Switched capacitors 9-level module (SC9LM) with reduced device count for multilevel DC to AC power conversion

• Published in: IET electric power applications Vol. 13; no. 10; pp. 1544 - 1552
• Main Authors: Bhatnagar, Pallavee, Agrawal, Rekha, Kumar Dewangan, Niraj, Jain, Sanjay K, Kumar Gupta, Krishna
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 01.10.2019
• Subjects: bridge circuits; capacitor switching; circuit analysis; DC‐AC power convertors; fundamental switching frequency; high‐voltage stress; H‐bridge switches; input DC source; invertors; low input voltage applications; multilevel DC to AC power conversion; peak inverse voltage; power switches; reduced device count; SC 9‐level module; single SC9LM; Special Issue: Medium Voltage Power Electronics Technologies for Electrical Energy Generation, Conversion and Storage; switched capacitors 9‐level module; switching convertors; switching losses minimisation; voltage gain; single SC9LM; low input voltage applications; SC 9-level module; bridge circuits; high-voltage stress; switched capacitors 9-level module; circuit analysis; voltage gain; switching losses minimisation; power switches; DC-AC power convertors; switching convertors; H-bridge switches; invertors; multilevel DC to AC power conversion; peak inverse voltage; input DC source; reduced device count; capacitor switching; fundamental switching frequency
• ISSN: 1751-8660; 1751-8679; 1751-8679
• DOI: 10.1049/iet-epa.2019.0053

Switched capacitors (SCs)-based modules are being increasingly used for multilevel DC to AC power conversion, especially for low input voltage applications. Many of these topologies operate in two stages involving H-bridge switches, which endure high-voltage stress. The SC 9-level module (SC9LM) presented here operates in a single stage with one DC source and two capacitors. In addition, the peak inverse voltage of all power switches is confined to the voltage of the input DC source. The proposed 9-level module ensures a reduced number of power switches. In addition, with appropriate utilisation of states, two of the eleven switches in the module operate at fundamental switching frequency, thereby minimising the switching losses. A single SC9LM achieves a voltage gain of two. The proposed module is validated through circuit analysis followed by simulation and experimental results.