Extended high gain DC-DC converter with switched-inductors, switched-capacitors and soft-switching: Analysis and implementation

This paper proposes an extended DC-DC converter with high voltage conversion ratio and soft-switching ability. The proposed converter has active switched-inductors, switched-capacitors included in the conventional high gain converter and operates in continuous conduction mode (CCM). Simple auxiliary resonant elements are added on the primary leg of the converter to provide design freedom for soft-switching operation. The significant merits of the proposed converter are lesser voltage and current stresses, high voltage gain with reduced component count and better efficiency. Additional feature of this converter is soft-switching operation under different load conditions and duty ratios without considerably increasing stresses. The zero voltage switching (ZVS) turn-on operation is obtained for all switching devices. Therefore, switching power losses are minimized greatly. This paper presents the description, principles of operation and steady state analysis in comparison with the existing high gain converters. The theoretical analysis is verified with a 350 W prototype operated at input is 20 V and output is 220 V. The overall efficiency achieved is 96.7%. The obtained results confirm ZVZCS operation at full load.