Bahare Salehi - Isfahan University of Technology
Mahdi Tadayon - Behrad Consulting Engineers Isfahan, Iran
Hamid Reza Karshenas - Isfahan University of Technology

This paper is concerned with the optimal placement of protection devices in a microgrid (MG) using genetic algorithms. The occurrence of power outages indistribution networks is higher than that of other parts of the grid. This phenomenon may impose substantial damage on customers with sensitive loads. The new concepts of distributed generation (DG) and microgrid (MG) in modern distribution systems can reduce the number of outages andassociated damages by supplying a feeder from multiple sources. However, microgrids and distribution networks with DG require significant effort for the coordination ofDGs and their protection devices. Therefore, the placement of protective equipment in order to limit the scope of the fault is one of the important issues which power engineers face. Adding DGs to a distribution system creates different sets of operating conditions such as reverse power flow and increased fault levels. In this paper, using the graph theory, various branches of a feeder are identified and theconstraints for using genetic algorithm to optimize the location of protective equipment are derived. In the proposed algorithm, the location, type and direction ofrelays are optimized simultaneously. The results of implementing the proposed approach on a 33-bus test network confirm the performance and accuracy of this method.

Microgrid, Genetic Algorithm, Protection Coordination, Graph theory