Transient stability limit conditions analysis using a corrected transient energy function approach

This paper addresses the issue in developing tool for transient stability l imit conditions analysis in on-line power system operation, Concepts, inclu ding corrected potential energy and corrected potential energy boundary sur face, are proposed for improving use of hybrid method in transient stabilit y limit conditions analysis. It is shown that the value of Corrected Transi ent Energy Function (CTEF), which is the sum of corrected kinetic energy an d corrected potential energy, is of conservation (maintains constant value) during post-fault transient period. Efficient criteria in identifying firs t swing stability behavior are also developed and used in the approach inco rporating CTEF analysis in hybrid method to evaluate corrected hybrid trans ient energy margin. Initial simulation results on the l0-machine New Englan d and on the 50-generator IEEE test power systems show that the approach is promising in evaluations of transient stability limit conditions of power systems both for plant and inter-area mode disturbances.