Current Measurements in High Performance Polymers Used in Aeronautic Cables

Nowadays, electrical energy is presented as the best alternative to be used in the non-propulsive aeronautic applications compared to hydraulic and pneumatic energies. The increase of embedded power in the aircraft causes the development of DC network over AC one, keeping the actual power transmission cables that will be subjected to new constraints. The anticipation of electric conductivity within the cable insulating system becomes essential in order to predict the electric field distribution and prevent any electric breakdown within insulating materials. This article presents experimental characterisation of PI (polyimide, Kapton-FN) and PTFE (polytetrafluoroethylene), two polymers used as insulators in the actual aeronautic cables. Current measurements are performed for different electric fields and temperatures, and the current behaviour is analysed with the help of a conductivity law. We then discuss the conductivity law and its optimized parameters.