A Nonisolated Soft Switching Interleaved Converter With Extended Duty Cycle and Low Output Current Ripple

In this article, a new nonisolated interleaved dc–dc converter with extremely extended duty cycle and low current ripple is presented. The applied interleaved architecture along with complementary operation of the switches provide zero voltage switching condition for all switches and reduce the output current ripple. Both of diodes turn ON and turn OFF under zero current switching condition, and thus the reverse recovery losses associated with the diodes are eliminated. In the proposed converter, energy-transferring capacitors are used as voltage sources to reduce the input voltage and the switches voltage stress. Also, the coupled inductors are applied to extend the duty cycle while the leakage energy is absorbed without imposing extra voltage stress across the switches. As a result, extremely high step down voltage conversion ratio is achieved and the overall efficiency is improved. In this architecture, the input shares the ground with the output and any auxiliary circuit is not required. The operating modes of the proposed converter are analyzed and the presented experimental results confirm the theoretical analysis.