Direct ranking for voltage contingency selection

The authors present a direct ranking algorithm for contingency selection in power systems taking into consideration voltage security problems. In direct ranking, the performance index for a contingency case is formulated in such a way that detailed knowledge of postcontingency voltages at each individual bus is not necessary. Compared with 1P-1Q iteration screening methods with second norm index, this direct ranking method has a higher computation speed and almost the same accuracy. The proposed algorithm is more concise and can be implemented more efficiently than existing algorithms