Evaluation of single-stage power converte topologies for grid-connected Photovoltaic

Renewable energy sources such as Photovoltaics (PVs) and Fuel Cells (FCs) generate DC voltage/current and have a high internal resistance/nonlinear V/I dependence, which is why a digitally controlled power electronic interface is always needed to facilitate connection to an AC grid and maximum power extraction. This paper evaluates four single-stage power electronic converters for PVs: the traditional voltage source (VSI) and current source (CSI) inverters and the newly proposed Z-source (ZSI) inverter and CSI with series connected AC capacitors (CSI+SC).