Participation of PMSG-based wind farms to the grid ancillary services

•A design of a supervision strategy for wind farms using the Direct Drive technology is proposed.•The designed controller allows the participation of PMSG_based wind farms to the grid ancillary services.•A wind farm model is developed in order to test the performances of the wind farm controller.•Supervision performances are evaluated in terms of compliance with control functions required by Danish TSOs.

With the increased penetration of wind energy in many utility grids throughout the world, transmission system operators (TSO) are facing further difficulties regarding power system control and stability. Therefore, modern wind farms should participate to the primary voltage and frequency control of power systems. This paper presents the design of a supervisory control strategy for grid-connected wind farms. Wind turbines within the investigated wind farm are pitch controlled and use the Direct Drive technology. It has a total installed capacity of 50 MW and it includes 25 PMSG-based wind turbines with a rated power of 2 M each. The proposed supervisor is developed with all features that make the wind farm able to provide active and reactive power control. It includes automatic voltage and frequency control with droop and dead band. Performances of this supervisor are evaluated in terms of compliance with the Danish TSO requirements.