Indices for fast contingency ranking in large electric power systems

The liberalization of the electricity market induces a large variety of scenarios that may lead power systems close to their operation limits. This supports the need for on-line dynamic security assessment (DSA) of the grids, in order to provide operators with a clear insight of the current network state. The on-line application of DSA to a realistic network needs adequate methods to screen the large amount of contingencies to be examined by DSA tools. This paper proposes some practical heuristic indices for Transient Stability contingency pre-filtering and ranking in an on-line DSA session.