DE and GWO Evaluation for Overcurrent Relay Coordination using Non-Conventional Time Curves

This article presents a strategy for coordinating Directional Overcurrent Relays (DOCRs) using unconventional timing curves for online applications. The off-line coordination is degraded due to the increase of dynamic conditions by generation and topology changes of the electrical network. In meshed systems, when the same time curve for overcurrent relays is used results in numerous violations of coordination constraints. Instead, when the time curve is determined for each coordination pair nonconventional curves are obtained, this improves coordination times. The Grey Wolf Optimizer (GWO) and Differential Evolution (DE) algorithms have been adapted to solve the highly complex and nonlinear optimization problem, a comparison is made between both algorithms to analyze their performance. Tests have been carried out on the IEEE systems and show that the proposal is feasible, obtaining the desired results.