  Electric machines with very power-to-weight ratios are inevitable for hybrid
electric aircraft applications. One potential technology that is very promising
to achieve the required power-to-weight ratio for short-range aircraft, are
superconductors used for high current densities in the stator or high magnetic
fields in the rotor. In this paper, we present an indepth analysis of the
potential for fully and partially superconducting electric machines that is
based on an analytical approach taking into account all relevant physical
domains such as electromagnetics, superconducting properties, thermal behavior
as well as structural mechanics. For the requirements of the motors in the NASA
N3-X concept aircraft, we find that fully superconducting machines could
achieve 3.5 times higher power-to-weight ratio than partially superconducting
machines. Furthermore, our model can be used to calculate the relevant KPIs
such as mass, efficiency and cryogenic cooling requirements for any other
machine design.
