Expert System for Wide Area Protection Zone Selection

Load shedding has been proven to be effective and inexpensive counter measure to prevent the power grid from cascade collapse to blackout. In wide area adaptive protection, adaptation of backup protection relays, as well as load shedding can be used to reduce the likelihood of catastrophic failure in power system. In this paper, a graph theory based expert system is developed to divide electric power grid into protection zones containing substations and the coordination of backup protection relays and load shedding can be carried out considering the power of generators, load, backup spin capacity, transmission lose of the region, as well as the redundancy transmission capacity of its tie lines according to the power balance based protection system