Early fault diagnosis method for electric brush and slip ring of doubly-fed wind generator

Abstract

The invention discloses an early fault diagnosis method for an electric brush and a slip ring of a doubly-fed wind generator. The early fault diagnosis method comprises the steps of: S01, calculatingequivalent resistance and an equivalent resistance jump quantity during ignition according to parameters of the electric brush and the slip ring; S02, calculating a corresponding rotor current jump quantity according to the equivalent resistance jump quantity, and taking the rotor current jump quantity as a jump quantity reference value; S03, sampling A rotor current at a fixed time interval, andestablishing a current waveform after calculation and processing; S04, and calculating to determine whether the current jump quantity reaches a jump quantity reference value or not according to the current waveform, and if so, determining that an early fault exists. The early fault diagnosis method has the substantive effects that the controllability of rotor side electric quantity information ina doubly-fed wind power generation system is fully utilized, so that instantaneous and random slip ring and electric brush early faults are reflected more simply, conveniently, visually and quickly, the detection precision is high, existing hardware equipment in the doubly-fed wind power generation system is utilized, extra equipment does not need to be additionally arranged, and the upgrading andreconstruction cost is low.

Description

technical field [0001] The invention belongs to the technical field of on-line monitoring of wind power generators, in particular to an early fault diagnosis method for brushes and slip rings of double-fed wind power generators. Background technique [0002] For megawatt-class doubly-fed wind turbines, the excitation current is relatively large, and there are usually multiple brushes distributed in the same phase, so it is difficult to guarantee the mutual current sharing effect. In actual operation, the change of the resistance between the brush and the slip ring can easily lead to the secondary distribution of the brush current and overload some of the brushes. If the ambient air humidity is high or the resistance of the brush itself changes, the slip ring will The probability of sparking between the ring and the brush will increase significantly, which will cause pitting of the slip ring in the slightest, and damage to the brush of the slip ring of the generator in severe...

AI Technical Summary

Problems solved by technology

[0006] Aiming at the problems of high monitoring cost, complex calculation and low accuracy in the prior art, the present invention provides an early fault diagnosis method for brushes and slip rings of doubly-fed wind turbines, which does not need to add additional equipment, is simple to implement, and has directivity Strong, clear mechanism, can realize the judgment of early fault waveforms with strong transient randomness

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