• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2008년도 추계종합학술대회 B
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• pp.179-182
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• 2008

전기 전자 및 제어기의 직류 안정화 전원으로 널리 이용되고 있는 DC-DC 전력 변환기인 기존의 승압 컨버터는 반도체 소자의 고속스위칭에 의해 고효율, 소형 및 경량화 되어가고 있지만, 전류 평활용으로 철심 리액터 및 콘덴서가 존재하여 한계가 있다. 기존의 승압용 DC/DC 전력 변환기는 에너지 전달을 위해 하나 이상의 인덕턴스가 필요로 하며, 이는 철손으로 인한 효율 저하 및 경제성에 큰 단점이 되고 있다. 일반적으로 DC/DC 컨버터에서 리액터의 추가는 1개당 $1{\sim}2[%]$의 효율저하를 초래한다. 따라서 최근 고효율 DC/DC 컨버터에서 리액터의 제거 및 최소화에 대한 연구가 활발히 진행되고 있다. 본 논문은 공심 리액터를 이용한 DC/DC 컨버터에 대한 연구로서, ZCS용 공심 리액터를 사용하는 새로운 구조의 절연형 다중레벨 DC/DC 컨버터를 제안하고, PSIM을 이용한 시뮬레이션을 통하여 그 타당성을 검증하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1146-1147
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• 2008

PV Power Conditioning System (PCS) must have high conversion and low cost. Generally, PV PCS uses either a single converter or multilevel module integrated converter (MIC). Each of these approaches has both advantage and disadvantage. For a high conversion efficiency and low cost of PV module, this paper proposes series connection of module integrated DC-DC converter's output with PV panel. Output voltage of PV panel is connected to the output capacitor of flyback converter. Thus, converter's output voltage is added to the output voltage of PV panel. Isolated DC-DC converter generates only the difference voltage between the PV panel voltage and the required total output voltage. This method reduces power level of DC-DC converter and enhances the energy conversion efficiency compared with conventional DC-DC converter.

• 조명전기설비학회논문지
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• 제29권7호
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• pp.87-94
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• 2015

Recently, renewable energy sources are under the spotlight. due to the depletion of fossil fuels and environmental problem for the carbon dioxide. Among them, research on the Photovoltaic System using solar energy systems has been actively conducted. In this paper, we propose boosting the insulated DC/DC converter topologies Applied to soft-switching methods used in photovoltaic PCS. The proposed topology is of a type that combines a series of full-bridge converter and a boost converter, a full bridge converter and applying the insulation and soft switching system, the output voltage boost stage is carried out for the boost control. The proposed circuit validity was verified through the PSIM simulation and 5kW PV PCS Prototype and experiments.

• Journal of Power Electronics
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• 제13권4호
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• pp.592-599
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• 2013

This paper investigates a new isolated single-phase AC-DC converter, which integrates a modified AC-DC buck-boost converter with a DC-DC forward converter. The front semi-stage is operated in discontinuous conduction mode (DCM) to achieve an almost unity power factor and a low total harmonic distortion of the input current. The rear semi-stage is used for step-down voltage conversion and electrical isolation. The front semi-stage uses a coupled inductor with the same winding-turn in the primary and secondary sides, which is charged in series during the switch-on period and is discharged in parallel during the switch-off period. The discharging time can be shortened. In other words, the duty ratio can be extended. This semi-stage can be operated in a larger duty-ratio range than the conventional AC-DC buck-boost converter for DCM operation. Therefore, the proposed converter is suitable for universal input voltage (90~264 $V_{rms}$) and a wide output-power range. Moreover, the voltage stress on the DC-link capacitor is low. Finally, a prototype circuit is implemented to verify the performance of the proposed converter.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.181-184
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• 2005

Operating conditions of photovoltaic power generator is very sensitive to the PV modules. The PV module's control is an importance issue in the removing DC ripple noise. In this paper, the phase-shifted-carrier technique, which is a new three-step dc-dc power multi-converter schemes, is applied to solar generator system to improve the output current waveform. The novel type of three-step dc-dc converter presented has many features such as the good output waveform, high efficiency, low switching losses, low acoustic noise. The circuit configuration is constructed by the conventional full-bridge type converter circuit using the isolated DC power supply for which the solar cell is very suitable. In the end, a circuit design for understanding three-step dc-dc converter and new solar power system were presented

• Journal of Power Electronics
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• 제18권4호
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• pp.955-964
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• 2018

In this paper, an active capacitor-diode-switch (CDS) snubber is proposed for L-type current-fed isolated DC-DC converters. The proposed CDS-clamped converter has a number of advantages. It can achieve wide range zero-voltage switching (ZVS) on two switches, a continuous input current with a low ripple, a reduction of one active switch and high efficiency. The operating principles, analysis and parameter design guideline are presented. A 300 W prototype is built to test the proposed converter. Simulation and experimental results are shown at 30 V input voltage and 400 V output voltage.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 F
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• pp.2207-2209
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• 1997

This Paper Presents the design automation for isolated DC-DC converters. Isolated DC-DC converts have many advantages such as protection, wide range variation, and multiple output. Prosedures consist of several steps. There are the selection of converter topology, the selection of switching devices. the calculation for the value of inductances and capacitances, and the design of transformers. We verified it with many practical examples from databooks.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 전력전자학술대회
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• pp.320-321
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• 2018

A non-isolated high voltage gain bidirectional DC-DC converter for battery storage system has been presented in this paper. The topology is composed of boost converter and traditional SEPIC converter. The proposed converter can achieve higher voltage conversion ratio with reduced voltage and current stresses in the switches. In additional, a reduced number of components are included in this topology. The PSIM simulation is carried to validate the analysis and operation of the converter.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2012년도 추계학술대회 논문집
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• pp.50-51
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• 2012

The paper presents a non-isolated bidirectional DC-DC converter for use in renewable power generation, battery, electric vehicles (EV) and small scale DC-UPS systems. In the propose design, the conventional interleaved operation of two-inductor boost structure is modified to accommodate bidirectional operation, and zero-voltage-transition (ZVT) is applied, where both the switch and the rectifier diode achieve soft condition without increasing their voltage and current stresses. The proposed converter has the merits of simple circuitry, reduced size, low cost and high efficiency. The operation principle of the converter is analyzed and verified. Also, simulation results of the proposed bidirectional dc-dc converter is shown.

• Journal of Power Electronics
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• 제18권2호
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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.