Study on Responses of SPDs Against the Transient Voltages Generated by CG Flashes

This study presents the behavior of surge protecting devices (SPDs) against transient over voltages generated by cloud to ground (CG) flashes. Analysis revealed that lightning generated transient over voltages have a potential to impart detrimental effects on the SPDs. Moreover, it was concluded that comparisons between IEC laboratory impulse and the real transient voltages are remote due to factors such as peculiar time domain voltage profiles, random polarities, multiple surges with very narrow inter pulse durations in the order of microseconds. Further, observed that SPDs would not always retain within the limits specified by the manufactures under all circumstances.