Study of Degradation Phenomena of Solid Insulation used in Extra High Voltage Cable under Alternating Voltage Stress

In order to balance the power demand against the population growth the applications of power cables are getting important role in the field of extra high voltage power transmission. Most of the power cables are insulated with Cross Linked Polyethylene (XLPE) as it offers high dielectric strength against the high voltage stress. Such power cables are failed to carry the huge power due to internal discharge i.e., partial discharge occur inside the insulation. Partial discharge in polymeric insulation of high voltage power cable causes cumulative damage that progressively deteriorates the insulation, leading to eventual failure. In view of the above, the condition monitoring of such power cables is very much essential to get early indication of degradation processes inside the XLPE insulation which leads to catastrophic failure in power system network and moreover to cope up with the huge power demand. In this work, the formation of electrical tree inside the XLPE insulation consider as one of the vital cause of insulation failure due to partial discharge has been conducted in high voltage laboratory.