Partial Discharge Behavior on Solid- Air Interfaces at AC Stress Condition

Partial discharge (PD) is one of the major factors that damage dielectric materials in medium and high voltage components. Therefore, partial discharge evaluation is generally used to observe the status of electrical insulation in high and medium voltage components used in the performance appreciation of an insulation system. In this work, partial discharge behavior on solid- air interfaces has been investigated commonly characterized as surface discharge. The investigation was performed by PD measurement as well as by adequate modelling for different insulating materials as the Natural Rubber (NR), Silicone Rubber (SiR), Ethylene Propylene Diene Monomer Rubber (EPDM) and High-Density Polyethylene (HDPE). Through modeling the partial discharge process, a better conception of the phenomenon may be achieved. The model of different homogeneous insulating materials has developed using Finite Element Analysis (COMSOL) software in parallel with MATLAB programming function. The results of the study indicate that the repetition rate and the peak apparent charge increased with the insulating material relative permittivity increase while the inception voltage does not change significantly.