A NOVEL CASCADED H- BRIDGE MULTILEVEL INVERTER BASED ON OPTIMAL PWM TECHNIQUE

In this paper, a novel cascaded H- bridge multilevel inverter has been proposed using less number of switches. A standard cascaded multilevel inverter requires 4h number of switches for (2h + 1) levels whereas h is the number of dc sources. This proposed scheme allows less number of switches for the same level. A novel cascaded H- bridge multilevel inverter fed induction motor shows better performance due to fundamental frequency switching scheme using  optimal PWM Technique (OPWM). High quality output is derived due to the absence of lower order harmonics. High conversion efficiency is also achieved for induction motor drive when it is operated with the proposed method. When the levels are increased, the number of switches used is very less compared to the conventional cascaded H-bridge multilevel inverter. The performance of three phase cascaded H- bridge multilevel inverter with equal dc sources is simulated by using MATLAB platform. Harmonic analysis is done on a novel cascaded H- bridge multilevel inverter with various levels.