Overview of Frequency Control Techniques for DFIG- Based Variable Speed Wind Turbines

In power systems, new converter-based power sources such as wind and solar farms must offer frequency control to prevent severe stability issues. The Variable Speed Wind Turbines (VSWTs), particularly Doubly Feed Induction Generator based VSWTs (DFIG-VSWTs), have become popular due to environmental concerns. By utilizing the control loops integrated in the Rotor-side converter, the DFIG-VSWTs can generate extra power from Stored Kinetic Energy (SKE) for frequency response. This paper provides a comprehensive review of the current literature on up-to-now frequency control techniques and issues of DFIG-VSWTs in interconnected power systems.