2L3L inverter

This paper proposes a single-phase inverter with four levels at the output converter side. The proposed inverter can be considered as an intermediate configuration between the 3-level 4-switch H-bridge and 5-level 8-switch H-bridge topologies. It is called as 2L3L inverter, since it is composed of one two-level leg and one three-level leg. The most important characteristics of the proposed configuration are: reduced number of semiconductor devices, the same blocking voltage for all switching devices, and no low frequency current circulating in dc-link capacitors. Details regarding the operation of the configuration and modulation strategy is presented, as well as the comparison between the proposed H-bridge inverter and the conventional NPC four-level inverter. Simulated and experimental results are presented to validate the theoretical expectations.