Fast Transient Stability Assessment Revisited

Energy Liapunov-like criteria are devised, their essential characteristics are assessed, and, depending upon the particular needs they are called to meet,the most appropriate among them are identified. The criteria derive from the conjunction of various Liapunov-like functions ("global", "individual", and Taylor series based ones) with two different estimates of practical stability domains; bound to these criteria, rules for the proper identification of the system "relevant" machines are also proposed. Many variants are thus envisaged and investigated through a large number of simulations, carried out on eight different power systems. They allow highlighting criteria\´s salient merits, and suggesting appropriate selection among them.