A Novel Framework for Designing Asymmetrical Multilevel Circuits to Improve Fidelity and Practicality

Incorporated across diverse applications ranging from traditional energy utilization to cutting-edge instrumentation, multilevel converters encounter a fundamental trade-off between fidelity and switching loss or module quantity. Amidst this dilemma, asymmetrical multilevel circuits emerge as a compelling solution, offering precision with a reduced number of modules. However, prevailing asymmetrical patterns often exhibit significant voltage deviation between modules, posing implementation challenges. In this study, we propose a new framework of asymmetrical multilevel circuits, which encompasses enhanced geometric schemes and novel patterns such as arithmetic distribution and optimization-based irregular schemes. We evaluated the output fidelity of all considered asymmetrical schemes across various output profiles. We critically examine the rationale behind existing patterns, particularly the binary setup. The newly proposed framework guides the design of asymmetrical multilevel circuits towards achieving high fidelity with acceptable voltage differences.