Study on power system vulnerability assessment based on cascading failure model

The scale-up of power grid arouses wide concerns on the security and stability of power system operation from industry and academia. How to defend power grid against cascading failures and large-scale blackout accidents by identifying weak areas has become one of key issues to be solved in power system research. To study power system vulnerability assessment, a kind of uncertainty analysis method based on cascading failure model is proposed in this paper. According to the cascading failure model, taking the randomness of line power flow and cascading failure spreading mode into consideration, the influence of line outage failure on system vulnerability is analyzed via risk and probability theory. Moreover, the positive correlation between probability of line outage failure and the extent of limit violation of power flow is studied. Finally, simulation results from IEEE 118-bus test system demonstrate the effectiveness and validity of the proposed model and indices.