Analysis of Electric Power Distribution System Planning (Case Study at PLN ULP East Binjai)

Abstract

Voltage quality is one of the main indicators in the reliability of the electric power distribution system, where excessive voltage drops can reduce the quality of service and directly impact the performance of customer electrical equipment. This study was conducted on the distribution network of PLN ULP Binjai Timur with the analysis focus on the outgoing line of a 100 kVA distribution transformer that supplies the load through aluminum conductor cables with a cross section of 35 mm² and 70 mm² with a length of 400 meters. The load current data obtained on each phase is 53 A for phase R, 50 A for phase S, and 51 A for phase T, with an average power factor of 0.85. Based on calculations, the use of 35 mm² cables results in a phase-neutral voltage drop of 8.50%–9.01% and a phase-phase voltage of 8.56%–9.07%, which clearly exceeds the maximum technical standard limit of 5%. This condition has the potential to cause higher power losses and voltage instability on the customer side. In contrast, the use of 70 mm² cables showed significant improvements, with phase-neutral voltage drops ranging from 4.51%–4.78% and phase-to-phase voltage drops of 4.53%–4.81%, thus still meeting voltage service standards. These results confirm that selecting larger cable cross-sectional sizes in distribution networks not only reduces voltage drops but also supports energy efficiency, extends equipment lifespan, and improves customer satisfaction. These findings can be used as a basis for technical considerations in the planning and development of electricity distribution systems in PLN's operational areas, particularly in areas with rapid load growth.