Sze Sing Lee, Yam P. Siwakoti, Reza Barzegarkhoo, and Kyo-Beum Lee, "Switched-Capacitor-Based Five-Level T-Type Inverter (SC-5TI) With Soft-Charging and Enhanced DC-Link Voltage Utilization," IEEE Transactions on Power Electronics, vol. 36, no. 12, pp. 1 > Paper

The emerging switched-capacitor-based multilevel inverters (SC-MLIs) offer interesting merits such as self-balancing of capacitor voltages and boosting of voltage gain. While the switched-capacitors (SCs) in these topologies are charged in parallel with the dc source, severe current spikes issue is inevitable, rendering them impractical at high power. This paper proposes a novel switched-capacitor-based T-type inverter that mitigates the current spikes by enabling soft-charging for its integrated SCs, where both SC in the topological structure charges through a dedicated circuit comprises of an inductor and two switches. The proposed topology is capable of 5-level ac voltage generation and when compared to a classical T-type/ANPC inverter, it achieves higher dc-link voltage utilization since its maximum attainable voltage gain is doubled. Theoretical findings of the proposed topology are validated by both the simulation and experimental results.