SIME: A hybrid approach to fast transient stability assessment and contingency selection

We propose an integrated scheme for transient stability
assessment which in a sequence screens contingencies and
scrutinizes only the selected ones. This scheme is based on a
hybrid method, called SIME for Single Machine Equivalent.
SIME relies on a particular direct method coupled with time-domain
programs so as to combine the strengths of both,
namely: 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 techniques for transient stability
assessment per se and for contingency screening, and finally
integrates these two techniques in a fully general function,
i.e. able to comply with any power system modelling and
stability scenario, and to assess any type of stability limits
(critical clearing times or power limits). Throughout, real-world
examples illustrate the proposed techniques and highlight
their performances.