Hierarchical dynamic active wake control for wind farm power generation enhancement and fatigue load suppression with participation in secondary frequency regulation

Wind farms (WFs) are required to participate in secondary frequency regulation (SFR), and operate in power reference tracking (PRT) or power generation enhancement (PGE) modes. Existing studies inadequately address PRT control under poor wind conditions and overlook the negative fatigue load impact of PGE control. To address this, a dynamic active wake control (AWC) strategy is proposed for simultaneous WF PGE and fatigue load suppression (FLS). The strategy employs a hierarchical control structure: an upper-level controller optimizes global control commands, while a lower-level controller refines these for specific operational modes (PRT or PGE), explicitly avoiding the control issues caused by the delay time of wake effect. In PRT mode under poor wind, the strategy significantly enhances SFR performance (reducing PRT error by 83.02%) while simultaneously suppressing fore-aft and side-side tower displacement amplitude and fluctuation (by 11.60%, 3.28%, 5.02%, and 16.83%, respectively). In PGE mode, the strategy achieves a more balanced fatigue load distribution with only a 1% sacrifice in total power generation. This results in reduced fore-aft tower displacement average and fluctuation (by 12.77% and 9.72%) and side-side displacement fluctuation (by 9.97%).