Effect of AC ageing on space charge evolution in XLPE

This paper reports on space charge dynamics in XLPE samples, which have been pre-stressed under ac electric stress, when subjected to 30 kV/sub dc//mm dc electric stress for 24 hours. The samples used for this study were planar XLPE samples of /spl sim/220 /spl mu/m thick aged under 30 kV/sub pk//mm, 30 kV/sub rms//mm and 60 kV/sub pk//mm at 50 Hz ac condition for 24 hours. In addition, the experiments were also extended to samples that were pre-aged under 1 Hz and 10 Hz ac 30 kV/sub pk//mm for 24 hours.