Controlling grid integrity after power system emergencies

An emergency strategy for dealing with multiple contingencies that can lead to system voltage instability has been incorporated into a program for studying post-disturbance power system dynamic events. Pattern recognition allows simple logic for a practical and reliable means of safeguarding the grid and offering a means for preventing the multimillion dollar collapses that befall worldwide interconnected systems. The proposed automatic arrangement only needs low cost measures and is able adapt to multiple contingencies. The timely responses to emergencies would allow higher power flows on lines constrained for system voltage stability as well as raising security levels by taking advantage of the initial system resilience without need for its costly augmentation.