Posters

Abstract

The power performance of a wind turbine is often tested at sites consisting of several turbines in a row, as the power performance is assumed to be the same as if the turbine was isolated. Therefore, the main objective of this work is to investigate whether the power performance of five turbines in a row is different from that of an isolated wind turbine, which operates under the same conditions. We evaluate the blockage effects in a single row of five wind turbines through both Reynolds-averaged Naviers-Stokes (RANS) simulations and measurements. A number of simulations are performed, with variation of the turbine inter-spacing (between 1.8 and 3 rotor diameters (D)), the flow direction (within ± 45° around the orthogonal line to the row), and the free-stream velocity (values cover a wide range of the power curve). Therefore, the numerical setup complies with the requirements set by the IEC standard procedure for power performance tests. Additionally, we simulate wind speed measurements through both virtual nacelle-mounted lidars and meteorological masts. The numerical results show power deviations between the five turbines in the row and the isolated turbine. Additionally, we show how these power deviations might affect power performance tests. The numerical results are validated with measurements from a real site consisting of five wind turbines in a row. Furthermore, several induction-correction models are used to correct the global-blockage effect in order to evaluate how these models perform in the single-row case.