dc.description.abstract | The substation is an electrical installation that functions to receive and distribute electricity in large quantities. In practice, the substation must have a control system and protection system so that it becomes a reliable electric power system. The interlock system is an example of a control system that can facilitate the maintenance of existing equipment at a substation without the need to stop the distribution of electric power to the load. The protection relay is responsible for incoming faults to be immediately intercepted within a certain time as determined by the characteristics of the relay and if a failure occurs, backup protection must operate to isolate the part experiencing the fault. In this final project, an interlock analysis will be carried out at the substation and an analysis of the values of differential relay settings, overcurrent relays and ground fault relays. The interlock system starts from DS 1 or DS 2 close, then closes CB HV and closes CB LV. DS 2 cannot close if DS 1 is already closed. CB cannot close if DS 1 or DS 2 is still open. Test simulations will be carried out using ETAP 19.0, the Omicron CMC 356 test tool and the Test Universe 4.20 application. Through the simulation, it can be seen that the simulation results use a star protective device on ETAP 19.0 with a 3-phase internal fault in the transformer, the differential relay works well. When there is a fault on bus 3 of 0.295 kA, the OCR on the HV side works at 503 ms, has a time difference with the simulation results with Test Universe, namely with a time of 508.5 ms which results in a time deviation of 0.97%. And also when there is a 3-phase fault on bus 4 of 2.104 kA, the OCR on the LV side works at 497 ms different from the Test Universe simulation results of 501.7 ms which results in a time deviation of 1.007%. | en_US |