Background: Due to cost effectiveness and operational safety online monitoring of rotor blades is recommended, especially for offshore wind energy converters. Method of Approach: Statistic evaluation of wind speed and power output of a wind energy converter is used to monitor the overall rotor performance including increased blade surface roughness. Nacelle oscillation spectral analysis methods are applied to monitor the rotor faults mass imbalance and aerodynamic asymmetry. Results: Results of ISET’s research work related to online rotor condition monitoring are presented. A description of the fault effects on the rotor, the sensor and data acquisition equipment and a description of the developed signal processing and fault prediction algorithms are given. The paper also presents results from experiments and field tests. Conclusions: The developed algorithms have been verified due to their monitoring capabilities and suitability in commercial online condition monitoring systems.

1.
Oppenheim, A. V., and Schafer, R., 1989, Discrete-Time Signal Processing, Prentice–Hall, Englewood Cliffs, NJ.
2.
Patton, R. J., Frank, R. J., and Clark, P. M., 1989, Fault Diagnosis in Dynamic Systems, Theory and Application, Prentice–Hall, Englewood Cliffs, NJ.
3.
Thomsen, K., Rasmussen, F., O̸ye, S., and Petersen, S. M., 1993, “Loads and Dynamics for Stall Regulated Wind Turbines,” Report Risø-R-655(EN), Risø National Laboratory, Denmark.
4.
Bothe, H., 1995, Fuzzy-Logic, Springer-Verlag, Berlin, Germany.
5.
Caselitz, P., Giebhardt, J., Kru¨ger, T., and Mevenkamp, M., 1996, “Development of a Fault Detection System for Wind Energy Converters,” Proceedings of the EUWEC 1996, Go¨teborg, Sweden, pp. 1004–1007 Internet download: http://www.iset.uni-kassel.de/abt/FB-E/public/ffe/ffe_euwec_96_dl.pdf
6.
Meybert, S., 1998, “Mehrkriterielle Alarmierung fu¨r die Fehlerfru¨herkennung in Windkraftanlagen mittels Trendanalyse und Fuzzy-Klassifikation,” Diploma thesis (in German), ISET, Germany.
7.
Caselitz, P., Giebhardt, J., and Kewitsch, R., 1999, “Advanced Condition Monitoring System for Wind Energy Converters,” Proceedings of the EWEC 1999, Nice, France Internet download http://www.iset.uni-kassel.de/abt/FB-E/public/ffe/ffe_ewec_99_dl.pdf
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