@thesis{thesis,
		author={Mangapul  and Siregar  Muhammad Sutan Iqbal and Wasri Hasanah  Aas},
		title ={Pergantian Rele Diferensial Mekanik ke Rele Differensial  Numerik},
		year={2020},
		url={http://156.67.221.169/3438/},
		abstract={The transformer is the main component in the substation. So that the transformer 
must remain optimal. Differential relay is the main protection system on the transformer 
which protects the transformer from interference. Differential relaxation must be moved 
nominal transformers that flow on the high voltage and low voltage sides, and work  without time delay. To increase the reliability of the electric power protection system, old 
or old equipment is needed to become a newer (differential relay) equipment. The  purpose of this research is to learn how to replace differential release and conduct  individual testing, function testing and stability testing of newly installed releases. This  research was conducted by taking data at the Serpong Substation, South Tangerang.  Results Calculation theory to ascertain whether the measurement value when testing is 
correct or not. The test results of differential relay measurements on the primary side or  the 150 kV side and the 20 Kv secondary side are quite good. From the test results, the 
relevant upstream (Ipu) and return flow (Ir) obtained a comparison of 95.22% which shows  that the test results are quite good. From the test results, the differential relay function 
can describe PMT and indicators such as alarms, announciators that are functioning  properly. For the results of differential relay stability testing for stable and unstable  conditions, it can be seen from the difference in phase angles, while the current read is  stable in IDiff conditions but there is still Ibias while in unstable conditions there is IDiff which  starts to rise but Ibias remains.}
		}