Dielectric spectroscopy measurements on polyethylene aged in AC fields in dry and humid environments

This paper presents results of dielectric spectroscopy measurements performed over a wide frequency range on high voltage grade low density polyethylene aged in AC fields in dry and humid environments. The aim of the measurements was to establish differences in the dielectric response of the insulation aged under two different conditions and to determine the diagnostic value of such measurements. To better understand the mechanism of ageing Fourier Transform Infrared (FTIR) measurements were also performed.