Stand und Entwicklung von Prüfverfahren zur Bewertung dynamischer Hydrophobieeigenschaften polymerer Isolierstoffe für den Hochspannungseinsatz

This contribution shows the ongoing development of test procedures for evaluating the dynamic hydrophobicity proper-ties. In case of the Hydrophobicity Transfer Test method (HTT) the influence of the artificial pollution layer on the transfer speed is investigated. Based on experiments with different pollution layer base materials the robustness of the procedure against variations of grain size distributions, possible pre-treatments and storage temperature is evaluated. The influence of local pollution layer thickness variations and the drying process of the pollution layer slurry are dis-cussed. For evaluating the retention of hydrophobicity modified test parameters for the Dynamic Drop Test (DDT) are proposed and applied in parametric studies, which cover the influence of electrolyte conductivity and inclination angle of the electrode arrangement. Employing special DDT interval tests, the recovery of hydrophobicity is evaluated.