• 전력전자학회:학술대회논문집
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• 전력전자학회 2006년도 전력전자학술대회 논문집
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• pp.143-145
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• 2006

This paper proposes a snubber circuit for a PWM AC-AC Cuk converter. The proposed snubber applies a modified Undeland snubber as a commutation aid. The snubber circuit has some good features such as reduction of voltage/current stress of the main switches, improved efficiency. The experiment results show the adaptability and feasibility of the proposed snubber circuit.

• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.916-924
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• 2015

Electromagnetic Interference (EMI) is a system to system or environment to system phenomenon. The literature survey proved that the Randomized Pulse Width Modulation (RPWM) technique is a promising technique to reduce EMI. A new Constant Trailing Edge, Randomized Pulse Width Modulation (CTERPWM) technique is proposed in this paper. The effect of the proposed RPWM technique for mitigation of conducted-EMI on Cuk converter operating in Continuous Conduction Mode (CCM) is simulated and tested. In this paper, the analytical expressions for the Power Spectral Density (PSD) are derived for the proposed RPWM technique and are validated by experimental measurements. The effectiveness of the proposed RPWM technique on the mitigation of conducted-EMI is verified comparing simulation and experimental results and it is identified that both the results are almost similar with allowable experimental deviations. The comparative investigation proves that the proposed RPWM technique can mitigate and spread the dominant peaks of conducted-EMI over the complete spectrum for the Cuk converter. Based on the investigation the CTERPWM technique is recommended for adoption.

• Journal of Power Electronics
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• 제19권4호
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• pp.894-906
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• 2019

In this paper, a DC-DC converter is proposed based on the Cuk converter. The proposed converter has high efficiency and it can be used in multilevel DC-DC converters. A reduction of the inductors size in comparison to Cuk converter and a reduction in the inductors resistance negative effects on efficiency are the important points of the proposed converter. Its voltage ripple is reduced when compared to other converters. Its output voltage has a high quality and does not contain spikes. A theoretical analysis demonstrates the positive points of the proposed converter. The design and analysis of the converter are done in continues conduction mode (CCM). Experiments confirm the obtained theoretical equations. The proposed converter voltage gain is similar to that of a conventional Boost converter. As a result, they are compared. The comparison illustrates the advantages of the proposed converter and its higher quality. Furthermore, a prototype of the proposed converter and its combination with a 2x multiplier are built in the lab. Experimental results validate the analysis. In addition, they are in good agreements with each other.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.151-154
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• 1988

Quantum converters, a subset of resonant converters operating with optimal conditions are modeled. It is shown that series resonant converter(SRC) can be modeled as buck/boost converter with an equivalent inductor and parallel resonant converter(PRC) can be modeled as Cuk converter, with an equivalent capacitor. Also new resonant circuits with boost, buck-boost and Cuk converter characteristics are proposed. From these models, the quantum converters can be designed to be controlled with closed loop feedback, having many advantages such as low device switching stress, reliable high frequency operation and low EMI.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.73.2-73.2
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• 2010

휴대용 전자기기들의 소비전력 증가에 따라 2차전지에 비해 에너지 밀도가 높은 연료전지를 이용한 충전기의 필요성이 부각되고 있다. 대다수의 충전기는 On-Grid 방식으로 벅타입 컨버터를 이용한 감압 방식이었으나, 연료전지를 이용할 경우 승압식 컨버터를 통한 배터리의 충전이 요구된다. 또한 배터리는 일반 저항부하와 달리 큰 커패시턴스 성분을 가지고 있기 때문에 컨버터의 출력단에 인덕터가 없는 경우 큰 출력 리플전류를 유도하게 되어 시스템의 효율과 배터리의 수명에 좋지 않은 영향을 끼치게 된다. 또한 이를 해결하기 위해 절연형 감압 컨버터를 사용하는 경우 변압기 사용에 의한 부피 증가와 부가 소자의 사용에 따른 가격 상승을 피하기 어렵다. Cuk 컨버터는 주스위치의 ON/OFF 동작에 관계없이 출력으로 에너지가 항상 전달되며, 이상적으로 리플이 거의 존재하지 않아 충전용으로 적합하다. 또한, 승압 및 감압이 자유롭기 때문에 배터리의 정격전압에 상관없는 범용 충전기의 설계도 가능하다. 따라서 본 논문에서는 Cuk 컨버터를 이용하여 배터리 충전기를 설계하고, 그의 상태공간 모델링, 주파수 특성 해석 및 제어기 설계에 대해 기술한다. 제안된 제어 방식은 소형 연료전지 스택을 이용하여 실제 배터리를 대상으로 한 정전류 및 정전압 제어를 실행하여 그 성능 및 안정성을 검증한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.408-409
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• 2010

본 논문에서는 소형 PEM(Proton Exchange Membrane) 연료전지를 이용하는 충전기에 관해 서술한다. 기존에 개발된 대부분의 충전기는 On-Grid 방식으로 벅타입 컨버터를 이용한 감압 충전방식을 사용하였으나, 연료전지를 이용할 경우 승압식 컨버터를 통해 배터리를 충전하여야 한다. 그러나 승압형 컨버터의 출력단에 인덕터가 없는 경우 큰 리플전류를 유도하게 되며, 이는 시스템의 효율 및 배터리의 수명에 좋지 않은 영향을 끼치게 된다. 본 논문에서는 Cuk 컨버터를 이용하는 충전용 전력변환기의 제어방법에 관해 제안하고 그 타당성을 검증하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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• pp.355-358
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• 2004

Currently, to overcome the limit of a 14V power supply system and to enhance the stability of this system high and to make the fuel efficiency better, a research development of a 42V power supply system is actively the progress. As an intermediate step to change into an unity power supply system, a 42V/14V dual power supply system uses a DC/DC Converter as one of structure elements. Considering the main electric power sources in the next generation of the car is a 42V system a 14V power supply system has advantages as follows : In be managed efficiently and to increase the redundancy at start, to jump start with any vehicles, etc. We need the introduction of a hi-directional converter that can flow the energy each other in a dual 42V-l2V system. This paper proposed the ZVS hi-directional CUK DC/DC converter which decrease the weight with the size of the DC/DC Converter and minimize the loss when the switching happen. In this paper, a circuit design method and an action principle of the circuit was proposed. To verify the proposed circuit, a comprehensive evaluation with theoretical analysis, simulation results is presented.

• 전력전자학회논문지
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• 제9권5호
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• pp.478-484
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• 2004

본 논문에서는 두 개의 무손실 스너버 셀을 제안하여 고주파에서 동작할 수 있는 컨버터를 일반화하였다. 컨버터 구현 시 스너버 셀의 선택은 컨버터 구조에 따라서 결정된다. 스너버 셀의 구성은 한 개의 포화 인덕터와 LC 공진회로, 두 개의 다이오드로 구성된다. 인덕터는 컨버터 주 다이오드의 역회복 손실을 저감시키는 역할을 하는데 포화 인덕터를 사용하면 셀 내의 공진 에너지를 감소시켜 컨버터가 고주파에서 동작될 수 있는 특성을 갖는다. 컨버터의 일반화는 무손실 스너버 셀을 벅(Buck), 부스트(Boost), 벅-부스트(Busk-Boost), 척(Cuk), 제타(ZETA) 및 세픽(SEPIC)에 추가하여 실현하였다. 제안된 컨버터의 고주파 동작 및 고효율 특성은 400 kHz, 125 W 부하에서 실험하여 기존의 PWM 컨버터에 비하여 고효율로 동작함을 확인하였다.

• Journal of Power Electronics
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• 제8권1호
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• pp.51-59
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• 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.

• Journal of Electrical Engineering and Technology
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• 제1권3호
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• pp.343-350
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• 2006

This paper introduces a new high efficient bi-directional, non-isolated DC/DC converter. Through variations of the topology of the conventional Cuk converter, an optimum bi-directional DC/DC converter is proposed. Voltage and current in the proposed DC/DC converter are continuous. Furthermore, the efficiency in both step-up and step-down mode is improved over that of the conventional bi-directional converter. To prove the validation for the proposed converter, simulations and experiments are executed with a 300W bi-directional converter.