Wind Turbine Blade Crack Detection Method

Abstract

A windmill blade crack detection method is characterized in that the method comprises the following steps: 1, installing an acoustic emission sensor on a windmill blade, transmitting a received acoustic emission signal to an acoustic emission acquisition system, and determining the sampling frequency, the sampling length and the filtering frequency of the signal; 2, optimizing a bandwidth parameter of an Morlet wavelet basis function based on Shannon wavelet entropy to obtain the Morlet wavelet basis function matched with the characteristics of acoustic emission signals of an expansion crack and a generated crack, and calculating the redistribution scale spectrum of the acoustic emission signals in order to determine the crack state; and 3, determining the expansion state of the crack fault according to the time frequency characteristic parameters of the extracted crack acoustic emission signals. The method can rapidly and accurately detect the dynamic expansion state of the blade cracks, guarantees the safety and the high efficiency of the wind mill blade, prolongs the service life of the wind mill blade, and reduces the maintenance cost.

Description

technical field [0001] The invention relates to a detection method of a blade of a wind power generator, in particular to a method for detecting cracks of a blade of a wind power generator for detecting fine cracks on the surface of the blade of a wind power generator. Background technique [0002] Blades are the key components for wind turbines to obtain wind energy. When operating in harsh natural environments, blades not only bear centrifugal force, bending stress, aerodynamic force, thermal stress, etc., but also are eroded by frost, rain and snow, and damaged by lightning strikes. Wind turbines When the blades run continuously under a sharply changing heavy load, it is very easy to cause cracking, deformation, falling off and breaking of the main beam, surface skin and bonding materials, which poses a serious threat to the safe operation of the entire unit and even leads to major accidents. , blade cracks have become a common safety hazard in large-scale wind farms. ...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to overcome the above-mentioned deficiencies existing in the prior art, aiming at the problems that the acoustic emission signal features of fine cracks are difficult to extract and the special material properties of wind turbine blades, a new crack detection method for wind turbine blades is proposed

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