Comparison between a Two-Level and Three-Level Inverter fed Induction Motor including Losses and Efficiency

This paper aims to present a comparative study between a three phase two-level and neutral-point clamped (NPC) three- level inverter controlled by a PWM technique and induction motor used as a load. The comparison takes into account losses, efficiency and total harmonic distortion (THD), depending on the switching frequency. Methods for calculating inverter losses and efficiency are well known and widely used in the literature. In this paper a simple model has been developed using Matlab/Simulink package to compute losses and efficiency in both of two-level and three-level inverter investigating analytical expressions given in the literature. The simulation results obtained prove that, the three-level inverter seems to be the most efficient topology.