Blade imbalance fault diagnosis method based on stator current of double-fed wind generating set

Abstract

The invention relates to a blade imbalance fault diagnosis method based on a stator current of a double-fed wind generating set. The blade imbalance fault diagnosis method comprises the following steps of: 1, controlling the double-fed wind generating set to operate in a detection mode, and keeping the wind generating set to operate at a constant rotating speed; 2, synchronously acquiring a set stator phase current iA and a generator rotating speed r in the constant-speed operating stage, which meet requirements; 3, according to the acquired generator rotating speed r, calculating a 1-multiple frequency of an impeller speed, carrying out signal processing by an envelope spectrum to obtain an envelope spectrum if signal after carrying out wavelet filtering processing on the stator phase current iA, extracting a 1-multiple frequency amplitude M (1) and a k-multiple frequency amplitude M(k) of the impeller speed in the envelope spectrum if signal and using the 1-multiple frequency amplitude M (1) and the k-multiple frequency amplitude M(k) of the impeller speed as features, wherein k represents a blade number; 4, judging sizes of the 1-multiple frequency amplitude M (1) and the k-multiple frequency amplitude M(k), and if M(1) is greater than a*M(k), determining that blade imbalance exists, wherein a represents a preset amplitude ratio. The blade imbalance fault diagnosis method is simple and easy to operate, excellent in accuracy, and good in applicability.

Description

technical field [0001] The invention belongs to the technical field of wind turbine state monitoring and fault diagnosis, and relates to a blade unbalance fault diagnosis method based on a doubly-fed wind turbine generator stator current. Background technique [0002] The blade is one of the key components of the wind turbine, accounting for about 20% of the production cost of the wind turbine, and its quality directly affects the efficiency, life and performance of the wind turbine. However, due to the harsh working environment of wind turbines, the blades are exposed to sand wear, icing, strong wind, etc., and due to the randomness of the wind, the operating conditions of wind turbines are changeable, all of which lead to cracks and damages on the blades, resulting in The aerodynamic imbalance of the blades will affect the power generation efficiency of the wind turbine, increase the fatigue load of the wind turbine, and cause the wind turbine to fail and even cause an acc...

AI Technical Summary

Problems solved by technology

[0004] In order to overcome the deficiencies of the existing doubly-fed wind turbine blade unbalance detection methods, which are complex, poor in accuracy and poor in applicability, the present invention provides a simple, easy to implement, good in accuracy and good in applicability based on Fault diagnosis method for blade unbalance of stator current of doubly-fed wind turbine

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