Reduced device count version of single-stage switched-capacitor module for cascaded multilevel inverters

摘要

Switched capacitors are being increasingly employed in multilevel inverters for various applications. Of the new topologies that have been recently introduced, single-stage switched-capacitor module ((SCM)-C-3) has gained a lot of attention. In this work, a modified version of (SCM)-C-3 is presented that leads to a significant reduction in a number of power switches, with a simultaneous reduction in total peak inverse voltage. The proposed topology can generate 9 voltage levels in symmetric configuration and 11 voltage levels in asymmetric configuration with two dc sources, two capacitors, and eight power switches. Moreover, for the higher voltage-rated power switches in the structure, the switching losses are minimised by fundamental frequency operation of these switches. The operation and the performance of the proposed topology have been validated through simulation and experimental results of a single-phase prototype with symmetric and asymmetric source configurations.