Use of AE Testing Data for Condition Monitoring in Wind Turbine Gearbox

Abstract

Acoustic emission (AE) method of nondestructive check is based on exertion wave radiation and their registration during fast local material structure reorganization. It is used as a means of analysis of materials, constructions, productions control and diagnosis during operating time. In the article, it is applied to structural health monitoring of Wind Turbine Gearbox (WTG). Acoustic emission testing has been used for years to test metallic structures. More recently it has become the primary method of testing WTG; all are present in the failure of WTG. AE has been very successful at detecting all of these failure mechanisms and sometimes identifying them from amplitude analysis of the AE signals. However in large structures, the high acoustic attenuation in WTG precludes amplitude analysis unless the origin of the individual signals can be identified and corrections for the distances traveled applied to the signal amplitudes. The usual method of testing WTG structures has been to apply an array of sensors spaced so that a moderate amplitude AE signal occurring midway between them will just barely trigger each sensor.

A Survey of Condition Monitoring and Fault Diagnosis toward Integrated O&M for Wind Turbines

“…In the case of gearbox failure, noise will be generated, and friction will also lead to temperature rise. AE signal and temperature signal are also worth considering [30,31].…”

“…A method for predicting the residual life of the gearbox and the shaft by combining AE with vibration signal was proposed [23]. AE can also be used to monitor the sound when the gearbox fails individually [31]. The advantage of AE is that it does not need to be close to the fault components, and it is a non-invasive methods of fault detection.…”