FAST CONTINGENCY SCREENING FOR VOLTAGE-REACTIVE CONSIDERATIONS IN SECURITY ANALYSIS

This paper presents an efficient contingency screening method for voltage limit violations. The essential points are: 1) The Q-mismatches are calculated exactly for the buses situated in the vicinity of the outaged element and approximatively for the buses that are electrically away from the perturbation. In this step, the convergence rate of individual nodes outside the perturbation area is exploited and the small Q-mismatches are zeroed. 2) It uses the electrical distance concept (1) to predict the buses on which major voltage shifts can occur after the contingency. Computational efforts are saved using the approximate Q-mismatch calculations and by using the sparse vector techniques for the non-zero mismatches (Fast Forward/Back solutions). The number of bus voltages to be solved is drastically reduced and the accuracy of the solution remains good . Results of tests with a 206 buses-299 branches of 400 kV reduced French network are given to illustrate the performance of the method.