Advance measurement of gusts by laser anemometry

Harris, Michael; Bryce, David J.; Coffey, Adrian S.; Smith, Dale; Birkemeyer, J.; Knopf, Ullrich

doi:10.1016/j.jweia.2007.02.029

Cited by 38 publications

(28 citation statements)

References 7 publications

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“…New developments in optical fiber and related components from the telecommunications industry offered a promising approach to lidar construction. The team successfully demonstrated CW all-fiber lidar anemometers (at a wavelength 1.55µm) in the late 1990s [9,16] and have remained at the forefront with the development of a commercial fiber lidar system (ZephIR) that has an established track record of successful wind measurement in a number of applications related to the wind power industry [17][18][19][20][21].…”

Section: The Qinetiq Zephir Lidar Systemmentioning

confidence: 99%

“…In the first experiment of this type to our knowledge, an early prototype of the QinetiQ ZephIR system was mounted on the nacelle of a Nordex N90 wind turbine at Postlow, 5 km west of Anklam in northeast Germany [20]. The lidar was configured as a continuous-wave (CW) monostatic design, capable of measuring lineof-sight wind speeds up to 39 m s -1 .…”

Section: Previous Workmentioning

confidence: 99%

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Lidar for Turbine Control: March 1, 2005 - November 30, 2005

Harris¹,

Hand²,

Wright³

2006

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Section: The Qinetiq Zephir Lidar Systemmentioning

confidence: 99%

Section: Previous Workmentioning

confidence: 99%

Lidar for Turbine Control: March 1, 2005 - November 30, 2005

Harris¹,

Hand²,

Wright³

2006

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“…However, as we shall see later, for measurements over ordinary terrain this may not be a valid assumption, as pointed out by Bingöl et al (2009), and the error committed on the horizontal mean wind speed may be up to 10% depending on the steepness and complexity of the terrain. A second application of the instrument in wind energy has been the investigation of flow around a wind turbine (Harris et al, 2007;Bingöl et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Flow tilt angles near forest edges – Part 2: Lidar anemometry

2010

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Abstract.A novel way of estimating near-surface mean flow tilt angles from ground based Doppler lidar measurements is presented. The results are compared with traditional mast based in-situ sonic anemometry. The tilt angle assessed with the lidar is based on 10 or 30 min mean values of the velocity field from a conically scanning lidar. In this mode of measurement, the lidar beam is rotated in a circle by a prism with a fixed angle to the vertical at varying focus distances. By fitting a trigonometric function to the scans, the mean vertical velocity can be estimated. Lidar measurements from (1) a fetch-limited beech forest site taken at 48-175 m a.g.l. (above ground level), (2) a reference site in flat agricultural terrain and (3) a second reference site in complex terrain are presented.The method to derive flow tilt angles and mean vertical velocities from lidar has several advantages compared to sonic anemometry; there is no flow distortion caused by the instrument itself, there are no temperature effects and the instrument misalignment can be corrected for by assuming zero tilt angle at high altitudes. Contrary to mast-based instruments, the lidar measures the wind field with the exact same alignment error at a multitude of heights.Disadvantages with estimating vertical velocities from a lidar compared to mast-based measurements are potentially slightly increased levels of statistical errors due to limited sampling time, because the sampling is disjunct, and a requirement for homogeneous flow. The estimated meanCorrespondence to: E. Dellwik (ebde@risoe.dtu.dk) vertical velocity is biased if the flow over the scanned circle is not homogeneous. It is demonstrated that the error on the mean vertical velocity due to flow inhomogeneity can be approximated by a function of the angle of the lidar beam to the vertical and the vertical gradient of the mean vertical velocity, whereas the error due to flow inhomogeneity on the horizontal mean wind speed is independent of the lidar beam angle. For the presented measurements over forest, it is evaluated that the systematic error due to the inhomogeneity of the flow is less than 0.2 • .The results of the vertical conical scans were promising, and yielded positive flow angles for a sector where the forest is fetch-limited. However, more data and analysis are needed for a complete evaluation of the lidar technique.

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“…Nacelle lidar systems were demonstrated in the field as early as 2003 [29], while simulation-based studies of lidar-assisted feedforward control began in 2005 [30]. Since then, lidar-assisted control (LAC) has been investigated for several applications including:…”

Section: Lidar For Turbine Controlmentioning

confidence: 99%

IEA Wind Task 32: Wind Lidar Identifying and Mitigating Barriers to the Adoption of Wind Lidar

Clifton

Clive²,

Gottschall

et al. 2018

Remote Sensing

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IEA Wind Task 32 exists to identify and mitigate barriers to the adoption of lidar for wind energy applications. It leverages ongoing international research and development activities in academia and industry to investigate site assessment, power performance testing, controls and loads, and complex flows. Since its initiation in 2011, Task 32 has been responsible for several recommended practices and expert reports that have contributed to the adoption of ground-based, nacelle-based, and floating lidar by the wind industry. Future challenges include the development of lidar uncertainty models, best practices for data management, and developing community-based tools for data analysis, planning of lidar measurements and lidar configuration. This paper describes the barriers that Task 32 identified to the deployment of wind lidar in each of these application areas, and the steps that have been taken to confirm or mitigate the barriers. Task 32 will continue to be a meeting point for the international wind lidar community until at least 2020 and welcomes old and new participants.

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Advance measurement of gusts by laser anemometry

Cited by 38 publications

References 7 publications

Lidar for Turbine Control: March 1, 2005 - November 30, 2005

Lidar for Turbine Control: March 1, 2005 - November 30, 2005

Flow tilt angles near forest edges – Part 2: Lidar anemometry

IEA Wind Task 32: Wind Lidar Identifying and Mitigating Barriers to the Adoption of Wind Lidar

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