Experimental and simulated investigation of a single-phase transformerless H5 inverter topology

Abstract

This paper aims to simulate and experimentally apply a single-phase transformerless H5 inverter topology. The H5 inverter topology is simulated in MATLAB/Simulink environment as both off-grid and grid-connected. The simulation results of the grid-connected system are evaluated in terms of output voltage/current, total harmonic distortion (THD), and injected active and reactive powers into the grid. The off-grid system is evaluated regarding load current, inverter output voltage, efficiency, and THD. Despite the variable output load, the results offer good THD values that comply with the IEEE 1547 standard. Additionally, experimental studies are conducted on the single-phase off-grid transformerless H5 inverter. A digital processing unit is utilized to control and display the output voltage of the H5 inverter system in real-time mode. PI and Fuzzy PI controllers are used for output voltage control. The obtained results reveals that the investigated topology outperforms its counterparts.