Single-Phase Single-Stage Transformerless PV Inverter Used for the Minimization of Leakage Current in the Grid Connected Systems

Abstract

This paper introduces a solution using a single-phase single-stage PV transformerless five-level inverter to address leakage current issues. By utilizing a single PV source, the proposed inverter generates five output voltage levels. The design involves cascading two converters to achieve the proposed single-phase single-stage PV transformerless five-level inverter. Operating in both buck and boost modes, the proposed single-phase single-stage PV transformerless five-level inverter demonstrates distinct output voltage peak values: matching the input PV voltage in buck mode and doubling the input PV voltage in boost mode. The paper elaborates on the switching states necessary to produce these five output voltage levels in both operational modes. The key innovation lies in maintaining a constant common-mode voltage, effectively reducing leakage current. This feature remains consistent in both buck and boost modes. Additionally, the paper includes simulation results validating the functionality of this proposed single-phase single-stage PV transformerless five-level inverter.