Symmetrical hybrid multilevel DC-AC step-up/down converters — Single phase circuits

The study and simulation of a new family of symmetrical hybrid multilevel inverter is presented, based on three level cell (TC)[1] able to obtain step up and step down voltages, focused on Adjustable Speed Drive (ASD) systems and/or non-conventional renewable energy system applications, where DC-link voltage present a high variability. The main advantages of these circuits, is the possibility to obtain an output voltage higher or lower than the input voltage. Moreover, due to the arrangement of multilevel, voltage stresses in each device are markedly reduced, compared to other topologies. Finally, due to the drive pattern used, it is possible to obtain a low distortion in the output voltage. To validate the theoretical expressions, are shown digital simulations of each converter.