Surge arrestors on long lines?

[WvH]

Given surge arrestors (SA's) installed at the termination of long lines (>30km) at substations, is it necessary to install SA's somewhere along the line in a high lightning density area? E.g. a set of SA's for every 30km of line length?

 

[cuky2000]

QUESTION: ….Is it necessary to install SA's somewhere along the line in a high lightning density area?

SUGGESTION: Not necessarily SA need to be installed along the line. All depend of the line and system reliability goals. This is a function of many factors such as line importance, acceptable number of faults, voltage level, ground flash density or keraunic level, lightning strike intensity, line and substation equipment BIL, system reclosing capability, structure height, cable configuration, shielding protection, etc.

There is not doubt that surge arresters deployed along the line could help to mitigate the number of flashover and control the overvoltage. However, with the limited information available there is only possible to suggest a generic information obtained from Sediver, ABB and other manufacturers as shown below in the enclose sketch.

I hope this could help.