Influence of the load representation in voltage stability studies

In English The critical effect of load representation in voltage stability studies is discussed in this paper. Under the same conditions in the system, the load representation will affect the location of the operating point in a P-V curve representation, leading the system closer to or further from the collapse point. The use of dynamic load models in voltage stability studies is motivated, especially in those cases where the load shows a thermostatic effect. Simulations show that the recovery of this type of loads during a voltage disturbance may lead the system to heavily loaded conditions and to voltage instability. However, during that recovery time, there is a relief in load, and by taking effective and quick control actions the stability of the system may be maintained. Moreover local generation, activation of gas turbines, is presented as a new approach to re-establish this stability, providing reactive support but also increasing the loadability of the system.