A contingency ranking method for voltage stability in real time operation of power systems

A contingency ranking procedure regarding voltage stability to be used in a real time operation environment is proposed in this paper. The procedure can be added to the existing ranking procedures (for MW overloads and voltage violations) with mild modifications and small extra computational effort. A performance index (PI) is computed for each contingency. The PI is defined in terms of a branch-based voltage stability proximity index. Several simulations show that the most critical contingencies can be identified correctly.