Conventionally, Transient Security Assessment (TSA) has
been performed using off-line simulations.
In this process,
time domain analysis is usually conducted for each credible
contingency under a variety of operation conditions. In real
time operation, however, conditions frequently do not match
those studied off-line.
Consequently, the guidelines and limits
produced are usually too conservative.
For a transient stability
limited system, considerable savings may thus be achieved if
more economic operating arrangement can be found to guarantee
the transient security condition duringnormal operation.
Hence, there is a pressing need for inclusion of on-line TSA
capabilities in modern energy management systems. This paper
addresses the issue to develop tools for evaluations of first
swing transient stability limited conditions.
Analytical sensitivity approach [1] has been developed for the
stability limit analysis, but it can only be used for systems represented