An Interleaved Soft Switching High Step-Up Converter With Low Input Current Ripple and High Efficiency

This paper proposes a high step-up low-ripple dc-dc converter for sustainable energy conversion. A high step-up voltage gain is obtained with an input-current doubler and a switched-capacitor circuit rather than having to use a transformer with a high turn ratio. A low input current ripple is achieved since the current ripples of two input inductors cancel each other out when the primary-side branches work in an interleaving way. A low output voltage ripple is got by charging and discharging complementarily with each other of two output capacitors. In addition, the proposed converter achieves zero-voltage switching (ZVS) for all power switches and zero-current switching (ZCS) for all rectifier diodes, which reduces the switching loss significantly. Moreover, an active-clamp capacitor is installed on the input-current doubler to suppress the voltage spike across the switches. A 400-W prototype converter was realized to demonstrate the above-mentioned performance.