Analysis of the Frequency Response of Wind Turbines with Virtual Inertia Control

In this paper, frequency response of a typical DFIG-based wind turbine is analyzed. To achieve an inertial response in this machine, two control loops are added to the indirect power control loop to emulate inertia, these are the virtual inertia loop, which acts on the frequency derivative, and the primary regulation droop, which acts on the frequency deviation. As the parameter of these loops are user-defined, both can be tuned freely, but inadequate tuning can result in certain conflicts and instabilities in the grid. The importance of virtual inertia loop will be discussed given that the dynamics of the primary regulation droop can be fast enough to provide a sufficient inertial response. Simulation results show that, with adequate control parameters, this response can improve system frequency response even with high penetration levels.