High gain bidirectional DC-DC converter with reduced component count

Abstract

Solar Photovoltaic system as a source and battery as an intermediary load necessitates the development of bidirectional dc-dc converter. Conventional battery loads are rated at 12 V to 48 V. High gain is required both in step up and step down modes to supply the ac grid or charge from the grid. Conventional isolated transformer based topologies can be designed with high gain at the expense of increase in component count and requirement of snubber circuits for protection as the leakage inductance causes a spike across the switch resulting in losses, complex control schemes and the requirement of over rated components. Non isolated converter circuits with coupled inductors are used for low power systems. The size of the converter, magnetic losses increase with increase in the inductance for higher power capability. The proposed converter is a non isolated converter requiring minimum number of switches. Various operating modes and the analysis of the converter are discussed. Simulation results of the system with MATLAB and PSIM are presented.