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

This paper presents a novel single-phase, single-stage transformer less five-level inverter for grid-connected photovoltaic (PV) systems, designed to minimize leakage current and improve system efficiency. Traditional transformer-based inverters suffer from increased size, weight, and cost, whereas transformer less inverters introduce leakage current due to the absence of galvanic isolation. The proposed inverter topology cascades two converter stages, maintaining a constant common-mode voltage to mitigate leakage currents. It operates in both buck and boost modes, generating five distinct output voltage levels that either match or double the PV input voltage. Simulation results validate the inverter’s effectiveness in reducing leakage currents, enhancing power quality, and ensuring stable grid operation. The proposed topology offers a compact, efficient, and cost-effective solution for grid-connected PV applications.

Keywords: Common mode voltage, leakage current, PV systems, five-level inverter.