1.21_Reinwardt: Measuring Dynamic Wake Characteristics with Nacelle Mounted LiDAR Systems
| Main Authors: | Reinwardt, Inga, Schilling, Levin, Dalhoff, Peter, Steudel, Dirk, Breuer, Michael |
|---|---|
| Format: | info Proceeding eJournal |
| Bahasa: | eng |
| Terbitan: |
, 2019
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| Online Access: |
https://zenodo.org/record/3362800 |
Daftar Isi:
- Light Detection And Ranging (LiDAR) systems have gained a great importance in today's wake characteristic measurements. The aim of this measurement campaign is to track the wake meandering and in a further step to validate the wind speed deficit in the meandering frame of reference (MFR) and the fixed frame of reference (FFR) using nacelle mounted LiDAR measurements. Related studies to this topic can be found in [1], [2] and [3]. The investigated onshore wind farm located in the southeast of Hamburg (Germany) consists of five Nordex turbines (1 x N117 3 MW and 4x N117 2.4 MW) with small turbine distances. Two turbine nacelles are equipped with a pulsed scanning LiDAR system (Galion G4000). The meandering time series is determined with the help of either a one- or a two-dimensional Gaussian fit as presented in [2]. One of the most challenging parts of this specific measurement campaign is the low ray update rate of the LiDAR system, which is considerably smaller than the previously introduced measurement campaigns. This issue is compensated by an optimized scan pattern determined by LiDAR and wind field simulations. The simulations incorporate LiDAR specifications (e.g. beam update rate and scan head angular velocity) and wind farm site conditions. The simulated LiDAR “takes measurements” in a simulated wind field with wake effects that is generated with the Dynamic Wake Meandering (DWM) Model (see, e.g., [4]). From these ”measured” wind speeds the meandering is determined with the previously mentioned Gaussian fit as it is implemented in the real measurement campaign. Simulations were performed for one- and two-dimensional scan patterns at different ambient conditions and downstream distances to determine the optimal scan pattern, which consists of only 11 measurement points and is currently used in the real measurement campaign. In addition to the determination of the position of the wind speed deficit, the possibility of estimating the shape of the wind speed deficit in the MFR has been simulated. [1] Bingöl F, Mann J and Larsen G C 2010 Wind Energy 13(1) 51-61 [2] Trujillo J J, Bingöl F, Larsen G C, Mann J and Kühn M 2011 Wind Energy 14(1) 61-75 [3] Machefaux E, Larsen G C, Troldborg N, Gaunaa M and Rettenmeier A 2015 Wind Energy 18(12) 2085-2103 [4] Larsen G C, Madsen H A, Thomsen K and Larsen T J 2008 Wind Energy 11(4) 377-395