A New Asymmetric 23-Level Inverter Topology with Nearest Level and Unipolar Phase Disposition Control Techniques

Abstract

AbstractIn this paper, a new 23-level inverter topology has been proposed with two different modulation schemes, viz., Nearest Level Control (NLC) and Unipolar Phase Disposition (UPD) techniques. It comprises six unidirectional switches, three bidirectional switches, and five DC sources. A backend H-bridge is not needed to produce negative voltage levels because all levels are naturally produced. The main advantage of this topology is that in every state, only three switches are in conduction mode, and the rest are in the OFF state. Here, switching losses are significantly reduced due to the NLC technique's fundamental switching frequency, which is also particularly appropriate for a wide range of levels. Similarly, the UPD technique is a high switching frequency technique and because of absolute function, the number of carrier count can be reduced by half as compared with the conventional In-Phase Disposition (IPD) technique. Finally, with a step-change in input dc voltage, the proposed topology has been tested with two different control schemes and validated through MATLAB/Simulink platform.KeywordsMultilevel DC link inverterNearest level controlUnipolar phase disposition