Preventive control design for voltage stability considering multiple critical contingencies

A new methodology for selecting a global group of the most effective preventive controls in the context of voltage stability analysis in electrical power systems for a set of multiple critical contingencies is developed in this paper. This methodology is based on a sensitivity analysis of the maximum loadability point with respect to voltage controls. Considering not only the effectiveness of the control elements but also their availability, coordination, and cost, the methodology determines a set of controllers to simultaneously eliminate all critical contingencies. The methodology is fast and suitable for online assessment of preventive control. The methodology was successfully tested in a reduced south-southeast Brazilian system composed of 107 buses.