Fault discrimination method and device for rolling bearings of doubly-fed generators for wind power

Abstract

The invention discloses a method and device for judging faults of a wind electricity doubly-fed generator rolling bearing. The method comprises the following steps: respectively detecting acceleration signals of a doubly-fed generator driving end and a non-driving end, respectively extracting acceleration extreme point signals so as to obtain a time sequence of acceleration extreme points, respectively calculating elastic support force to obtain a time sequence of the elastic support force, respectively performing DFFT (Discrete Fast Fourier Transform) so as to obtain bearing fault characteristic frequency signal, respectively performing fault judgment on the a doubly-fed generator driving end and the non-driving end according to the bearing fault characteristic frequency signal, and outputting the judgment result. The device comprises a first acceleration sensor, a second acceleration sensor, an acceleration extreme value point extracting module, an elastic support force calculation module, a fault characteristic frequency calculation module and a fault judgment module. The method and the device have the advantages of precise fault detection, high accuracy, convenience and rapidness in detection, convenience in use, and low bearing management and maintenance cost.

Description

technical field [0001] The invention relates to the technical field of wind power generation, in particular to a method and device for identifying faults of rolling bearings of double-fed generators for wind power. Background technique [0002] Because wind doubly-fed generator sets are usually in complex operating conditions, which is not conducive to regular maintenance, failures of components such as doubly-fed generator bearings and other failures occur. For the case where the same type of rolling bearings are installed at the front and rear ends of the wind power doubly-fed generator set, since the fault characteristic frequency of the outer ring, inner ring, rolling element, and cage are consistent, the front and rear ends of the wind power doubly-fed generator are installed with the same type. The fault characteristic frequency of rolling bearings is the same, so when the collector collects the bearing fault characteristic signal, it is impossible to determine which b...

AI Technical Summary

Problems solved by technology

[0002] Because wind doubly-fed generator sets are usually in complex operating conditions, which is not conducive to regular maintenance, failures such as doubly-fed generator bearings and other component failures occur

For the case where the same type of rolling bearings are installed at the front and rear ends of the wind power doubly-fed generator set, since the fault characteristic frequency of the outer ring, inner ring, rolling element, and cage are consistent, the front and rear ends of the wind power doubly-fed generator are installed with the same type. The fault characteristic frequency of rolling bearings is the same, so when the collector collects the bearing fault characteristic signal, it is impossible to determine which bearing the bearing fault information measured by the sensor comes from, and it is also impossible to judge the fault degree of each bearing.

Therefore, in order to replace the faulty bearing in time when the bearing fails, ensure the normal and reliable operation of the wind turbine, prolong the service life of the wind turbine and its components, and at the same time prevent misjudgment of the fault-free (or minor fault) bearings, the Replacement of new bearings that can operate normally will lead to unnecessary economic losses. Preventing the reliability of the fan from being reduced or unnecessary replacement costs due to over-diagnosis or under-diagnosis has become a key technical issue that needs to be solved urgently.

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