ESTUDO DAS DISTORÇÕES HARMÔNICAS (THD) EM INVERSORES MULTINÍVEIS

Multilevel inverters have become a relevant technological alternative in medium- and high-power applications, especially in electrical drives, photovoltaic systems, and high-voltage direct current transmission. One of the main advantages of these topologies is the reduction of harmonic content in the output voltage and current when compared with two-level inverters. This work presents a study of total harmonic distortion (THD) in multilevel inverters, analyzing the impact of the number of levels and voltage modulation techniques. The most commonly employed topologies, such as Neutral Point Clamped (NPC), Flying Capacitor (FC), and Cascaded H-Bridge (CHB), are discussed, highlighting their structural characteristics and implications for power quality. Simulation results reported in the literature are qualitatively analyzed, showing the progressive reduction of THD with an increasing number of levels. In this work, three-, five-, and seven- level inverters are presented, and the harmonic distortions among them are compared. Finally, remaining challenges are pointed out, such as control complexity and implementation costs, as well as future trends in the field.