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This paper presents the experimental outcomes regard to the flashover performance of pin, shackle and disc insulators under contaminated conditions. For making contaminated surface various samples are made like salt, dust, industry pollution and miscellaneous foreign particles of wet and dry conditions as per IEC testing techniques. Moreover, each insulator has been tested under above mentioned conditions. For each insulator its breakdown voltages were measured. After doing performance analysis of different insulators under contaminated condition measurement of breakdown voltages are done with incorporation of real field application of insulators and making analogy with various regions of India.

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The expansion of forthcoming high voltage network and smart grid has upraised the desires on reliability and performance of insulating materials used in electrical power system to deal with more vigorous and volatile operating conditions. Since from long decades, in conjunction with paper the mineral oil or synthetic oil is mainly being applied as an insulating medium in many of the high voltage apparatuses. Concomitant development of advanced new materials with high insulation and thermal gains will ensure a significant upgrade in the reliability of liquid power equipment and hence the electrical network. These novel specific desires have brought the challenges to the transformer manufacturing companies to design the transformers with enhanced electrical and thermal properties. The transformer oil modified by nanotechnology has the potential to switch mineral oil base products in the marketplace due to its superiority in function and definite insulating and thermal properties. This paper discusses on the influence of nanoparticle's permittivity over the electrical performance of transformer oil.

The dispersion of dissimilar nanoparticles (NPs) in transformer oil (TO) has a major impact on fast propagating positive streamers. This work investigates the positive streamer dynamics in TO modified by dispersing both Fe3O4 and Al2O3 NPs at a homogenous concentration. The hydrodynamic drift diffusion model of positive streamer evolution and propagation are solved using the commercial software package COMSOL Multiphysics. The impact of multiple NPs (MNPs) has been analysed for streamer propagation, electric field intensity, electron density, and space charge density of modified TO. MNPs successfully reduce streamer propagation velocity by 50%, 17%, and 37.5% comparing to pure oil, Fe3O4 based nanodielectric fluids (NDFs), and Al2O3 based NDFs, respectively. The spatial distribution of electron density reveals the loss of electrons from the ionization region until the saturation of NPs. A comparative study demonstrates that MNPs significantly alter the streamer dynamics and augment the dielectric strength of TO compared to individual NPs.