Design of a Power-Dense Aviation Motor With a Low-Loss Superconducting Slotted Armature

This article describes the design and analysis of a 2.5-MW, 5000-r/min electric motor with a slotted armature employing rare-earth barium copper oxide (REBCO) high-temperature superconductors (HTS). The alternating current and field in the armature induces ac losses in the superconductors, requiring cryogenic cooling. Therefore, the aim is to design a machine with sufficiently low losses to make this cooling realistic, which simultaneously outperforms the state-of-the-art. The reasoning behind the key design choices is presented before the model used for 2-D finite element analysis (FEA) is described. Then, HTS ac losses are studied with the T-A-formulation, examining the impact of various operating conditions. Aligning the HTS tapes with the field was found to successfully reduce ac losses, while filamentization was only successful for more than ten filaments. The final design had an active torque density of 50.9 N
$\cdot$
m/kg and an estimated efficiency of 99.8% when the HTS are operated at 40 K.