Decentralized Adaptive Protection Coordination Based on Agents Social Activities for Microgrids With Topological and Operational Uncertainties

A decentralized adaptive scheme is proposed in this article for protection coordination for microgrids with topological and operational uncertainties. This protection coordination scheme is performed in two stages. In the first stage, a traditional fault protection is deployed to clear the fault. If the fault is isolated successfully, the protection system returns to the regular fault-free state. If the fault is not cleared due to operational uncertainties in the protection system, the second stage of protection coordination is initiated. In this stage, based on a federation structure, a set of agents around the fault location negotiate to reach the best protection coordination strategy upon the occurrence of a single or multiple fault(s). Considering the operational uncertainties of the respective circuit breakers and communication links, the best fault clearance strategy is determined by analyzing the probability of correct operation of all proposed strategies and considering the least number of probable load outages. Two major factors impacting the probability of correct operation are fault currents flowing through the respective circuit breakers and the latency of the communication links. The efficiency of the proposed scheme is demonstrated by comparing the simulation results with their experimental counterparts and those obtained using the conventional centralized and decentralized adaptive methods.