Preventive control actions to enlarge the load margin using VSCOPF & sensitivity techniques

In this paper the problem of voltage security is studied under the system operator´s (SO) point of view, who should take the correct actions to avoid voltage collapse phenomena. The aim of the SO is to decide which parameters, among those under his control, to use to enlarge the loading margin of the system and, consequently, move the collapse point away from the current operation point. To do so, an heuristic tool based on a particular OPF and a sensitivity analysis is presented, moreover, the different strategies that the SO could take are explained. The optimization model used to compute the loading margin to voltage collapse gives, as an additional information, the loading margin sensitivities with respect to some typical control parameters in different loading situations. The processing of this information is presented in this paper.