Fluorinated epoxy insulator with interfacial conductivity graded material for HVDC gaseous insulated pipeline

In this paper, a novel procedure is put forward to fabricate epoxy insulators with surface functionally graded material (SFGM) with optimized surface conductivity as obtained from the field non-uniformity and the leakage current. For fabrication, a temperature control system is employed to form a spatial temperature gradient, thus regulating fluorination from top to bottom of the insulator surface. Flashover tests are reported under DC voltage, and with DC voltage with polarity reversal; the results show the effectiveness of the SFGM to improve the performance of the insulator. A trap distribution and carrier transport model are utilized to analyze the improved flashover characteristics.