• Journal of Power Electronics
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• v.18 no.3
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• pp.651-661
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• 2018

This paper suggests a new non-isolated high voltage gain DC-DC converter with two switches. The proposed two-switch converter has the following characteristics: a high voltage gain, a continuous input current with a small ripple, a reduction in the size of the inductor, and a simple circuit with only a few elements. A theoretical analysis, guidelines for parameter selection, and a comparison with conventional non-isolated high step-up converters are presented. A prototype of 250 W is set up to demonstrate the correctness of the proposed converter. Results obtained from simulations and experiments are presented.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.1973-1976
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• 1998

Recently, new trend in telecommunication device is to apply low voltage, about 3.3V-1.5V. However, it is undesirable in view of high efficiency and power desity which is the most important requirement in the distributed power system. Rectification loss in the output stage, in on-board converter for distributed power system are constrained to obtain high efficience at low output voltage power suppies. This paper explains the basic operational principles of three kinds of ZVS DC/DC converters with self-driven synchronous rectifier. The three topologies are analyzed by simulation and exprimentation, and the characteristics comparisons of high efficience converter are carried out in view of the minimized rectification losses in the out stage.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1049-1050
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• 2006

This paper is proposed to a novel DC-DC converter operated high efficiency for loss-less snubber capacitor. The general converters of high efficiency is made that the power loss of the used switching devices is minimized. To achieve the soft switching operation of the used control switches, the proposed converter is constructed by using a loss-less snubber capacitor. The proposed 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 converter is high. The soft switching operation of the proposed converter is verified by digital simulation and experimental results.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.301-302
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• 2013

본 논문은 고효율 LLC 컨버터 구동을 위해 단일 트랜스포머를 이용한 풀 브릿지 및 하프 브릿지 DC-DC 컨버터 하이브리드 제어 방법을 제안한다. 제안한 방법은 입력 전압 및 부하 변동에 대해서도 스위칭 주파수 변동폭을 최소화하여 스위치 손실을 저감하여 효율을 극대화한다. 출력 13 [V]/500 [W] LLC 컨버터의 이론적 분석을 바탕으로 최적 운전점을 도출하고 시뮬레이션을 통해 검증하고자 한다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.251-255
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• 2005

This paper proposes a new soft switching technique for a phase-shift controlled bi-directional DC-DC converter. The described converter employs a low profile high frequency transformer and two active full-bridge converters for bidirectional power flow capability. A new soft switching technique is proposed, which guarantees soft switching over wide range (no load to full load) without any additional circuit components. In the proposed switching scheme, the switch pairs in the diagonal position of the converter each are turned on/off simultaneously by the switching signals with a variable duty ratio depending on the phase shift amount, and the converter is operated without freewheeling interval.

• Journal of Power Electronics
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• v.9 no.1
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• pp.18-25
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• 2009

Conventional series-resonant pulse frequency modulation controlled DC-DC high power converters with a high-frequency transformer link which is designed for driving the high power microwave generator has the problem of hard switching commutation at turn-on and turn-off of active power switching devices. This problem is due to the influence of the magnetizing current of the high-frequency transformer. This paper presents a novel prototype for a high-frequency transformer using parasitic parameters with a lossless inductive snubber and a series resonant capacitor assisted series-resonant zero current switching pulse frequency modulated DC-DC power converter, which is designed using a high power magnetron for microwave ovens. In order to implement a complete and efficient soft switching commutation, the performance of the new converter topology is practically confirmed and evaluated in the prototype of a power microwave generator.

• Journal of Power Electronics
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• v.12 no.6
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• pp.859-868
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• 2012

In this paper, a novel bidirectional DC-DC converter employing soft switching technique was proposed. Compare to conventional bidirectional converters, the main switches of proposed converter are operated without switching losses. Moreover, auxiliary switches are used, and the switches are operated under zero voltage switching (ZVS) and zero current switching (ZCS) condition. To verify the validity of the proposed converter, mode analysis, design procedure, simulation and experimental results are presented.

• Journal of Power Electronics
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• v.12 no.6
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• pp.878-885
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• 2012

A new sustainer with primary-side integration of DC/DC converters and energy recovery(SPIDER) circuits is proposed. The proposed circuit operates as a DC-DC converter during address period and energy recovery circuit during sustain period. Therefore, the conventional three electronic circuits composed of the power supply, X-driver, and Y-driver can be reduced to one circuit. As a result, it has desirable advantages such as a simple structure, less mass, fewer devices and cost reduction. Moreover, since the Zero Voltage Switching (ZVS) of all power switches can be guaranteed, a switching loss can be considerably decreased. To confirm the operation, validity, and features of the proposed circuit, experimental results from a prototype for 42-inch PDP are presented.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.364-365
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• 2019

대부분의 전력 전자 컨버터에서 사용되는 dc-link 커패시터는 입력 전원과 출력 부하 사이의 순간 전력 차이를 균형화하고, dc-link의 전압 변화를 최소화하기 위해 널리 사용된다. 일부 애플리케이션에서는 유지 시간 동안 충분한 에너지를 제공하는 데에도 사용된다. 하지만 커패시터는 시간이 지남에 따라 전기 및 환경과 같은 다양한 원인에 의해 고장이 발생하여, 전체 시스템의 가용성을 저감 시킬 수 있다. 따라서, 커패시터 고장을 발생시키는 메커니즘에 대한 검토를 통하여 예측적 유지 보수를 수행하여 전체 시스템의 가용성을 개선할 수 있을 것이다. 본 논문에서는 필름 커패시터의 고장 메커니즘, 고장 모드 및 수명 모델 검토 등을 통하여 dc-link 애플리케이션 연구에 대한 명확한 통찰력을 제공하고 필름 커패시터와 그 dc-link 애플리케이션에 대한 과제와 향후 연구방향을 확인하는 역할을 한다.

• Journal of IKEEE
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• v.23 no.1
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• pp.273-279
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• 2019

A high boost dc-dc converter based on the switched-inductor cell (SL-cell) is suggested in this paper. The suggested converter can provide a high voltage gain that is more than 6. Moreover, the voltage gain can be easily increased by extending a SL cell or a modular voltage boost stage. This paper shows the key waveforms, the operating principles at the continuous conduction mode (CCM), and a comparison between the suggested converter and the other non-isolated converters. In addition, the extension of the suggested converter is presented. The simulation results were shown to reconfirm the theoretical analysis.