Determination Priority of Lines Interrupt Connected to Substation for Reduction of Graphite Bomb Damages

The Graphite Bomb (GB) is one of the military applications of graphite fiber and the power system substations are the critical locations to do this attack. By throwing a GB on a substation, severe short circuit faults and simultaneous lines outages will be very probable which endanger power system stability. With the assumption of graphite attack detection, the purpose of this study is proposing a remedial scheme to reduce the GB damages and to increase the power system dynamic stability consequently. In other words the lines breakers should open by a predetermined plan, before hitting the GB to the substation. To achieve this goal, two issues have been considered, including: the lines outages priority and the time interval between outages. The static index of average rate of change of the line active power and the dynamic index of the first swing of generators used respectively to solve the issues. The proposed scheme performance has been evaluated on the IEEE 39-bus test system and the results show its effectiveness to improve power system dynamic stability.