A flying capacitor multilevel dual-active bridge converter for interfacing high voltage in more-electric aircraft

More-electric aircraft (MEA) replace traditional mechanical and hydraulic subsystems with electrically powered equivalents, improving system-level power density, reliability, and maintainability. As MEA architectures approach the megawatt scale, both power generation and distribution voltage levels must increase, placing new demands on the power converters interfacing high-voltage buses with low-voltage buses and storage. While the dual-active bridge (DAB) converter has traditionally served this role, its reliance on single high-voltage devices constrains achievable switching frequency, resulting in bulky magnetics. The addition of a flying-capacitor multilevel (FCML) converter provides a high-frequency alternative that enables use of medium-voltage GaN technology, reduced magnetics volume, and improved theoretical efficiency across its operating range. The 6-level FCML-DAB converter is explored in this work, with a 700:28 V prototype achieving a peak efficiency of 93.75%.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Electrical & Computer Engr

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Freeman, Andrew J.

Contributors dc:contributor

• Stillwell, Andrew R

• more-electric aircraft
• power conversion
• power electronics
• flying capacitor multilevel
• FCML
• dual-active bridge
• DAB

Statement dc:rights

• Copyright 2025 Andrew Freeman

Language dc:language

en

Handle dc:identifier

https://hdl.handle.net/2142/132604

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/132604