Key Factors Analysis of Cascading Failure Propagation in Power Grids

Key equipment or vulnerable equipment always intensify the development of cascading failure, so it is of great importance but also challenging to find them. Recent researches present the ranking of vulnerable equipment according to complex network theory, while lacking the information of system risk. In this paper, we explore the relationship between system risk and vulnerable equipment as well as the relationship between equipment, we puts forward an approximate equation of failure propagation based on the correlation matrix, and draw the conclusion that the probability of initial failure and the max-eigenvalue of correlation matrix determine the propagation of cascading failure. Extensive simulation results show the positive correlation between blackout risk and max-eigenvalue of correlation matrix when initial failure probability is fixed. And top 10 vulnerable equipment, which has higher PageRank value, also has bigger value among the eigenvector of the max-eigenvalue. Furthermore, this paper analyzes the role of vulnerable equipment identified by PageRank and Electric Betweenness methods, using the cascading failure simulation. The results show the complementarity of the PageRank and Electric Betweenness methods at different stages of failure.