Space charge dynamic at the physical interface in cross-linked polyethylene under DC field

In this paper the behavior of positive charge formed in the vicinity of the Semi-conducting sheet anode at room temperature and under applied dc has been investigated just after the reversal of the sample, and when the sample was combined with another sample without pre-stressing using the pulsed electro acoustic (PEA) method. The results suggest that the PEA system can only show the net charge density, and the space charge distribution is drastically changed when the sample is reversed just after the removal of the applied voltage (depolarization), or when this sample was combined with another without prestressing. A positive charge injected at the dielectric interface XLPE/XLPE under electric field (polarization) and high temperature has been paid much attention. It is found that the positive charge injection takes place under all the test conditions and this charge can be affected by the electric field and/or the temperature. Physical interfaces constituted by the association of two identical dielectrics store the positive carriers for long time.