Hybrid optimization algorithm for directional overcurrent relay coordination

This work presents a method for directional overcurrent relay (DOR) coordination in a meshed power system by optimizing its operating time. The meshed power system is part of a Brazilian power transmission system, which has been evaluated via CAPE (Computer-Aided Protection Engineering) software for short circuit studies. A hybrid optimization algorithm was developed by combining linear programming and genetic algorithms. The results show that the correct settings for DOR can be obtained meeting all the constraints imposed by the coordination problem. The coordination solution calculated for the main system topology was also assessed for specific topology changes, revealing that the coordination integrity in other system configurations should be checked to ensure proper operation of the protection system.