• Journal of Power Electronics
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• 제15권2호
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• pp.319-326
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• 2015

In this paper, a cost-effective single switch multi-channel LED (light emitting diode) driver is proposed. While conventional LED drivers require as many non-isolated DC/DC converters as the number of LED channels, the proposed LED driver needs only one power switch and several balancing capacitors instead of expensive non-isolated DC/DC converters. Therefore, the proposed driver features a simpler structure, with a lower cost and a higher efficiency. Because its power switch can be turned off under the zero current switching condition, it has very desirable advantages such as improved electromagnetic interference characteristics and high efficiency. Moreover, it uses only a small number of DC blocking capacitors with no additional active devices for the current balancing of multi-channel LEDs. As a result, the proposed driver exhibits high reliability and is cost effective. To confirm the validity of the proposed driver, a theoretical analysis is performed, and design considerations and experimental results obtained from a prototype that is applicable to a 46" LED-TV are presented.

• 전기학회논문지P
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• 제54권4호
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• pp.171-178
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• 2005

The proposed dual-output DC-DC converter that bases on flyback converter can obtain two output voltage with non-isolated main-output and isolated sub-output at the same time using single-winding high frequency transformer. It can solve problems in multi-winding converter that use one main-switch, and also control quality of isolated sub-output voltage can be improved by additional sub-switch to the second. For analysis and design of the proposed converter system, converters are classified as operation mode from switching state and are become modeling by applying state space averaging method. Steady-state characteristics and dynamic characteristics are analyzed by DC component and perturbation component from state space averaging model. From experiment converter, validity of analysis and design for the propose converter system is confirm.

• Journal of Power Electronics
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• 제16권5호
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• pp.1669-1677
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• 2016

A new auxiliary circuit for boost, buck, buck-boost, Cuk, SEPIC, and zeta converters is introduced to provide soft switching for pulse-width modulation converters. In the aforementioned family of DC-DC converters, the main and auxiliary switches turn on under zero current transition (ZCT) and turn off with zero voltage and current transition (ZVZCT). All diodes commutate under soft switching conditions. On the basis of the proposed converter family, the boost topology is analyzed, and its operating modes are presented. The validity of the theoretical analysis is justified by the experimental results of a 100W, 100 kHz prototype. The conducted electromagnetic emissions of the proposed boost converter are measured and found to be lower than those of another ZCT boost converter.

• 전력전자학회논문지
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• 제22권1호
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• pp.44-52
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• 2017

This paper describes a 100 kW high-efficiency isolated DC-DC converter for DC distribution system. The DC-DC converter consists of two dual-active-bridge (DAB) converters in parallel. The operating principle of the DAB converter is explained, and the algorithm for parallel operation of the DAB converters is proposed. Simulation and experiments are conducted to verify the performance of the proposed system. Experimental results demonstrate that the developed converter excellently marks 97.4 percent of peak efficiency under its normal operating condition.

• 전자공학회논문지S
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• 제36S권4호
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• pp.101-109
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• 1999

본 논문에서는 절연형 DC-DC 컨버터의 설계자동화 도구를 제시한다. 절연형 DC-DC 컨버터는 입력과 출력 측의 분리에 의한 회로 보호, 다중출력으로의 확장, 승압 및 강압의 용이성 등의 장점을 가지고 있다. 설계자동화의 과정은 여러 단계로 나눌 수 있다. 토폴로지 선택, 전압 및 전류용량이 적절한 스위치 소자 선택, 인덕턴스와 캐패시턴스의 값 결정, 그리고 변압기 설계의 순서로 컨버터 회로의 자동합성이 진행된다. C언어를 이용하여 자동화 도구를 구현하였고 SMPS 데이터 북으로부터 얻은 실제 회로의 사양을 가지고 다양한 컨버터 회로를 합성함으로 검증하였다.

• Journal of Power Electronics
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• 제18권3호
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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.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
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• pp.406-408
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• 1999

In order to reduce the overall size and cost, researchers attempted to integrate the functions of power factor correction(PFC) and isolated dc-dc conversion into single power stage. However, single-stage isolated PFC converters have higher voltage stress and heavier loss when compared with a normal dc-dc converters. In this paper, we propose to add active clamping circuit to keep the switch voltage stress low and to achieve soft switching of electronic devices.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권8호
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• pp.423-429
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• 2006

Recently, the high frequency isolated boost DC/DC converter has been widely used for the PCS (Power Conditioning System) system because of its small size and low cost. However, the high frequency isolated boost DC/DC converters applied the conventional voltage-fed converter and current-fed converter have the problems such as the high conduction losses and the surge voltage due to the high circulating current and the leakage inductance, respectively. To overcome this problems, in this paper the secondary LLC resonant converter is proposed, and the experimental results of the secondary LLC series resonant converter for boost DC/DC converter are verified on the simulation based on the theoretical analysis and the 700W experimental prototype.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2015년도 추계학술대회 논문집
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• pp.91-92
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• 2015

본 논문에서는 DAB(Dual Active Bridge) 타입의 절연형 양방향 DC/DC 컨버터의 출력전압 제어기법을 제시한다. SPS(Single-phase shift) PWM 기반의 고조파 모델에 대해 슬라이딩 모드 제어기(SMC)를 설계한다. 제시된 기법은 시뮬레이션 결과에 의해 성능이 검증된다.

• Journal of Power Electronics
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• 제10권2호
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• pp.125-131
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• 2010

Switched-resonator converters are a new family of soft switching DC-DC converters where the energy is transferred via a resonator. This paper introduces some isolated topologies of this family. The achieved advantages include, load independent soft-switching, self short-circuit protection, and optimization capability due to topology variety. Compared to conventional series-resonant converters, outstanding advantages such as a smaller fewer number of switches and diodes, a smaller transformer, and lower current stresses are achieved. A general synthesis scheme, functional topologies, and essential relations are included. Experimental results from a laboratory prototype confirm the presented theoretical analysis.