Effect of Modified Carbon Black on the Performance of Semiconductive Composites for High-Voltage Direct-Current Cable Applications

The semiconductive shielding layer is located between the conductive core and the insulation layer of high-voltage direct current cables, which plays a role in homogenizing the electric field and suppressing the effect of space charge injection into the insulation layer. However, the positive temperature coefficient (PTC) effect is still the main cause of thermal breakdown and interface failure of the insulation layer. In this paper, carbon black was etched and modified, and then blended with low density polyethylene (LDPE) and Ethylene-vinyl acetate (EVA) to prepare composites. The modification of carbon black enhanced suppression of space charge injection. Moreover, the PTC effect decreased by 15.4%.