Lyapunov methods applied to multimachine transient stability with variable inertia coefficients

The paper is a contribution to the transient-stability study of multimachine power systems by Lyapunov´s direct method. The mathematical model used is more rigorous than those already taken into account in that the machines´ inertia coefficients are no longer considered as constant but varying with angular speed. This constitutes a more accurate approach to the transient-stability problem. A 9-machine realistic power system illustrates the proposed method, and permits comparisons and conclusions to be made.