004

다목적 실용위성(KOMPSAT) 시리즈는 전력버스가 위성의 배터리와 직접 연결되어 있어 버스전압이 배터리와 동일하며, 전력조절기(Power Regulator)의 스위칭 듀티 값이 위성 탑재 소프트웨어에 의해 제어되는 소프트웨어 제어방식의 비조절형 버스 시스템 (Unregulated Bus System)을 사용한다. 본 논문에서는 이와 같은 소프트웨어 제어방식 비조절형 버스시스템을 채택하는 위성의 전력조절기 모듈화에 적용 가능한 새로운 전원단 회로를 제안하며 제안된 전원단의 모드별 동작 특성을 해석하고 시뮬레이션 결과와 비교, 검토한다. (중략)

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1002-1004
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• 2001

In conventional zero-current-switching(ZCS) PWM converters, the switching loss, stress and noise can't be minimized because they adopt auxiliary switches operated in hard-switching. In this paper, new ZCS-PWM converters of which auxiliary switches always operate with soft-switching are proposed. Therefore, the proposed ZCS-PWM converters are most suitable for systems requiring high-power density. The characteristics of these converters are verified by experimental results.

• 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.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.401-404
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• 1998

This paper proposes a new soft switching single stage AC/DC full bridge converter with unit power factor and isolated output. This circuit shows that it is possible to combine the boost converter which is for PFC(Power Factor Correction) and full bridge converter which is for DC/DC converter. A simple auxiliary circuit which includes neither lossy components nor active switches eliminates ringing of secondary side of the transformer. The characteristics of the proposed circuit are investigated and the validity is verified by the simulation results.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.477-478
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• 2010

In this paper, soft switching boost converter with ZVT(Zero Voltage Transition) method was proposed. Each switch of the proposed ZVT converter is operated under soft switching condition through using auxiliary resonant circuit. Also, the ZVT converter is verified through operation modes analysis and simulation.