The objective of protective relay coordination is to achieve selectivity without sacrificing sensitivity and quick fault clearance time. A methodology is adopted for the consideration of backup relays in the optimal coordination of directional overcurrent relays. The calculation of the Time Dial Setting ...
The fault current flows into the polarity mark of the CT connected to Circuit Breaker 3, so the Directional Overcurrent (67) relay sees the fault in the forward direction. If the fault current is larger than the overcurrent setting, the relay will trip. Directional overcurrent protection schem...
The optimal settings of both TDS multipliers and protection-curve coefficients for the inverse-time OC function could be easily implemented in a digital relay. Furthermore, several previous studies have not considered both the reliability of fault-current calculation results and the proper selection of...
The extracted optimal setting is inserted into the ETAP program to implement and evaluate the obtained overcurrent relay setting. The calculation of Incident Energy is based on IEEE1584 while AFIE level is determined by NEPA 70E 2009. This work presents a comparative analysis for the proposed ...