Research On Large-scale Wind Turbine For Load Measurement

With the in-deeping development of wind power industry in china and the consistingof wind turbines structure becoming more complex, increasingly wide load range isimposed to the components of wind turbines. These problems has lead quality problems ofwind turbine,which the problem that wind turbine components which worse resistingfatigue ability is more cause for concern. As the long-term work in harsh environments towind turbine, different levels of random loads is imposed to the wind turbine with the windturbine itself running with the external environment, and many other factors.Fatigue loadshave the most significant fatigue to wind turbine components. Determine the actual loadoperation and fatigue damage has become a key issue through the load measurement towind turbine components, so that the research of wind turbine load measurement has greatsignificance.Firstly,the targeted measurement methods to the fundamental load of windturbines,related meteorological parameters and operating parameters is analyzed,includingthat principle of the strain gauge sensor and the steps of paste detailed analysis, and thediscussion of the full bridge circuit in the actual project application and the relate schemeof error compensation scheme,and the analysis of the calibration methods inengineering.Secondly,method of bins is used to the work of data collection, as well as thedata acquisition program is established according to the related rules,and the optimizationplan of the data acquisition were discussed to the main measurement system in bottoms ofthe wind and the measurement systems of the wind.The load data is analyzed based on the rainflow counting method and statisticalextrapolation method. In this study, firstly,the algorithm about reducing uncertainty of theload statistics is researched, secondly, threshold is selected to fit the probability distributionof data by calculating the density of fatigue damage,and to the data over the threshold,three probability distribution models are proposed which including three-parameterWeibull distribution, generalized Weibull distribution and generalized normaldistribution,in which the second one is closer to the tail of the load distribution though comparative analysis.The approach to fatigue load spectrum of wind turbine components is researchedbased on statistical extrapolation methods. In this part, firstly, short-term load spectrum tosteady-state operation and transient operating conditions of wind turbine is integrated.Secondly, short-term load spectrum of steady-state operation is weighted using the annualwind speed distribution and then summed to find the total operating load spectrum. Thenumber of significant transient events is projected and then added to the operatingspectrum, then the result is the total load spectrum on the wind turbine.Finally, the bladeroot flapwise moments lifetime load spectrum is studied by using matlab softwareprogramming in this paper.