Sensitivity of stability index based on the trajectory analysis

Trajectory analysis method is an effective approach for evaluating the power system transient stability by proposed stability/instability indices based on the individual machine trajectory. The sensitivity of stability index with respect to some key parameters will be useful for control strategy making in power system operation. A trajectory sensitivity based algorithm for calculating the sensitivity of stability index has been proposed in this paper. This algorithm can also be expanded to calculate critical fault clearing time. The validity of the method has been demonstrated in a one machine infinite bus (OMIB) system and an EPRI 8-machine 36-bus system. The test results show that the proposed method is effective and reasonable.