A Zero Ripple High Step-up DC/DC Converter With Three-winding Coupled Inductor

High step-up DC/DC converters with zero input current ripple have attracted much attention for the renewable energy grid-connected generation system. A zero ripple high step-up DC/DC converter with three-winding coupled inductor was deduced in this paper, which combined a high step-up DC/DC converter with coupled inductor and a passive zero ripple circuit. The characteristics of high step-up and zero ripple were realized by using the three-winding coupled inductor. The voltage gain was improved by using the voltage multiplier, meanwhile, the voltage spikes of the resonance between the leakage inductance and the diode stray capacitor were cancelled. Two switches were clamped by each other, which reduced the switch turn-off voltage spikes, and zero-voltage-switching operation was achieved. The voltage stresses of all components are far below the output voltage, so the efficiency of the converter can be further improved by choosing low-voltage rated components. Finally, a 250W, 48V/380V prototype was built to confirm the validity of the theoretical analysis.