Wind Turbine Wake-Redirection Control at the Fishermen’s Atlantic City Windfarm

摘要

In this paper, we will present our work towards designing a control strategy to mitigate wind turbine wakerneffects by redirecting the wakes, specifically applied to the Fishermen’s Atlantic City Windfarm, proposedrnfor deployment within the next few years off the shore of Atlantic City, New Jersey. As wind turbinesrnextract energy from the air, they create low-speed wakes that extend behind them. Full wake recovery tornthe undisturbed wind speed takes a significant distance. In a wind energy plant the wakes of upstreamrnturbines may travel downstream to the next row of turbines, effectively subjecting them to lower windrnspeeds, meaning these waked turbines will produce less power.rnWakes can be redirected laterally to some degree, though, by applying yaw misalignment to thernwake-generating turbine (i.e., not pointing the turbine directly into the wind). Yaw misalignment causesrnpart of the rotor thrust vector to be pointed in the cross-stream direction, deflecting the flow and the wakernin that direction. Yaw misalignment reduces power production, but the global increase in wind plantrnpower caused by decreased wake effects creates a net increase in power production. With the increase inrnpower can come an increase in fatigue loads, though, caused by yaw misalignment. However, ifrnmisalignment is applied properly, and it is layered with individual blade pitch control, the load increaserncan be mitigated. To explore the idea of wake redirection, we used high-fidelity computational fluidrndynamics.rnOur computational fluid dynamics simulations predict that when winds are aligned with the row, whichrnis one of two predominant wind directions, wake-redirection control can create a 10% increase in energyrncapture efficiency. This means that, for a given wind energy plant’s electrical generating capacity, ifrnwake-redirection control were employed, turbines could be more closely spaced, thereby reducing thernwatersheet area of the wind plant. Likewise, for a given watersheet area, the total electrical generatingrncapacity can be increased.rnIn this paper, we discuss the concept of wake redirection through wind turbine yaw misalignment andrnpresent our computational fluid dynamics results of the Fishermen’s Atlantic City Windfarm project. Wernalso discuss the implications of wake-redirection control on annual energy production and fatigue loads,rnas well as plans to implement wake-redirection control at Fishermen’s Atlantic City Windfarm when it isrnoperational—something not done before at a commercial wind plant.