Investigation on Dry Band Arcing Induced Tracking Failure on Nanocomposites of EPDM Matrix

For outdoor electrical insulation applications, ethylene propylene diene monomer (EPDM) is among the most prominent materials by virtue of its better contamination performance in the field. However, EPDM is prone to thermally depolymerize due to temperature build-up on the surface during dry band arcing which initiates carbonized tracking. This paper investigates the tracking lifetime and thermal distribution of functionalized nano-BN filled EPDM matrix. BN particles (50 nm) were procured for the fabrication of EPDM nanocomposites. The inclined plane test according to IEC 60587 was carried out; the tracking voltage method 2 was adopted with an initial applied voltage of 3 kV and a ramping rate of 0.25 kV/h until failure. Measurement results show nanocomposites exhibit substantially higher tracking failure time as compared to pristine form of EPDM and linearly increased with BN addition. Moreover, maximum surface temperature is remarkably reduced in the nanocomposites which could be due to better thermal stability and thermal conductivity. Furthermore, the nano-BN increase the surface area of particles in the nanocomposites due to smaller interparticle distances which provides better barrier to dry band arcing.