Localization of Insulation Degradation in Medium Voltage Distribution Cables

The paper presents a methodology for successful localization of degraded insulation in medium voltage cables. Extensive work has been performed on development of cable models and characterization of new and degraded cable material to support the diagnostic technique. A non-destructive technique has been developed using differential time domain reflectometry (TDR) measurements. The main application has been localization of water treed sections of XLPE cables where the voltage dependence of the permittivity of water treed insulation has been used as diagnostic criteria.