Intelligent Method for Online Adaptive Optimum Coordination of Overcurrent Relays

In power distribution systems, various abnormal events like faults may happen sometimes, which requires a reliable protective system. Overcurrent relays are most commonly employed in distribution systems among other types of protection systems. For the overcurrent relays, the coordination between them is very important in protection system. Coordination is to find the most appropriate settings for each relay including time dial settings (TDS) and pick up current settings. Current optimal coordination methods are developed under assumption of constant load and fixed DG output, which is a static condition. Therefore, they may not provide most appropriate, optimal settings of each relay for coordination in distribution system. This paper presents an intelligent online adaptive optimum coordination method for overcurrent relays using genetic algorithm for distribution systems when there are variations of load and distributed generations outputs. We have presented evaluation studies to demonstrate the proposed method.