Energy-guided time-domain simulation for critical clearing time reassessment in the TTS-CUEP/BCU method

The two-time scale (TTS) CUEP/BCU method provides the correct calculus of the (uniform) controlling unstable equilibrium point (CUEP) for TTS power system models in transient stability problems. The energy of CUEP can be used to locally approximate the stability boundary and to provide a conservative critical clearing time (CCT) estimate, however the TTS-CUEP/BCU method also provides a CCT estimate for the fast subsystem, associated with the original TTS power system model, which potentially can be used as a better (less conservative) estimate of the CCT for the TTS model. Despite this fact, the TTS-CUEP/BCU method does not take advantage of this fast CCT estimate in the assessment of the CCT estimate of the TTS system. This paper propose a energy-guided timedomain simulation to accomplish this task.