Implementation of a new high step-up DC-DC converter for applications in renewable energy conversion of a smart grid

A high step-up DC-DC converter with three-winding coupled inductor and clamp capacitor is proposed in the paper. The three-winding coupled inductor and voltage doubler are used to increase the voltage conversion ratio without an extreme duty ratio. The input current is operated at continuous conduction mode (CCM) with reduced input current ripple; the lifetime and reliability of the input filter can be improved accordingly. Clamp capacitor in the proposed converter is to clamp and reduce the voltage stress of active switch. The active switch with low power-rating and low on-resistance can thus be employed to reduce switching and conduction losses. In the proposed circuit, the leakage energy can also be recycled to the output capacitor at the load terminal and the reverse-recovery problem of output diode can be alleviated to increase the efficiency. Simulated and experimental results have been presented to verify the effectiveness of the proposed circuit.