Qualitative analysis of diode clamped multi level inverter fed induction motor with phase shifted SPWM

The requirement of escalating power quality in the past years leads to the development of multilevel inverters due to its effectiveness and control methods. In this work, three level, five level, seven level and nine level diode clamped inverter (DCMLI) are considered with different modulation indices for induction motor (IM). This work focuses on sinusoidal pulse width phase shift modulation (SPWPSM) for DCMLI over other modulation schemes because it adopts simple control logic for gate signal generation. Comparative analysis is observed to reduce the distortions in speed and electromagnetic torque characteristics of a DCMLI fed Induction motor using PI controller in MATLAB environment. Also it is observed that the THD of phase current and voltages reduces as the level and modulation indices increases.