Solution of Power Flow With Automatic Load-Frequency Control Devices Including Wind Farms

This paper proposes the integration of steady-state models of several types of wind generators into a power flow algorithm with automatic load-frequency control. Since the system frequency deviation is considered a state variable to be computed by the power flow solution, this formulation helps identify the operating point of wind generators after the action of the primary frequency control when power imbalances have occurred. The mathematical formulation of fixed-speed wind generators is presented based on the steady-state representation of the induction generator. Furthermore, as variable-speed wind generators keep gaining prominence in power systems, their potential contribution to frequency support is also analyzed herein. These models are formulated within the power flow approach by using a unified single frame of reference and the Newton-Raphson algorithm. The proposed approach is then applied to the analysis of a three-machine, eight-bus system and the IEEE-14 bus test system.