Vulnerability analysis of power system by modified H-index method on cascading failure state transition graph

Abstract

The mechanism of the cascades and the vulnerability of the power grids have been widely concerned due to the blackouts around the word in recent years. It is urgent to propose an effective method to estimate the vulnerability of the power grids. In this paper, a modified H-index method is proposed to identify the critical lines in power grids based on the cascading failure state transition graph. First, a two-level cascading failure state transition graph is constructed according to the power flow transfer on transmission lines after the cascading failures to describe the state transfer relationship when the transmission line is cut off. Then, the state transition graph is decomposed into the fault propagation graph and the fault infection graph, respectively in view of the infectiousness and propagation of the line faults. And a vulnerable line identification method is proposed based on the modified H-index method. Finally, the simulations on the IEEE-39 bus system and the NE power grid show that the transmission lines which are prone to propagate faults or have weak anti-interferences can be identified effectively by the proposed method.