With our extensive knowledge of gearboxes manufactured by Winergy, Hansen, Moventas, Lohmann & Stolterfoht, Metso, Bosch Rexroth, Siemens, Flender and others, our independent wind turbine gearbox inspections are unsurpassed within the wind energy sector. We utilise all our collective diagnostic tools, skills, experience and knowledge for this most vital of preventative maintenance inspections.
In order to present the client with the most comprehensive and detailed assessment covering all potential operational issues, mechanical wear or underlying defects affecting the gearbox, we employ the following condition monitoring techniques on every inspection:Acoustic Analysis: to determine initial gearbox and generator related issues from emitted noise conducted at the base of the wind turbine
In combination with powerful software, we can extrapolate the collected data and determine a date to failure, thereby introducing a (less costly/reduced downtime) predictive and preventative maintenance routine as opposed to a (more expensive/increased downtime) reactive method. By using FFT (fast Fourier transform) spectral analysis in combination with an enveloping filter, we are able to distinguish between a cage or a roller defect occurring on a bearing and identify which gear in the drive train is worn, misaligned or damaged.
Additional processing techniques such as synchronous time waveform analysis, real-time recordings and dual channel bode plots allows us to accurately determine the condition of non-rolling element bearings such as the main rotor shaft support bearings and identify issues occurring on the low speed section of the gearbox such as the planetary ring and sun-wheel pinion, which are not easily accessible using remote visual inspection methods. Transients (momentary events) and resonance-related issues can also be captured and analysed by using these techniques.
Real-time acoustic readings can be easily obtained inside the base of the wind turbine tower with the wind turbine still in operation. By using a sophisticated Sound Level Meter, with FFT (fast Fourier transfer) functionality and an onboard recording module, we can determine the low, mid-range and high-frequency attributes of the installation without having to ascend the wind turbine, which is a major advantage of using noise and acoustic analysis.
By utilising this method, it is possible to highlight and isolate areas of concern with either the gearbox or generator and can serve as a very useful 'heads up' condition monitoring tool before ascending the wind turbine.
Ideally, acoustic analysis should be implemented in advance during a separate visit on all the wind turbines in succession. A single reading take less than twenty seconds to collect and as data is obtained very quickly at the base of each wind turbine under similar wind speeds, an entire wind farm can be completed typically in less than a day! The results from this data can then determine which turbines are operating within specification and those that require further investigation using additional techniques.
Acoustic analysis also serves a useful means of cross-referencing the additional data obtained using vibration analysis.In addition to analysing the acoustics of mechanical-induced noise, we can also independently assess environmental and noise nuisance complaints using the same diagnostic equipment.
By detecting anomalies often invisible to the naked eye, thermography allows us to determine the condition of wind turbine high voltage transformers, switch gear, power cables, high and low voltage control panel components etc. Mechanical components such as bearings, couplings, drive shafts, brake discs and gearboxes which are often subjected to high levels of stress can also be quickly and easily identified using thermography. In addition to electrical and mechanical anomalies, blocked or contaminated filter systems and flow issues can also be ascertained using an infrared thermal imaging camera, capable of measuring temperature differentials within a tenth of a degree.This proven non-destructive technique is also extremely effective at detecting the qualitative structural deformities occurring on wind turbines such as subsurface and hairline cracks and other irregularities occurring on towers, foundations and in particularly blades.