A Seven-Level Switched Capacitor-Based RSC-MLI Topology with Suppressed Inrush Currents for Grid-Connected Applications

A pre-requisite of an efficient inverter topology with less device count and limited dc source requirements has led to the developed of the switched capacitor based reduced switch count (RSC) multilevel inverters (MLI). Most often, switched capacitor (SC) topologies involves a single dc source switched in series/parallel with multiple capacitors such that it promotes the voltage-boosting ability with limited device count. However, switching energized capacitor in series to the dc-source produces high in-rush currents, which further increases the device current ratings. Also, the extreme reduction in device count restricted the switching redundancies effected the DC voltage balancing ability. Thus, the most popular SC topologies produces either produces high-rush currents or suffers with limited redundancies. Thus, this paper aims to discuss the features and limitations of most popular SC-based RSC-MLI configurations and then proposes a modified switched capacitor configuration with reduced in-rush currents, self-balancing and voltage-boosting ability.