• The Transactions of the Korean Institute of Power Electronics
• /
• v.9 no.5
• /
• pp.478-484
• /
• 2004

In this paper, two lossless snubber cells are proposed to generalize high frequency converter with losslless snubber. The selecting of snubber cells, which generalize high frequency converters, are depended on converter topologies. The cells have a saturable inductor, LC resonant tank and two diodes. In the cells, the saturable inductors extremely reduce resonant energy in the LC resonant tank. By minimizing resonant energy, the converter, which applies snubber cells, can operate at high frequency. These cells are applied for Buck, Boost, Buck-Boost, Cuk, ZETA, and SEPIC to generalize converter which have lossless snubber. The boost type converter has been implemented, with 400 kHz switching frequency for 125 W load to verify the converter characteristics.

• Proceedings of the KIPE Conference
• /
• 2018.07a
• /
• pp.320-321
• /
• 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.

• Proceedings of the KIEE Conference
• /
• 2006.07b
• /
• pp.933-934
• /
• 2006

본 논문에서는 새로운 양방향 ZVS PWM Sepic/Zeta 컨버터를 제안한다. 제안한 컨버터는 PWM 제어가능한 컨버터로서 입력과 출력전압의 극성이 같은 비반전 컨버터의 특징을 지니며 DC 전압의 전달함수가 양방향 모두 M=D/(1-D)로 동일하다. 또한 각방향으로 전력전달시 다이오드와 병렬로 연결된 MOSFET가 다이오드의 'ON'시 동시에 'ON'되어 Sychronous Rectifier로 동작하므로 도통손을 저감하였으며, Auxiliary Resonant Commutated Pole를 사용하여 저감된 스위칭 손실을 갖는 특성을 지니고 있다. 또한 Transformer 버전이 존재하므로 입력과 출력사잉에 전기적 절연을 필요로 하는 실제응용에 유용하게 사용할 수 있다.

• Proceedings of the KIEE Conference
• /
• 2003.07b
• /
• pp.1211-1213
• /
• 2003

A pulse width modulation(PWM) method for single-phase Sepic-type rectifier is introduced in this paper. The characteristics of the proposed PWM system are high performance high power factor with low input current harmonic distortion. The proposed control method is based on the average-current-mode using the dedicated integrated circuit UC3854 this technique it is possible to implement a very simple control circuit for unitary power-factor in CCM operation and also to provide over-current protection.

• Journal of Power Electronics
• /
• v.8 no.1
• /
• pp.51-59
• /
• 2008

This paper addresses several issues concerning the analysis, design, modeling, simulation and development of single-phase, single-switch, power factor corrected AC-DC high frequency switching converter topologies with transformer isolation. A detailed analysis and design is presented for single-switch topologies, namely forward buck, flyback, Cuk, Sepic and Zeta buck-boost converters, with high frequency isolation for discontinuous conduction modes (DCM) of operation. With an awareness of modem design trends towards improved performance, these switching converters are designed for low power rating and low output voltage, typically 20.25W with 13.5V in DCM operation. Laboratory prototypes of the proposed single-switch converters in DCM operation are developed and test results are presented to validate the proposed design and developed model of the system.

• New & Renewable Energy
• /
• v.1 no.2 s.2
• /
• pp.11-18
• /
• 2005

A modular photovoltaic PCS with high-frequency isolation is proposed. The proposed system consists of a SEPIC converter and a full-bridge inverter Using the power slope versus voltage of the PV array, the MPPT controller is proposed that produces a smooth transition to the maximum power point. The dc current of the PV array is estimated without using a dc current sensor The disturbance of the line voltage is detected using a fast sensing technique. Experimental results obtained on a 500W prototype show high performance such as almost unity power factor, $90\%$ power efficiency, $3.6\%$ THD.

• Proceedings of the KIPE Conference
• /
• 2015.07a
• /
• pp.93-94
• /
• 2015

최근 자동차 조명시장에서 LED를 이용한 헤드램프 개발이 빠르게 이루어지고 있다. LED 헤드램프는 기존의 할로겐 앰프와 다르게 에너지 효율이 높으며, 헤드램프뿐만 아니라 차량 내부에 다양하게 활용이 가능하다는 장점을 갖는다. 현재 차량에 적용되어 있는 LED 헤드램프 대부분은 SEPIC을 이용한 LED전류제어를 한다. 이러한 경우 헤드램프의 효율은 SEPIC에 의해 대부분 결정이 되며, 부수적인 기능추가를 위해서는 보조 ECU가 추가적으로 필요하다. 따라서 본 논문에서는 차량용 헤드램프를 위한 DC/DC컨버터를 제안하고, 이에 대해 검증한다.

• Journal of Power Electronics
• /
• v.16 no.5
• /
• pp.1669-1677
• /
• 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.

• Journal of the Korean Society for Precision Engineering
• /
• v.32 no.5
• /
• pp.455-461
• /
• 2015

This paper deals with an experimental verification of a temperature-dependent power loss model of a DC/DC converter in severe temperature conditions. The power loss of a DC/DC converter is obtained by summing the losses by the components constituting the converter including switching elements, diodes, inductors, and capacitors. MIL-STD-810F stipulates that any electronic devices must be operable in the temperature ranging from $-50^{\circ}C$ to $70^{\circ}C$. We summarized the temperature-dependent loss models for the converter components. A SEPIC-type converter is designed and built as a target. Using a constant-temperature chamber, a test rig is set up to measure the power loss of the converter. The experimental results confirm the validity of the loss model within 4.5% error. The model can be useful to predict the efficiency of the converter at the operating temperature, and to provide guidelines in order to improve the efficiency.

• Journal of the Korean Society of Industry Convergence
• /
• v.20 no.2
• /
• pp.97-104
• /
• 2017

In the present industrial field, the demand for the development of the solar power source device and the charging device for the solar cell is gradually increasing. The solar charger is largely divided into a DC-DC converter that converts the voltage generated from the sunlight to a charging voltage, and a battery and a charger that are charged with an actual battery. The conventional charger topology is used either as a Buck converter or a Boost converter alone, which has the disadvantage that the battery can not always be charged to the desired maximum power as input and output conditions change. Although studies using a topology capable of boosting and stepping have been carried out, Buck-Boost converters or Sepic converters with relatively low efficiency have been used. In this paper, we propose a new Buck Boost combination power converter topology structure that can use Buck converter and Boost converter at the same time to improve inductor current ripple and power converter efficiency caused by wide voltage control range like solar charger.