ANALISIS REDISTRIBUSI BEBAN ANTAR FASA UNTUK MENURUNKAN ARUS NETRAL PADA GARDU DISTRIBUSI PLN ULP TELAGA

ABSTRACT Load imbalance in low-voltage distribution networks can cause neutral current and compromise operational performance. This case study analyzes the phase imbalance at the GT-240 distribution substation of PLN ULP Telaga using field measurements, phasor calculations, and ETAP 22.5 unbalanced load-flow simulation. The measured peak-load data for Outgoing 1 were 154.6, 159.3, and 151.9 A across phases R, S, and T, with a measured neutral current of 41.6 A; the corresponding idealized 120° phasor calculation yielded approximately 6.5 A. For Outgoing 2, the measured neutral current was 96.9 A, while the calculated phasor magnitude was approximately 87.2 A. The calculated incoming neutral current before redistribution was approximately 88.1 A, distinct from the ETAP simulated value of 90.7 A. Under the simulated load-redistribution scenario, the ETAP indicated a decrease in the incoming neutral current from 90.7 A to 6.7 A (84.0 A or approximately 92.6%). The differences between measured, analytical, and simulated results highlight the need to distinguish their assumptions and measurement conditions. The proposed balancing scenario has not been reported as field-implemented. ABSTRAK Ketidakseimbangan beban pada jaringan distribusi tegangan rendah dapat menimbulkan arus netral dan memengaruhi kinerja operasi sistem. Penelitian studi kasus ini menganalisis ketidakseimbangan antar fasa pada Gardu Distribusi TR GT-240 PLN ULP Telaga melalui pengukuran lapangan, perhitungan fasor, dan simulasi aliran daya tidak seimbang menggunakan ETAP 22.5. Pada outgoing 1, arus fasa terukur R, S, dan T berturut-turut adalah 154,6 A, 159,3 A, dan 151,9 A, dengan arus netral terukur 41,6 A; perhitungan fasor dengan asumsi sudut 120° menghasilkan arus netral sekitar 6,5 A. Pada outgoing 2, arus netral terukur sebesar 96,9 A, sedangkan hasil perhitungan fasor sekitar 87,2 A. Arus netral incoming hasil perhitungan fasor pada kondisi awal adalah sekitar 88,1 A, berbeda dari hasil simulasi ETAP sebesar 90,7 A. Dalam skenario redistribusi beban yang disimulasikan, arus netral incoming ETAP turun dari 90,7 A menjadi 6,7 A, atau berkurang 84,0 A (sekitar 92,6%). Perbedaan hasil ukur, hitung, dan simulasi perlu dibaca sesuai metode dan asumsi masing-masing; realisasi penyeimbangan di lapangan belum dilaporkan.