Computation of generation rejection in on-line dynamic security assessment using a new hybrid method

This paper presents a MUI (Marginally Unstable Injection) method which is a variation of the so-called hybrid methods to incorporate energy function analysis into conventional time-domain simulation for transient stability assessment. Using the concept Slow Energy Function (SEF) and a sequence of short pseudo-faults, the proposed method provides an improved stability index by impelling a stable system to a marginally unstable state. The resulting stability index is then utilized for estimating the amount of generation rejection required to maintain transient stability within a framework of on-line dynamic security assessment. The technique developed is applied to a 700-bus North America system. Copyright (C) 1998 IFAC.