Five-level F-type inverter with buck-boost converter-based equalization channels

Multilevel inverters have been widely used in various applications, as they provide out-put voltage with better quality, lower dv/dt, and lower Total Harmonic Distortion (THD). Mul-tilevel inverter such as Neutral Point Clamped (NPC) inverter uses a large number of semiconductor devices (IGBTs and diodes) which negatively affects the inverter cost and efficiency. Recently, a three-level (3L) F-type inverter has been proposed with lower switch voltage stresses, cost, and losses compared to 3L T-type and NPC inverters. This paper proposes a five-level (5L) F-type inverter as an extension for the 3L F-type inverter. Like a 5L NPC inverter, the voltages of the involved dc-link capacitors should be kept at a certain voltage level. To achieve that, buck-boost converter-based Equalization Channels (ECs) are employed. To show the pros and cons of the 5L F-type inverter, a comparison between the proposed inverter and other existing multilevel inverters has been held. The numerical assessment also shows that the proposed architecture has a lower kVA rating and losses than the conventional 5L NPC inverter. Finally, different Simulation and experimental results of the proposed 5L F-type inverter are presented. The presented results show the viability of the proposed converter.(c) 2022 THE AUTHORS. Published by Elsevier BV on behalf of Faculty of Engineering, Alexandria University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).

Automated summary

This paper introduces the wide application of multilevel inverters in various fields, providing output voltage of better quality, lower dv/dt, and lower THD. A five-level F-type inverter is proposed, with equalization channels based on buck-boost converters to maintain the voltage level of the involved dc-link capacitors. A comparison is made between the proposed inverter and other existing multilevel inverters, showing that the proposed architecture has lower kVA rating and losses than the conventional 5L NPC inverter.