Analysis of Partial Discharge Characteristics and Dielectric Strength in Multilayer Insulation Systems for MVDC Cables in Future All-Electric Wide-Body Aircraft

The design of lightweight, high-power medium-voltage direct current (MVdc) cables is crucial for future all-electric aircraft (AEA) to ensure reliable performance and durability under harsh environmental conditions. These cables must effectively mitigate partial discharge (PD) and insulation degradation to support the high-power demands of next-generation aviation. In our previous work, we developed multilayer multifunctional electrical insulation (MMEI) systems to tackle these challenges. This article presents the detailed experimental studies conducted on these MMEI structures, both as flat samples and cable prototypes. Among all the designed MMEI structures, previously designed ARC-SC-T-MMEI was selected for PD study due to its multifunctionality. First, the flat sample for the selected MMEI design is fabricated, and the fabrication process is optimized by analyzing the PD characteristics observed under different fabrication conditions. Building upon these findings, a cable prototype is created using the optimized MMEI samples. Subsequently, the PD behavior of the optimized fabricated samples is investigated under varying pressure levels to replicate the actual conditions encountered in an aircraft environment. The PD behavior of this cable prototype is rigorously studied and analyzed using the Pearson correlation coefficient to assess its performance and reliability in operational conditions. Furthermore, the dielectric strength of these samples is examined under dc voltage. A two-parameter Weibull distribution is used to analyze the effect of pressure on the breakdown of the fabricated samples. This article provides detailed insights into the fabrication and performance analysis of MMEI systems under dc voltage at atmospheric and low pressures.