Extreme Risk Assessment in Power System Considering Cyber Attacks

Recently, wide concern of extreme risk events in power system has been aroused due to several big blackouts at home and abroad. The present study is designed to assess the extreme risk of power system considering cyber attacks, which can not be reflected by using traditional risk assessment method. Based on the theory of value at risk(VaR) and extreme value theory(EVT) in financial terms, a method to evaluate and quantize extreme risk of power system is proposed to determine the potential risk resulted from extreme events with low probabilities and serious consequences. The method is applied to evaluate the extreme risk of cyber attacks in power system and comparisons between evaluation results of commom risk and extreme risk are conducted. Statistically significant results have justified the validity of extreme risk assessment method, which could be regarded as a complement and improvement to traditional risk assessment. It is recommended that further study is needed to be conducted for risk prevention so as to enhance the operation security and reliability of power system.