A Single-Stage Transformer-less Five-Level Grid-Tied Inverter with Boosting Capability

Abstract

In this study, a single-phase single-stage grid-connected structure without transformer is presented. The proposed structure has the ability to boost the input voltage level without adding an extra dc-dc stage. In addition, being transformer-less makes it cost-efficient and small. Since in positive and negative half cycles there is a route for the capacitor to get charged, the capacitor has less volume compared with traditional topologies. It makes the inverter benefit from more power density. Peak Current Controller (PCC) has been used as the control system of the inverter to support powers (active and reactive) by providing modulation signals for the nine switches. The proposed converter is compared with similar solutions in a comparison table. Simulation results are demonstrated in order to validate the theoretical investigations.