A High Efficiency Input/Output Magnetically Coupled Interleaved Buck–Boost Converter With Low Internal Oscillation for Fuel-Cell Applications: CCM Steady-State Analysis

Abstract

The performance of dc-dc converters plays a vital role in the exploitation of renewable energy sources such as solar and fuel cell (FC). This paper demonstrates the feasibility of using the input/output (I/O) magnetically coupled interleaved buck-boost converter, improving the conventional interleaved cascaded buck-boost converter in FC applications. While keeping the same step-up/step-down voltage transfer ratio, the proposed topology facilitates operating conditions with its nonpulsating I/O currents and high efficiency using interleaved technique and reducing switches' voltage stresses, respectively. The steady-state operation of the converter is analyzed based on the state-space-averaging method and supported with simulation results. The prototype setup of 360-W and 36-V output voltage for an FC with a brand of “FCgen 1020ACS” Ballard Power Systems, Inc. was implemented. Experimental results are presented to verify the theoretical expected merits of the converter, including high efficiency and nonpulsating I/O currents.