Doubly-fed induction generator slip ring breakdown diagnosis method based on vibration

Abstract

The invention discloses a doubly-fed induction generator slip ring breakdown diagnosis method based on vibration. The method includes the following steps: adopting a Nico data acquisition instrument, a DC voltage source, and a PC signal processing machine to establish a vibration signal acquisition system structure; sampling a slip ring surface slip ring vibration signal; according to the wavelet packet decomposition, conducting 4-tier wavelet packet decomposition on the acquired vibration signal to obtain 16 sub-frequency bands; using the method based on wavelet power spectrum, conducting energy statistics analysis on the energy of the vibration signal at different frequency bands after the vibration signal is subject to wavelet packet decomposition; on the basis of the energy-intensive frequency band, determining that an armature slip ring is at which of the following four working conditions, normal operation, slip ring surface entirety scratch-type injury breakdown, slip ring surface local superficial injury breakdown and slip ring surface loop circular degree injury breakdown. The method can realize real-time online monitoring of the operation state of the slip ring, has a vibration signal which is very sensitive to breakdowns, has wide engineering practicality and is easy to promote.

Description

technical field [0001] The invention belongs to the technical field of generators, in particular to a vibration-based fault diagnosis method for slip ring devices of double-fed asynchronous generators. Background technique [0002] The brush slip ring system is an important dynamic-static conversion device for large-scale doubly-fed asynchronous wind turbines, and plays a vital role in the stable operation of the generator. However, damage to the contact surface of the slip ring device in operation often occurs, such as overall scratches on the slip ring surface, local superficial damage, and ring roundness damage, which will lead to disordered operation of the generator and cause huge economic losses. Therefore, it is urgent to study the fault diagnosis method of the motor slip ring device. [0003] After the contact surface of the slip ring is damaged, it will lead to various failure phenomena, such as spark discharge, electrical value change, local overheating, etc. Jap...

AI Technical Summary

Problems solved by technology

[0004] To sum up, although there are many researches on the spark monitoring, temperature monitoring and electrical quantity diagnosis technology of the brush slip ring system, most of them lack certain flexibility, accuracy and effectiveness, and the practice is difficult, and the engineering application value is low

Especially for the local superficial damage of the slip ring surface, the fault characteristics are not obvious, and the above methods cannot effectively monitor and diagnose

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