@thesis{thesis,
		author={Ispranyoto  Edy and YAMIKHO  FREZZIO},
		title ={STUDI PERENCANAAN KOORDINASI RELE OCR DAN GFR PADA
TRANSFORMATOR-4 150/20 KV 60 MVA DI GARDU INDUK
CAWANG LAMA},
		year={2019},
		url={http://156.67.221.169/1472/},
		abstract={The role of power transformers in electrical power distribution systems is very important. A power transformer is a device that supplies electrical power, so it must be protected. Protection system serves to protect electrical equipment from
interference that occurs so that the equipment does not turn off, minimize the outages, and outages. One of the transformer protection equipment is protection relay. In connection with the installation of the 150 / 20kV-4 transformer; For 60 MVAs in the Cawang Lama Substation, selective relay coordination planning is needed. From the calculation, the magnitude of the short-circuit current to the ground is 26,408.79 A on the 20 kV side and 20,472.83 A on the 150 kV side. For three phase short circuit current of 27,311.79 A on the 20 kV side and 20,594.08 A on the
150 kV side. Based on this, it is necessary to selective relay settings that can protect the transformer from interference. Relay coordination when interference occurs, besides requiring selective relay settings, it also requires an appropriate time setting so that the installed relay can work wherever interference occurs.}
		}