On Turbulence Models and LiDAR Measurements for Wind Turbine Control

Abstract

Abstract. To provide comprehensive information that will assist in making decisions regarding the adoption of LiDAR assisted control (LAC) in wind turbine design, this paper investigates the impact of different turbulence models on the coherence between the rotor effective wind speed and LiDAR measurement. First, the differences between the Kaimal and Mann models are discussed, including the power spectrum and spatial coherence. Next, two types of LiDAR systems are examined to analyze the LiDAR measurement coherence based on commercially available LiDAR scan patterns. Finally, numerical simulations have been performed to compare the LiDAR measurement coherence for different rotor sizes. This work confirms the association between the measurement coherence and the turbulence model. The results indicate that the LiDAR measurement coherence with the Mann turbulence model is lower than that with the Kaimal turbulence model. In other words, the value creation of LAC, evaluated using the Kaimal turbulence model, will be diminished if the Mann turbulence model is used instead. In particular, the difference in coherence is more significant for larger rotors. As a result, this paper suggests that the impacts of different turbulence models should be considered as uncertainties while evaluating the benefits of LAC.

The space-time structure of turbulence for lidar-assisted wind turbine control

“…For example, Simley et al [12] and Schlipf et al [17] derived the coherence using the Kaimal model. Dong et al [18] compared the coherence computed using Mann and Kaimal models. In these studies, the turbulence parameters given by the IEC 61400-1 standard were used.…”