• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집 특별세미나,특별/일반세션
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• pp.623-628
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• 2009

There is an increasing demand for efficient high power/weight auxiliary power supplies for use on high speed traction application. Many new conversion techniques have been proposed to reduce the voltage and current stress of switching components, and the switching losses in the traditional pulse width modulation(PWM) converter. Especially, the phase shift full bridge zero voltage switching PWM techniques are thought most desirable for many applications because this topology permits all switching devices to operate under zero voltage switching(ZVS) by using circuit parasitic components such as leakage inductance of high frequency transformer and power device junction capacitance. The proposed topology is found to have higher efficiency than conventional soft-switching converter. Also it is easily applicable to phase shift full bridge converter by applying an energy recovery snubber consisted of fast recovery diodes and capacitors.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.321-324
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• 2008

Recently, there is an increasing demand for efficient high power/weight auxiliary power supplies for use on high speed traction application. many new conversion techniques have been proposed to reduce the voltage and current stress of switching components, and the switching losses in the traditional pulse width modulation(PWM) converter. Among them, the phase shift full bridge zero voltage switching PWM techniques are thought most desirable for many applications because this topology permits all switching devices to operate under zero voltage switching(ZVS) by using circuit parasitic components such as leakage inductance of high frequency transformer and power device junction capacitance. The proposed topology is found to have higher efficiency than conventional soft-switching converter. Also it is easily applicable to phase shift full bridge converter by applying an energy recovery snubber consisted of fast recovery diodes and capacitors.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 전력전자학술대회 논문집
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• pp.321-322
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• 2014

In this paper, a zero-voltage switching (ZVS) phase shift full-bridge converter is analyzed. The small-signal model is derived to design a digital controller. PLECS simulation shows how sampling method effects on transfer function of ZVS phase shift full-bridge converter.

• 전력전자학회논문지
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• 제23권4호
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• pp.273-280
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• 2018

This paper proposes a zero-voltage-transition pulse-width modulation (PWM) DC-DC converter that uses a new active-snubber-cell. The converter main switch can be turned on and off with ZVS, while the snubber switch is turned on with ZCS and turned off with ZVS. Other semiconductor devices are operated under the soft-switching condition. Normal PWM control can be used, the proposed active-snubber-cell does not impose any additional voltage and current stresses. The active-snubber-cell is suitable for high-power applications due to its easy integration into interleaved converters. This paper discusses the operation of the converter, presents some design guidelines, and provides the results of an experiment with a 100 kHz and 1 kW prototype. A peak efficiency of 97.8% is recorded.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.195-197
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• 1995

In this paper, for a constant switching frequency, the configuration and the control strategy of the resonant buck-boost type converter are proposed by the combination of zero voltage switching(ZVS) and zero current switching(ZCS) with PWM method. Also, in the configuration of power control circuit, transformer is not used in the viewpoint of economy. And the circuit has fewer power switching elements than a general resonant power converter, simulation results and experiments make show the advantages mentioned.

• 전력전자학회논문지
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• 제10권6호
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• pp.598-609
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• 2005

기존의 위상 천이 풀-브릿지 컨버터는 변압기 2차측 다이오드의 전압 스트레스를 증가시키는 심각한 전압 진동 문제를 가지고 있으며, 이를 해결하기 위한 부가적인 스너버의 사용은 전체 시스템 효율의 저하를 초래한다. 본 논문에서는 부가적인 스너버의 사용없이 효과적으로 전압 진동 문제를 해결하는 위상 천이 풀-브릿지 컨버터의 새로운 동작 방식을 제안한다. 또한 제안된 방법은 동작 특성 상 넓은 영전압 스위칭 범위를 보장하므로 향상된 효율을 기대할 수 있다. 기존의 동작 방식과 비교하여 제안된 전압 진동 제거 기술의 동작 원리, 전압 진동 분석 및 설계 고려 사항을 나타내었으며, 420W사양의 시험모델을 제작하여 제안된 전압 진동 제거 기술의 타당성을 입증하였다.

• 대한전기학회논문지
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• 제45권4호
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• pp.517-525
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• 1996

A Simple AC complex circuit analysis for LCL type series resonant converter with phase shift control is proposed. Based on these analyses, a set of characteristic curves which allows a optimal design procedure for this converter is shown, without increasing the volt-ampere rating of tank circuit Especially, inverter output peak current can be minimized in both full load and partial load conditions. The presented design considerations can make the load range wide from full loads to light loads achieving turn-on with zero voltage switching (ZVS) operation. The detailed analysis and experimental results show the effectiveness of the proposed design algorithms. (author). refs., figs., tab.

• Journal of Power Electronics
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• 제19권1호
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• pp.58-67
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• 2019

This study presents a new portable eight-output light emitting diode (LED) driver. The eight output-channels are divided into two equal groups, and their output powers can be controlled individually by three active switches. In addition, a simple capacitor-based passive current balancing circuit (CBC) is employed in each port to guarantee that the currents of the four LEDs are the same. When compared with the conventionally used separate two-output isolated converters, the proposed one uses one less active switch. Moreover, zero-voltage-switching (ZVS) is achieved, which improves the power efficiency of the driver. Finally, a highly compact prototype is built, which can reach an efficiency of 94.6%.

• Journal of Power Electronics
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• 제11권5호
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• pp.662-668
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• 2011

This paper presents an analysis of a 4th order LCLC resonant converter with a capacitive output filter using the state-space approach. The analysis of the converter shows that there are four intervals in a half period. In each interval, the state-space equations are obtained. Due to the soft switching of the converter, an exact equation for the Zero Voltage Switching (ZVS) time and the maximum dead time of the inverter switches are presented. The simulation and experimental results obtained from a 10kv, 370w prototype confirm the validity of the theoretical analysis.

• 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.