What is transient stability in power systems?

Transient stability is the power system's ability to maintain synchronism when subjected to large disturbances like faults or generator trips. During a fault, accelerating power develops as mechanical input exceeds reduced electrical output. If fault clears quickly enough, the system recovers; otherwise, generators lose synchronism. Analysis uses swing equations and equal area criterion. Critical clearing time depends on fault severity, generator inertia, and system strength. Fast fault clearing and strong ties improve stability.