High step-up voltage-doubling DC-DC converter with coupled inductors

In this paper, a novel high step-up DC-DC converter is presented. The proposed topology is composed by a nonlinear-gain boost converter with two coupled inductors and integrated with two voltage-doubler circuits to accomplish high step-up voltage ratio. In addition, the energy stored in leakage inductance can be retrieved during switch-off period. Moreover, the voltage across the switch is effectively clamped under a lower voltage rating and therefore a low on-resistance power switch can be adopted to reduce the conduction loss. Attributing to the above-mentioned merits, the conversion efficiency can be apparently improved. Finally, a novel high step-up DC-DC converter with 18~26 V input voltage, 400 V output voltage and 200 W output power is implemented to verify the proposed topology.