Electrical tracking characterization of LLDPE-Natural Rubber blends filled with nanofillers

Abstract

Electrical tracking is a process of formation of permanent conducting path across the insulating material due to the surface erosion under high voltage application. The existing of leakage current (LC) on the wet contaminated material surface causes the generation of surface discharges that resulted to the material degradation. Electrical tracking test can be indicated as failure when LC exceed 60 mA for more than two seconds or at least 25mm of formation of carbon track or erosion breaks through the thickness of the sample. In this paper, a new formulated thermoplastic elastomer material which composed of Linear Low-Density Polyethylene with Natural Rubber (LLDPE/NR) filled and unfilled with different percentage of silicone oxide (SiO 2 ) or titanium oxide (TiO 2 ) as nanofiller is presented. The compound was tested based on IEC 60587 inclined plane tracking test procedure. The analysis of LC and rate of carbon track development were also conducted. Surface morphology analysis was carried out for investigating the degraded surface structure of the materials. The formulation of pure LLDPE/NR has shown the highest average leakage current whereas the composition of LLDPE/NR-TiO 2 with 1 % wt of nanofiller was found to be the best electrical tracking resistance due to the lowest average leakage current and no carbon track appeared. The blends of LLDPE/NR-SiO 2 show that low average leakage current and no carbon track in less than 5 % wt nanofiller. The usage of 5% wt or more for both nanofiller had shown the worst in carbon track formation.

A review of thermoplastic elastomeric nanocomposites for high voltage insulation applications

“…In the study, they concluded that different blend compositions as well as surface physical conditions affected leakage current and discharges, which further influenced the electrical tracking performance of the TPE blends. Jamail et al reported further investigation on the electrical tracking performance of the LLDPE/NR blend by adding silica and titania nanofiller at different concentrations. The results showed that the tracking resistance of LLDPE/NR improved with the presence of nanofiller, where sample with 1 wt% titania showed the lowest average leakage current, and exhibited the highest resistance to electrical tracking.…”

Effect of regular and core shell nano fillers on the partial discharge and tracking performance of low density polyethylene

“…The results of electrical tracking resistance and leakage current of Linear Low-Density Polyethylene with Natural Rubber (LLDPE/NR) nanocomposites with silicone oxide (SiO 2 ) and titanium dioxide (TiO 2 ) nano fillers were reported in [17]. It was clear that low leakage current means less development of carbon tracks.…”

Modelling on Tracking Test Condition of Polymer Nanocomposite using Finite Element Simulation

“…An experimental test on the same composition of sample A3 was conducted by other researchers and they found that this composition shows lowest LC and no carbon track formation. [5]. However, simulation results also show that sample A1, A3 and A5 have a good resistance in tracking and erosion test due to the lowest current density and electric field distribution of range of 0.285 to 0.286 A/cm 2 and 1.09 to 1.10 kV/cm, respectively.…”

“…To study the electrical performances of polymeric insulating materials, LC measurement are used as the tools to indicate the deterioration of the materials [4,5].The online monitoring of LC has been developed by previous researchers and this LC are acquired throughout the duration of six-hour [6][7][8]; Indeed, the obtained LC are proportional to degradation of polymer materials [9,10]. The influence of contaminant conductivity was studied using three conditions which are coastal with conductivity of 4746 µS/cm, industrial (818µS/cm) and NH 4 Cl (550 µS/cm) and the result shows that industrial contaminant gives a smallest LCvalue of 327.6 mA with the lesser degradation [11].…”