A New Single-Phase Two-Stage Five-Level Photovoltaic Inverter with Low Leakage Current

Abstract

The increased attention towards transformerless inverters (TI) is attributed to their compact size and cost effectiveness. Various topologies have been proposed to address the issue of leakage current, a significant concern in TI. This paper introduces a single-phase two-stage five level inverter designed for renewable applications. The topology comprises a DC-DC buck-boost converter and a five-level inverter. The operational principle along with a detailed presentation of a simple Level-shifted Pulse Width Modulation (LS-PWM) technique are outlined. The presented topology is characterized by its voltage enhancing capability and reduced switch count. Performance evaluation is conducted MATLAB/Simulink, encompassing an analysis of leakage current and the Common Mode Voltage (CMV) associated with the inverter. The total harmonic distortion (THD) is also analyzed. A method for controlling grid current is employed to generate gating pulses for the switching device and managing both active and reactive powers. This paper provides significant insights into transformerless inverters emphasizing a solution-oriented approach to address leakage current concerns in the context of renewable energy applications.