• 전력전자학회:학술대회논문집
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• 전력전자학회 2019년도 전력전자학술대회
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• pp.139-141
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• 2019

Capacitive power transfer has an advantage in the simplicity of the energy link structure. So, the conventional phase -shift full bridge sometime is not always the best choice because of its complexity and high cost. On the other hand, the link capacitance is usually very low and requires high-frequency operation, but, the series resonant converter loses zero-voltage switching feature in the light load condition, which makes the switching loss high especially in CPT system. The paper proposes a new low-cost topology based on asymmetric half-bridge to achieve simplicity as well as wide zero voltage switching range. The design procedure is presented, and circuit operations are analyzed and verified by simulation.

• Journal of Power Electronics
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• 제14권1호
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• pp.30-39
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• 2014

This paper studies a new three-level pulse-width modulation (PWM) resonant converter for high input voltage and high load current applications. In order to use high frequency power MOSFETs for high input voltage applications, a three-level DC converter with two clamped diodes and a flying capacitor is adopted in the proposed circuit. For high load current applications, the secondary sides of the proposed converter are connected in parallel to reduce the size of the magnetic core and copper windings and to decrease the current rating of the rectifier diodes. In order to share the load current and reduce the switch counts, three resonant converters with the same active switches are adopted in the proposed circuit. Two transformers with a series connection in the primary side and a parallel connection in the secondary side are adopted in each converter to balance the secondary side currents. To overcome the drawback of a wide range of switching frequencies in conventional series resonant converters, the duty cycle control is adopted in the proposed circuit to achieve zero current switching (ZCS) turn-off for the rectifier diodes and zero voltage switching (ZVS) turn-on for the active switches. Finally, experimental results are provided to verify the effectiveness of the proposed converter.

• 전력전자학회논문지
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• 제15권6호
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• pp.432-440
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• 2010

본 논문에서는 단일 스위치를 사용한 LC 직렬 공진형 부스트 컨버터를 제안하였다. 제안하는 토폴로지는 별도의 보조 스위치의 추가 없이 일반 부스트 컨버터에 수동소자만을 추가하여 스위치 턴-온, 턴-오프 시 영전압 스위칭(ZVS; Zero Voltage Switching)을 수행한다. 이 토폴로지는 LC직렬 공진에 의해 스위치 오프 타임이 결정되므로, 스위치 온 타임을 가변하여 출력전압을 조절하는 온 타임 가변형 주파수 변조 기법으로 제어된다. 전류 도통 경로에 따라 제안된 회로의 동작 모드를 구분하였고, 제안된 컨버터의 동작모드와 특성은 수학적 해석과 시뮬레이션 및 실험을 통해서 검증하였다.

• 조명전기설비학회논문지
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• 제15권2호
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• pp.64-72
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• 2001

본 논문에서는 비접촉 충전 에너지 전달을 위한 포워드 ZVS MRC(Zero Voltage Switching Multi Resonant Converter)를 제안하였다. 포워드 ZVS MRC는 기생성분을 흡수하는데 그리고 스위칭손실을 최소화하는데 효과적이다. 이것은 높은 주파수동작에 적합하며 따라서 이것을 비접촉 충전에너지 전달에 적용하였다. 사용된 컨버터는 분리형 트랜스포머와 동기식정류기를 이용하였다. 갭의 크기에 따른 결합계수(k), 누설인덕턴스, 결합인 덕턴스 그리고 공진 주파수를 측정하였다. 구해진 값을 이용하여 회로를 설계, 구현하였으며 제안된 회로는 PSPICE로 시뮬레이션하였고 실험하였다. 주스위치의 전압 스트래스와 출력전력을 측정하였으며 제안된 컨버터가 비접촉 충전 에너지 전달에 적합함을 보였다.

• Journal of Power Electronics
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• 제13권2호
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• pp.177-185
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• 2013

This paper studies a soft switching DC/DC converter to achieve zero voltage switching (ZVS) for all switches under a wide range of load condition and input voltage. Two three-level PWM circuits with the same power switches are adopted to reduce the voltage stress of MOSFETs at $V_{in}/2$ and achieve load current sharing. Thus, the current stress and power rating of power semiconductors at the secondary side are reduced. The series-connected transformers are adopted in each three-level circuit. Each transformer can be operated as an inductor to smooth the output current or a transformer to achieve the electric isolation and power transfer from the input side to the output side. Therefore, no output inductor is needed at the secondary side. Two center-tapped rectifiers connected in parallel are used at the secondary side to achieve load current sharing. Due to the resonant behavior by the resonant inductance and resonant capacitance at the transition interval, all switches are turned on at ZVS. Experiments based on a 1kW prototype are provided to verify the performance of proposed converter.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.1065-1067
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• 2000

This paper describes performance analysis of ARCP Inverter, which can offer zero voltage switching at nominal voltage stress. The system consists of a voltage-source inverter with sort-switching module. Each main switch is connected in parallel with resonant capacitor and two auxiliary switches are placed in series with a resonant reactor for soft-switching capability. The described ARCP inverter could be effectively applied for active power filter reactive power compensator, and UPS.

• 전력전자학회논문지
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• 제2권4호
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• pp.1-10
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• 1997

공진형 듀얼 컨버터는 스위칭손실이 낮은 고주파 스위칭으로 전력변환을 실현할 수 있는 회로방식으로서 주목받고 있다. 본 논문에서는 유도전동기를 부하로 하여 구동과 회생운전이 가능한 쌍방향 공진형 전력변환 시스템을 구축하고, 이 시스템의 실제적인 적용을 위하여 일련의 실험을 통해 제작시스템의 운전특성을 검증한다. 고찰부분으로서는 입출력특성, 공진부특성, 주소자와 클램프소자에서의 턴 오프특성 및 영전압특성에 대한 실험결과를 대상으로 한다. 본 연구에서는 관측된 파형들을 검증함으로서 제작시스템에 있어서의 문제점을 고찰하고 금후의 연구를 위한 제안을 제시하고자 한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.68-73
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• 1998

This paper presents a novel prototype of active voltage clamped quasi-resonant ZVS-PWM forward DC-DC converter designed for specific low voltage high current application. We establish the soft-switching forward converter with a high frequency isolated link which can efficient operate over wide load ranges under conditions of zero voltage soft-switching and active voltage clamped switching. In addition, we evaluate connection of the soft-switching forward converter with large capacitor which capacitance is over 100[F].

• 전력전자학회논문지
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• 제21권3호
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• pp.224-230
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• 2016

In this study, a single-power-conversion series-resonant ac-dc converter with high efficiency and high power factor is proposed. The proposed ac-dc converter consists of single-ended primary-inductor converter with an active-clamp circuit and a voltage doubler with series-resonant circuit. The active-clamp circuit clamps the surge voltage and provides zero-voltage switching of the main switch. The series-resonant circuit consists of leakage inductance $L_{lk}$ of the transformer and resonant capacitors $ C_{r1}$ and $ C_{r2}$. This circuit also provides zero-current switching of output diodes $D_1$ and $D_2$. Thus, the switching loss of switches and reverse-recovery loss of output diodes are considerably reduced. The proposed ac-dc converter also achieves high power factor using the proposed control algorithm without the addition of a power factor correction circuit and a dc-link electrolytic capacitor. A detailed theoretical analysis and the experimental results for a 1kW prototype are discussed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 학술대회 논문집 전문대학교육위원
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• pp.66-70
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• 2000

This paper deal with a design and a constant output power control of Zero Current Zero Voltage Switching(ZCZVS) resonant type DC-DC converter by a digital I-PD phase shift controller. When the DC-DC converter for a high density and a high effect control is operated in high speed switching, the switching loss and switching stress of the switching devices are increased. So, the ZCZVS method, which has the phase shift control with the digital I-PD controller, must be use in order to reduce its. And the constant output power voltage that controlled by the digital I-PD controller tracks a reference without steady state error in variable input voltage. The validity of control strategy that proposed is verified experimental results by the Digital Signal Processor TMS320C32.