Blade detection method based on blade load analysis

Abstract

The invention discloses a blade detection method based on blade load analysis, and belongs to the technical field of wind driven generators. The method comprises the following steps: 1, monitoring and acquiring vibration signal data of a fan blade through a sensor for detecting vibration of the fan blade, and converting the vibration signal data into modal data; 2, constructing the modal data in the step 1 into a model through a finite element analysis (FEA) tool, and adding an orthotropic material constitutive relation and geometrical characteristics of a plate-shell theory on the model to obtain a cantilever beam model comprising parameters of a fan blade load F and a stiffness matrix K; 3, conducting static load analysis on the cantilever beam model obtained in the step 2, and calculating the deformation u of the cantilever beam model, wherein u = {F} / [K], {F} represents comprehensive force borne by the blade and comprises self gravity and wind power, and [K] represents the stiffness matrix; and 4, conducting dynamic load analysis on the cantilever beam model obtained in the step 2, applying full constraint to the root of the blade, conducting modal analysis on the single blade through finite element software, obtaining the first six-order vibration mode and the inherent frequency of the blade, and obtaining the vibration mode node position of the blade fault position in the blade bending direction, so that the defect position and the defect type of the to-be-detected blade are obtained.

Description

technical field [0001] The invention relates to the technical field of wind power generators, in particular to a blade detection method based on blade load analysis. Background technique [0002] Wind energy is an important renewable energy source. With the expansion of my country's wind energy market, the fan manufacturing industry has gradually entered a period of rapid development. [0003] The current wind turbine development trend is towards higher power, lower cost megawatt machines. Offshore wind farms have recently become a popular investment direction. They mainly use high-power wind turbines above 5MW. At present, the maximum diameter of wind rotors designed and manufactured in China is close to 200m. presents a daunting design challenge. Because the fan load increases with the diameter, if the load is large, it will affect the reliability and performance of the fan. [0004] In addition to increased loads, larger rotor diameters make the turbine more susceptibl...

AI Technical Summary

Problems solved by technology

The downtime caused by blade failure usually requires a long maintenance time, which brings huge economic losses to the wind farm. The maintenance and repair of blade failure will greatly increase the manpower and material resources of the wind farm, which is not conducive to the sustainable and healthy development of the wind power industry.

Images