Switched-Capacitor-Based Multi-Source Multilevel Inverter With Reduced Part Count

In this article, we propose a switched-capacitor (SC)-based multisource multilevel inverter (MSMLI) for high-frequency ac power distribution systems. The proposed topology is a potential alternative in applications involving asymmetric dc voltage sources (in the case of renewable source-based ac microgrids). Using the available dc sources as an aggregated input eliminates the need for paralleling of inverters. In addition, the proposed topology offers a common ground among the multiple input sources and, thus, has a more straight forward design and avoids stacking voltage sources. By employing nine switches, two diodes, and two SCs, an 11-level voltage waveform is synthesized. The SC voltages are self-balanced owing to their series-parallel charging technique. A simple selective harmonic elimination technique is used to obtain the desired output voltage level and simultaneously eliminate the lower order harmonics. A detailed comparison of the proposed MSMLI is carried out, and the test results obtained from a laboratory prototype are presented to validate the feasibility and highlight the benefits of the proposed topology.