1. European Wind Energy Conference 2009 16 – 19 March, Marseille, France Fused Acoustic Emission & Vibration Techniques for Health Monitoring of Wind Turbine Gearboxes and Bearings D. J. Lekou, F. Mouzakis Centre for Renewable Energy Sources (CRES) A. A. Anastassopoulos, D. Kourousis Envirocoustics S. A.

2. European Wind Energy Conference 2009, Marseille, France 2 Drive Train Main Shaft Gearbox High speed shaft Respective bearings

3. European Wind Energy Conference 2009, Marseille, France 3 Drive Train Component Failures Roller Bearings  Ring & Roller cracks  Wearing, Spalling, Brinelling & Fluting Gear Elements  Tooth cracking, Micro-pitting  Abrasion & Spalling Shafts  Cracks & Imbalances

4. European Wind Energy Conference 2009, Marseille, France 4 Condition Monitoring Vibration measurements Wind Turbine Operation Measurements Complemented by:  Oil analysis  Debris monitoring  Temperature monitoring  Visual Inspections (incl. Bore-scope)

5. European Wind Energy Conference 2009, Marseille, France 5 Vibration analysis - Classification Low Frequency (0 – 20 kHz)  Monitoring of total oscillatory motion  FFT, Spectrum analysis Medium Frequency (20 – 100 kHz)  Detection of waves @ the speed of sound  HFE, “Stress wave”, “Spike Energy”, etc. High Frequency ( >100 kHz)  Detection of transient elastic waves  Acoustic Emission

6. European Wind Energy Conference 2009, Marseille, France 6 Vibration analysis – Low Frequency Low Frequency (0 – 20 kHz)  Monitoring of total oscillatory motion  FFT, Spectrum analysis Medium Frequency (20 – 100 kHz)  Detection of waves @ the speed of sound  HFE, “Stress wave”, “Spike Energy”, etc. High Frequency ( >100 kHz)  Detection of transient elastic waves  Acoustic Emission

7. European Wind Energy Conference 2009, Marseille, France 7 Vibration analysis – Medium Frequency Low Frequency (0 – 20 kHz)  Monitoring of total oscillatory motion  FFT, Spectrum analysis Medium Frequency (20 – 100 kHz)  Detection of waves @ the speed of sound  HFE, “Stress wave”, “Spike Energy”, etc. High Frequency ( >100 kHz)  Detection of transient elastic waves  Acoustic Emission

8. European Wind Energy Conference 2009, Marseille, France 8 Vibration analysis – High Frequency Low Frequency (0 – 20 kHz)  Monitoring of total oscillatory motion  FFT, Spectrum analysis Medium Frequency (20 – 100 kHz)  Detection of waves @ the speed of sound  HFE, “Stress wave”, “Spike Energy”, etc. High Frequency ( >100 kHz)  Detection of transient elastic waves  Acoustic Emission

9. European Wind Energy Conference 2009, Marseille, France 9 Acoustic Emission Detection of transient events Due to rapid release of energy Localized Source

10. European Wind Energy Conference 2009, Marseille, France 10 Acoustic Emission Signal & Features Continuous type  Time-Driven Data RMS ASL Absolute Energy Burst type  AE Hit  Descriptors e.g. Amplitude Counts Energy

11. European Wind Energy Conference 2009, Marseille, France 11 Experimental Set-Up Measuring Loads & Vibrations  Wind Inflow parameters  Wind Turbine Operational Parameters  Mechanical Loads on Drive – Train  Vibration & Displacement on Gearbox Acoustic Emission System  PAC PCI-2 18-bit A/D card  CH1: R30a (100kHz – 400kHz)  CH2: PICO (200kHz – 750kHz)

12. European Wind Energy Conference 2009, Marseille, France 12 Experimental Set-up details

13. European Wind Energy Conference 2009, Marseille, France 13 Indicative Results – Simulated source kHz SS V Magnitude

14. European Wind Energy Conference 2009, Marseille, France 14 Indicative Results – Operational AE Hit kHz SS V Magnitude

15. European Wind Energy Conference 2009, Marseille, France 15 Indicative results – AE & Vibration 2ms

16. European Wind Energy Conference 2009, Marseille, France 16 Indicative Results – Time-driven data Time (s) Absolute Energy ASL Power (kW)

17. European Wind Energy Conference 2009, Marseille, France 17 Indicative results – e.g. ASL vs POWER

18. European Wind Energy Conference 2009, Marseille, France 18 Conclusions - Discussion Footprint of normal operation  Capturing Time-driven data  Capturing Transient events Simulation of failure upper limit  Different characteristics from “normal” Both methods have limitations Combination of methods preferred

19. European Wind Energy Conference 2009, Marseille, France 19 Future Work Footprint of failures  Introduction of failures  Use of Pulser Simulator Increase data base  Application on other Wind Turbine Types

20. European Wind Energy Conference 2009, Marseille, France 20 Thank you for your attention Acknowledgements  Partially supported by the European Regional Development Fund and the Greek Secretariat for R & D through AKMON  Part of the work was performed within the EC co-funded project PROTEST (212825)