• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.184-185
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• 2013

In this paper, design of a variable inductor using MR Fluid Gap is proposed for wide load range efficiency improvement of a bidirectional DC-DC converter. As compared to conventional constant value inductor designed to have negative current for ZVS at heavy load but suffers high losses at light load due to its small inductance, the proposed variable inductor not only have small inductance at high current for ZVS but also it has large inductance at low current to decrease light load losses.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1318-1320
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• 2000

In this paper, DC/DC converter has been composed of a capacitor which has not only a source division function but a resonant function instead of a previous source division capacitor. In addition to the proposed circuit is introduced a soft switching technique (ZVS). The proposed paper certified that theoretical waveforms are equal to experiment waveforms of power, output voltage, voltage ripple etc. and to be possible to control using division ratio.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.194-196
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• 2005

본 논문에서는 소프트 스위칭 회로 기술을 도입한 고주파 링크 DC-DC 컨버터로서 먼저 기존의 1 차측 위상 천이 PWM DC-DC 컨버터의 문제점을 지적하고 해결책으로 제안한 2차측 위상 천이 PWM DC-DC 컨버터를 조합하여 방전등 구동용 직류 전원장치를 개발하고자한다. 개발하고자 하는 방전등 구동용 직류 전원장치는 시뮬레이션과 실험을 통하여 그 타당성을 서술하고자 한다.

• ETRI Journal
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• v.35 no.4
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• pp.603-609
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• 2013

In this paper, we present a 600-V reverse conducting insulated gate bipolar transistor (RC-IGBT) for soft and hard switching applications, such as general purpose inverters. The newly developed RC-IGBT uses the deep reactive-ion etching trench technology without the thin wafer process technology. Therefore, a freewheeling diode (FWD) is monolithically integrated in an IGBT chip. The proposed RC-IGBT operates as an IGBT in forward conducting mode and as an FWD in reverse conducting mode. Also, to avoid the destructive failure of the gate oxide under the surge current and abnormal conditions, a protective Zener diode is successfully integrated in the gate electrode without compromising the operation performance of the IGBT.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.2
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• pp.31-37
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• 2001

This paper propose ZVS-HB type resonant DC/DC converter have earth different output characteristics using division ratio, not only a source division function but a resonant function and soft switching technique(ZVS, ZCS) instead of conventional source division capacitor. Circuit analysis generally described using normalized parameters most of characteristics with division ratio of source division capacitor. Also, this paper citified a rightfulness of characteristic analysis in comparison with a theoretical values and a experimental values obtain from experiment using Power-MOSFET.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.383-386
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• 2005

In this paper, proposed new partial resonance ZCS PWM controlled High frequency insulated Full-bridge DC-DC converter not using exciting current of high frequency transformer. It is compared with the existing principles in characteristics. It also realizes a widely stabilized ZVS operating using new ON-OFF control method at synchronized power rectification MOSFET of high frequency insulated transformer secondary. Besides, it is brought over 97[%] measurement efficiency by proposed DC-DC converter.

• Journal of Power Electronics
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• v.2 no.4
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• pp.312-324
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• 2002

This paper presents a new PWM DC/DC converter with dual output power using single power stage, which has the isolation characteristics between each dual output. The proposed converter topology consists of two switches ($S_B$ and $S_F$) and only single secondary winding. Therefore, the proposed converter has better advantages of not only low cost and small size but also high power density because of using minimum components and devices compared with conventional methods which use multi winding transformers or several converters. The operating principle of the proposed converter topology, which includes the conventional auxiliary ZVT (Zero-Voltage-Transition) circuit to implement soft switching of the main switch, is illustrated in detail and the validity of the proposed converter is verified through several simulated and experimental results.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.3
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• pp.291-299
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• 2000

형광등의 수명은 형광등 안정기의 시동 시나리오와 형광등 전류의 파고율에 영향을 받는다. 본 논문에서는 특히 파고율을 주로 다루며, 파고율을 줄이기 위한 새로운 방법을 제시하고자 한다. 제안하고자 하는 방법은 펄스 주파수 변조기법(Pulse Frequency Modulation, PFM)을 이용하며, PFC(Power Factor Correction)가 만드는 50% 벨리필 전압 파형을 PFM 제어 신호로 사용한다. 본 논문에서는 제안하는 PFM 제어 기법으로 파고율을 1.7 이하로 낮출 수 있음을 모의 실험과 실험을 통해 확인하여, 제안한 기법의 타당성을 검증한다.

• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.6
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• pp.510-516
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• 2017

This paper proposes a single-stage interleaved totem-pole on-board battery charger with a simple structure and a reduced component count. Apart from achieving ZVS turn-on of all switches and ZCS turn-off of all diodes, this charger does not require an input filter due to its CCM operation and bulky electrolytic capacitors, which in turn result in a high power density. A single-stage power conversion technique is applied to the interleaved structure in order to achieve a high power density and high efficiency. A 2.5 kW prototype of the proposed charger is also built and tested to validate the proposed operation.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.174-175
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• 2017

본 논문에서는 배전압 셀을 이용한 비절연 고승압 소프트스위칭 컨버터를 제안한다. 제안하는 컨버터는 동일 듀티로 기존의 하프브리지 컨버터보다 약 2.5배의 승압비를 얻을 수 있고, CCM에서도 스위칭 소자의 소프트 스위칭이 가능하다. 또한, 스위칭 소자와 수동소자의 전압정격이 출력전압의 약 1/3로 감소되어 낮은 도통손실과 스위칭손실을 갖는 스위칭 소자 선정이 가능하며 전체 수동소자 에너지량이 될 수 있다. 1kW급 실험을 통해 동작을 확인하였다.