A method for real-time transient stability emergency control

We propose a method able to perform real-time transient stability emergency control. It relies on real-time measurements that it processes in such a way so as to infer multimachine power system stability from a one-machine equivalent. More precisely, the method attempts to : (i) assess in real-time the system stability; (ii) appraise the severity of instability, whenever detected; (iii) identify the location and size of corrective actions to be taken (e.g. how much generation to shed and (out of) which generator(s)). The use of the one machine equivalent is crucial to the method; in particular, it makes it able to predict (in)stability, to provide margins and to identify critical machines, in virtually negligible computing times even in comparison with the very short durations of transient stability phenomena. In this paper, a generation shedding scheme is further proposed. This, together with the overall transient stability emergency approach are illustrated on the Hydro-Quebec EHV power system. Copyright (C) 1998 IFAC.