Sensitivity techniques for the fast assessment of security margins to voltage collapse

This paper presents a simple, fast and efficient method for determining the security margin to voltage collapse (SMVC) of electric power systems. The computation procedure is based on the utilization of sensitivity techniques. The basic idea is that load increments influence the behavior of the reactive power injected by generators (slack and PV buses). Therefore, sensitivity analysis may be a very interesting tool for voltage stability analysis and applications. The proposed method, with a static approach, is based on solving a certain number of load flow calculations for different load levels. The path to reaching the maximum loading point, which allows the estimation of the SMVC consists of simple load increments or curtailments. The results are accurately obtained after a few load change steps.