Influence of atmospheric conditions on the power production of utility-scale wind turbines in yaw misalignment

TL;DR

This paper investigates how atmospheric conditions influence the power output of yaw misaligned wind turbines, proposing a new aerodynamic model validated through field experiments to optimize wake steering strategies.

Contribution

It introduces a novel aerodynamic blade element model that accounts for atmospheric variability in yaw misaligned turbines, validated with real-world data.

Findings

Power production varies nonlinearly with yaw misalignment and atmospheric conditions.

The model accurately predicts power output under different wind scenarios.

Yaw misalignment effects are significantly influenced by atmospheric stability and wind shear.

Abstract

The intentional yaw misalignment of leading, upwind turbines in a wind farm, termed wake steering, has demonstrated potential as a collective control approach for wind farm power maximization. The optimal control strategy, and resulting effect of wake steering on wind farm power production, are in part dictated by the power degradation of the upwind yaw misaligned wind turbines. In the atmospheric boundary layer, the wind speed and direction may vary significantly over the wind turbine rotor area, depending on atmospheric conditions and stability, resulting in freestream turbine power production which is asymmetric as a function of the direction of yaw misalignment and which varies during the diurnal cycle. In this study, we propose a model for the power production of a wind turbine in yaw misalignment based on aerodynamic blade elements which incorporates the effects of wind speed and direction changes over the turbine rotor area in yaw misalignment. A field experiment is performed using multiple utility-scale wind turbines to characterize the power production of yawed freestream operating turbines depending on the wind conditions, and the model is validated using the experimental data. The resulting power production of a yaw misaligned variable speed wind turbine depends on a nonlinear interaction between the yaw misalignment, the atmospheric conditions, and the wind turbine control system.