Simulation and Analysis of Single-Phase Cascaded H-Bridge Multilevel Inverter for Solar PV Application

Abstract

In this work, symmetrical and asymmetrical topologies of cascaded multilevel inverter (CMLI) are presented for a photovoltaic (PV) system which can be interconnected to grid along with suitable modulation technique. The solar system is interconnected with grid through a cascaded H-Bridge (CHB) inverter by considering both types, i.e. equal and unequal DC sources, called symmetric and asymmetric topology, respectively. The comparison between both the topologies is also described which is the main deciding factor of the suitability for practical applications. The simulation analysis is carried out in MATLAB/SIMULINK platform, and further, their THD level is compared. Considering same number of switches, asymmetric topology is better because it has more voltage levels as compared to symmetrical topology. It is observed from the analysis carried out that asymmetric topology is capable to provide better sinusoidal voltage and current with the use of suitable controllers.