Kinerja relay proteksi pada kubikel gardu tembok GUO terhadap keandalan sistem distribusi tenaga listrik

This study aimed to analyze the performance of the protection relays installed in the cubicle of the GUO wall substation and their contribution to the reliability of the electric power distribution system. A descriptive qualitative approach was used through technical document review, field observation, and interviews with maintenance personnel. The analysis focused on the suitability of the overcurrent relay (OCR) and ground fault relay (GFR) settings to the load characteristics and fault currents, the speed of the relays in isolating faults, and their impact on the SAIDI and SAIFI values. The results showed that the protection relays in the GUO cubicle functioned as the main protection that limited the faulted area so that the fault did not spread to other feeders. However, relay performance depended heavily on setting accuracy, the condition of the switching equipment, and the consistency of maintenance. Setting mismatches or component degradation could slow down fault isolation and thereby reduce the reliability of power delivery. These findings confirmed that optimizing protection relay performance is a key factor in maintaining service continuity in medium-voltage distribution systems.