Stress test model of cascading failures in power grids

Cascading failures in electric power systems are one of the major causes of large power blackouts. The operators in control centers of electric power systems need an online tool to monitor the risk of cascading failures when transferring large quantities of power over long distances. In this paper, we propose a two-stage stress test model of cascading failures. The stress test model is intended to emulate the effect of security-constrained economic dispatch (SCED) in support of the required power transfer level, and at the same time, to account for relay actions in response to a given set of severe disturbances, called maximum credible disturbances. The model includes an inner stage, which simulates cascading outages due to relay actions in the system at a given state under disturbances, and an outer stage, which moves the operating point of the system as the power transfer increases as a result of SCED. We use the stress test model to simulate cascading failures in a real 3000-bus power system when increasing its power transfer level in different directions.