Comparative Study of Partial Discharge Characteristics and Dielectric Strength in Multilayer Multifunctional Electrical Insulation (MMEI)-Based and Conventional MVdc Power Cables for All Electric Aircraft

Achieving net-zero emissions in aviation requires the adoption of fully electric propulsion, with all-electric aircraft (AEA) relying on lightweight, high-power-density electric power systems (EPSs). Medium-voltage dc (MVdc) architectures are favored over low-voltage alternatives due to their improved efficiency and reduced cable mass, particularly for wide-body aircraft. However, at cruising altitudes around 12.2 km, the ambient pressure drops to 18.8 kPa, drastically limiting convective heat transfer. This results in unique thermal challenges for power cables, with surface emissivity and installation geometry further influencing heat dissipation. Our prior work proposed several multilayer multifunctional electrical insulation (MMEI) systems to address these issues. Among them, the ARC-SC-T-MMEI structure, developed via compression molding, demonstrated superior thermal regulation, arc resistance, and electromagnetic interference (EMI) shielding. This study extends our findings by evaluating its dielectric strength and partial discharge (PD) characteristics under both atmospheric and high-altitude pressure conditions, comparing it with conventional terrestrial MV cables to validate its performance in aerospace environments.