The Transient Energy Function Method (or Generalized Lyapunov Method) for Power Systems can be used when network topology is changing. Researchers are developing methods for selection of optimal actions for Contingency Arming Schemes (generator tripping, load shedding, fast turbine valving, dynamic braking, high speed reposing) on an analytical basis instead of "cut and try" or sensitivity methods. They are also developing theory, algorithms, and programs for nonlinear models of Power Systems. These algorithms permit one to choose actions for Contingency Arming Schemes for off-line computations and on-line dynamic security analysis in a power system Control Center. Utilities benefit by: increase of power reliability; decrease of electrical energy underproduction during fault and post-fault regimes; and selection of control actions depending on disturbance strength in order to guarantee the steady-state, and transient stability and the necessary transient performance.Commercial Applications:Results of this research would serve to choose correct and efficient actions for Contingency Arming Schemes in the power systems.