  Nano oils comprising Graphene nanoflakes and CNTs have been experimentally
observed for the first time to exhibit augmented dielectric breakdown strengths
compared to the base transformer oils. Variant nano oils comprising different
Gr and CNT samples suspended in two different grades of transformer oils have
yielded consistent and high degrees of enhancement in the breakdown strength.
The apparent counter intuitive phenomenon of enhancing insulating caliber of
fluids utilizing nanostructures of high electronic conductance has been shown
to be physically consistent thorough theoretical analysis. The crux mechanism
has been pin pointed as efficient charge scavenging leading to hampered
streamer growth and development, thereby delaying probability of complete
ionization. The mathematical analysis presented provides a comprehensive
picture of the mechanisms and physics of the electrohydrodynamics involved in
the phenomena of enhanced breakdown strengths. Furthermore, the analysis is
able to physically explain the various breakdown characteristics observed as
functions of system parameters, such as, nanostructure type, size distribution,
relative permittivity, base fluid dielectric properties, nanomaterial
concentration and nano oil temperature. The mathematical analyses have been
extended to propose a physically and dimensionally consistent analytical model
to predict the enhanced breakdown strengths of such nano oils from involved
constituent material properties and characteristics. The model has been
observed to accurately predict the augmented insulating property, thereby
rendering it as an extremely useful tool for efficient design and prediction of
breakdown characteristics of nanostructure infused insulating fluids.
