Transient voltage dip in power systems: computation and sensitivity analysis using the hybrid method

The authors describe a voltage dip computation and a sensitivity analysis for large-scale power systems using the hybrid transient stability method. Low voltage dip values during the postcontingency period are a major concern for some power utilities. The ability of the hybrid method to predict voltage dips will enhance its applicability in transient stability studies and dynamic security assessment. The sensitivity analysis is derived relative to changes in generation levels, loads, active and reactive elements, and generator terminal voltages. A good assessment is obtained for the voltage dip. The sensitivity analysis technique is a potentially effective tool for preventive control for maintaining voltage dips above specified limits