Asymmetrical cascade multilevel inverter design using modified level shift pulse width modulation

Abstract

Multi-level inverter technology emerges as extremely significant choice in region of high-power medium voltage energy control. The multi-level inverter(MLI) generate a quasi sinusoidal voltage from various level of dc voltage. The proposed inverter design for 21 level cascaded MLI inverter by using Level Shifted-Sinusoidal Pulse Width Modulation (LS-SPWM) technique with new carrier and evaluate the Total Harmonic Distortion(THD). The proposed inverter design has the least number of components to lessen the cost and get better reliability of converter for medium power applications. The presented control techniques are applicable to cascaded H-bridge 21 level inverter to get better voltage regulation and thereby, lead the better efficiency,reliability and economic improvement. The selected pattern gave superior result in Total Harmonic distortion.