Model-Free Fast Frequency Support of Wind Farms for Tracking Optimal Frequency Trajectory
This work addresses the difficulty of controller implementation for frequency regulation in wind farms, offering a model-free approach that is incremental but practical for power grid stability.
The paper tackles the challenge of implementing fast frequency support in wind farms without relying on accurate governor dynamics models, proposing a proportional-integral controller that tracks optimal frequency trajectories and demonstrating its validity in single- and multi-wind farm systems.
The fast frequency support (FFS) towards frequency trajectory optimization provides a system view for the frequency regulation of wind farms (WFs). However, the existing frequency trajectory optimization-based FFS generally relies on the accurate governor dynamics model of synchronous generators (SGs), which aggrandizes the difficulty of controller implementation. In this paper, a proportional-integral (PI) based FFS of WFs is designed for tracking the optimal frequency trajectory, which gets rid of the dependence on the governor model. Firstly, the prototypical PI-based FFS of WFs is proposed and its feasibility for tracking the optimal frequency trajectory is analyzed and demonstrated. Then, based on the "frequency-RoCoF" form of the optimal frequency trajectory, a more practical PI controller is constructed, avoiding the time dependence of the prototypical PI controller. Besides, an adaptive gain associated with PI parameters is designed for multi-WF coordination. Finally, the validity of the proposed method is verified in both the single-WF system and the multi-WF system.