Converters
Overview
Power converters are an essential component in most EAP aircraft concepts, as they are used to convert from ac to dc power, or vice versa. They are an order of magnitude larger, lower weight, and higher efficiency compared to state of the art on aircraft.
NASA is sponsoring or performing work to achieve power densities 2-3 times the state of the art for converters in the MW or larger class. Research work conducted by NASA sets the path to achieving the performance, functions, and safety needed for large electric and hybrid electric aircraft.
X-57 HLMC

High Lift Motor Controller (HLMC)
- IASP – X-57 Aircraft
- 11-14kW*, 11kW/kg, η = 97.6%, 538V
- 6 Switch, DC -> AC 3-phase
- Microcontroller-Based Control
- OML Passive Air Cooling
GIMC-HEIST

Generalized Intelligent Motor Control (GIMC) Hybrid Electric Integrated System Testbed (HEIST)
- AAVP – Advanced Air Transport Technology (AATT)
- 11kW, 3.5kW/kg, 400V
- 6 Switch, DC -> AC 3-phase
- Microcontroller-Based Control
- OML Passive Air Cooling
HEATheR

High-Efficiency Electric Aircraft Thermal Research (HEATheR) Converter
- CAS
- 72kW, η = 98.6%, 538V
- 36 Switch multi-level interleaved
- DC -> AC 3-phase
- COTS FPGA Control
- Liquid Cold Plate Cooling
X-57 CMC

Cruise Motor Controller (CMC)
- IASP – X-57 Aircraft
- 36kW, 4.4kW/kg, η > 97%, 538V
- 6 Switch, DC -> AC 3-phase
- Outsourced FPGA Control
- Passive Air Cooling
250 kW Converter

Advanced Power Electronics Group 250kW Converter
- AAVP – Advanced Air Transport Technology (AATT)
- 250kW, 10.6kW/kg, η =99.3%*, 1kV
- 72 Switch multi-level interleaved
- DC -> AC 3-phase
- Custom FPGA Control
- Liquid Cold Plate Cooling
SUSAN 25% MAGIC

Motor And Generator Intelligent Converter (MAGIC)
- CAS – SUSAN 25% Aircraft
- 37.5kW, 5kW/kg*, η > 97%*, 270V
- 6 Switch, DC -> AC 3-phase, or AC 3-phase -> DC
- Microcontroller-Based Control
- Liquid Immersion Cooling
Additional Power Converter Efforts
Silicon carbide and gallium nitride converters are being developed with conventional cooling as well as a cryogenically cooled converter
Continuous power rating, MW |
Specific power goal, kW/kg |
Efficiency goal, % |
Topology | Switch material | Cooling | |
General Electric | 1 | 19 | 99 | 3 level | SiC/Si | Liquid |
University of Illinois | 0.2 | 19 | 99 | 7 level | GaN | Liquid |
Boeing | 1 | 26 | 99.3 | Si | Cryogenic |
Related Publications
Title | Authors | Date |
---|---|---|
Combined Analysis of NASA's High Efficiency Megawatt Motor and Its Converter | Anderson et al. | 11 February 2022 |
Concept Design of a 1.4 MW Drive for Rotor Loss Minimization in a Partially Superconducting Motor | Jansen et al. | 07 July 2022 |
Design of a High Power Density, High Efficiency, Low THD 250kW Converter for Electric Aircraft | Avanesian et al. | 28 July 2021 |
Development of an 11 kW Lightweight, High Efficiency Motor Controller for NASA X-57 Distributed Electric Propulsion Using SiC MOSFET Switches | Kowalewski et al. | 27 December 2019 |