Condition Monitoring Systems (CMS) of Wind Power Plants: Status Quo, User Experience, Recommendations, Part I

Project Number 383

Condition monitoring of technical assets aims at detecting changes in their condition that represent deviations from the normal operational behaviour and indicate a developing fault.

Condition monitoring systems are well established in many industrial sec-tors. However, wind turbines differ from the former areas of application with respect to strongly varying loads and rotational speeds in combination with a rough operating environment, which might compromise sensor reliability. Vibration-monitoring of multi-MW turbines is in addition complicated by their low rotational-speed.

In general, a key challenge lies in the limited fault-detection certainty of present CMS for wind turbines. This causes a large number of false alarms, especially in the conventional stand-alone CMS without coupling to the turbine SCADA systems, but also to unforeseen failures. Additional limitations of today’s condition-monitoring practices lie in the determination of suitable alarm threshold values as well as in the severity assessment, i.e. the estimation of the residual useful life and thus the urgency of maintenance measures, which - due to a lack of quantitative methods - is strongly dependent on the subjective judgment of the CMS analysts.

The opinions with respect to the cost-effectiveness of different wind-turbine CMS vary widely, not least since the cost-optimal solution typically depends on a number of different factors. For project developers and operators of wind turbines, making the right choice among the broad spectrum of available condition-monitoring options is a complex and challenging task. A cost-benefit analysis is therefore of particular interest to the VGB member companies of the European Working Group “Wind Energy”.
The project is structured into the following steps and tasks:

  • State-of-the-art study based on a review of literature, studies, standards and product information. The study covers existing CMS for wind-turbine components with or close to practical applicability and takes account of SCADA-data. A cost-benefit analysis will be performed.
  • Survey among VGB-associated wind-turbine operators. The experience of the operators will be included in the study and will be the guide to further investigations.
  • Workshop for dissemination and discussion: The purpose of this event is to discuss the project results identifying key challenges and limitations which require further R&D from the operator’s point of view as the basis of part II of the project.

The members of the European Working Group “Wind Energy” have explicitly expressed that there is a need to optimize the existing CMS, to analyse the cost-benefit ratio and that the experience from the operator’s point have to be taken into account.

The project is supervised by the VGB-European Working Group “Wind Energy”.