The Effect of Nanofiller And Temperature on Dielectric Properties of Polypropylene-Based Dielectric Material

In this paper, the dielectric properties of five HVDC cable-grade polypropylene (PP)-based dielectric materials are discussed. Two type of nanofiller, codename N1 and N2, with different weight percentages (% wt), were considered. Breakdown strength, temperature-dependent dissipation factor, dielectric constant, and space charge behavior were measured to characterize the materials. It is found that the addition of nanofiller could increase DC breakdown strength. Temperature-dependent dissipation factor on filled samples is slightly higher than unfilled sample but still below 0.4% at 200 C. 1% wt N1-filled samples shows slightly higher dielectric constant than unfilled sample, while as wt is increased to 2% it becomes slightly lower than unfilled sample. 1% wt N2-filled samples shows slightly lower dielectric constant than unfilled sample. Space charge injection threshold of 1% N1-filled samples is slightly higher than unfilled ones, while the accumulated charge is strongly dependent on the electric field applied. At 50 kV/mm electric field of weight percentages of N1 and the addition of N2 filler could decrease space charge accumulation, lower than the unfilled sample.