I. Introduction
With the scale of power system network increasing, the system endures huge potential risks. Since 2003, many countries have blackouts in large scale, which causes wide attention of scholars on the power grid operating risks, and which makes people gradually realize the disadvantage of deterministic criteria in power risk. It is necessary to study models and methods which consider influences of various uncertain to improve the effect of existing tools [1], [2]. Meanwhile, the “Twelfth Five-Year Plan” and the “three sets of fives” strategy of China State Grid Corp put forward more stringent requirements clearly to power system operation risk assessment and risk management.