Dual Boost Five-Level Switched-Capacitor Inverter With Common Ground

Abstract

This brief presents a five-level common ground type (5L-CGT) inverter topology with double voltage boosting. This topology uses only eight switches, two capacitors that can be charged equal to the input source. The advantageous feature of this topology is the CGT configuration between the input source and output load, which ensures minimal common-mode voltage and leakage current. A detailed analysis is done to select and size capacitors, along with quasi-soft charging to minimize the charging current ripples across the capacitors. The performance of the proposed 5L-CGT inverter is tested for inductive load, varying the modulation index/load/input voltage under experimental test conditions. A detailed comparison is done with the existing state-of-art that shows the merits of the proposed topology in terms of equal voltage stress across the capacitor with voltage boost. The power loss analysis for the inverter is carried out using PLECS with efficiency to be 97.20%, and the experimental efficiency is found to be 96.54% for the 900W inverter prototype.