Active Power Control of Waked Wind Farms: Compensation of Turbine Saturation and Thrust Force Balance

Wind farm control for wake-loss compensation, thrust balancing and load-limiting of turbines

“…Reducing the variation of thrust forces across the farm extends the aggregated turbine life. The main idea of the thrust force balance controller is to balance the thrust forces of all turbines to their mean value while the wind farm power tracking is maintained [38]. Hence, in addition to the power compensator feedback, a thrust control loop is synthesized by using each of the estimated instantaneous thrust forces FT, 𝑖 .…”

“…For brevity, the reader is referred to [38] for more details. Finally, the corresponding correction terms in 𝛥𝑢 𝑘 TB ∈ R 𝑁 T are added to demanded powers 𝑃 𝑘 dem ∈ R 𝑁 T to balance all thrust forces of unsaturated turbines.…”

“…As consequence, the degradation of high-loaded turbines is reduced together with their associated maintenance costs. In addition, the total farm available power can be increased by the cooperative farm operation, as seen in [38]. Lastly, a loadlimiting strategy using the instantaneous thrust estimations derived from regular turbine measurements, i.e.…”

Active power control of wind farms: an instantaneous approach on waked conditions

“…The algorithm was successfully tested in a large-eddy simulation environment under heavy-waked conditions, but with simplistic static actuator disk models for the turbine rotors. Then, Silva et al [22] extend on that work by also adding a secondary control loop which balances the aerodynamic loads on the turbines, while exploring its benefits on turbine saturation scenarios using ALMs.…”

“…This is investigated in Section 3.2 5. The derivation can straightforwardly be extended to include time dependency in αi, as in Silva et al[22] by an additional closed-loop with the thrust forces. Also, time-varying distributions can be designed to consider constrained load turbines due to detected faults and failures 6.…”