Switched-Capacitor-Based Seven-Level Inverter With Reduced Component Count and Current Stress

Switched capacitor-based multilevel inverters (SC-MLIs) suffer from high current spikes due to their paralleling with the input dc source. To negate this detriment, a new capacitor-based seven-level inverter topology with inherent boosting capability and reduced component count is presented. The capacitor is soft-charged through an inductor based on the principle of buck-boost operation. The proposed topology can easily be built using commercially available half-bridge intelligent power modules with simplified bootstrapping gate drivers, which simplifies the driver circuit complexity. The capacitor and the input dc source are connected in series to achieve the desirable voltage boosting characteristics with a gain of three. The operation of the proposed topology is detailed and verified through extensive experimental tests. The obtained results confirming the practical viability of the proposed topology are presented. Finally, a detailed comparison with other SC-MLIs is included to highlight the merits of the proposed topology.