This project on multi-level converters is a collaboration between LaunchPoint EPS Inc. and Prof. Pilawa-Podgurskis lab at UC Berkeley. Multi-level converters enable increased power density of the converter itself, and, by producing higher quality power signals, they enable dramatic improvements in EMI filter power density and also improvements in motor power density. In a compelling example of a DC-to-AC converter from Prof. Kolars group at ETH, moving from 2 to 3 levels reduced EMI filter weight by an astounding 89% of the converter weight. We call this system-level effect the Multi-Level Multiplier (MLM) effect and define the MLM quantitatively in the project as a measure of propulsion system improvements made possible with a multi-level converter. The innovations in this project are 1) use of the MLM to think about, choose, and optimize converters as components of propulsion systems, and 2) augment our MAAP® software design tool such that full propulsion systems incorporating flying capacitor multi-level (FCML) converters can be optimized. The resulting power-density advances are critical and significant to our existing customer projects and future megawatt-level projects. Our technical objective in Phase I is to demonstrate, by analysis, that FCLM converters indeed yield transformative MLMs. The objective will be attained by designing two propulsion systems comprised of combined EMI filter/converter/motor systems. One design will be based on an updated version of our standard 2-level converter models, and the other design will be based on 3-copies of our 10-level FCML converter rated at 13.46 kW, 26.7 kW/kg, 98.6% efficient to form a 3-phase motor drive. Anticipated
Benefits: Electrical power conversion systems have critical and broad applications in NASA aircraft and space programs. Power density is essential to all NASA systems and there is a growing recognition that electromagnetic interference (EMI) is a challenge in electric aircraft and in systems hosting sensitive sensor payloads. Specific NASA applications include the High-Efficiency Megawatt Motor (HEMM) project, the Turbine Electrified Energy Management (TEEM) project, and NASA research on hybrid electric aircraft. LaunchPoint EPS is experiencing concrete market traction for high-power-density converters in eVTOL, UAM, and broader aerospace markets. The latter is expanding to include all airborne power conversion needs: jet engine starter/generators, auxiliary power units and other turbogenerators, drone hybrid power, cooling systems that require lightweight pumps, and electromagnetic actuation.
