Dynamic control strategy for the participation of variable speed wind turbine generators in primary frequency regulation

This paper introduces a novel strategy for the participation of variable speed wind turbine generators in primary frequency regulation. The proposed strategy is based on modifying the droop and inertia emulation control loops in such a way to help the wind turbine provide a secure frequency response throughout the dynamic control of the turbine tip-speed ratio and de-loading percentage. The proposed control does not directly act on the active power reference such as classical droop and inertia controls but on adjusting the rotor speed set-point and the pitch angle directly in response to the frequency deviation. The wind turbine is assumed to operate at 10% de-loading percentage under normal conditions. The over-speed, pitch control, and de-rated control are combined together to provide a power reserve. The control strategy is valid for all the wind speed ranges and does not require any direct wind measurements as a control input. The simulation results confirm that the proposed frequency response strategy improves effectively the frequency stabilization of the power system and has the ability to provide transient and steady-state power-sharing within the stable and secure limits.