Y-connected topologies composed of three three-leg converters with two-level and three-level legs

This paper proposes possibilities of Y-connected three-leg topologies, that are built from combinations of two-level and three-level legs (hybrid structures). Therefore, four topologies are studied and compared in aspects such as harmonic distortion of output voltages and rating of power switches. Additionally, semiconductor losses comparisons in different scenarios of load (either high current or voltage) are carried out. The hybrid solution allows improvements in quality of output converter voltages, reducing harmonic distortion of grid currents. This advantage can be turned into semiconductor losses reduction through operation in lower switching frequency. These structures appear as good alternatives for achieving multilevel voltages without affecting costs drastically. Furthermore, circuit model equations, simulation and experimental results are presented.