A New Method for Transient Stability Assessment Based on Critical Trajectory

This paper proposes a new method for transient stability analysis for electric power systems. Different from existing methods, a minimization problem is formulated for obtaining critical conditions for transient stability. The method is based on the computation of a trajectory on the stability boundary, which is referred to as critical trajectory in this paper. The critical trajectory is defined as the trajectory that starts from a point on a fault-on trajectory and reaches an unstable equilibrium point (UEP), in which the former point is called the exit point and the latter points, controlling UEP (CUEP). The solution of the minimization problem provides critical clearing time (CCT), exit point, and CUEP simultaneously.