A New Symmetric and Asymmetric Multilevel Inverter Circuit with Reduced Number of Components

Abstract

Multilevel inverters (MLIs) have emerged as a feasible option for medium-voltage energy conversion applications with excellent power quality. These inverters have exhibited different advantages over the two-level inverters due to the development of various modulation schemes. In recent years, they have received a lot of attention for a variety of industrial applications, including adjustable speed drives, renewable energy systems, electric vehicles and uninterruptible power supply. The main aim of this paper is to propose a new symmetric- and asymmetric-type multilevel inverter circuit with a reduced number of circuit components. The proposed circuit consists of three DC voltage sources and nine power electronic switches. The proposed topology creates a staircase-type 7-level output voltage waveform under a symmetric condition and a 15-level output voltage waveform under an asymmetric condition, with fewer components and low total harmonic distortion, without using an active filter circuit. A comprehensive comparative analysis is presented to illustrate the advantage of the proposed inverter circuit. The performance of the proposed MLI is verified through many simulation studies in MATLAB/Simulink. Furthermore, to highlight the merits and superiorities of the suggested MLI, a full comparison is performed with the best performance of the existing MLI topologies.