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In this article, a quasi-resonant bridgeless power factor correction (PFC) converter is presented. Aiming to improve the input current total harmonic distortion, a single auxiliary switch with low voltage stress than the similar counterparts is employed. Due to resonant operation, the size and value of the passive components are reduced and maximum voltage gain of four is achieved which is higher than that of conventional buck PFC converter. Also, soft switching condition for the main semiconductor elements is realized from 20% of nominal power to full load and entire input voltage range (90 to 130 Vrms) without employing any extra component. The operating modes are explained and the theoretical analysis is discussed in details. A straightforward design procedure for the proposed converter is presented. A 200 W, 160 kHz laboratory prototype is implemented to verify the theoretical analysis and the effectiveness of the proposed topology. [ABSTRACT FROM AUTHOR]

A nonisolated bidirectional dc–dc converter with high voltage gain, low voltage stress, low component count, and soft-switching features is presented in this paper. In this topology, coupled inductors and voltage multiplier cells are merged to achieve high step-up/down voltage gain. Also, due to using active clamp circuits, the voltage stress of power switches is relatively low. Thus, the low voltage switches with low on-resistance can be employed to reduce the conduction losses. Furthermore, zero-voltage switching is accomplished in both high step-up and high step-down modes for all power switches, and due to zero-current switching operation of all antiparallel diodes, the reverse recovery losses are reduced. In order to verify the theoretical analysis and the converter performance, a 200 W prototype circuit of the proposed converter is implemented in the laboratory. [ABSTRACT FROM AUTHOR]

This paper proposes a soft switching nonisolated dc/dc interleaved converter incorporating coupled inductors and switched capacitors for high step-up applications. The converter integrates the interleaved structure and winding-cross-coupled inductors technique to reduce current stress of semiconductor devices and diminish the input current ripple considerably. In addition, the interleaved converter has the automatic current sharing characteristic. The applied zero voltage transition cell provides soft switching in a wide range of load variations with a minimum number of elements. In this topology, all semiconductor devices are soft switched, having eliminated switching losses and alleviating the reverse recovery problem of the output diodes. In addition, the voltage stress across the switches is very low. The theoretical analysis and design procedure of the introduced topology are presented. Also, the proposed converter is compared to the latest similar soft switched high step-up converters. The accuracy of the theoretical analysis is validated by a 200-W prototype operating at 100 kHz. [ABSTRACT FROM PUBLISHER]