• Journal of Power Electronics
• /
• v.3 no.1
• /
• pp.17-23
• /
• 2003

A new three-phase soft-switching active front-end inverter is presented. The topology consists of a quasi-resonant PWM boost converter with an additional resonant branch, which provides low loss at high frequency operation. This leads to a high conversion efficiency and a remarkable reduction in the siBe of the input inductor. To synchronise the PWM pattern with the resonance cycle, a modified space vector modulation with asymmetrical PWM pattern is used. A high power factor can be achieved for both power flow directions. Due to a new control strategy the converter features a low content of harmonics in the line currents even for distorted line voltages.

• Proceedings of the KIPE Conference
• /
• 2005.07a
• /
• pp.459-462
• /
• 2005

Recently, the PDP is the most remarkable media for a next generation display device. But the PDP is a high power consumption device. It is to required a high efficiency power supply. We reported the experimental result the high efficiency PDP power supply for 550w class. The proposed converter is quasi-resonant flyback topology, it achieves soft-switching in the single-switch flyback converter. As a result, we realize to very high efficiency power supply for PDP of 95% at 400v dc input and 550Watt output.

• Proceedings of the KIPE Conference
• /
• 2013.07a
• /
• pp.184-185
• /
• 2013

In this paper, design of a variable inductor using MR Fluid Gap is proposed for wide load range efficiency improvement of a bidirectional DC-DC converter. As compared to conventional constant value inductor designed to have negative current for ZVS at heavy load but suffers high losses at light load due to its small inductance, the proposed variable inductor not only have small inductance at high current for ZVS but also it has large inductance at low current to decrease light load losses.

• Proceedings of the KIEE Conference
• /
• 2000.07b
• /
• pp.1318-1320
• /
• 2000

In this paper, DC/DC converter has been composed of a capacitor which has not only a source division function but a resonant function instead of a previous source division capacitor. In addition to the proposed circuit is introduced a soft switching technique (ZVS). The proposed paper certified that theoretical waveforms are equal to experiment waveforms of power, output voltage, voltage ripple etc. and to be possible to control using division ratio.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.15 no.2
• /
• pp.31-37
• /
• 2001

This paper propose ZVS-HB type resonant DC/DC converter have earth different output characteristics using division ratio, not only a source division function but a resonant function and soft switching technique(ZVS, ZCS) instead of conventional source division capacitor. Circuit analysis generally described using normalized parameters most of characteristics with division ratio of source division capacitor. Also, this paper citified a rightfulness of characteristic analysis in comparison with a theoretical values and a experimental values obtain from experiment using Power-MOSFET.

• Journal of Power Electronics
• /
• v.19 no.2
• /
• pp.431-442
• /
• 2019

This paper proposes a unified high-frequency bipolar buck-boost (UHFBB) control strategy for a dual-active-bridge (DAB), which is derived from the classical buck and boost DC/DC converter. It can achieve optimized current stress of the switches and soft switching in wider range. The UHFBB control strategy includes multi-control-variables, which can be achieved according to an algorithm derived from an accurate mathematical model. The design method for the parameters, such as the transformer turns ratio and the inductance, are shown. The current stress of the switches is analyzed for selecting an optimal inductor. The analysis is verified by the experimental results within a 500W prototype.

• Proceedings of the KIPE Conference
• /
• 2001.10a
• /
• pp.146-150
• /
• 2001

A new three-phase soft-switching active front-end inverter is presented. The topology consists of a quasi-resonant PWM boost converter with an additional resonant branch, which provides low loss at high frequency operation. This leads to a high conversion efficiency and a remarkable reduction in the size of the input inductor. To synchronise the PWM pattern with the resonance cycle, a modified space vector modulation with asymmetrical PWM pattern is used. A high power factor can be achieved for both power flow directions. Due to a new control strategy the converter features a low content of harmonics in the line currents even for distorted line voltages.

• Proceedings of the KIEE Conference
• /
• 2001.07b
• /
• pp.950-952
• /
• 2001

This paper proposes a new zero-current transition (ZCT) pulse-width modulation (PWM) switch cell that overcomes the limitations of the conventional ZCT converters. The proposed ZCT cell provides zero-current-switching (ZCS) condition for the main switch and the auxiliary switch. The conduction loss and current stress of the main switch are minimized, since the circulating current for the soft switching does not flow through the main switch. The proposed ZCT PWM switch cell is suitable for the high power applications employing IGBTs. Design guidelines with a design example are described and verified by experimental results from the 1 kW prototype boost converter operating at 70kHz.

• Proceedings of the KIPE Conference
• /
• 2017.07a
• /
• pp.14-15
• /
• 2017

본 논문은 브릿지형 양방향 전력변환장치의 기본 제어 방식을 유지하면서 효율을 향상시키기 위하여 소프트 스위칭을 하는 준공진 회로를 비교한다. 각 회로의 이론적 분석 및 시뮬레이션 검증을 통하여 제어 방식과 효율 개선 관점에서 장단점을 분석한다. 분석결과를 기반으로 전력변환장치의 정격용량 및 스위칭 주파수에 적합한 준공진 스위칭 셀을 도출한다.

• Proceedings of the KIPE Conference
• /
• 2015.07a
• /
• pp.175-176
• /
• 2015

위상천이 풀브리지 컨버터는 소자의 기생성분과 PWM의 위상천이를 이용한 소프트 스위칭을 통해 고효율을 얻을 수 있기 때문에 산업현장에서 널리 사용되어 왔다. 그러나 ZVS(Zero Voltage Switching) 범위가 한정적이며, 누설인던턴스에 의해 듀티 손실이 발생하고, 특히 경부하시 순환전류에 의한 손실 증가로 인해 효율이 낮아지는 단점이 있다. 본 논문에서는 2차측에 프리휠링을 위한 스위치와 다이오드를 추가함으로써 기존의 위상천이 풀브리지(PSFB) 컨버터가 가지는 단점들을 극복한 새로운 소프트 스위칭 풀브리지 컨버터를 소개하고, 3kW급 프로토 타입을 통하여 그 유효성을 검증하였다.