Novel intelligent multi-agents system for hybrid adaptive protection of micro-grid

Abstract

The decrease of short-circuit current in islanded mode due to the existence of resources with low inertial, topology changing, multi-directional current, and telecommunication are the most critical issues encountered by micro-grid protection. The central adaptive protection schemes are widely used for micro-grids, but due to the lack of reliability of this schemes, they are not perfect methods. In this paper, a hybrid scheme of adaptive and multi-agent protection for micro-grid is discussed, which will be able to provide safety protection at several layers and levels, using the equipment in the micro-grid with distributed generation including renewable and nonrenewable energy resources. The proposed scheme calculates relays pickup current with a formula that uses the superposition theorem. To demonstrate the proposed scheme performance, it is implemented and simulated on a sample micro-grid in MATLAB/Simulink, and its results have been analyzed and discussed. Simulations and numerical results show that for 96% of simulated topologies in single and multi-event faults, the relay settings are updated correctly and detect subsequent faults at the right time. Also, due to the use of offline calculations in the equipment layer, the time delay due to sending information to higher layers is minimized for single-event faults in the micro-grid.