Development and Comparative Analysis of Reduced-switch Multilevel Inverter Topology for Grid-connected Application: Asymmetric DC Source Configuration

Multilevel inverters (MLIs) are becoming more appealing due to their ability to produce high-quality AC output with better efficiency and reduced harmonic without the need for filter circuits. As a result, MLIs have been widely implemented in industrial applications, motor drives, renewable energy and also as grid integration inverter. However, conventional MLIs require numerous switches, leading to increase complexity, cost and higher potential of failure. Hence, a 15-level reduced-switch multilevel inverter (RSMLI) topology with an asymmetric DC source configuration is introduced in this paper. The RSMLI aims to provide an alternative for a more compact and cost-effective solution. PSIM software is used to model and analyse the circuits focusing on the influence of the number of DC sources, switches, voltage stress and circuit complexity on inverter performance. The findings indicate that a higher variety and rating of DC source can increase operating circuit stress and switch ratings, subsequently increase the inverter’s cost. Therefore, the proposed RSMLI topology mitigates these issues by utilizing less DC source variety and lower-rated switches, making it a promising alternative for various applications, especially grid-connected systems.