A Novel Strategy for Variable-Speed Wind Turbines' Participation in Primary Frequency Control

This paper proposes a novel strategy for participation of variable speed wind turbines in primary frequency control. The proposed strategy is based on the deployment of the kinetic energy of the rotating masses to reduce the need for deloaded operation while still being able to provide the required power reserve for the defined time frame. A steady-state deloaded operating point is optimized with respect to the amount of kinetic energy stored in the rotating masses. The parameters of the algorithm are calculated offline and stored in lookup tables. The proposed strategy is tested using a modified Nordic 32-bus test system for various operating scenarios. The results show that part of the primary frequency control power reserve of the thermal units can be replaced by the reserve provided by wind power, while retaining the desired frequency response following a disturbance. A comparison with the conventional deloaded strategy shows that between 1.16% and 2.79% energy savings can be achieved on a yearly basis, depending on the wind regime of the sites analyzed.