Understanding the Flashover Characteristics across Stay Arm Insulator due to Lightning Stroke

The lightning strike on any electrical system hampers reliability of the system. In this work, the effect of lightning stroke on the flashover characteristics of stay arm insulator of a traction mast is studied. To understand the flashover characteristics across stay arm insulator, firstly the effect of lightning stroke with different peak magnitude and steepness is studied. Secondly the effect of lighting striking at different polarity of sinusoid conductor voltage is studied. It is observed that lightning stroke parameters affects the overvoltage characteristics across stay arm insulator. However flashover behavior largely depends on leader propagation and ionization of soil. The polarity of conductor voltage also affects overvoltage and flashover behavior. It is seen in either case, soil ionization and leader propagation behavior may explain the occurrence of flashover.