Analysis of the Effect of Installing Polymer Insulators and Dedicated Grounding Systems on the Number of Faults Due to Lightning Strikes of Transmission 150 Kv

Transmission 150 kV Koto PanjangPayakumbuh has a high Isokeraunik Level (IKL) of 173 days/year. Based on PLN UPT Padang fault data in 2021-2022, there were 20 faults caused by lightning strikes, which resulted in 189 pieces of flashover ceramic insulators and 10 strings of polymer flashover insulators. In 2023-2024, there have been 5 faults and 7 strings of polymer flashover insulators, so replacement must be carried out immediately at a large cost. In this study, an analysis of the effect of installing polymer insulators and Dedicated Grounding System (DGS) on the number of faults due to lightning strikes based on lightning characteristics, the probability of protection failure due to lightning strikes using Anderson method calculations, and simulated using the ATPEMTP program. During 2021-2024, there were 3002 lightning strikes and 699 lightning strikes recorded by the DGS counter. The average lightning strike current is 38.25 kA, and the average tower leg resistance is <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{8. 2 4}$</tex> ohm. The results of the calculation of the probability of faults due to lightning strikes using Anderson's method are 2.95 times <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$/ 100 ~\text{km} /$</tex> year, the probability of the tower experiencing flashover is <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{1 2}$</tex> towers out of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{9 5}$</tex> towers that have been installed with polymer insulators and DGS with the last fault lightning impulse of 109 kA because they have a tower resistance value of more than the PLN standard of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{1 0}$</tex> ohm.