Searching for feasible splitting strategies of controlled system islanding

Abstract

Controlled system islanding, also called system splitting, can effectively prevent blackouts of power systems. The splitting strategy determining how to split a power network into islands should be given in real time. Previous papers proposed an ordered binary decision diagram method to search for the splitting strategies satisfying necessary steady-state constraints, e.g. generation–load balance and transmission-line capacity constraint, and also showed that, without any other corrective controls, the splitting strategies may produce unstable islands according to a further simulation study. A modified method to find feasible splitting strategies in real time for large power network is presented. Each feasible splitting strategy not only satisfies necessary steady-state constraints but also easily produces stable islands to prevent a blackout. The method also introduces new techniques into strategy searching to increase its efficiency and practicality, e.g. network partitioning and parallel processing, generator classifying, deriving splitting strategies from cut-set splitting strategies, etc. Simulations on the IEEE 118-bus system show that the real-time portion of the modified method finds feasible splitting strategies in less than one second.