Isolated ZVS-ZCS DC–DC High Step-Up Converter With Low-Ripple Input Current

This article proposes a galvanically isolated high step-up dc–dc converter for dc microgrid applications. By the use of an inductor, a transformer, a voltage multiplier, and an active clamp, the proposed converter is able to provide very high dc voltage gains along with reduced voltage stress across the semiconductors, zero-voltage and zero-current switching for the switches and the diodes, respectively, low ripple input current, and reduced component count. The analysis of the converter in continuous conduction mode (CCM) and a comparison with other previously published isolated topologies are also presented. Finally, a prototype has been built for a power of 250 W to verify the functionality of the proposed converter in CCM operation, with an input voltage range of 20–28 V and an output voltage of 400 V.