Abstract
Scanning electron Microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX) were used for qualitative and quantitative trace element analysis of inception sites of vented water-trees in a modern HV XLPE cable aged in salt water. The aim of this paper is to examine different methodologies based on SEM/EDX to identify localized high concentrations of ions responsible for the initiation and growth of vented water trees. Long vented water trees were observed initiated at the insulation and conductor screens with lengths larger than 600μm after 4 months of ageing at 500 Hz. The initial results presented in this paper indicate that measurements at the sample sub-surface only, are likely not sufficient to reliably detect the ions causing vented water treeing. The FIB - milling technique showed to be a promising technique.