Comparison of diagnostic test techniques on laboratory aged water treed MV-XLPE cables

All major power utilities are extensively using XLPE insulated high voltage cables. One of the most important processes that can adversely affect the performance and reliability of these cables is water treeing phenomenon which occurs due to presence of moisture and electrical stress. In many utilities a large percentage of these cables are approaching the end of their designed life. The utilities are now faced to take decision to maintain, repair, refurbish, or replace such cables in their networks. Therefore, non-destructive diagnostic tests are required to assess the cable system through organized condition based asset management program. At the high voltage laboratory of King Saud University, 15 kV rated XLPE cables are being water treed through accelerated multifactor aging. Connected in parallel, three promising non-destructive testing techniques are keeping track of this deterioration. This methodology will not only compare these diagnostic methods but will also find the best approach that can be applied to test and classify `in-service´ aged cables.