Evolution of Space Charge with Increasing Electric Field in High Temperature Materials Used in Hybrid Propulsion Systems

The role of space charge in the design of cable insulation for direct current (DC) has been well recognized. Electric field represents one of the most critical parameters governing the evolution of space charge. This paper reports an experimental study on the evolution of charge distribution in a special group of materials including five polymeric dielectrics used in high temperature (HT) applications. The charge distribution has been measured for each sample under different electric fields including 1, 5, 10, 15, 20, 40, and 70 kV/mm during 15 minutes at room temperature. Moreover, based on the charge distribution profiles, the electric field distributions and maximum electric fields have been calculated for each material. The results of this study show that PI and PEEK have better performance in terms of space charge distribution, electric field distortion and maximum electric field enhancement compared with other materials.