Simulation and implementation of multilevel inverter based induction motor drive

The main objective of this paper is to control the speed of an induction motor by using three level diode clamped multilevel inverter. To obtain high quality sinusoidal output voltage with reduced harmonics, multicarrier PWM control scheme is proposed for diode clamped multilevel inverter. An open loop speed control can be achieved by using V/f method. This method can be implemented by change the supply voltage and frequency applied to the three phase induction motor at constant ratio. The proposed system is an effective replacement for the conventional method which produces high switching losses, results in poor drive performance. The simulation results reveal that the proposed circuit effectively controls the motor speed and enhances the drive performance through reduction in total harmonic distortion (THD). The effectiveness of the system is verified through simulation using MATLAB 7.2 simulink package.