A fundamental study of pollution flashover phenomena

The flashover of polluted and wet insulators is a complex and relatively slow electro-thermal process, which is entirely dependant on the level of pollution and on a few other parameters such as insulator geometry, wetting rate, type and nature of the pollutant, particle size, washing, etc. It is also apparent that the partial arcs occur at certain locations on the insulator, and these partial arcs (scintillations) may further extend to contribute flashover depending upon the conductivity of the pollution layer. Two types of breakdown process are involved in the flashover phenomena, air breakdown and surface breakdown. In the present investigation an attempt has been made to study the breakdown voltages and gradients for both the cases under dry, wet and polluted conditions.