Impact of Initial Stressor(s) on Cascading Failures in Power Grids

Cascading failures in the power grid refer to a chain of events triggered by an initial event such as a single or a combination of failures in a generator, a transmission line, communication or control action. The initial event can be attributed to a natural disaster or an intentional human-made attack. In this paper, cascading failures in the power grid are analyzed under various initial conditions. First, Gaussian, circular and linear stressor(s) are used as the initial events to model the probability of transmission line failure due to the stressor(s). Second, Monte-Carlo simulations are used to analyze the impact of cascading failures in the power grid based on the initial failure patterns. The reported results show that upon the occurrence of an initial triggering event, a combination of parameters (e.g., the number of stressor(s), the number of failed transmission lines in each stressor location, the capacity of the failed transmission lines, the power-grid loading level, the load-shedding constraints at the time of the stressor event) strongly influence the dynamics of cascading failures and may lead to massive blackouts.