A Single Source Cascaded Multilevel Inverter Based on Switched-capacitor with Series and Parallel Connectivity

A cascaded switched-capacitor (SC) multilevel inverter (MLI) achieving voltage step-up and self-balancing is presented. Unlike the conventional cascaded H-bridge (CHB) inverters, only one voltage source is required for the proposed SCMLI to produce multilevel output voltage output with increased magnitude. By employing the proposed bipolar series-parallel conversion operation, each of the SC units can produce positive and negative voltage components. This eliminates the need of high voltage unfolding H-bridge. The voltage stress of individual components in the proposed topology can be restricted to the input voltage level. Therefore, this SCMLI provides modularity for forming high voltage AC output with low voltage components. In this paper, the key features and working principle of the proposed topology are elucidated with the support of simulation and measurements.