Symmetrical and Asymmetrical Multilevel Inverter Topologies With Reduced Device Count: A Review

TLDR: In this article, the authors analyze the multilevel inverters (MLI) topologies into two categories which are symmetric and asymmetric configuration which contain the reduced number of switches.

Abstract: Multilevel inverters (MLIs) are extremely influential in renewable energy systems, are used to convert DC power into AC. MLIs are more beneficial in comparison to the two-level conventional inverter in terms of lower total harmonic distortion (THD), lesser electromagnetic interference (EMI), increases the capability of fault tolerance, and are more efficient. The major aspect of this review article is to analyze the recent (MLI) topologies into two categories which are symmetric and asymmetric configuration which contains the reduced number of switches $(\mathrm{N}_{\mathrm{S}\mathrm{W}})$. currently, Researchers have an eye on the using reduced number of components in MLI topologies for lesser voltage stress and high efficiency. Performance parameters such as total standing voltage (TSV), THD, and modulation techniques are briefly discussed in this article. furthermore, the general comparison of these topologies is depicted in tabular & graphical representation based on the required number of switches, number of the gate drivers $(\mathrm{N}_{\mathrm{G}\mathrm{D}})$, Number of dc voltage sources $(\mathrm{N}_{\mathrm{D}\mathrm{C}})$, THD, and the number of level $(\mathrm{N}_{\mathrm{L}})$ that are obtained through the multilevel inverter topologies.