The effects of additives on space charge in XLPE insulation-crosslinking reagent and antioxidant

This paper presents the experimental results of space charge distribution in crosslinked polyethylene (XLPE) by using a pulsed electroacoustic method. The effects of additives, crosslinking reagents and antioxidants on space charge distribution in XLPE is studied. Under low electric fields, carrier sources are unlikely to be generated by the antioxidant, but the by-product of the crosslinking reagent acts as a key carrier source, allowing heterocharge distribution to be formed near the interface between both electrodes and insulation. Under high electric fields, the antioxidant acts as a key carrier source, allowing heterocharge distribution to be formed. However, this accumulated charge produced a saturation phenomenon in a few hours and thereafter the heterocharge begins to diminish gradually. It is considered that this phenomenon occurs because the electric field at the interface between electrodes and insulation is intensified to such a point where the charge injection from the electrodes increases.<>