Improved Harmonic Performance of Seven-Level CHB Inverter using Multicarrier Modulation and Varying the Modulation Index

Abstract

This paper proposed the design of a multicarrier modulation with symmetrical voltage input of a single phase seven-level cascaded H-Bridge multilevel inverter (CHBI). The selection of the topology is mainly due to the easy implementation as well as presence of lesser components. The simulation design of the inverter is done by using MATLAB Simulink. The modulation control technique for the power switches of the inverter is the multicarrier PWM technique which focuses specifically on PD technique. The modulation index is varied and the results are measured in terms of THD. The results obtained are analyzed and discussed in this article. The results indicate that the THD is decreasing for increasing values of modulation index.