A Five-Level X-Type Boosting Inverter With Reduced Stored Energy of Switched-Capacitors

Abstract

This brief proposes a novel five-level (5L) common ground type (CGT) inverter based on switched capacitors (SCs) with dual voltage boosting ability. In the conventional 5L CGTs, using a capacitor rated for peak output voltage is inevitable, negatively affecting the inverter&#x2019

s power density. In the proposed topology, the SCs are rated for half of the peak output voltage, resulting in a lower voltage diversity factor and reduced energy storage requirement. Further, in case of any capacitor failures, the proposed inverter can sustain operation with reduced voltage levels. In addition, the proposed topology features SC self-voltage balancing, low dv/dt, and sensorless operation. The circuit description and operating principle of the proposed inverter are detailed. A comparative assessment of the state-of-the-art CGT topologies with the proposed inverter is presented to emphasize the distinctive features of the proposed inverter. Finally, the operation and feasibility of the proposed inverter is validated through experiments on a laboratory prototype, and the results are presented for stand-alone and grid-connected operation. IEEE