Development of methods to include wind plants in security control of dynamic security of power systems
Penetration of wind power into power systems significantly increases the uncertainties present in system operation and stability, due to the stochastic nature of the wind. In this sense, this thesis proposes a methodology for representing and including the wind power uncertainty and available control resources of wind generators in voltage stability assessment of the day-ahead operation planning. In the dynamic security assessment, the voltage stability margin (VSM) of the electrical system is evaluated under contingencies, however, the possible deviations from the predicted output wind power can also lead the system to an insecure operation point. This thesis presents an approach based on Cross-Entropy method to identify the deviations from the predicted output power level of wind power plants that should be included in the list of critical scenarios, such as a contingency, for planning preventive control actions. Then, a methodology, based on hierarchical approach, is used to select the preventive control set considering their effectiveness, availability, coordination, and cost of the controls. The method is validated using a test system model based on a real bulk power network and the results show that the method can be very effective to ensure that the system operates even under contingency conditions or critical wind generation scenarios, with a VSM that meets safety restrictions.