FAST CONTINGENCY SCREENING FOR VOLTAGE-REACTIVE CONSIDERATIONS IN SECURITY ANALYSIS

This paper presents an efficient contingency screening method for volt age limit violations. The essential points are: 1) The Q-mismatches ar e calculated exactly for the buses situated in the vicinity of the out aged element and approximatively for the buses that are electrically a way from the perturbation. In this step, the convergence rate of indiv idual 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 th e contingency. Computational efforts are saved using the approximate Q -mismatch calculations and by using the sparse vector techniques for t he non-zero mismatches (Fast Forward/Back solutions). The number of bu s voltages to be solved is drastically reduced and the accuracy of the solution remains good . Results of tests with a 206 buses-299 branche s of 400 kV reduced French network are given to illustrate the perform ance of the method.