Application of advanced after-laying test to long-distance 275 kV XLPE cable lines

Long-distance XLPE cable lines were laid over a distance of 26.9 km using the newly established 275 kV XLPE cable technology and in-situ jointing technique. Field AC HV withstand testing was conducted on these lines as the after-laying test-the first such test for long-distance EHV XLPE cable lines. For this test, small resonance type AC withstand HV test equipment was developed. A new system was also established for direct and simultaneous measurement of partial discharge over the entire cable length. One latent defect was detected in this test, proving that the test method is extremely effective in confirming the quality of XLPE cable lines.>