Transient instability detection using line transient potential energy

Transient instability detection is investigated using a new analytical tool derived from the line transient potential energy. Instead of following the conventional approach of observing the rotor swings or comparing the critical energy and transient energy at fault clearing time, a new instability detection criterion based on the examination of the line potential energy along post-fault trajectory is developed. The main advantage of this method is that only local dynamic measurements of transmission line variables (power and phase angle differences) are required for detecting first- or multi-swing transient instability. Case studies on the 10 machine 39 bus IEEE test system showed that the proposed method is very effective and opens up new possibilities of studying transient stability and control using local transient network energy.