Power Quality Improvement Using Nine-Level Cascaded H-Bridge Voltage Source Inverter for PV Applications

Multilevel Inverters (MLI) are widely embraced in renewable energy applications such as photovoltaic (PV) solar systems and wind due to their compatibility with distributed generation. This article focuses on designing symmetrical cascaded H-Bridge Voltage Source Inverter (VSI) topologies, with up to nine levels, using Sinusoidal Pulse Width Modulation (SPWM). A comparison is made with a conventional two-level inverter under resistive and resistive-inductive load conditions. The simulation of multilevel inverter topologies is performed in the MATLAB/Simulink environment. As the number of voltage levels increases, the generated waveform gradually approximates a sinusoidal shape, which leads to a reduction in Total Harmonic Distortion (THD) and improved power quality. The experimental validation of the designed multilevel inverter is conducted using Hardware-in-the-Loop (HIL) testing.