Derivation of stability limits using analytical sensitivity of thetransient energy margin

It is noted that the transient energy function (TEF) method has matured to a stage where reliable and accurate assessment of transient stability of a multimachine power system is possible. Stability limits in terms of plant generation limits, load changes, or network configuration changes are derived using analytical sensitivity of the energy margin. A detailed development of the analytical sensitivity procedure is presented. The technique is tested on the 17-generator Iowa network, and a good assessment of the stability limits is obtained. Experience based on more than 2500 runs on several actual power networks indicates that, for the classical power system model, the TEF method gives stability results as accurately and as reliably as conventional time-domain simulation programs