HEMM is a 1.4MW wound field synchronous motor with a stretch performance goal of 16 kW/kg and efficiency of 99 percent
The motor combines a conductively self-cooled, DC superconducting rotor windings with a slotless stator, allowing the motor to achieve exceptional specific power and efficiency without inheriting the external cooling weight penalty commonly attributed to superconducting machines.
Aircraft Level Impact
Fuel Burn: STARC-ABL studies have shown that increasing motor efficiency from 96% percent (state-of-the-art) to 99% will reduce fuel burn an additional 2 percent
Thermal System: Improving from 96% efficiency to 99% will reduce the amount of waste heat and related thermal management systems by a factor of 4.
Uses standard aircraft cooling systems
Direct drive at optimal turbomachinery speeds (no gearbox)