Timing of a Controlled Islanding Strategy

Controlled islanding is a ´last line of defense´ for avoiding catastrophic blackouts in an electric power system approaching global instability. The design of an intentional controlled islanding strategy must be inherently predictive in nature, as well as reliable. An algorithm is presented that monitors the synchronous stability of the system at a global level using the Prony method, and is coupled with detection of local out-of-step conditions to decide when controlled islanding should be initiated. The boundaries of the islands are derived from the groups of slow coherent generators. The objective is to minimize the potential blackout extent in the system