Multi-swing trajectory analysis using time-varying One-machine Infinite Bus equivalents

In this paper a method for identifying the multi-swing stability is presented. The method is based in finite-differences of the time-varying one-machine infinite-bus (OMIB) equivalents. Conventionally the problem of transient stability has been studied by means integration methods being limited to the analysis of first oscillation. The key of this article to expand the conventional methodology to study the stability multi-oscillations by means of the analysis of a criterion based on the derived of the angle OMIB. The proposed method establishes the multi-swing stability on the power system using the second derivate test criterion based on the gradient OMIB. The effectiveness of the proposed technique is tested on a realistic 45-machine power system model representing parts of the Mexican interconnected system.