A Novel Five-Level Transformer-less Inverter Topology with Common-Ground for Grid-Tied PV Applications

This paper proposes a new common ground transformer-less step-up 5-Level inverter using a single dc voltage source without leakage current for grid-connected PV applications. The proposed inverter is based on the flying capacitor concept which uses seven switches, three dc capacitors and a single dc source to generate a 5-level discrete output voltage. The main merits of the proposed single-stage topology include common-ground type, reactive power support, boosting capability and a fewer number of components compared with recently introduced five-level topologies. The proposed inverter has double voltage boosting gain without utilizing any step-up dc/dc converter which makes it a promising structure for grid-tied PV applications. The superiority of the proposed inverter is compared with similar existing five-level topologies in order to highlight its advantages. Moreover, a 1-kVA experimental prototype is implemented to show the proficiency of proposed inverter.