The Growth Characteristics of Electrical Trees Under Low Atmospheric Pressure

MEA technology will become a critical development direction for future aircraft systems. According to the 2025 Technology White Paper issued by the International Air Transport Association (IATA), over 2,300 MEA aircraft are currently in operation globally, representing 68% of all wide-body passenger aircraft. As aircraft voltage levels and electrical capacity continue to rise, the power transmission process has garnered increasing attention, with power cables playing an indispensable role in this context. However, cable aging is unavoidable during power transmission. The low atmospheric pressure environment encountered during flight exacerbates partial discharge intensity, thereby accelerating the aging process of power cables. Consequently, investigating the aging mechanism of aircraft power cables and identifying partial discharge characteristics during this process is crucial for ensuring the reliable operation of the power transmission system. This study establishes a platform for analyzing the growth of electrical trees under low atmospheric pressure conditions and examines the growth process and aging mechanism of electrical trees in cable insulation across varying pressure gradients. The findings indicate that under low atmospheric pressure conditions, the growth rate of electrical trees, the probability of tree formation, and the intensity of partial discharge all increase, with the rate of increase becoming more pronounced as pressure decreases. Below 60 kPa, the growth rate and initial probability of electrical trees in cross-linked polyethylene (XLPE) insulation increase significantly.