JEE_V2_N3_RP7 G. Pandian S. Rama Reddy Journal on Electrical Engineering 2230 – 7176 2 3 82 86 induction motor, nine level inverter, PWM, active harmonics elimination This work presents the simulation and analysis of three phase nine level inverter fed induction motor drive. The poor quality of voltage and current of a classical inverter fed induction motor is due to presence of higher order harmonics and hence there is significant level of energy losses. The inverters with large number of levels can generate high quality voltage waveform. The nine level can follow a voltage reference with accuracy and with the advantage that the generated voltage can be modulated in amplitude instead of pulse-width modulation. The nine level inverter is used to reduce the harmonics. An active harmonic elimination method is applied to eliminate any number of specific higher order harmonics of multilevel converters with unequal dc voltages. The total harmonic distortion of the proposed system is very low compared to that of classical inverter system. The circuit model of the induction motor system has been developed and simulated successfully using Matlab / Simulink. The simulation results of voltage waveforms, current waveforms, motor speed and frequency spectrum for the output were obtained. The inverter system can be used for industries where the adjustable speed drives are required and significant amount of energy can be saved as the system has less harmonic losses. January - March 2009 Copyright © 2009 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=266