Design optimization of a high step-Up DC-DC converter for photovoltaic microinverters

A design optimization of a generalized high step-up dc-dc converter applied as front-stage in a photovoltaic (PV) microinverter is proposed. The design methodology optimizes the weighted California Energy Commission (CEC) efficiency of the generalized converter considering not only the classical parameters, as turns ratio and switching frequency, but also the topology structure through different connections of voltage multiplier cells. Two design optimizations have been carried out. The first maximizes only the CEC efficiency, obtaining results around 98%. In the second it was added terms related to cost and volume in the objective function, which results in a converter with lower CEC efficiencies — around 96% — but with a higher power density and lower cost.