Surface discharge studies of insulation materials in aviation power system under DC voltage

The complicated electrical installation system in airspace environment is exposed to harsh operation condition such as high conductive and low pressure atmosphere which deteriorate the insulation between different electrical parts. The elevated DC voltage level in power distribution system of hybrid propulsion systems has raised the concern about high risk of degradation due to partial discharge in insulated wiring and cabling system. Since widely accepted systematic procedure for PD studies including test method and analysis strategy at DC voltage has not been established to assess insulation condition, different PD representations have been obtained and discussed in this work. Surface discharge behavior on three specific kinds of high-temperature insulation films which are commonly used in aviation systems (PTFE, ETFE and Kapton-CR) have been investigated at partially vacuumed condition (20kPa). The signatures of PD from recorded data have been extracted and used for PD pattern representation and PD behavior study occurred on the surface of material affected by environmental pressure. The content of this paper could be of great significance for the development of new hybrid thrusters for aircrafts.