MULTILEVEL INVERTER FED INDUCTION MOTOR DRIVES

Abstract

Induction motor drive is used in almost all industries including oil and gas sectors, production plants and process industries. Speed control of induction motor is a major concern. The proposed technology implements a better speed control for induction motor drives using a multilevel inverter. The switching sequences are generated by optimized pre-calculated angles for controlling induction motor. And also with the use of a multi-level inverter there is lower distortion of output voltages and Total Harmonic Distortion (THD) of machine currents under steady state operating conditions can be minimized. THD can be further reduced by optimizing the switching angles. This technology can be extended to higher levels of output voltages by using an n state multilevel inverter. In this paper, a seven level multilevel inverter is proposed, its simulation is done in MATLAB/Simulink and the results were verified by experimenting on a hardware prototype. This could be extended to higher levels of voltage waveform and can be used in photovoltaics. A multilevel inverter could be a better choice as a dc-dc converter in solar power circuits.