Low AC-Loss Superconducting Cable Technology for Electric Aircraft Propulsion

The availability of low AC loss magnesium diboride (MgB2) superconducting wires enables much lighter weight superconducting stator coils than with any other metal or ceramic superconductor. This, together with Hyper Tech’s capability to fabricate long piece-length (potentially 60 km) wires, in turn enables lighter superconducting motors/generators, essential components in the turboelectric aircraft propulsion system with high power densities (over 10 kW/kg) and high efficiency superconducting components envisioned in next generation Air Vehicle Technologies. To that end, this proposed SBIR Phase II program focuses on developing MgB2 multifilament superconducting cables with exceptionally low AC losses (targeting a loss budget of 1 W/cm3) because superconductors in a cable form is arguably the only easily-accomplished and viable way to push down AC losses while retaining high operating current levels in the stator coils. Two recent advancements at Hyper Tech greatly increase the odds of success in developing superconducting cable technology in the Phase I: 1) the development of cutting-edge superconductor strand architecture designs with fine filaments, small twist pitches and resistive components for reducing AC losses and 2) improved wire manufacturing capability to fabricate multi-strand cables in significant length. A second benefit of using superconducting cable technology, beyond AC loss reduction, is the much lower heat load produced or enabled by the conductor.