Detection of Defect Presence inside the Insulation of Cable Accessories through Changes in Cable Capacitance

This paper presents a study of defect presence detection inside the cable accessories through identifying changes in cable capacitance. This was done through simulations of “healthy” cable system, free from any kind of defects and the one with presence of defect in the form of electrode bounded cavity inside the cable accessories. The comparison was made through numerical calculation of cable capacitance for “healthy” cable system and the one containing defect. Also it has been shown that the electric field intensity inside the defect exceeds the threshold value for triggering the partial discharge (PD) process in air. The simulations were carried out using finite element tool Comsol Multiphysics software and the results showed that defect presence reduces cable capacitance. This could be used as the indicator of defect presence and by proper maintaining strategy forestalls the early failures caused by the PD activity inside the air filled cavities.