High voltage dielectric diagnosis using automatic capacitance & dissipation factor test system

Failure of dielectric material in power equipment usually results into undesired outages and expensive replacements. Chances of failure increase with increase in electric stress on dielectric materials at high voltages. It is therefore; necessary to assess the electrical insulating properties of the materials before their practical use. This research work was aimed to determine different inherent properties of dielectric materials like volume resistivity; dielectric constant; loss tangent and co-relate them on an empirical basis by using variables predicted by basic theory. A simple equation to predict dielectric strength using ASTM electrode system; has been proposed for insulating materials like Leatheroid; Diamond dotted paper; Paper phenolic sheet; Glass bonded mica paper; Nomex and Epoxy resin fiber glass. Values of the parameters required in the equation may be obtained by performing non-destructive dielectric diagnostic measurements using an advance capacitance and tan delta bridge. This is expected that the suggested equation will be useful to practicing engineers and designers for quick estimation of electric stresses in dielectric materials studied in this research work.