关键词: 110k 交联聚乙烯电缆, 等温松弛电流法, 逐级耐压法, 局部放电试验, 剩余寿命

Abstract: Short and long samples from the cables running for over twenty years were cut out． Then，the short samples as well as the long samples before and after the electric heating process were tested by means of the isothermal
relaxation current method． The results show that the long samples have a larger aging factor because they have cable
joints，which means that the cable joints constitute the weak link in the cables，and the joints under the electric
heating process are easier to get aging． After the electric heating process，the aging factor of the long samples increases due to the increase of their internal defects，which means that the electric heating process can aggravate the
aging degree of the cables． From the voltage-endurance tests，it is found from the voltage-endurance tests that the
residual life of the samples ranges from ten to twenty years，which is consistent with the expected life in their design． Thus，it comes to the conclusion that the XLPE cable can be more comprehensively judged by combining the
isothermal relaxation current method with the stepwise voltage-endurance method，which means that the aging degree and the residual life can be respectively assessed by using both methods．

Key words: 110 kV cross-linked polyethylene cable, isothermal relaxation current method, stepwise voltage-endurance method, partial discharge test, residual life