• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권6호
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• pp.342-348
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• 1999

A new welding machine which adopts zero voltage and zero current switching(ZVZCS) full bridge(FB) DC-DC converter is proposed. The proposed ZVZCS FB DC-DC converter uses auxiliary transformer to obtain ZCS for leading leg. It has capability of controlling load current even in short circuit condition and is suitable for arc welding machines. The power rating of the auxiliary transformer is about one 5th to one 10th of the main transformer. Experimental results for 10KW prototype are shown to verify the principle of operation.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권9호
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• pp.431-436
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• 2005

This paper studies a novel boost DC-DC converter operated high efficiency for discontinuous current mode (DCM) control. The converter worked in DCM eliminates the complicated circuit control requirement, reduces a number of components, and reduces the used reactive components size. In the general DCM converter, the switching devices are turned-on the zero current switching (ZCS), and the switching devices must be switched-off at a maximum reactor current. To achieve the zero voltage switching (ZVS) at the switching turn-off, the proposed converter is constructed by using a new loss-less snubber circuit. Soft-switched operation of the proposed boost converter is verified by digital simulation and experimental results. A new boost converter achieves the soft-switching for all switching devices without increasing their voltage and current stresses. The result is that the switching loss is very low and the efficiency of boost DC-DC converter is high.

• 한국정보기술응용학회:학술대회논문집
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• 한국정보기술응용학회 2005년도 6th 2005 International Conference on Computers, Communications and System
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• pp.119-122
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• 2005

A algorithm for control and performance of a pulse-density-modulated (PDM) series-resonant voltage source inverter developed for corona-dischange precesses is presented. The PDM inverter produces either a square-wave ac-voltage state or a zero-voltage state at its ac terminals to control the average output voltage under constant dc voltage and operating frequency. Moreover it can achieve zero-current-switching (ZCS) and zero-voltage-switching (ZVS) in all the operating condition for a reduction of switching lost. Even though the corona discharge load with a strong nonlinear characteristics, new high frequency resonant inverter is shown the wide range power control from 5% to 100%.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.953-955
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• 2001

This paper presents a new zero current switching (ZCS) inverter for grid-connected photovoltaic single phase inverter system. The auxiliaey circuit for the soft-switching consists of two resonant inductors and two resonant capacitors as well as two auxiliary switches rated at lower power. The proposed circuit provides zero current switching condition for all the switches, which reduces switching losses significantly. It is controlled to extract maximum power from the solar array and to provide sinusoidal current into the mains. The validity of the proposed system is verified by experimental results from the 1.2kW prototype inverter operating at 40kHz.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.499-502
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• 2003

This paper presents the voltage source type half bridge lossless auxiliary inductor snubber assisted series capacitor compensated resonant high frequency inverter for induction heated fixing roller in copy machines. This high-frequency inverter treated here can completely achieve zero current soft switching (ZCS) commutation for wide power regulation range under its constant frequency pulse density modulation (PDM) scheme. Its transient and steady-state operating principle is originally presented fur a constant frequency PDM control strategy under a ZCS operation commutation, together with its output effective power regulation characteristics-based on the PDM strategy. The experimental operating performances of this ZCS-PDM high frequency inverter using IGBTs are illustrated as compared with computer simulation ones. Its power losses and actual efficiency are evaluated and discussed on the basis of simulation and experimental results.

• 전력전자학회논문지
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• 제15권2호
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• pp.127-133
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• 2010

본 논문에서는 전기자동차용 리액터리스 고효율 승압형 DC/DC컨버터를 제안한다. 제안한 컨버터는 1차측 Full Bridge의 모든 스위치에서 영전류 스위칭을 적용하여 턴 온/턴 오프시 스위칭 소자에 생기는 전력 손실을 감소시키므로서 효율을 개선한다. 그리고 ZCS(Zero Current Switching)를 위한 L-C공진 회로 중 리액턴스 성분을 1, 2차 절연을 위한 고조파 변압기의 누설인덕턴스 성분으로 대체함으로서 별도의 리액터를 추가하지 않기에 시스템 사이즈 및 비용을 줄일 수 있다. 제안된 컨버터의 타당성 검증을 위하여 본 논문에서는 PSIM을 이용하여 시뮬레이션을 수행하였으며 실제 5[KW]급 DC/DC컨버터를 제작하여 실험을 수행하였다. 실험결과 제안된 컨버터의 효율이 매우 우수함을 확인하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2015년도 추계학술대회 논문집
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• pp.167-168
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• 2015

본 논문에서는 전기자동차 충전용 자기유도방식 무선전력전송 (IPT) 시스템에서 zero current switching (ZCS) 동작으로 인한 스위치 손상을 방지하는 제어 알고리즘을 제안한다. 알고리즘을 제안하기 위해 IPT 시스템에서 공진전류 위상 변화를 일으키는 bifurcation 현상과 금속성 이물질의 영향에 대해 분석하고, 분석 결과를 고려하여 동작 주파수 제어 알고리즘을 제안한다. 제안한 알고리즘은 시스템을 zero voltage switching (ZVS) 영역에서 동작하게 하고 일정한 출력 전압을 얻도록 제어한다. 제안한 알고리즘의 타당성을 PSIM 시뮬레이션을 통해 검증한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.79-84
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• 1998

A novel zero voltage and zero current switching (ZVZCS) full bridge (FB) PWM converter with low output current ripple is presented. A simple auxiliary circuit added in the secondary provides ZVZCS conditions to primary switches, ZVS for leading-leg switches and ZCS for lagging-leg switches, as well as reduces the output current ripple (ideally zero ripple). The auxiliary circuit includes neither lossy components nor additional active switches which are demerits of the previously presented ZVZCS converters. Many advantages including simple circuit topology, high efficiency, low cost and low current ripple make the new converter attractive for high performance high power (＞1kW) applications. The principle of operation, features and design considerations are illustrated and verified on a 2.5kW, 100KHz IGBT based experimental circuit.

• Journal of Electrical Engineering and Technology
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• 제11권6호
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• pp.1634-1644
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• 2016

In this paper, a current-fed two-inductor bi-directional DC/DC converter using resonance (CF-TIBCR) and its design method are proposed. The CF-TIBCR has characteristics of low current ripple and a high current rating because of two separated inductors. Also, it achieves zero voltage switching for all switches and zero current switching for switches of a low voltage stage by using the resonant tank. Besides, a voltage spike problem in conventional current-fed converters is solved without the need for an additional snubber or clamping circuits. As a result, the CF-TIBCR features high step-up and high efficiency. Since the proposed converter has difficulty achieving the soft-switching condition when the converter requires the low voltage transfer ratio, a method that varies the number of resonant cycles is adopted to extend the output voltage range with satisfying the soft-switching condition. The principles of the operation characteristics are presented with a theoretical analysis, and the proposed converter is verified through results of an experiment using a laboratory prototype.

• 전기학회논문지P
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• 제66권2호
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• pp.63-68
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• 2017

This paper proposes a new non-isolated DC conversion circuit topology of the voltage source coupled inductor series resonant high-frequency PFM controlled boost chopper type DC-DC power converter using two in one IGBT power module, which can efficiently operate under a principle of zero current soft switching for wide output regulation voltage setting ranges and wide fluctuation of the input DC side voltage as well as the load variation ranges. Its steady state operating principle and the output voltage regulation characteristics in the open-loop-based output voltage control scheme without PI controller loop are described and evaluated from theoretical and experimented viewpoints. Finally, in this paper the computer-aided simulation steady-state analysis and the experimental results are presented in order to prove the effectiveness and the validity of voltage regulation characteristics of the proposed series resonant zero current soft switching boost chopper type DC-DC power converter circuit using IGBTs which is based on simple pulse frequency modulation strategy more than, 20kHz.