An innovative methodology to estimate wind field characteristics from turbine-mounted lidars is presented along with experimental results in a scientific paper by Antoine Borraccino, David Schlipf, Florian Haizmann and Rozenn Wagner. The article was submitted to the Wind Energy Science journal. To read it and/or participate in the online discussion forum: http://www.wind-energ-sci-discuss.net/wes-2017-10/
Paper abstract:
Profiling nacelle lidars probe the wind at several heights and several distances upstream the rotor. Yet, it is still unclear how to condense the lidar raw measurements into useful wind field characteristics such as speed, direction, vertical and longitudinal gradients (wind shear). In this paper, we demonstrate an innovative method to estimate wind field characteristics using nacelle lidar measurements taken within the induction zone. Model-fitting wind field reconstruction techniques are applied to nacelle lidar measurements taken at multiple distances close to the rotor, where a wind model is combined with a simple induction model. The method allows robust determination of free stream wind characteristics. The method was applied to experimental data obtained with two different types of nacelle lidar (5-beam Demonstrator and ZephIR Dual-Mode). The reconstructed wind speed was within 0.5% of the wind speed measured with a mast top-mounted cup anemometer at 2.5 rotor diameters upstream of the turbine. The technique described in this paper overcomes measurement range limitations of the currently available nacelle lidar technology.