Advanced Technology of Electrical Engineering and Energy
The non linear properties of leakage current in XLPE cable insulation containing water treeing has been studied by contrast experiments between applied voltages of 0.1Hz and 50Hz in this paper. It is found from the test results that the phase, at witch the distortion of leakage current wave shape appears, is related with the integrating voltage over time. It is considered that appearing of harmonic in leakage current is caused by water penetrating into the crackle of micro voids under action of electrical stress. This leakage current detecting technique can be used to off line diagnose the water treeing situation in XLPE cable insulation.