Characteristics of Partial Discharge During Electrical Tree Growth Under Low Atmospheric Pressure

Owing to the rapid advancement of more-electric aircraft (MEA), power transmission systems on aircraft have garnered significant attention. The low atmospheric pressure environment in which cables are situated can substantially exacerbate partial discharge phenomena, particularly when insulation defects such as electrical trees exist, potentially impacting the service life of the cables. Consequently, comprehending the partial discharge characteristics of highvoltage cables under low atmospheric pressure conditions is crucial for ensuring their reliable operation. This study develops a low atmospheric pressure experimental platform to simulate and analyze the partial discharge phenomenon during the growth of electrical trees in a low atmospheric pressure environment. Specifically, this paper employs PRPD diagrams to statistically characterize the partial discharge pulses at varying atmospheric pressures. The experimental findings reveal that as electrical trees develop, the partial discharge phenomenon diminishes to some extent, with the reduction being more pronounced in terms of discharge amplitude. In contrast, the discharge frequency decreases initially but stabilizes within a certain range during the later stages of electrical tree growth. Furthermore, the results indicate that the PRPD diagram of partial discharge during electrical tree growth under low atmospheric pressure conditions exhibits greater similarity to internal discharge, characterized by a “rabbit ear” shape, whereas under normal atmospheric pressure, the PRPD diagram demonstrates stronger resemblance to surface discharge.