Carrier Pulse width Modulation for Three Phase Multilevel Inverter to Minimise THD and enhance the Performance of Induction motor

This paper presents the simulation of multilevel inverter fed induction motor drive. The poor quality of voltage and current of a conventional inverter fed induction machine is due to the presence of harmonics and hence there is significant level of energy losses. To obtain high quality sinusoidal output voltage with reduced harmonics, SPWM control scheme is proposed for diode clamped multilevel inverter. An open loop speed control can be achieved by using V/f method. 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