Short Circuit Fault Distance Analysis Based on Fault Current Value and Fault Type Classification for Ciamis Substation Protection System Evaluation

Abstract

Complex electrical power systems demand high reliability to minimize damage caused by short-circuit faults, which frequently occur on feeders. The impedance of the feeder significantly affects the fault current, a greater distance from the source increases the impedance, thereby limiting the magnitude of the fault current. This study aims to determine the fault location based on current values and fault classifications to optimize the protection system in the LSCM feeder at the Ciamis Substation. The methodology involves manual calculations of sequence impedance and simulations using ETAP 19.0.1 software across distance scenarios of 0%, 11,6%, 25%, 50%, 75%, and 100%. The analyzed fault types include three-phase, phase-to-phase, phase-to-phase-to-ground, and phase-to-ground faults. The analysis results show a decrease in fault current values as the distancce increases, for three-phase faults, the current decreases from 7451,31 A (0%0 to 1481,9 A (100%), while phase-to-ground faults decrease from 7451,33 A (0%) to 1303,2 A (100%). Optimization was achieved by resetting the OCR current setting are 2078,4 A (incoming), 432,96 A (outgoing), and 277,08 A (recloser), while the GFR settings are 86,6 A (incoming), 18,04 A (outgoing), and 11,54 A (recloser). Coordination simulations demonstrate that the protection system operates selectively and responsively, with the PBCL recloser acting as the fastest primary protection.