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

#### Abstract

*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.*

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Tamilnadu, India, on April 7, 19 She received her B.E degree in Electrical and Electronics Engineering from V.M.K.V Engineering College, Salem, in 2004, the M.E degree in Power Electronics and Drives from Government College of

Engineering, Salem, in 2008.

Currently she is pursuing Ph.D. She has presented 4 papers in various national and international conferences. She has also published two papers in the international journal. Her current research interests include simulation and control techniques of AC drives, inverter topologies and harmonic suppression. Dr. I. Gnanambal was born in Tamilnadu, India. She received her B.E degree in Electrical and Electronics Engineering from Government College of Engineering, Salem, in 1981, the M.E degree in Applied Electronics in

Government College of Technology, Coimbatore, in 2002 and Ph.D. degree in Networking from Anna University, Chennai in 200 She has presented more than 50 papers in various national and international conferences. She has also published more than ten papers in international journals. Her research interests include power electronics, solid state drives, networking and special electrical machines.