A Novel Reduced Device Count Multilevel Inverter Structure using Non-isolated Power Supplies

摘要

The aim of this paper is to present a novel structure of multilevel inverter (MLI). The proposed structure uses 4 number of equal non-isolated DC sources, 8 number of unidirectional switches and 1 bidirectional switch. The structure is able to generate 9 output voltage levels across the load terminals. A detailed comparison study with recently published MLI structures shows that the proposed structure is able to produce output voltage levels using minimum number of switches, drivers and provides minimum TSV (Total Standing Voltage) with respect to other structures. Further, the comparison of overall cost of different structures is presented by considering a CF (Cost Function). It has been observed that the proposed structure provides lowest cost function as compared to other topologies at same output voltage level. The proposed structure is analyzed for low frequency as well as for high frequency modulation strategies. The performance of the structure is verified by an extensive simulation study in MATLAB/Simulink for low as well as high frequency modulation strategies under different load conditions.