Development of diagnostic methods for characterization of physical-chemical evolution of on-site and laboratory high voltage cable insulations

Contaminant measurement methods for polyethylene insulation cables have been studied. Water measurement based on the Karl-Fischer method is applicable to aged polyethylene cables insulation in order to detect water obtained by diffusion. Nothing can be concluded from impurity migration analysis diagnostic methods. PIXE and NAA at ppm concentrations indicated no impurity diffusion in aged polyethylene cable insulation. Improvements in the potential measurement method, particularly in preparing a waterproof measurement electrode, do not allow one to observe any ionic diffusion in aged polyethylene cable insulation