OHL 150 kV Jatirangon - Cibubur is a 7.99 kms long transmission network consisting of 21 towers that function to distribute electrical energy from GI 150 kV Jatirangon to GI 150 kV Cibubur. Based on the history of lightning strikes in the FALLS Application, the tower area has an average strike intensity per year of 30 times per tower and based on the history of disturbances in the FOIS Application for the period 2013-2024, this 150 kV SUTT has experienced 8 disturbances due to lightning. After analysing the data, it is known that the value of the angle of protection against lightning strikes whose value is above 15 degrees (not in accordance with the SPLN T5.014-1: 2021 standard) is found in the #1 phase R circuit tower number T.6, T.8, T.10, T12, T.14, T.15 and in the #2 phase R circuit tower number T.9, T.10, T.15, T.18 and T.20. Meanwhile, from the results of the analysis of the lightning impulse voltage value due to direct strikes on the tower and ground wire, all suspension type towers have the potential for back flash over (BFO) interference. This is because the basic level insulation (BIL) voltage value of the installed insulator is smaller than the lightning impulse voltage. From the results of this study, it is known that the cause of the OHL 150 kV Jatirangon Cibubur fault is due to flash over due to the failure of the protected angle and due to BFO due to the value of the installed insulator BIL voltage is smaller than the lightning impulse voltage value. So the mitigation that can be done to eliminate the disturbance is to modify the tower traverses so that the phase wire is parallel to the ground wire so that the protection angle value is in accordance with the SPLN T5.014-1: 2021 standard and replace the insulator so that the BIL voltage value of the insulator is greater than the lightning impulse voltage value.
Keywords: Lightning Strike Disturbance, Shielding Failure, Flash over, Back