Inclined-plane tracking parameters variability in indentifying leakage current and carbon track of polymer nanocomposites

Abstract

Surface discharge is a phenomenon of insulating surface failure due to intensive leakage current (LC) flow. The existence of LC on the wet contaminated material surfaces causes a permanent conducting path to the insulating material due to surface erosion, which is due to high-voltage stress. Conventionally, the standard experimental test requires the inclined plane tracking (IPT) test hardware arrangement and sample material preparation. This experiment is also time consuming and costly. Hence, this thesis proposes field simulation using finite element analysis software to investigate the LC and electric field during surface discharge activity. Different compounds of linear low-density polyethylene (LLDPE) and natural rubber (NR) blended with different percentage of silicone oxide (SiO2) and alumina hydroxide (Al(OH)3) nanofillers were tested using the IPT test and field simulation at 4.5 kV with a contaminant flow rate of 0.60 ml/min. The controlled parameters of applied voltage, conductivity and permittivity of material as well as contaminant solution were also tested in the IPT test and field simulation. Due to the limitation in the field simulation, the LC obtained displays similar impression though not explicit. Thus, correction factors (f) were determined to achieve absolute value of LC. LLDPE-NR/SiO2 at 1wt% (A1) was found to be the lowest LC for both experimental and simulation results. In the experiment, the consequence of LC with the carbon track rate, hydrophobicity loss, and morphological analysis was investigated to obtain the tracking and erosion performance of the insulator materials. The high distribution of LC causes severe carbon track rate and larger hydrophobicity loss on the composition as demonstrated on LLDPE-NR samples. Morphological analysis on the surface also showed greater deterioration of the surface structure. The field simulation approach can be used as another option in investigating surface tracking resistance as the results due to LC could be forecasted.