Analysis of various control schemes for minimal Total Harmonic Distortion in cascaded H-bridge multilevel inverter

Multilevel inverters are becoming more popular in the power conversion systems for high power and power quality demanding applications. The MATLAB based simulation on SIMULINK platform is presented for the Single Phase five level cascaded H-bridge Multilevel Inverter (CHB-MLI) topology with less number of switches and with different control schemes and Sinusoidal Pulse Width Modulation (SPWM) schemes. A detailed comparison of various control schemes is presented in this paper with reference to Total Harmonic Distortion (THD) in the output voltage and utilization factor of the power devices. It is observed that among all the control schemes, the THD is minimum in the Sinusoidal Pulse Width Modulation-Phase Disposition (SPWM-PD) scheme with variable carrier wave magnitude.