A Multilevel Inverter with Minimized Components Featuring Self-balancing and Boosting Capabilities for PV Applications

Cascaded H-bridge Multilevel Inverter (CMI) attracts much attention as a versatile converter in photovoltaic (PV) applications. Requiring several isolated dc sources and many switches are the main demerits of the CMI. In PV applications with the CMI, PV modules can be used as the isolated dc sources, which, however, may contribute to intermodule and grid leakage currents due to the module stray capacitors. In this context, a switched-capacitor-based cascaded half-bridge multilevel inverter is proposed in this paper to address the above issues. The proposed topology only requires one dc source, and it achieves the minimum number of switches, spontaneous capacitor charging, voltage boosting, and continuous input current. The inter-module leakage currents can also be eliminated in the proposed topology. The feasibility and effectiveness of the proposed topology are validated through simulations and experimental tests.