• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.2
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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.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.111-115
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• 1997

This Paper is concerned on developing DC-DC converter using ZVS-FB-PWM Converter. The converter output is 28V and regulated by phase shift control methode. MOSFET is used by the main switching device and high frequency transfomer is made for operating at 300㎑ switching frequency. When the load vary widely, converter's ZVS characteristic is expressed by experiment result.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.7
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• pp.982-987
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• 2012

The power supply devices applied to the electric vehicle are required for high efficiency and high power density. This paper presents a bidirectional ZVS DC-DC converter. A bidirectional DC-DC converter using the planar transformer has advantages of high efficiency, simple circuit, and lightweight. The operating principle, theoretical analysis, and design guidelines are provided in this paper. The simulation waveforms of the proposed converter are shown to verify its feasibility.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.615-619
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• 2004

A new asymmetrical zero voltage switching (ZVS) active clamp forward converter is proposed. Since the ripple current of secondary inductor plays a key role in the ZVS operation of main power switch, the proposed converter shows an excellent ZVS performance. The synchronous rectification is employed to reduce the rectification loss. The operational principle and ZVS analysis are presented. Experimental results demonstrate that the proposed converter can achieve an excellent ZVS performance throughout all load conditions and the significant improvement in the efficiency for the 100W(5V,20A) prototype converter.

• Journal of Power Electronics
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• v.6 no.3
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• pp.187-194
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• 2006

A new asymmetrical pulse width modulation (PWM) half bridge converter with improved ZVS performance is proposed. The ZVS operation of the proposed converter can be maintained from no load to full load conditions since the magnetizing current of the transformer contributes to the ZVS operation at light loads without considerable conduction loss of the transformer and switch. Synchronous rectification is employed to reduce the rectification loss. Operational principles, large signal modeling, ZVS analysis and design equations are presented. Experimental results demonstrate that the proposed converter can achieve a large ZVS range and significant improvement in efficiency for a 100W (5V, 20A) prototype converter.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.1-4
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• 1998

In this paper, we proposed the alternated forward zero voltage switching multi-resonant Converter (AT Forward ZVS MRC). The AT forward ZVS MRC has similar characteristics with clamp mode forward ZVS MRC. So it can reduce the voltage stress to tow or three times a input density [W/inch2]. The proposed converter type is verified through the experimental converter with 48V input voltage, 5V/50W output voltage/power. The measured maximum voltage stress is 170V of 2.9 times the input voltage and the maximum efficiency of 81.66% is measured.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.150-152
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• 1998

ZVS Half-Bridge converter is proposed. This converter is operating in fixed switching frequency to regulate output voltage. The ZVS is maintained by Partial resonance during the OFF interval of both switches. Using self-driven synchronous rectifier, this circuit minimizes the Power loss in the rectification circuit. 50[W] ZVS Half-Bridge converter is simulated and built. Two results has been compared.

• Journal of Power Electronics
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• v.14 no.2
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• pp.237-248
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• 2014

Pulse-width modulated (PWM) full-bridge boost converters are used in applications where the output voltage is considerably higher than the input voltage. Zero-voltage-switching (ZVS) is typically implemented in these converters. A new ZVS-PWM full-bridge converter is proposed in this paper. The proposed converter does not have any of the disadvantages associated with other converters of this type, including a complicated auxiliary circuit, increased current stresses in the main power switches, and load-dependent ZVS operation. The operation of the proposed converter, its steady-state characteristics, and its design are explained and examined. The feasibility of the converter is confirmed with results obtained from an experimental prototype.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.12
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• pp.101-108
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• 2013

This paper presents A Zero-Voltage-Switching(ZVS) Three-Level DC/DC Converter using Primary Clamping Diodes. The Previous ZVS Three-Level DC/DC converter realizes ZVS for the switches with the use of the leakage inductance(or external resonant inductance) and the output capacitors of the switches, however the rectifier diodes suffer from recovery which results in oscillation and voltage spike. In order to solve this problem, this paper proposes a novel ZVS Three-Level DC/DC converter, which introduces two clamping diodes to the basic Three-Level converter to eliminate the oscillation and clamp the rectified voltage to the reflected input voltage.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.2
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• pp.202-215
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• 2013

This paper proposes a SEPIC-input, self-driven, active clamp ZVS converter, where an auxiliary winding and a RC delay circuit are employed to drive the active clamp switch and to achieve asymmetrical duty control without any other extra circuits. Based on the fixed dead time and the resonance between capacitors and inductors, both the main switch and the auxiliary switch can rule the ZVS operation. Detailed operation modes are presented to illustrate the self-driven and ZVS principles. Furthermore, an accurate state-space model and the transfer functions of the proposed converter have been presented and analyzed in order to optimize dynamic performance. The model provides efficient prediction of converter operations. Experimental results, based on a prototype with 80V input and 15V/20A output, are discussed to verify the transient and steady performance of the proposed converter.