• Journal of Power Electronics
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• 제12권4호
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• pp.643-653
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• 2012

An interleaved DC/DC converter with series-connected transformers is presented to implement the features of zero voltage switching (ZVS), load current sharing and ripple current reduction. The proposed converter includes two half-bridge converter cells connected in series to reduce the voltage stress of the switches at one-half of the input voltage. The output sides of the two converter cells with interleaved pulse-width modulation are connected in parallel to reduce the ripple current at the output capacitor and to achieve load current sharing. Therefore, the size of the output chokes and the capacitor can be reduced. The output capacitances of the MOSFETs and the resonant inductances are resonant at the transition instant to achieve ZVS turn-on. In addition, the switching losses on the power switches are reduced. Finally, experiments on a laboratory prototype (24V/40A) are provided to demonstrate the performance of the proposed converter.

• 조명전기설비학회논문지
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• 제29권8호
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• pp.55-62
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• 2015

This paper deals with a switching method to minimize the current ripple component of 3-phase interleaved bidirectional DC-DC converter for charging and discharging of the battery. The characteristics of the output current ripple in 3-phase and 2-phase operation modes according to the variation of battery voltage is analyzed and a phase conversion method for minimizing the magnitude of the current ripple is proposed. The proposed method can extend the light load range because the switching frequency is lower than that of a 3-phase operating system. Simulation and experimental results show the usefulness of the proposed method.

• 전력전자학회논문지
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• 제19권1호
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• pp.15-22
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• 2014

Recently, parallel operation of dc-dc converters has been widely used in distributed power systems. In this paper, a control method to achieve parallel operation of three-phase bi-directional isolated interleaved dc-dc converters is discussed for the battery charging and discharging system which consists of the 32 battery charger/dischargers and two three-phase bi-directional isolated interleaved dc-dc converters. In the boost mode, the battery energy is delivered to the grid, whereas the grid energy is transferred to the battery in the buck mode operation. The average current sharing control method is employed to obtain an equal conducting of each phase current in the three-phase dc-dc converter. By using the proposed method, the imbalance factor is gratefully reduced from 8 percent to 1 percent. Two 2.5kW three-phase bi-directional dc-dc converter prototype have been built and the proposed method has been verified through experiments.

• 조명전기설비학회논문지
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• 제23권12호
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• pp.127-135
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• 2009

본 연구에서는 2개의 인덕터를 이용한 인터리브 AC/DC 승압형 컨버터의 듀티 사이클이 0.5 이상일 때 배압 회로 특징을 나타내었다. 일반적으로 AC/DC 승압형 컨버터는 낮은 입력전압(입력 AC 110[V])이 높은 입력전압(입력 AC 220[V])에 비하여 낮은 효율을 갖는다. 제안된 인터리브 AC/DC 승압형 컨버터는 낮은 입력전압에서 배압 회로로 동작함으로 인하여 낮은 입력전압을 사용하는 기존의 컨버터와 비교하여 높은 역률과 향상된 효율을 갖는다. 본 연구에서는 배압 회로 동작하는 하는 인터리브 AC/DC 승압형 컨버터를 제안하고, 모드별 해석과 특성을 논의하였으며, 300[W]급 시작품을 제작하여 그 타당성을 검증하였다.

• Journal of Power Electronics
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• 제12권3호
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• pp.377-386
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• 2012

An interleaved bridgeless buck-boost AC/DC converter is presented in this paper to achieve the characteristics of low conduction loss, a high power factor and low harmonic and ripple currents. There are only two power semiconductors in the line current path instead of the three power semiconductors in a conventional boost AC/DC converter. A buck-boost converter operated in the boundary conduction mode (BCM) is adopted to control the active switches to achieve the following characteristics: no diode reverse recovery problem, zero current switching (ZCS) turn-off of the rectifier diodes, ZCS turn-on of the power switches, and a low DC bus voltage to reduce the voltage stress of the MOSFETs in the second DC/DC converter. Interleaved pulse-width modulation (PWM) is used to control the switches such that the input and output ripple currents are reduced such that the output capacitance can be reduced. The voltage doubler topology is adopted to double the output voltage in order to extend the useable energy of the capacitor when the line voltage is off. The circuit configuration, principle operation, system analysis, and a design example are discussed and presented in detail. Finally, experiments on a 500W prototype are provided to demonstrate the performance of the proposed converter.

• 전력전자학회논문지
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• 제19권3호
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• pp.220-226
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• 2014

Input current ripple and harmonic components of the power device are main causes of electromagnetic interference (EMI). Although the discontinuous conduction mode (DCM) operation can reduce harmonic components of the power device by reducing reverse recovery current of diode and turn-off voltage spikes of the switch, input current ripple increases due to high peak to peak inductor current. Therefore, in this paper, frequency control algorithm is proposed to reduce the input current ripple of DCM operated interleaved boost converter. In the proposed algorithm, duty ratio is fixed either 0.33 or 0.67 to minimize the input current ripple and the switching frequency is controlled according to operating conditions. 600 W 3-phase interleaved boost converter prototype system is built to verify proposed algorithm.

• 전기전자학회논문지
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• 제24권2호
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• pp.586-591
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• 2020

본 논문에서는 인터리브된 전류 주입형 고승압 DC-DC 컨버터가 제안된다. 높은 전압 이득 외에도 인터리빙 방식을 채택하여 낮은 리플 입력 전류가 달성된다. 또한 제안 된 컨버터의 소프트 스위칭 특성은 전력 스위치의 스위칭 손실을 줄이고 변환 효율을 높인다. 변압기의 누설 인덕턴스를 활용하여 다이오드의 전류 변화율을 제어함으로써 출력 정류기의 역 회복 문제도 완화된다. 200W 프로토 타입에서 얻은 실험 결과에 대해 설명한다.

• 전력전자학회논문지
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• 제16권6호
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• pp.618-626
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• 2011

태양전지는 미래에너지를 위한 중요한 신재생에너지원이다. 본 논문에서는 태양광 발전 (PV PCS)를 위한 2단구성 DC/DC컨버터와 동작제어를 제안한다. 넓은 입력전압 제어범위를 갖는 제안된 DC/DC컨버터는 1차 병렬 2차 직렬로 연결된 Two Tank LLC공진컨버터와 Interleaved 승압 컨버터로 구성되어있고, 태양광모듈 전압범위에 따라 하나의 시스템 또는 두 개의 시스템으로 동작시켜 전체 평균효율을 증가시키는 방법을 제안한다. 제안된 컨버터에 대한 동작특성에 대해 분석, 서술되어 있으며, 2.2kW급 시제품 제작 및 실험을 통하여 적용 가능함을 보였다.

• 전력전자학회논문지
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• 제21권3호
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• pp.260-266
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• 2016

A new method for the current ripple reduction of a three-phase interleaved bidirectional DC-DC converter is proposed. The converter used in this study operates in discontinuous mode to minimize the switching losses. All the switches are turned on at ZVS and ZCS conditions, and turned off at ZVS condition. The charging and discharging power of the battery is controlled by varying the switching frequency while maintaining the discontinuous mode operation. A 3 kW 20 kHz power converter is designed and implemented. Simulation and experimental results show the validity of the proposed method. The proposed control method can be used to reduce the battery ripple current significantly.

• 전력전자학회논문지
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• 제27권3호
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• pp.247-255
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• 2022

This paper proposes a multiphase interleaved zero-voltage-transition boost converter with a single soft-switching cell for high-voltage DC-DC converter (HDC) of fuel cell systems. The proposed single soft-switching cell structure can reduce the system volume by minimizing the passive and active elements added even in the multiphase-interleaved structure. To analyze the feasibility of the proposed structure, this paper mathematically analyzes the operation modes of the converter with the proposed single soft-switching cell structure and presents guidelines for design and considerations. In addition, the feasibility of the 210[kW] HDC was confirmed through PSIM simulation, and the system volume reduction of up to 10.48% was confirmed as a result of the 5[kW] HDC test-bed experiment considering the fuel cell system. Through this, the validity of the proposed structure was verified.