@thesis{thesis,
		author={Pangestu  Witjaksono Adi and Purnama Sari  Dewi},
		title ={ANALISIS KEANDALAN TRANSFOMATOR 100 MVA DENGAN MENGGUNAKAN SISTEM PENGAMAN REF (Restricted Earth Fault) PADA PT. PLN PERSERO GARDU INDUK SEKAR PUTIH MOJOKERTO JAWA TIMUR},
		year={2021},
		url={http://156.67.221.169/3931/},
		abstract={In the transformer there are several disturbances that occur, one of which is a short circuit, which is a condition where the magnitude of the current is very high which can cause damage to electrical equipment connected to the power source. To prevent short-circuit disturbances in the transformer, a safety device, namely restricted earth fault (REF) is needed which has as a back-up protection from the main safety, namely a differential relay. Coordination on transformer safety is to ensure that the work area of each safety is in accordance with the value of the short-circuit current that causes the disturbance. For this reason, it is necessary to analyze and calculate the work area on the back-up protection of restricted earth faults (REF). By using a short circuit fault simulation in the power system analysis application to find the best setting value on the transformer REF relay. Where it is obtained by simulating a short circuit fault at a 70 kV bus voltage, the phase voltage setting is 5.5138 volts with a minimum voltage of 10 volts and the primary operating current in the transformer is 247.0643 A. differential and restricted earth fault (REF) is 30%. With the results of the setting of the REF relay, it is hoped that it can be a reference and increase the reliability of the protection coordination due to the accuracy of the fault work area.}
		}