A Modified Less-Switch-Count Switched-Capacitor Multilevel Inverter for Solar PV-Applications

Abstract

This paper presents a modified single-sourced multilevel inverter (MLI) structure that produces an II-level output voltage with a boosting of 1.25 times the DC-source. The inverter operation suggests low inrush currents through the DC link capacitors, making it a suitable candidate for Solar PV applications with increased reliability in the long-run scenario. It employs 12 switches and two electrolytic capacitors. The modification is performed on a recently introduced Cross-Connected Compact Switched-Capacitor MLI ($\mathrm{C}^{3}-$SCMLI), where IGBTs replace the diodes. Further, the redundant states of the inverter are utilized to maintain the capacitor DC-link at Vdc/2. As the capacitor charging and discharging is through the load, the continuous high inrush current experienced in $\mathrm{C}^{3}-$SCMLI reduces by a multitude. Moreover, the ratings of the switches employed also exhibit lower blocking capability. The operation of the inverter is described and implemented in this work on MATLAB/Simulink.