ABSTRACT:
Theoretical studies and experimental surveys related to overvoltage induced on power lines by lightning
strikes have shown that the waveshapes are different from that of the standard impulse in the presently
adopted standards [1]. A considerable amount of analysis has been made on the frequency of the
multiple stroke of lightning. It has been shown that between 60% to 70% of ground flashes have more
than one stroke [2] with an average of 3 or 4 strokes/flash and the possibility of more than 10
strokes/flash is about 5%. A multiple stroke ground flash is a sequence of multiple pulses separated by
time intervals of tens of milliseconds. These multi-stroke flashes can impose surges of exceptional
severity on service equipment and protective devices such as distribution surge arresters, insulators,
opto isolator and surge varistor.