Analisa Indeks Keandalan Sistem dan ENS (Energy Not Supplied) pada Jaringan Saluran Udara Tegangan Menengah di Penyulang Bandung RC Pematang Duku PT PLN (Persero) ULP Bengkalis

This practical work research was conducted at PT PLN (Persero) ULP Bengkalis with the aim of analyzing the reliability level of the electricity distribution network system at the Bandung RC Pematang Duku Feeder. The analysis was carried out using three main indicators, namely the System Average Interruption Duration Index (SAIDI), the System Average Interruption Frequency Index (SAIFI), and Energy Not Supplied (ENS), based on power outage data for the period January–June 2025. The results of the analysis showed that the SAIDI value was in the range of 4.79–10.08 hours/month, exceeding the standard limits set by ULP Bengkalis and SPLN 68-2:1986 in most months, so that the duration of the blackout was declared unreliable. On the other hand, the SAIFI value of 0.40–0.71 times/month fully met both standards, indicating that the main problem lies in the length of system recovery, not the frequency of interruptions. Based on the ENS calculation and the estimated economic loss, the total loss was Rp 9,369,283.2 during the observation period. These results are expected to serve as a reference in efforts to improve the reliability of distribution networks in the relevant work areas.