International Journal of Emerging Technology and Advanced Engineering Website: www.ijetae.com (ISSN 2250-2459 (Online), Volume 4, Special Issue 1, February 2014) International Conference on Advanced Developments in Engineering and Technology (ICADET-14), INDIA. Lord Krishna College of Engineering (An ISO 9001:2008 Certified Institute) Ghaziabad, Uttar Pradesh, INDIA. Page 416 "Sharpening Skills..... Serving Nation" Application of Multilevel Inverter Using Modulation Technique For Running Induction Motor Smoothly Sandeep Kumar 1 , Ishtiyaque Ahmed 2 1 Student, M.Tech, 2 Assistant Professor, Dehradun Institute of Technology, Dehradun Abstract - The Multilevel Inverter topology is advantageous in high-power and power-quality demanding application without use of transformer with reduced harmonic distortion. This paper explain the basic type of Multilevel Inverter such as diode clamped multilevel inverter (neutral point clamped), flywheel capacitor multilevel inverter (capacitor clamped), cascade multilevel inverter also the modulation and control technique like Pulse Width Modulation, Space Vector Modulation, Selective Harmonic Elimination are applied on MLI and the gate signal through modulation technique is given to MLI in such a way to reduce Harmonic Distortion with the fact that when Induction Motor are fed through MLI, motor run smother. Induction motor has advantage like reduced total harmonic distortion and higher torque. The effectiveness of the system is verified through simulation using MATLAB / SIMULINK package Keywords--Induction Motor, Multi-Level Inverter, Modulation technique I. INTRODUCTION In two inverter technology output waveform is of two values (level) include increase harmonic distortion, ripple factor, higher voltage derivative, torque pulsation in induction motor. Multilevel inverter [1]-[4] is considered as a state of art power conversion from DC to AC for high power and power quality demanding applications. Multilevel inverter is useful in some application as transport, mining, manufacturing and others. Recently they have been proposed to enable new possibility for other important applications like electronic and hybrid vehicle, wind energy conversion, UPS, photovoltaic energy conversion and others. Multilevel is suitable for high power and power quality demanding application. Some of the other feather of Multilevel Inverter is as follows 1- The output generated voltage is of extremely low distortion and lower voltage derivative 2- The switching frequency on which they are operated are of lower order 3- Reduce the stress in motor bearing by generating smaller common mode voltage 4- Produce voltage with reduce harmonic content and near sinusoidal waveform The term Multilevel was first introduced by Nable el al;[5] as number of levels increase in inverter the output voltage has more steps generating a staircase waveform with a reduced harmonic distortion but a higher number increase the control complexity. PWM, SVM, SHE, DTC etc are the modulation and control strategies [6] developed for multilevel inverter. Fig 1. (a) two levels, (b) three levels, (c) n levels This paper emphasizes on the fact that when induction motor are fed with Multilevel Inverter [7]-[9] it torque pulsation are reduced and motor run smoothly. In this manner efficiency of induction motor are also increase and losses are reduced. II. MULTILEVEL INVERTER Voltage source inverter produces an output voltage or current with two levels. Two levels inverter have some limitation in operating due to harmonic content and switching losses.