Method for detecting and diagnosing aerodynamic imbalance of impellers of wind turbine

Abstract

A method for detecting and diagnosing aerodynamic imbalance of the impellers of a wind turbine is provided which comprises steps of: obtaining a comparison between an impeller radial vibration amplitude and historical data under the same working condition, and assigning 0 to an impeller radial vibration influence coefficient in the case of an unobvious vibration amplitude change; performing FFT on a radial vibration signal and assigning 1 to the radial vibration influence coefficient if a first-harmonic signal relative to the impeller rotating speed in the frequency spectrum is dominant in the low-frequency band and an vibration amplitude change is obvious, or assigning 0 to the radial vibration influence coefficient; performing the same diagnosis method on impeller radial vibration data and impeller hub radial displacement data; multiplying the obtained influence coefficients to obtain the probability of occurrence of the aerodynamic imbalance of the impellers of the wind turbine, and determining that the impellers of the wind turbine generates aerodynamic imbalance when the probability is equal to 1, and assigning 0 to the probability of occurrence of the aerodynamic imbalance of the impellers of the wind turbine as long as one of the three influence coefficients is 0. The method can effectively distinguish between impeller aerodynamic imbalance and mass imbalance of the impellers of the wind turbine, more accurately determines the aerodynamic imbalance of the impellers of the wind turbine, and increases the work efficiency and accuracy in the detection and diagnosis of the aerodynamic imbalance of the impellers of the wind turbine.

Description

technical field [0001] The invention belongs to the technical field of aerodynamic unbalance detection of wind turbine impellers, and in particular relates to a method for detecting and diagnosing aerodynamic unbalance of wind turbine impellers. Background technique [0002] At present, there are mainly two detection methods for the aerodynamic imbalance of wind turbine impellers: one is to detect the vibration signal at the main bearing of the wind turbine and analyze the vibration signal to determine whether there is an imbalance fault in the wind turbine impeller. The other is to take pictures of the three blades directly below the blades, and compare whether the images of the three blades are completely consistent to determine whether there is an imbalance fault in the wind turbine impeller. [0003] The mass imbalance of the wind turbine impeller will also cause the radial and axial vibration of the wind turbine main bearing. Only by detecting the vibration signal at th...

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Problems solved by technology

[0003] The mass imbalance of the wind turbine impeller will also cause the radial and axial vibration of the wind turbine main bearing. Only by detecting the vibration signal at the wind turbine main bearing, it is impossible to distinguish whether the wind turbine impeller has a mass imbalance fault or an aerodynamic fault by analyzing the vibration signal. unbalance fault

[0004] Wind turbine blades can only stay still when there is no wind at all, otherwise the blades will always be in a state of swing, and when taking pictures of the blades, no usable photos will be obtained

In addition, whether it is windy or calm, the photos taken will cause errors due to factors such as imaging equipment and the habits of the photographer, making it impossible to accurately determine whether the aerodynamic imbalance of the wind turbine impeller has occurred. This method has low accuracy. , less reliable

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