Trend Analysis for Conductivities of XLPE Considering Temperature, Time and Field Strength Dependent Effects

Inhalt:
Extruded high voltage direct current (HVDC) cables gain momentum in high voltage (HV) transmission concepts. Field distribution for steady state conditions is predominantly governed by conductivity. Conductivity of XLPE is affected by temperature and electrical field strength. In order to foster knowledge on time dependent conductivity trends under consideration of temperature and field strength, experimental investigations are carried out. Indicative values of time-resolved apparent conductivities of XLPE plaque samples are determined at different field strengths and temperatures. Besides an outline of the test setup, influences caused by thermal cycling on the measurement arrangement are mentioned and the obtained experimental results are discussed. Furthermore, methods for trend analysis with respect to time dependent apparent conductivities are presented and applied, including a discussion of the related results.