Residual charge method", which has been developed for detection of non-bridged water tree, is well known as a high reliability water tree deterioration diagnosis technique for XLPE cable, and it has been applied for on-site cable system diagnosis.Traditional residual charge method measures the amount of electrical charge, and the information of cable length is required to evaluate the result. In this paper, we would like to introduce our development of the new technique of residual charge method which does not need the information of cable length to evaluate the deterioration degree.

No abstract