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

General Electric Silicon Carbide Inverter

GE inverter implements SiC switch technology, using a 2400 V dc input and providing a three- phase output capability, generating an output fundamental ...

University of Illinois Gallium Nitride Inverter

The University of Illinois is building a 200-kW, multilevel, flying capacitor topology with gallium nitride power switches that is scalable to a 1-MW ...

Boeing Cryogenically Cooled Inverter

Boeing is developing a cryogenically cooled 1-MW inverter intended to be compatible with liquid natural gas or hydrogen cooling, but the experimental ...

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

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