Perpustakaan Digital ITB

Dielectrics for HVDC cables are constantly evolving, as better electrical and thermal properties are constantly sought by industry. Yet, researchers are facing some obstacles. The addition of nanocomposites into polymeric based insulation proved a promising solution. In this work, five Polypropylene (PP)-based dielectric material using two type of nanofiller, codename N1 and N2, with different weight percentages (% wt), were investigated. Dielectric properties such as breakdown strength, temperature dependent dissipation factor and dielectric constant, and space charge behavior were investigated. The correlation between dissipation factor/ tan? at power frequency and very low frequency, under various temperature, will also be presented as an additional information for diagnostics. It is found that the addition of nanofiller could increase DC breakdown strength. Temperaturedependent dissipation factor on filled samples is slightly higher than unfilled sample however, overall, it remains below 0.004, particularly at 200 C, increasing with temperature. Two different fillers were tested: N1 and N2. 1% wt N1-filled samples shows slightly higher dielectric constant than unfilled sample, while as it increased to 2% wt 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 of weight percentages of N1 and the addition of N2 filler could decrease space charge accumulation, lower than the unfilled sample. The quite strong relationship between dissipation factor measurement result under power and very low frequency and under different temperature, could be interpreted as a highly useful addition information to VLF-tan? diagnostic.