Analisis Koordinasi Isolasi Lightning Arrester Pada Gardu Induk 150 kV Kayu Agung

Abstract

Indonesia is located on Equator which has a tropical climate with high humidity, causing a greater density of lightning strikes. Lightning strikes can cause the surge to run, resulting in the emergence of high wave frequency, and can spread from the end of the channel to the end of the channel in the system. A lightning arrester is a protection system that can protect power system equipment from overvoltage surges. 150 kV Substation Kayu Agung in February there was a lightning strike with a lightning current of 33 kA to reach 136 kA. This lightning strike was caused by lightning striking the R and S phase wires, causing the arching horns to catch fire. Following the incident, the 150 kV Kayu Agung Substration will install a lightning arester as a lightning protection system. In this final project, lightning arrester insulation coordination analysis is carried out by modeling the location of lightning strikes and installing lightning arresters. Analysis of lightning arrester insulation coordination is carried out using ATP/EMTP software which can show the ability of lightning arresters to reduce overvoltages due to lightning strikes. The simulation results will show the peak voltage at the transformer with conditions before and after the installation of lightning arresters. After the installation of lightning arresters, the peak voltage value on the transformer has been reduced. The installation of lightning arresters is also considered in insulation coordination for the workability of lightning arresters against equipment insulation limits. The simulation results show that the effective installation location is done before the transformer by producing a peak voltage at the transformer nor exceeding the equipment insulation limit.