Precision and shortcomings of yaw error estimation using spinner‐based light detection and ranging

Kragh, Knud Abildgaard; Hansen, Morten Hartvig; Mikkelsen, Torben

doi:10.1002/we.1492

Cited by 49 publications

(46 citation statements)

References 9 publications

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“…LIDAR-assisted collective pitch control for load reduction is one option and has actually been demonstrated recently in field testing [1], [2]. Another potential beneficial use of LIDAR is to increase energy yield by LIDAR-assisted yaw control [3], [4].…”

Section: Introductionmentioning

confidence: 99%

Direct Speed Control using LIDAR and turbine data

Schlipf

Fleming

Kapp

et al. 2013

2013 American Control Conference

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Abstract-LIDAR systems are able to provide preview information of the wind speed in front of wind turbines. One proposed use of this information is to increase the energy capture of the turbine by adjusting the rotor speed directly to maintain operation at the optimal tip-speed ratio, a technique referred to as Direct Speed Control (DSC). Previous work has indicated that for large turbines the marginal benefit of the direct speed controller in terms of increased power does not compensate for the increase of the shaft loads. However, the technique has not yet been adequately tested to make this determination conclusively. Further, it is possible that applying DSC to smaller turbines could be worthwhile because of the higher rotor speed fluctuations and the small rotor inertia. This paper extends the previous work on direct speed controllers. A DSC is developed for a 600 kW experimental turbine and is evaluated theoretically and in simulation. Because the actual turbine has a mounted LIDAR, data collected from the turbine and LIDAR during operation are used to perform a hybrid simulation. This technique allows a realistic simulation to be performed, which provides good agreement with theoretical predictions.

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Section: Introductionmentioning

confidence: 99%

Direct Speed Control using LIDAR and turbine data

Schlipf

Fleming

Kapp

et al. 2013

2013 American Control Conference

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“…Methods for aligning the rotor with the inflow and the limitations of using a LiDAR sensor for inflow estimation are discussed in the work of Kragh, Hansen and Mikkelsen. 13 …”

Section: Upstream Inflow Measurementsmentioning

confidence: 99%

Sensor comparison study for load alleviating wind turbine pitch control

2013

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As the size of wind turbines increases, the load alleviating capabilities of the turbine controller are becoming increasingly important. Load alleviating control schemes have traditionally been based on feedback from load sensor; however, recent developments of measurement technologies have enabled control on the basis of preview measurements of the inflow acquired using, e.g., light detection and ranging. The potential of alleviating load variations that are caused by mean wind speed changes through feed-forward control have been demonstrated through both experiments and simulations in several studies, whereas the potential of preview control for alleviating the load variations caused by azimuth dependent inflow variations is less described. Individual or cyclic pitch is required to alleviate azimuth dependent load variations and is traditionally applied through feedback control of the blade root loads. In many existing studies, the performance of an advanced controller is compared with the performance of a simpler controller. In this study, the effect of three measurement types on the load alleviating performance of the same cyclic pitch control design is studied. By using a baseline cyclic pitch controller as test bench, the effect of the different measurement types on the controller performance can be assessed independent of control design. The three measurement types that are considered in this study are as follows: blade root out-of-plane bending moment, on-blade measurements of angle of attack and relative velocity at a radial position of the blades, and upstream inflow measurements from a spinner mounted light detection and ranging (LiDAR) sensor that enables preview of the incoming flow field. The results show that for stationary inflow conditions, the three different measurement types yield similar load reductions, but for varying inflow conditions, the LiDAR sensor-based controller yields larger load reductions than the two others. The results also show that the performance of the LiDAR sensor-based controller is very sensitive to uncertainties relating to the inflow estimation.

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“…This equips the low-cost lidar with the capability to measure not only the magnitude but also the direction of a 2D wind vector, assuming a relatively laminar wind flow. It makes the lidar system useful for applications like wind turbine yaw control [4]. By increasing the number of LOS and hence the velocity components that can be obtained, the lidar functionality can extend to wind shear measurement or perhaps even blade pitch control of wind turbines [5].…”

Section: Introductionmentioning

confidence: 99%

Eye-safe diode laser Doppler lidar with a MEMS beam-scanner

Hu¹,

Pedersen²,

Rodrigo³

2016

Opt. Express

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We present a novel Doppler lidar that employs a cw diode laser operating at 1.5 μm and a micro-electro-mechanical-system scanning mirror (MEMS-SM). In this work, two functionalities of the lidar system are demonstrated. Firstly, we describe the capability to effectively steer the lidar probe beam to multiple optical transceivers along separate lines-ofsight. The beam steering functionality is demonstrated using four lines-ofsight -each at an angle of 18° with respect to their symmetry axis. Secondly, we demonstrate the ability to spatially dither the beam focus to reduce the mean irradiance at the probing distance (R = 60 m) of each lineof-sight -relevant for meeting eye-safety requirements. The switching time of the MEMS-SM is measured to be in the order of a few milliseconds. Time-shared (0.25 s per line-of-sight) radial wind speed measurements at 50 Hz data rate are experimentally demonstrated. Spatial dithering of the beam focus is also implemented using a spiral scan trajectory resulting in a 16 dB reduction of beam focus mean irradiance.

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Precision and shortcomings of yaw error estimation using spinner‐based light detection and ranging

Cited by 49 publications

References 9 publications

Direct Speed Control using LIDAR and turbine data

Direct Speed Control using LIDAR and turbine data

Sensor comparison study for load alleviating wind turbine pitch control

Eye-safe diode laser Doppler lidar with a MEMS beam-scanner

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