This paper introduces a high–conversion ratio multi-phase non-isolated DC–DC topology built from generic series-capacitor boost cells. Using a stand-alone LC cell, the approach contributes to a high modularity of the resulting converters and enables high conversion ratios. The unique interaction between the capacitor and the inductor results in a soft charging operation, which curbs the losses of the converter and contributes to higher efficiency. The method was used to create a multi-phase step-up DC–DC module with maximum power point tracking (MPPT) control for microinverters. The new converter significantly extends the effective duty ratio and lowers the voltage stress of the transistors. In addition, it has inherent current sharing to balance the load between the phases. Experimental results of a modular interleaved two phase prototype demonstrate an excellent proof of design methodology concept and agree well with the simulations and theoretical analyses developed in this study.
