A Comparative Study on Partial Discharge and Dielectric Strength of MMEI Flat Samples under AC and DC Conditions at Atmospheric Pressure

The shift towards electrifying transportation systems has become a pivotal strategy in achieving net-zero emissions, driving extensive adoption across the transportation sector. Consequently, the aviation industry is transitioning to all-electric aircraft (AEA). For AEA, an electric power system (EPS) that delivers high power while maintaining low system mass is crucial. Cables are vital components in this future EPS, and one way to reduce their weight is by operating at higher voltages. However, designing insulation systems for higher voltages poses challenges due to increased partial discharge (PD) activity in harsh aviation environments characterized by extremely low pressures and moisture levels. To address these challenges, multilayer multifunction electrical insulation (MMEI) systems have been developed, offering higher breakdown strength compared to single-layer insulation systems. Our previous study proposed some novel MMEI designs for medium voltage direct current (MVDC) power cables capable of operating at low pressures. In this paper, the PD characteristics of these designed MMEI systems are analyzed using the OMICRON MPD 800 under both AC and DC conditions on flat samples. Additionally, the dielectric strength for AC and DC is tested and compared using the Weibull distribution method.