Experimental verification of floating-output interleaved-input DC-DC high-gain transformer-less converter topologies

In transformer-less fuel-cell energy conversion systems the voltage-gain is required to be as high as possible. Although component parasitic elements limit the practically realizable voltage-gain of any converter topology, this becomes a critical issue in the case of the basic step-up converter. In this paper, a comparative evaluation of two high-voltage-gain interleaved step-up derived converter topologies suitable for fuel-cell applications is documented. Both converter topologies offer lower input-current/output-voltage ripple and lower voltage/current ratings of the various circuit elements when compared to the basic step-up topology. Analysis and simulation results are provided and experimental results taken from low power laboratory prototypes are presented.