KOMBINASI LA DAN FCO SEBAGAI PENGAMAN TRANSFORMATOR DISTRIBUSI DI PT. PLN (PERSERO) AREA BALI SELATAN

Abstract

The 20 Kv distribution network at Dewa Ruci has 61 distribution substations using the SUTM
network with AAAC conductors 1 x 150 mm², because distribution substations are placed in the
open, lightning surge disturbances and overloads that result in damaged transformers,
transformers need protection against disturbances, so selected LA placement before and after
FCO to protect the transformer from lightning surge interference with a fast 4/10 us wave
propagation. Placement of LA before the FCO with a distance of 2 meters from the transformer
there is a voltage increase of 89.3515748 kV with a working voltage of LA 87 kV for a LA
protection factor of 95.7 kV, the possibility of LA failing to secure the transformer. Placement of
LA after FCO with a distance of 0.3 meters from the transformer there is a voltage increase of
13.40273622 kV still at the working voltage and LA protection factor so that the transformer is
still safe.