Blade fault diagnostic method based on strain energy response of wind-driven generator

Abstract

The invention relates to a blade fault diagnostic method based on a strain energy response of a wind-driven generator, which comprises the following steps of: (1) obtaining the natural frequencies and the modes of the first M orders of the blade of a wind generator set by performing dynamic modeling and model analytical calculation to the wind generator set; (2) simulating the rotational excitation load of the blade through finite element calculation to the wind generator set to obtain strain energy time domain responses corresponding to the cabin sensor set points of the first M orders of the blade of the wind generator set, and then calculating strain energy frequency domain responses; and (3) obtaining the running state characteristic values of the blade of the wind generator set from the strain energy frequency domain responses corresponding to the cabin sensor set points of the first M orders of the blade of the wind generator set through the strain energy and the rate of change thereof and the method of a support vector machine, and then comparing to obtain a diagnostic result. The blade fault diagnostic method based on the strain energy response of the wind-driven generator related to the invention is simple and easy, high in sensitivity and accuracy and low in diagnostic cost, and can effectively improve the safety and reliability of the blade of the wind generator set and accurately perform fault point positioning, fault qualification and prediction for the blade.

Description

technical field [0001] The invention belongs to the field of wind power generating sets, in particular to a blade fault diagnosis method based on the strain energy response of the wind power machine. Background technique [0002] With the advancement of wind turbine manufacturing technology and the increasing demand for energy, the development of wind turbines in my country is showing a trend of large-scale and marine. Blades are the key components of wind turbines to capture wind energy and are crucial to the normal operation of wind turbines. The blades of large-scale wind turbines weigh more than ten tons and are expensive to manufacture. Generally, the design life of wind turbine blades is more than 20 years, but the environment in which wind turbines are mostly located is very harsh. In particular, compared with onshore wind turbines, offshore wind turbines have more complex operating conditions. Therefore, under normal circumstances, after two years of operation of t...

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Problems solved by technology

Through-cavity trachoma will cause water to enter the blade during the rainy season, resulting in a decrease in the lightning protection index and lightning strike blade accidents

For about six years, the blades of some coastal wind turbines have been worn to the limit, and the windward surface of the blades is completely uneven with sand holes, the running resistance of the blades increases, and the power generation decreases.

The current blade vibration fault can only monitor the frequency change below 100HZ, that is, the severe vibration caused by strong wind can activate the monitoring and alarm system and make the entire wind turbine brake. However, it is very difficult to repair and maintain because the type and location of the fault are unknown. ; On the other hand, the first 20 natural frequencies of large wind turbine blades are only a few hertz, which belongs to extremely low frequency vibration. Therefore, effective diagnosis of blade faults cannot be realized at present

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