A method to improve lightning performance of transmission lines in high footing resistance areas

One of disadvantages of using sky wires in transmission lines is that it increases the tower height, which results in an enlargement of lightning collection area of the transmission line. Experiences showed that the effectiveness of partial installing lightning arresters in combination with sky was not clear in some towers. This paper analyzed a method to improve lightning performance of transmission lines by replacing sky wire by lightning arresters and underbuilt ground wire. Electromagnetic transient program (EMTP) simulation was performed in order to estimate the lightning performance of the lines before and after using the improvement method. Ratings of the arresters to be used were also suggested for a given range of footing resistance.