Bulk and surface properties of corona-aged HTV-SR/EPDM nanocomposites

Exploiting some obvious advantages of polymeric insulators, their use in high-voltage transmission has increased exponentially to substitute conventional ceramic insulators. In the present study, some potentially promising polymeric materials samples containing nano-sized fillers of boron nitride (BN) and silicon carbide (SiC) were fabricated to assess their anti-aging performance under corona discharge, a phenomenon that cannot be avoided on the insulators of high-voltage lines. The test samples were first subjected to aging by generating AC corona for 72 h using a specially designed electrode system, which ensured exposure of the sample’s surface to a uniform electric field. Thereafter, the diagnosis was performed using a state-of-the-art three-electrode system to determine their relative performance through measurement of surface and volume currents at different voltage and ambient temperatures. Fourier transform infrared (FT-IR) spectroscopy and thermo-gravimetric analysis (TGA) were also deployed for additional assessment. Through the measurement of leakage current and its subsequent analysis, it was revealed that surface damage is more pronounced as compared to volume degradation. Moreover, the results of FT-IR spectroscopy elucidated higher transmittance values of principal peaks in the corona-exposed test samples. The overall assessment showed that BN-doped samples have more resistance to aging as compared to SiC‐filled materials.