Improving The Lightning Performance of Overhead Distribution and Sub-transmission Lines Applying Additional Underbuilt Shield Wire

Abstract

This paper analyzes the lightning performance of 22 kV single and double circuit overhead distribution lines and 115 kV sub-transmission line with 22 kV circuit underbuilt by means of installation the additional underbuilt shield wire. The three different shield wire sizes of 25, 35 and 50 mm2 and the placement locations from ground which is taken into account the clearances from the phase conductors and ground have been considered. Evaluating were performed using ATPDraw and calculations by applying the equations from IEEE std. 1243-1997 and 1410-2010 to determine the best placement location and size. For the systems being studied, both for overhead distribution and sub-transmission lines, the additional underbuilt shield wire can be used to gain better lightning performance besides the overhead shield wire.