Analysis of different modulation techniques for multilevel inverters

Abstract

Analysis of different modulation techniques for multilevel inverter is discussed. To control the multilevel inverters, different modulation techniques have been used. Amongst them multi carrier Sine Pulse Width Modulation (SPWM) techniques are widely used for different multilevel inverter topologies. These modulation techniques are derived from the conventional two level inverter SPWM technique. Different modulation techniques are compared on the basis of the output THD, utilization of DC link voltages and common mode voltage. The detailed analysis of modulation techniques are shown on the basis of the output THD offered by the five level Neutral Point Clamped or Diode Clamped (NPC) inverter.