Institusion
Institut Teknologi Perusahaan Listrik Negara
Author
Haningsih, Debi
Rusli, Muhammad
Kurniasih, Novi
Subject
Teknik Elektro
Datestamp
2022-09-28 06:34:09
Abstract :
Based on fault data for a period of one year (January 2020-December 2020) it was found that there was a coordination error in the protection system in one of the feeders supplied by a 60 MVA power transformer number 3. The Ketapang 20 kV feeder which caused the recloser to fail to work so that the trip
went through to the outgoing GFR at the Aur Duri Jambi Substation. In order to assist the process of analyzing the coordination of this protection relay, using DIgSILENT Power Factory 15.1 as supporting software. From the three coordination conditions analyzed, it can be seen that there are Over Current
Relay (OCR) and Ground Fault Relay (GFR) settings which have grading times that are not up to standard. This condition can cause coordination errors that allow backup protection to also work (trip) because it does not provide sufficient time for main protection to work to cut off disturbances first. Based on the data from the calculation settings, it can be seen that the value of the grading time between the outgoing trip and the recloser on single phase to ground fault in front of the recloser which was originally with the existing setting was 0.109 s (too narrow) to 0.307 s. This coordination error has an impact on decreasing
system reliability and causing losses in the form of energy not served amounting to 82.446 kWh or equal to kWh of 121,772,178 IDR.