Mitigation of Power System Vulnerability due toHidden Failures of Protective Relays by UsingImportance Sampling to Identify Rare ContingenciesSession ۳: Operation, Control & Protection

In this paper, a vulnerability analysis based onimportance sampling is used to identify the scenarios that lead tosystem catastrophic events including hidden failures of theprotective relays. As the number of the possible scenarios isextremely large even for a moderate power system, the appliedcontingency analysis alleviates the difficulty of simulating rareevents by dramatically decreasing the number of vulnerablescenarios. The simulations are performed with alteredprobabilities, which make the unlikely events more likely andprocessing the simulation results so that the correct answers areobtained. Upon identification of severe contingencies that mightlead to cascading failures considering the hidden failures of theprotective relays, remedial actions are proposed to mitigate theconsequences of such an initiating event. The proposed solutionscould be blocking the vulnerable relays that have the potential tomalfunction in the captured scenario. This could be done bysending blocking signals to the identified vulnerable relays viathe communication media.

کلیدواژه ها:

protective relay ، vulnerability ، hidden failure