AEP Automatic Contingency Selector Branch Outage Impacts on Load Bus Voltage Profile

This paper presents the details of a computationally efficient automatic voltage contingency selection algorithm developed for implementation at the AEP´s new system control center in Columbus, Ohio. The methodology is based on the quantification of the real-time system-wide impacts of the transmission branch (line and transformer) outages on the load bus voltage profile via the fast computation of a quadratic system Performance Index (PI) for every branch, and subsequent sorting of the results according to the severity of effects. The algorithm enjoys superior computational complexity compared to the previously published work. An application of the algorithm to the AEP EHV real-time data base is presented as an illustration. The essence of the algorithm is to quickly rank branch contingency events in such a manner that sequential contingency testing could be carried out (with an on-line full AC load flow function, for example), starting with the most severe contingency (in terms of causing abnormal voltage profile) and terminating when the sequence of contingencies no longer poses problems.