Analysis of worst case Power system contingencies using vulnerability frontier
Abstract
One of the most important aspect in a power system network is to make a network secure against
unanticipated events. In general, a power system network is always made N-1 secure: any single
outage will not lead to instability in a network. The electrical transmission system is vulnerable
to extreme events which can cascade resulting in blackouts. In this thesis, we identify critical
corridors, subsets of those transmission lines that are most vulnerable to extreme events. It is
computationally difficult to take into account all possible multiple outages of lines. In this thesis,
we consider the worst case scenario in which the outages of a particular subset of transmission
lines result in maximum power imbalance. Subsets of transmission lines that appear with higher
frequencies are candidates for detailed study as they may lead to extreme events. We present a
vulnerability frontier (graph between number of lines cut and maximum power imbalance
corresponding to those lines cut) for 30, 118, 179, 225 and 1553 bus system. Tables listing the
frequencies at which a particular cut-set of transmission lines (for 30,118 and 179 bus system)
occur have also been presented.