Performance Analysis of Asymmetrical Cascaded H-Bridge Multilevel Inverter Topology Using Soft Tool

Abstract: In past few years, multilevel inverter technology is blooming and expanding for its medium and high-power industrial applications. Basically, there are three main multilevel inverter topologies namely - Neutral Point Clamped, Flying Capacitor and Cascaded H-Bridge (CHB). Among them, Cascaded H-Bridge has become popular because of its modular design, simple control, reliability, availability and the absence of capacitor imbalance problem. This paper focuses on two Asymmetrical topologies- binary Asymmetrical and trinary Asymmetrical CHB topologies. Here, performance of these topologies is compared based on Total Harmonic Distortion (THD), efficiency and number of power devices requirement. In addition to that, a computer simulation using MATLAB/Simulink has been developed for seven level and nine level Asymmetrical CHB and their performances have been analysed. Consequently, higher level Asymmetrical CHB proves to be an apt alternative for future endeavours in renewable energy sources.

Keywords: Multilevel Inverter (MLI), Symmetrical, Asymmetrical MLI, Cascaded H-Bridge, Total Harmonics Distortion (THD).