Effect of the Control of Generators and Turbines on the Transient Stability of a Power System

This article analyzes the effect of the control of generators and turbines on the transient stability of a power system. An example from the literature, whose solution is known without the effect of the control system, was taken as base case. Three standardized models for the control of excitation systems and one simplified model for the speed governor were applied. The main parameters of the control systems were varied, and the results were obtained by using two different generator models (transient/subtransient). The loads were modeled as constant impedances. The results show the transient behavior of the main variables, and the critical clearing times for a specific fault (three-phase bolted fault, at a specific point of one transmission line). In some cases, results show that the critical clearing times are greater when the control systems are included in the simulation, and the opposite occurs in other cases. Therefore, there is no a simple rule about the worst conditions for the simulation.