Search

In this study, the dielectric properties of unfilled as well as nanofilled polystyrene-silicone rubber blends are evaluated. Accordingly, the preparation of polystyrene-silicone rubber blends is carried out considering three different concentrations of polystyrene (3, 7 and 10%wt). Also, the preparation of polystyrene-silicone rubber nanocomposites is carried out considering different two types of nanoparticles. These nanoparticle types are TiO2 and SiO2 with the same average particle size of 20 nm. Different nanoparticle concentration levels of 1.5, 2 and 3%wt are studied. The effect of thermal aging on the dielectric properties of unfilled as well as nanofilled polystyrene-silicone rubber samples is evaluated. The samples are subjected to thermal aging for two months at a temperature of 130 °C. The average breakdown strength as well as the breakdown strength at 10% and 50% probabilities is evaluated before and after the thermal aging process. The dielectric response includes relative permittivity and dissipation factor which measured and evaluated under thermal aging. The obtained results show that adding small amount of polystyrene to silicone rubber improves its dielectric properties. Finally, adding small amounts of TiO2 and SiO2 nanoparticles to polystyrene-silicone rubber blends give more improvements in its dielectric properties. [ABSTRACT FROM AUTHOR]

In this paper, the role of the accumulated surface charge on the surfaces of nanoparticles on breakdown strength for liquid and solid dielectrics is presented. The breakdown strengths of a nanofilled liquid dielectric and a solid dielectric are evaluated. The evaluation was conducted considering different nanoparticle material types with different nanofiller loadings. Accordingly, the preparation of transformer oil nanofluid and silicone rubber nanocomposites was performed with different nanofillers of the same average particle size. Breakdown voltage was measured for all the prepared samples, both liquid and solid. The interpretation of the obtained results is presented. [ABSTRACT FROM AUTHOR]

This study presents theoretical as well as experimental studies in order to obtain interpretations about the role of nanoparticles in the breakdown mechanism of transformer oil. The published breakdown mechanisms for nanofilled transformer oil are briefly discussed in order to highlight the points of agreement and disagreement with these mechanisms. Moreover, a proposed breakdown mechanism for nanofilled oil is presented depending on a proposed particle charging mechanism that is theoretically discussed and experimentally validated. Finally, the obtained experimental results prove the efficacy of the proposed theoretical mechanisms. [ABSTRACT FROM AUTHOR]