The influence of individual parameters of the revitalized generators 1 and 2 of the Zakucac HPP, as well as the applied excitation system, on the transient stability of the electric power system in different operating modes is examined. Based on the simulation of the system operation during transient states caused by three-pole and single-pole close short circuits, oscillation curves were drawn for different values of the influential parameters of the revitalized generators and the critical time limit values were calculated.