Analisa Pengaruh Impedansi Kaki Menara Fungsi Dari Frekuensi Arus Petir Terhadap Back Flashover Pada Saluran Transmisi Menggunakan Simulasi ATPDraw

Indonesia has a tropical climate, resulting in Indonesia having a relatively high intensity of lightning strikes. This allows a direct strike to the ground wire or transmission line that can cause a back flashover (BFO). Apart from the high lightning amplitude, tower grounding also affects the occurrence of back flashover. In this final project, the influence of the tower grounding impedance is being analyzed as a function of the frequency of the lightning current. This study uses transmission line data of PT. PLN Sumatra Generation and Distribution modeled and simulated using ATP Draw. The J Marti transmission line model and the IEEE model arrester. Lightning current amplitude, lightning current front time, and lightning tail time were varied. Lightning tail timing determines the lightning frequency value. The results obtained for the effect of the frequency of lightning currents is that back flashover occurs in all phases with a frequency of 6.25 kHz, 8.3 kHz, 10 kHz for front time of 8μs and an amplitude of 30 kA, while at a frequency of 12 kHz, 25 kHz and 40 kHz, back flashover occurs in phase A and B for front time of 8μs and an amplitude of 30 kA. The effect of front time of lightning current is that back flashover occurs in all phases when the front time is 8μs and 10μs with an amplitude of 30 kA and a frequency of 6.25 kHz, while for front time of 12μs with an amplitude of 30 kA and a frequency of 6.25 kHz, back flashover occurs in phases A and B. The effect of the amplitude of the lightning current is that back flashover occurs in phases A and B for an amplitude of 20 kA with front time of 8μs and a frequency of 6.25 kHz, while for an amplitude of 30 kA with front time of 8 μs and a frequency of 6.25 kHz, back flashover occurs in all phases. All lightning overvoltage increases in all phases that cause back flashover can be reduced by arrester so that the lightning overvoltage is below the average CBFO (Critical Back Flashover) voltage value