A New Grid-Tied Transformerless SCMLI with Common Ground for PV Application

Abstract

Transformerless grid-connected multi-level PV (photovoltaic) inverters are not appropriate for low voltage PV applications due to their substantial concerns regarding leakage current and buck behavior of output voltage. In this study, a new nine-level inverter that offers four times the input voltage gain is proposed. It is based on a switched capacitor (SC) with a common grounding (CG) design. This inverter is therefore preferred for low voltage PV applications since it lacks an intermediary boost dc/dc converter stage. In order to permit nine steps in output voltage, two SC cells are used to step-up the input PV voltage. The proposed inverter topology's shared grounding feature aids in reducing leakage current. This new inverter can also manage reactive power whether the grid's power factor (pf) is lagging or leading. A proportional resonant (PR) controller is developed to govern the active and reactive grid power. There include sections on the PWM scheme, the inverter circuit details, and a comparison analysis. To verify that this proposed inverter is accurate, simulation results are presented.