The Aviation-class Synergistically Cooled Electric-motors with iNtegrated Drives (ASCEND) program supports the development of novel lightweight and ultra-efficient electric motors, drives[1], and associated thermal management system (collectively referred to as the all-electric powertrain) that will facilitate net-zero carbon emissions in the single-aisle, 150-200 passenger commercial aircraft segment. This FOA represents part of a wider ARPA-E effort in the development of enabling technologies for long-range (≥ 2,800 nautical miles), carbon neutral commercial aviation. The other part of the wider ARPA-E effort is included in a separate FOA targeting ultra-efficient and lightweight energy storage and fuel-to-electric power conversion system[2]. The overarching goal of the two FOAs is to reduce the emissions from commercial aviation by developing cost-competitive systems for the efficient conversion of the chemical energy of carbon-neutral liquid fuels (CNLFs)[3] to delivered electric energy, which is then further converted to thrust via propulsors driven by electric motors and associated motor drives. The focus of the ASCEND program is the development of an all-electric powertrain as the prime mover for long-range, narrow-body aircraft such as the Boeing 737. Current electric powertrains do not have high enough power density and efficiency to enable competitive and fully decarbonized aviation for the narrow-body class of aircraft.
The ASCEND program aims to take advantage of emerging materials, manufacturing techniques, and design topologies, with a focus on the co-design of electromagnetics, power electronics, and thermal management solutions. The ASCEND program requires demanding figures of merit for specific power (≥ 12 kW/kg) and efficiency (≥ 93%) for the fully integrated all‑electric powertrain systems; these targets, among others, are well beyond the capability of current state‑of‑the-art technologies and will require creative thinking and innovation in the electric motor and power electronics space.
The ASCEND program will incorporate two phases. Phase I calls for conceptual designs and computer simulations of motor, its drive, and their integration, as well as subsystem/component level demonstrations, as necessary, for the proposed key enabling technologies to support the design and simulated performance projections. Phase I will be 18 months long. Subject to the availability of appropriated funds, projects that achieve technical success in Phase I may, at ARPA-E’s sole discretion, proceed to the second phase of the program to develop, fabricate, and test an integrated motor and drive developmental prototype (≥ 250 kW) comprised of an electric motor, its drive and associated thermal management system (TMS).
If successful, the ASCEND program will accelerate innovations and cause disruptive changes in the emerging electric aviation field, which is poised to play a significant role in the near- and long-term. The program will also further enhance the U.S. technology dominance in the field of high-performance electric motors for hybrid electric aviation and a full range of other industrial applications beyond aviation, such as electric vehicles, maritime technologies, wind turbines, and off-shore drilling.
[1] A drive is the electronic device that harnesses and controls the electrical energy sent to the motor, utilizing power electronics and associated control logic. The drive can feed electricity into the motor in varying amounts and at varying frequencies, thereby enabling control of the motor's speed and torque.
[2] Range Extenders for Electric Aviation with Low Carbon Emission and High Efficiency (REEACH), DE-FOA-0002240 and DE-FOA-0002241.
[3] CNLFs are defined in REEACH as energydense liquid fuels with no net greenhouse gas emissions or net carbon footprint. They are made by converting molecules contained in air (N2, CO2), water, and/or biomass using renewable energy into energy-carrying fuels that are liquid at moderate temperatures and pressures (e.g. sustainable hydrocarbons and oxygenates).