A multi-agent system for protection coordination of radial systems in the presence of distributed generation

This presentation proposes a multi-agent system (MAS) approach to coordinate overcurrent relays, aiming to protect distribution systems with distributed generators. The connection of distributed generation units causes a reduction in the efficacy coordinating the protection systems and, in some cases, an increase of operating times. Coordination studies aim to guarantee the protection selectivity in a diversity of fault situations, also considering topological changes. Consequently, correct protection operation at every point of the system in every possible situation sometimes cannot be guaranteed. The proposed MAS uses communication between agents to achieve on-line coordination. In order to evaluate the approach, simulation tests of a real system were executed and the protection operating times using the proposed methodology are compared with the operating time of existing relays. The results show that this approach provides a noticeable reduction of protection operating time, and there is also an improvement of selectivity.