A novel method for transient stability margin evaluation of the post-disturbance power system

摘要

Transient stability assessment (TSA), especially the quantitative TSA, is of vital importance to power system stability analysis and control. In this paper, a quantitative method is proposed for the transient stability margin (TSM) evaluation of the post-disturbance power system. A novel TSM index is first proposed based on the phase trajectory's concave-convex feature. The index is demonstrated to be related to the transient energy of the power system, which gives it's a clear physical background. Besides, the proposed TSM index overcomes the demerits of other quantitative TSA methods, such as the difficulties in UEP prediction and critical transient energy determination. The computation of the index is simple and only requires the measurement data of generators, which enhance its application in real-time scenarios. Based on the proposed index, an online TSM evaluation scheme is finally proposed and its validity is verified in the Single Machine Infinite Bus (SMIB) system and IEEE 39 bus power system.