Single-phase cascaded multilevel inverter topology for distributed DC sources

A new single-phase cascaded multilevel inverter topology using an H-bridge inverter is proposed to reduce the number of active components and improve power quality. The topology is comprised of two or more cascaded H-bridges to increase the number of voltage levels and power handling capability. The basic unit of the proposed inverter is comprised of a voltage-level generator (VLG) connected to the input of the classical H-bridge. The main advantage of this setup is a significant reduction in the number of switches and voltage sources required to generate the desired number of voltage levels. As a result, the output power quality, cost and size are significantly improved. To verify the benefits of this topology, in a more complete way, both the symmetric and asymmetric configurations are investigated. MATLAB/Simulink models for symmetric 9-level and asymmetric 31-level cascaded multilevel inverter configurations are used to validate the performance of the proposed topology, and satisfactory results are reported.