Insulation Diagnosis for XLPE Cables Using Damping Oscillating High Voltage

6 to 60 kV class XLPE cables are widely used and playing important roles in power distribution and transmission systems in Japan. The aging degradation is dominated by water trees in these XLPE cables. Therefore, water tree diagnosis with high precision is quite important for operation, maintenance and replaces planning of these XLPE cables. The authors have been investigating the applicability of the Damping oscillating high voltage (DOHV) to the water tree detection as well as insulation diagnosis for these XLPE cables. This paper firstly proposes the nondestructive insulation diagnosis using DOHV application. Then, some empirical results obtained by its application to water-tree degraded XLPE cable are discussed.