A model predictive approach to protect power systems against cascading blackouts

摘要

Large scale blackouts normally go through several sequential phases according to the propagation speed of branch outages and the disruption level of power grids. It is crucial to eliminate the propagation of cascading outages in its infancy. In this paper, a model predictive approach is proposed to protect power grids against cascading blackouts. First of all, the cascading dynamics of power grids is described by the outage model of transmission lines and the DC power flow equation, which allows us to predict the cascading failure path. Then a nonlinear convex optimization formulation is established to terminate the cascading outages by adjusting the injected power on buses. Afterwards two protection schemes are designed according to the optimization formulation: one scheme carries out protective actions to terminate cascading outages once for all, while the other takes protection measures in two consecutive steps. Saddle point dynamics is employed to provide a numerical solution to the proposed optimization problem, and its global convergence is guaranteed in theory. Finally, numerical simulations on IEEE test systems are implemented to validate the proposed approach.