SIME - A HYBRID APPROACH TO FAST TRANSIENT STABILITY ASSESSMENT AND CONTINGENCY SELECTION

We propose an integrated scheme for transient stability assessment whi ch in a sequence screens contingencies and scrutinizes only the select ed ones. This scheme is based on a hybrid method, called SIME for Slng le Machine Equivalent. SlME relies on a particular direct method coupl ed with time-domain programs so as to combine the strengths of both, n amely: the flexibility with respect to power system modelling of time- domain methods; the speed and richer information of the direct method. This paper lays the foundations of SIME, devises appropriate techniqu es for transient stability assessment per se and for contingency scree ning, and finally integrates these two techniques in a fully general f unction, i.e. able to comply with any power system modelling and stabi lity scenario, and to assess any type of stability limits (critical cl earing times or power limits). Throughout, real-world examples illustr ate the proposed techniques and highlight their performances. (C) 1997 Elsevier Science Ltd