THD reduction in performance of multi-level inverter fed induction motor drive

Multi-level voltage source inverters offer several advantages such as a better output voltage with reduced total harmonic distortion (THD), reduction of voltage ratings of the power semiconductor switching devices and also the reduced electro-magnetic interference problems etc. This paper presents the application of simplified space vector modulation (SVM) method for three-level, five-level and seven-level diode clamped inverters feeding a three-phase Induction motor. The space vector diagram of the multi-level inverter is decomposed into six space vector diagrams of two-level inverters. This paper compares total harmonic distortion values of voltage and current waveforms of Induction motor to the conventional two-level inverter drive using diode clamped multi-level inverter (Three, five and seven level).