From laboratory to field measurements for wind turbine condition monitoring

Future trends and challenges in the development of methods

Company / Unternehmen: Centre for Renewable Energy Sources and Saving (CRES)
Speaker / Referent: Denja Lekou
Position: Head of the blade testing laboratory, Laboratory for Wind & Wind Turbine Testing, Wind Energy Department

Offshore wind turbines are unique structures called upon to operate in harsh environmental conditions under variable load unattended for a long period of time. To avoid unexpected failures and to improve maintenance procedures under such a constrained access environment condition monitoring systems are required.

In this presentation experience in the development of condition monitoring systems for offshore wind turbines are shared, focusing on the application of acoustic emission method for blades and drive train components on operating wind turbines. Due to its passive identification and location of existing/progressing damage through capturing transient elastic waves triggered by crack/damage development, acoustic emission has potential to form adequate structural health monitoring method for blades as well as a condition monitoring method for drive train components and pitch bearings. Common to both cases was the previous successful application in laboratory conditions. For application on the wind turbine data should be on-line combined with wind turbine operational parameters and specifically for the drive train data should be fused with traditional vibration measurements. Examples of the data handling and information attained by the analysis will be discussed.

Challenges present in on-line measurements taken on operating wind turbines are discussed and methodologies for future development of reliable condition monitoring methods designed for the needs of wind turbines are shown. Still missing elements for early fault/damage detection during operation of wind turbines are identified and recommendations are proposed.