Optimal Coordination of Numerical and Directional Over Current Relays using Hybrid Enhanced Grey Wolf Harris Hawk Optimization Algorithm

Growing demand as a result of the present trend in the world's energy crises is increasingly causing the distribution system to take mesh appearance. As a result, directional overcurrent relays (DOCRs) have become widely used for network coordination, protection and control in both distribution and transmission networks. Efficient and reliable network operation and control, requires optimal coordination of the DOCRs such that the overall operational time is minimized. However, the relay parameter settings must be carefully and optimally chosen (for example, Time Dial settings is bounded between 0.05s to 1s) such that any fault occurrence can be cleared as fast as possible, while still ensuring that void network topologies are avoided. As a result, setting the DOCR parameters is a challenging problem and attempt has been made through nonlinear optimization schemes to resolve this problem but poor convergence, misdetection, higher coordination time and complexity of solution became serious limitation to the effective operation of DOCR most especially when the network becomes large and complex. A quick convergent hybrid meta-heuristic optimization approach is suggested. The standard Grey-wolf optimizer (GWO) and Harris-hawk optimizer (HHO) were both improved, and a hybrid enhanced Grey-wolf Harris-hawk optimizer (HEGWHHO) algorithm was created. The effectiveness of the created HEGWHHO and its derivatives—conventional GWO, conventional HHO, hybrid GWO and HHO (HGWHHO), enhance GWO, and enhanced HHO were examined and contrasted with that of other pertinent algorithms in the literature. Including the IEEE 8 and 30 Bus networks, three DOCR coordination test systems, where utilized to test the developed algorithm's performance. In terms of DOCR setting optimization, all six algorithms that were taken into consideration in this work were successful.lower than the best performing methods in literature. Furthermore, the overall order of decreasing performance of the six algorithms investigated in this work have been found to be HEGWHHO > HGWHHO > EGWO > EHHO > GWO > HHO