Correlation evaluation of searching event chains in power system cascading failure

In recent years, blackout accidents taking place across different countries really shock the world, reminding electrical engineers that the power grid is still far from robust and strong enough against complex operating environment and uncertain load conditions. During the process of cascading failure, the event chains grow longer with the spreading of failures which are mostly caused by over-limit power flow or sudden increasing of current, while correlation evaluation among cascading failures is often not taken into account. In this paper, a practical cascading failure model is proposed to simulate the process of cascading failure and the correlation evaluation for new failures is proposed to recognize typical event chains leading to blackout. A detailed study on IEEE118-bus test system as benchmark is given to demonstrate the validity and effectiveness of the proposed cascading failure model. Some meaningful conclusions and comments pertinent to failure correlation are drawn.