@MASTERSTHESIS\{IMM2012-06365,
    author       = "C. Brown",
    title        = "Fast Verification of Wind Turbine Power Curves: Summary of Project Results",
    year         = "2012",
    school       = "Technical University of Denmark, {DTU} Informatics, {E-}mail: reception@imm.dtu.dk",
    address      = "Asmussens Alle, Building 305, {DK-}2800 Kgs. Lyngby, Denmark",
    type         = "",
    note         = "Supervised by Associate Professor Pierre Pinson, pp@imm.dtu.dk, {DTU} Informatics, and Mike Courtney, {DTU} Wind Energy",
    url          = "http://www.imm.dtu.dk/English.aspx",
    abstract     = "A new method has been developed for analyzing power performance measurements using a stochastic differential equation called the Langevin equation on high frequency wind turbine measurement data sampled at one sample per second or more. The aim of this method is to provide an alternative to the current industry standard described in {IEC} 61400-12-1. This new method was implemented and analyzed in a number of test cases to evaluate its effectiveness and robustness as a part of the FastWind project at the Technical University of Denmark’s (DTU) Wind Energy department. The FastWind project aims to develop and test this method for use in the Danish wind energy industry.
This new method was successfully implemented for use in this project as well as future work in the FastWind project. Several methods of estimating the power curve uncertainty were developed and implemented; including an analytical equation and two data resampling methods.
Using measurement data from {DTU}’s Nordtank wind turbine at the Ris{\o} site, the practical application of this new method was tested. It was found that the method is sensitive to some of the input parameters chosen by the user. Additionally, it was found to be sensitive to the coherence of high frequency wind speed and power measurements. These sensitivities indicate that the base method is not ready for application in industry but the method needs some further development to improve the robustness of the method’s results. However, potential solutions to these difficulties were proposed and show some promise for improving the outputs of the method.
Proponents of this new method claim that the method for effectively uses measurement data and therefore will require less data, and therefore shorter measurement campaigns, to obtain a power curve with a desired level of certainty. Additionally, it has been claimed that the method is insensitive to turbulence intensity and site specific conditions; unlike the standard {IEC} method. The potential benefits of this new method were tested and some positive results were obtained. The method was shown that it may converge faster than the standard {IEC} method requiring less data to obtain the same level of certainty. Furthermore, the method shows some insensitivity to turbulence intensity indicating that site specific turbulence will not affect the power curve obtained. Although this new method has some challenges associated with it, they are not unsolvable and these benefits show that the method may be worth the time invested to overcome these difficulties."
}