TY - JOUR N2 - Finding the most critical contingencies in a power system is a difficult task as multiple evaluations of load and generation scenarios are needed. This paper presents a mathematical formulation for selecting, ranking, and grouping the most critical N-1 network contingencies, based on the calculation of a Power Constraint Index (PCI) obtained from the Outage Transfer Distribution Factors (OTDF). The results show that the PCI is only affected by the impedance parameter of the transmission network, the topology, and the location of all generators. Other methods, such as the Performance Index (PI) and the Overload Index (OL) are affected by the power generation and demand variations. The proposed mathematical formulation can be useful to accelerate the calculation of other methods that evaluate contingencies in power system planning and operation. Furthermore, the fast calculation of indices makes it suitable for online evaluation and classification of multiple events considering the current topology. The results showed that the proposed al- gorithm easily selected and ranked the expected contingencies, with the highest values of the index corresponding to the most critical events. In the filtering process, the computa- tional calculation time improved without losing the robustness of the results. L1 - http://www.czasopisma.pan.pl/Content/104082/PDF/AEE-67-2-art02.pdf L2 - http://www.czasopisma.pan.pl/Content/104082 PY - 2018 IS - No 2 DO - 10.24425/119638 KW - contingency ranking KW - critical contingencies KW - power system operation KW - power system planning KW - sensitivity power factors A1 - Arenas-Crespo, Oswaldo A1 - Candelo, John E. PB - Polish Academy of Sciences VL - vol. 67 DA - 2018.06.05 T1 - A power constraint index to rank and group critical contingencies based on sensitivity factors UR - http://www.czasopisma.pan.pl/dlibra/publication/edition/104082 T2 - Archives of Electrical Engineering ER -