A Hybrid-Bridge Asymmetrical Transformerless Five-Level Photovoltaic Inverter

Abstract

This paper presents a new Hybrid-bridge asymmetrical transformerless five-level photovoltaic(PV) inverter and also addresses the behavior of common mode voltage(CMV) and their modulation scheme. The proposed inverter topology is derived from the combination of half-bridge and diode-clamped module, which shall be able to produce less variations in the total CMV and suppress the leakage current as per the DIN VDE 0126 1-1 standards. This can be done through an asymmetrical filter inductor introduced between the inverter and loads. Moreover, the losses due to switching and conduction are less because of the lower voltage stress and reduced switching count which results in higher efficiency of operation. The voltage/current THD of the proposed five-level PV inverter is also within the standard limits. To realize the operation of the five-level inverter output voltage, CMV and leakage current measurement the simulation work is performed in Matlab software and their results are presented.