Cascaded H bridge multilevel inverter topologies for PV application: A comparison

Multilevel inverters acts as a promising solution for medium voltage, high power applications due to their modularity and reduced voltage stress across the switches. Cascaded H Bridge Multilevel Inverters (CHB-MLI) are being considered as the best choice for grid connected Photovoltaic (PV) systems since they require several sources on the DC side. By means of MLI's, high quality output with less harmonic distortion is obtained compared to a two level inverter. In this paper, a comparative analysis of four levels of MLI's is presented. Control scheme based on Sinusoidal Pulse Width Modulation (SPWM) is adopted due to its ease of implementation. More number of levels results in reduced THD and nearly sinusoidal output. Simulation is performed using MATLAB/SIMULINK.