High voltage gain single-switch non-isolated DC-DC converters for renewable energy applications

A new class of single-switch non-isolated dc-dc converters with high-voltage gain and reduced semiconductor voltage stress is proposed in this paper. The proposed topologies utilize a voltage multiplier cell and/or hybrid switched-capacitor technique for providing high voltage gain without extreme switch duty-cycle. This enables the use of a lower voltage and R_DS-ON MOSFET switch, which will reduce costs as well as switching and conduction losses. The components' voltage ratings and energy volumes of passive components of the proposed converters are greatly reduced compared to other high step-up converters. In addition, the low voltage stress across the diodes allows the use of Schottky rectifiers for alleviating the reverse-recovery current problem, leading to a further reduction in the switching and conduction losses. Other advantages of the proposed topologies include: continuous input/output current, simple structure and control. The principle of operation, theoretical analysis, and performance comparisons between the proposed and other high step-up converters is performed. Experimental results of a 50 W / 240 V_dc with 24 V_dc input voltage are provided to evaluate the performance of the proposed scheme.