Optimization of the Reliability Index of the 20 kV Distribution Network Through the Implementation of Routine Maintenance Without Outages Using Direct-Contact Substation PDKB at PT PLN (Persero) UP3 Pematang Siantar

Abstract

The reliability of the electric power distribution system is one of the key indicators in assessing the quality of service provided by PT PLN (Persero) to its customers. Conventional network maintenance generally requires power outages, which can increase the frequency and duration of outages, leading to a decline in the distribution system’s reliability index. One effort to address this issue is through the implementation of Live-Line Maintenance (LLM) for Medium Voltage using the Direct Contact method. This study aims to analyze the contribution of implementing Direct Contact Medium Voltage LLM toward optimizing the reliability index of the 20 kV distribution network at PT PLN (Persero) UP3 Pematang Siantar. The research method used is a descriptive quantitative method utilizing actual OWM work data from 2024–2025, which includes the number of jobs, electricity saved, rupiah value saved, and contributions to the SAIDI and SAIFI indices. The results show that the number of PDKB projects increased from 421 in 2024 to 456 in 2025, representing an 8.31% increase. The amount of electricity saved increased from 1,881,711.57 kWh to 2,589,536.99 kWh, representing a 37.62% increase, while the rupiah value saved rose from Rp2,021,733,540 to Rp2,864,812,831, representing a 41.70% increase. The contribution of PDKB to system reliability has also increased, as indicated by the SAIDI value rising from 514.870 minutes/customer to 602.335 minutes/customer and the SAIFI value rising from 5.112 times/customer to 6.928 times/customer. The research results show that the implementation of the Direct Touch TM PDKB is effective in reducing the potential for customer outages, improving the continuity of electricity service, and supporting the optimization of the 20 kV distribution network reliability index at PT PLN (Persero) UP3 Pematang Siantar