A Novel Special Protection System to Prevent Long-Term Voltage Instability against Graffite Attacks

Graffiti bombs are one of the modern non-destructive weapons that by causing short circuit in the power systems result in blackout in these networks. The main purpose of this paper is to propose a Special Protection System (SPS) to prevent long-term voltage instability after graffite attacks. In this SPS, the power grid is divided into several voltage control area (VCAs) in order to carry out corrective actions in a coordinated manner and reduce the risk of the instability. Then, according to the voltage stability status of each area determined by RPRI index, the proposed SPS will be used to prevent long-term voltage instability. In this paper, using the DPL environment of DIgSILENT PowerFactory software, the proposed SPS is implemented and tested on IEEE 39-Bus and Nordic32 networks. The results of simulations performed under different N-1, N-2 and N-3 contingencies and comparison of them with previous ones verify the appropriate performance of the proposed method.