A new soft recovery (SR) quasi-resonant converter (QRC) having a multiple-order folding snubber network(MFSN) is introduced. It is obtained by combining a normal QRC with a folding snubber network of which the surrounding components are composed of passive devices only (diodes and capacitors). The reverse recovery loss of the main rectifier diode is eliminated by this method utilizing multiple ...

A zero voltage switching (ZVS) dc–dc converter with high voltage gain is proposed. It consists of a ZVS boost switch cell converter stage and a ZVS half-bridge converter stage with resonant converter and all these stages are merged into a single stage. The ZVS boost converter stage provides a continuous input current and ZVS operation of the power switches. The ZVS halfbridge converter stage pr...

A single-phase ac-to-dc converter using threephase modified series-parallel resonant converter is proposed in this paper. The three-phase resonant converter is analyzed using Fourier series approach. The design curves for a resonant converter of 2.5 kW rating are plotted. The converter components are selected based on the design curves. The converter is simulated for different load conditions u...

This paper deals with speed control of DC drive fed from parallel QRC. In this work the GA optimization technique is successfully applied for speed control of QRC fed DC drive. In general PI controllers are used as conventional feedback controllers but the advent of Fuzzy logic controllers (FLC) enhances the effectiveness of control. In addition the drive fed from Zero current switching Quasi-r...

The isolated bidirectional ac–dc converter is for the 380-V dc power distribution system to control the bidirectional power flow and to improve its power conversion efficiency. Here the high-side switches of the ac– dc rectifier employ IGBTs without anti-parallel diodes and SiC diodes. In addition, the low-side switches are consisting of two MOSFETs to reduce the conduction loss in the rectific...

A new converter using a switched-inductor cell integrated with a switched-capacitor cell within a boost-like structure is proposed. The converter can achieve a very high dc conversion ratio. It can serve as the front-end dc-dc converter for a fuel cell in a UPS system. The inductors and capacitors are switched in a parallel-series configuration. The charging circuit of the inductors from the so...

In hard-switched converters, the switching frequency is limited by switching losses and EMI problems. However, high-switching frequency is necessary to reduce the converter size. Hence, soft switching is imperative at high switching frequency to obtain good efficiency. Push–pull converter is a preferred topology at medium power level. This paper proposes a novel resonant transition topology for...

In this paper, a two-stage AC/DC converter is presented for a low-profile laptop adaptor. The system consists of a boost power factor pre-regulator and LLC resonant converter. The pre-regulator features high PF and high-efficiency, while secondary LLC converter features zero voltage switching (ZVS). The transformer in LLC converter is splited in two to reduce current stress and converter height...

This paper reports on the stability analysis of one member of a dual-channel resonant dc–dc converter family. The study is confined to the buck configuration in symmetrical operation. The output voltage of the converter is controlled by a closed loop applying constant-frequency pulsewidth modulation. The dynamic analysis reveals that a bifurcation cascade develops as a result of increasing the ...

The DC-DC Converter topologies have received increasing attention in recent years for Low power and high performance applications. The advantages DC-DC buck converters includes increased efficiency, reduced size, reduced EMI, faster transient response and improved reliability. The front end LCL-T in a buck converter is connected in sequence manner to improve the electrical performances and to r...