@thesis{thesis, author={Albihar Ahmad Raziq and Pratama Putera Rizki and Pujotomo Isworo}, title ={KAJIAN SISTEM PROTEKSI RELE DIFERENSIAL TERHADAP GANGGUAN INTERNAL PADA TRANSFORMATOR STEP – UP 150 KV PLTU TANJUNG PRIOK}, year={2020}, url={http://156.67.221.169/2908/}, abstract={Transformer and protection relay are two important components in a power generation system. Internal disturbances in these two components will cause major damage and cease operations if not handled quickly. This obstacle is often faced by the 150 kV Transformer at PLTU Tanjung Priok. So it is necessary to study the damage to be used as reference material to identify predictions of the next disturbance. This research method uses data from observations and interviews with the Tanjung Priok PLTU engineering party. There are six disturbances that arise and the causes are from cable installation, maintenance errors and on the differential protection relay, the most occurring, namely 4 times each in the last 5 years. Differential relay setting is the longest type of internal fault to be repaired, which is 130 minutes. Failure of the protection system results in disrupted electricity distribution and makes the highest kwh lost at 13464.57 kwh. Therefore, a CT ratio of 22 kV = 2000/5 A and 150 kV 300/5 A was determined with a mismatch error of 20 kV = 0.20% and 150 kV = 0.29%. And the current differential relay setting is 0.11 A. This is calculated to optimize the performance of the protection system of PLTU Tanjung Priok.} }