Losses comparison among carrier-based PWM modulation strategies in three-level neutral-point-clamped inverter

Abstract

This paper investigates the power losses in semiconductors for a three-phase, three level neutral point clamped (3L-NPC) inverter. Analytical expressions for the switching and conductor losses are derived. Three different modulation strategies are analyzed: sinusoidal modulation (SPWM); sine modulation with injection of the third harmonic (THIPWM); carrier based space vector modulation (CB-SVMPWM). Based on these strategies, the inverter losses are estimated through computational simulation under different operating conditions. The influence of these strategies on the losses is also analyzed.