• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권12호
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• pp.686-691
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• 1999

In a switching power supply, the high frequency switching makes the passive components small, but the losses and the stresses of switches are increased by the switching frequency. Therefore, zero crossing technology using resonant is used to improve defect in high switching. In generally, zero crossing switching consists of Zero Current Switching(ZCS) and Zero Voltage Switching(ZVS). This paper proposes A Buck ZC-ZVS Converter with Reduced Conduction Losses. Comparing with a conventional Buck ZC-ZVS Converter, the proposed converter operates with the smaller rated power. This is achieved by changing the auxiliary switch position, which reduces its rating power. Simulation results using Pspice program about test circuit with rated 160W(30V, 5.3A) at 30kHz and experiment result under same condition were described in the paper.

• 전력전자학회논문지
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• 제20권2호
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• pp.167-174
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• 2015

This study describes how digital time delay deteriorates control performance in zero voltage switching (ZVS) phase-shifted full bridge (PSFB) converter. The small-signal model of the ZVS PSFB converter is derived from the buck-converter small-signal model. Digital time delay effects have been considered according to the digital sampling methods. The analysis verifies that digital time delays reduce the stability margin of the converter, and the double sampling technique exhibits better performance than the single sampling technique. Both simulation and experimental results based on 250 W ZVS PSFB confirm the validity of the analyses performed in the study.

• 전기전자학회논문지
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• 제16권2호
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• pp.131-137
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• 2012

본 논문에서는 영전압 스위칭(ZVS)과 전류불연속 모드(DCM)에 의한 새로운 고효율의 DC-DC 컨버터에 대해 연구된다. 일반적으로 고효율의 컨버터를 만들기 위해서는 전력변환기내에 사용된 반도체 스위칭 소자의 손실을 최소화하여 이루어진다. 제안한 컨버터는 DCM에 의하여 스위치의 턴-온 동작을 영전류 스위칭(ZCS)으로 만들고, 또한 새로운 유사공진 회로를 접목하여 컨버터의 고효율을 실현시킨다. 제안한 컨버터에 사용된 제어용 스위칭 소자들은 유사공진 기법에 의해 소프트 스위칭, 즉 ZVS와 ZCS으로 동작시키고, 이에 따른 제어용 스위칭 소자들은 전압과 전류의 스트레스 없이 동작한다. 그 결과 제안한 컨버터는 스위칭 손실의 저감에 의해 고효율로 구동된다. 제안한 DCM-ZVS 컨버터의 소프트 스위칭 동작과 시스템 효율은 디지털 시뮬레이션과 실험결과를 통해 그 타당성이 입증된다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.114-117
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• 1999

This paper has described about principle and form of proposed circuit made use of soft switching technology ZVS(Zero-Voltage-Switching) to reduce turn on and off loss at switching. Also, the analysis of the proposed circuit was described by using normalized parameter and operating characteristics has been evaluated as to switching frequency and parameters. Based on the characteristics value, a method of the circuit design is proposed. The theoretical results are in good agreement with the experimental ones. The proposed circuit is considerated to be useful for induction heating and discharge lamp.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 추계학술대회 논문집
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• pp.130-132
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• 2008

In this paper, we have proposed a novel zero-voltage-switching (ZVS) soft-switching H-bridge inverter. Because the conventional H-Bridge inverter generates switching losses at turn on and off, the efficiency is reduced. The proposed inverter operates ZVS switching using an auxiliary switch and resonant circuit to improve the efficiency. in the DC-DC converter stage, it can reduce not only switching loss but also capacity and size of passive devices due to the resonant elements. DC-AC inverter stage supplies load with energy through the ZVS operation of 4 switches. A detail mode analysis of operating is in presented. We have presented the inverter topology, principle of operation and simulation results obtained from the PSIM simulator.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1996년도 창립기념 전력전자학술발표회 논문집
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• pp.71-75
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• 1996

As the Three-level ZVS PWM DC-DC converter operates likewise full-bridge ZVS PWM DC-DC converter and the blocking voltage of each switching device is a half of the DC-link voltage, it is suitable for the high imput voltage applications. However, it has some problems as follows; The blocking voltage of each devices is unbalanced and it causes the power losses of the inner switching devices to be increased. Also, it has narrow load range so that the switching losses and the efficiency are reduced as it goes to the light load. This paper presents an nove Three-level ZVS PWM DC-DC converter, which can reduce the overvoltage of the outer switches, eliminate the unbalance of the voltage sharing between the switches at turn-off due to the stray inductances, and operate from no load to full load. The characteristics and the performances of the proposed Three-level ZVS PWM DC-DC converter are verified by simulation and experimental results

• 전자공학회논문지T
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• 제35T권3호
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• pp.96-102
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• 1998

본 논문에서는 스위칭시 ZVS 기능을 갖는 풀 브리지 위상전이 컨버터의 디지털 컨트롤러의 설계에 대해 연구하였다. 디지털 컨트롤러는 인버터나 전동기 구동 시스템에서 넓게 사용되었다. 그러나 디지털 컨트롤러는 고주파 스위칭 파워 서플라이 (특히 풀브리지 DC/DC 컨버터)에는 적용되지 못했었다. 따라서 본 논문에서는 ZVS 기능을 가진 풀 브리지 위상전이 컨버터의 디지털 컨트롤을 위한 방법을 제안하고, 기존의 아날로그 컨트롤러와 비교하였다. 수치 연산 패키지인 MATLAB을 이용한 컴퓨터 시뮬레이션을 통해 제어기 설계를 최적화하였다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권12호
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• pp.632-640
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• 2003

In conventional Zero-Voltage-Transition(ZVT) PWM converters, zero-voltage turn-on and turn-off for main switch without increasing voltage/current stresses is achieved at a fixed frequency. The switching loss, stress, and noise, however, can't be minimized because they adopt auxiliary switches turned off under hard-switching condition. In this paper, new ZVS-PWM converters of which both active and passive switches are always operating with soft-switching condition are proposed. Therefore, the proposed ZVS-PWM converters are most suitable for avionics applications requiring high-power density. Breadboarded ZVS-PWM boost converters using power MOSFET are constructed to verify theoretical analysis.

• 조명전기설비학회논문지
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• 제15권6호
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• pp.49-57
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• 2001

본 논문에서는 single-stage, two-stage 두가지 역률보상(PFC)기법을 기존의 능동 클램프 플라이백 컨버터에 적용하여 역률개선을 하였다. 삽입된 플라이백 컨버터의 능동클램프회로가 주스위치와 보조스위치의 영전압스위칭(ZVS)을 구현하며, 스위칭 손실을 줄임으로써 고효율을 얻을 수 있고, 높은 주파수에서의 스위칭이 가능하다. 하지만 일반적으로 사용되는 다이오드정류기, 평활용커패시터에 의한 낮은 역률의 문제점이 남아있다. 본 논문에서는 300[W급] 능동 클램프 ZVS 플라이백 컨버터를 설계하여 single-stage two-stage방식을 적용, 입력역률개선을 시뮬레이션과 실험에 의해 입증하고자 한다.

• Journal of Power Electronics
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• 제15권6호
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• pp.1480-1488
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• 2015

In this paper, a revolutionary buck converter is proposed with soft-switching technology, which is realized by a coupled inductor. Both zero-voltage switching (ZVS) of main switch and zero-current switching (ZCS) of freewheeling diode are achieved at turn on and turn off without using any auxiliary circuits by the resonance between the parasitic capacitor and the coupled inductor. Furthermore, the peak voltages of the main switch and the peak current of the freewheeling diode are significantly reduced by the coupled inductor. As a result, the proposed converter has the advantages of simple circuit, convenient control, low consumption and so on. The detailed operation principles and steady-state analysis of the proposed ZVS-ZCS buck converter are presented, and detailed power loss analysis and some simulation results are also included. Finally, experimental results based on a 200-W prototype are provided to verify the theory and design of the proposed converter.