Multilevel inverters have recently emerged as one of the promising approaches to DC–AC conversion in several medium- and high-voltage, high-power applications. These converters can generate the output voltage by synthesizing multiple discrete levels and offer superior waveform characteristics, such as lower harmonic content, better power quality, and lower electromagnetic interference compared to conventional two-level inverter systems. Nevertheless, most of the multilevel inverter topologies proposed so far require a large number of power semiconductor switches and other associated components, thus resulting in increased circuit complexity, higher implementation cost, and elevated switching losses.
In order to overcome said limitations, this work proposes a novel topology of multilevel inverter for obtaining staircase-shaped output voltages using a minimal count of switching devices. This proposed configuration makes use of six isolated DC voltage sources along with sixteen power switches, effectively providing a forty-five-level output voltage across the load. Even with reduced switch count, this inverter provides a finely stepped output voltage with increased resolution for better output waveform quality. Another important advantage of the proposed topology is the reduction in voltage stress suffered by the semiconductor devices. The lower voltage stress improves the reliability of an inverter to a great extent and also helps to choose lower voltage-rated switches, which in turn contributes to cost and efficiency improvement. A detailed comparison is carried out on the proposed topology considering component requirement, obtainable output voltage levels, and the distribution of voltage stresses among the switches. The performance of the proposed inverter is validated by detailed simulation studies. All the simulation results show stable and reliable operations under a wide range of loading conditions, includingboth linear and nonlinear loads. These findings prove that the proposed multilevel inverter topology is quite suitable for practical implementation in medium- and high-power conversion systems.
