High-Gain ZVS–ZCS DC–DC Landsman Converter With Low-Input Current Ripple

This article introduces a new high step-up nonisolated dc–dc converter with continuous input current and minimal ripples. It is based on the conventional Landsman converter while incorporating coupled inductor and voltage multiplier techniques. By differentially connecting the load between the input and output capacitors, the converter's voltage gain is further enhanced. The converter also operates in a quasi-resonant mode (QRM), ensuring zero-current switching (ZCS) turn-ON and turn-OFF for diodes, while the current ripple of the magnetic devices aids zero-voltage switching (ZVS) turn-ON of active switches. This design yields reduced voltage stresses on the active switches and enables the usage of compact capacitors and magnetic devices, improving power density. To validate its performance, a prototype circuit was constructed with input voltage range of 35–45 V, output voltage of 400 V, and output power of 150 W. The efficiency tests indicate that the highest efficiency obtained is 97.6%, with weighted efficiencies exceeding 96.5% across the entire input voltage range. The analysis of the converter and a comparison with other similar topologies are also presented.