Star – Последовательность срабатывания

Protection & Selectivity in Industrial Facilities

PETRONAS RAPID project is the largest oil & gas refinery and petrochemical plant in Malaysia which is powered by a 1200MW utilities plant and connected to a 275kV Grid supply. The integrated ETAP model for the RAPID complex reached up to 5000 buses that consist of various distribution voltages from 400V up to 275kV. Protection Coordination evaluation study for the RAPID complex was performed using “PD Sequence-of-Operation” to identify abnormal relay behavior, which may not be observed in the conventional TCC curve. When simulating earth fault at 275kV system, there is sympathetic relay operation at all 275kV healthy feeders due to circulating earth fault current. The circulating earth fault current is more than 1pu, which will potentially cause a broader outage to the RAPID complex. Further analysis has been performed by the author and academician experts to ascertain the root cause of the circulating earth fault current. This presentation will discuss the root cause of sympathetic relay operation during 275kV earth fault simulations and the recommended solutions to mitigate the sympathetic operation. This will help engineering design firms and plant operators clearly understand the protection relay behavior during faults by utilizing ETAP special features.