Evaluasi Pemasangan Surge Arrester terhadap Keandalan Jaringan Distribusi 20 kV di Penyulang Salassae

Abstract

The electric power system requires reliable protection against overvoltage disturbances caused by lightning surges, particularly in 20 kV distribution networks with limited basic insulation levels. This study evaluates the insulation coordination and reliability of the 20 kV distribution network on the Salassae Feeder, ULP Tanete UP3 Bulukumba, following surge arrester installation. A quantitative descriptive method was employed using historical disturbance data from before installation (January-March 2026) and after installation (April-June 2026), along with technical data on arrester specifications and grounding systems. The results show that the required arrester rated voltage of 22.32 kV is met by the installed arrester (Ur 24 kV, Uc 19.2 kV, In 10 kA). However, the theoretical maximum separation distance of 8.7 meters yields only a 0% protection margin, necessitating an actual installation distance limited to a maximum of 5 meters to achieve a protection margin above 20%. The SAIFI index decreased from 6 to 3 times per customer and SAIDI from 10.72 to 3.28 minutes per customer per quarter, representing a 50% reduction in disturbance frequency and 69.40% reduction in outage duration. This study recommends improvements to arrester lead wire construction, grounding system enhancement, and limiting installation distance to a maximum of 5 meters from the protected transformer.