1. Accelerating Wind Energy 1 A physical approach to monitor tower base fatigue loads using standard signals Thesis presentation Freark Koopman Committee: Gerard van Bussel Dick Veldkamp Gijs van der Veen

2. Agenda 1.Wind Energy 2.Wind Turbines 3.Load monitoring 4.Physical approach 5.Results 6.Conclusions Accelerating Wind Energy 2

3. Wind Energy Accelerating Wind Energy 3 1

4. Wind Turbines Accelerating Wind Energy 4 2

5. Load monitoring Accelerating Wind Energy 5 2 3 Gain insight in the load history Prevent breakdown Check your design Reduce cost of energy Find abnormal turbine behaviour 3

6. Load monitoring Accelerating Wind Energy 6 Measure (Direct) Expensive Time consuming

7. Load monitoring Accelerating Wind Energy 7 Estimate (Indirect) Already available signals No extra sensors L

8. Load monitoring Accelerating Wind Energy 8 Standard signals Wind speed Pitch angle Power output Rotor speed Nacelle acceleration

9. Load monitoring Accelerating Wind Energy 9 Neural network Good results No insight in underlying process

10. Physical approach Accelerating Wind Energy 10 L 4

11. Physical approach Accelerating Wind Energy 11

12. Physical approach Accelerating Wind Energy 12

13. Physical approach Accelerating Wind Energy 13 Time AccelerationDisplacement

14. Physical approach Accelerating Wind Energy 14 Time Displacement ~150 m Fourier

15. Physical approach Accelerating Wind Energy 15 Fourier Time Amplitude

16. Physical approach Accelerating Wind Energy 16 Fourier Frequency Amplitude

17. Physical approach Accelerating Wind Energy 17 Time AccelerationDisplacement

18. Physical approach Accelerating Wind Energy 18

19. Results Accelerating Wind Energy 19 5 VS

20. Results Accelerating Wind Energy 20 Time Bending Moment

21. Results Accelerating Wind Energy 21 Time Bending Moment

22. Results Accelerating Wind Energy 22 = 1

23. Results Accelerating Wind Energy 23

24. Conclusions Accelerating Wind Energy 24 From nacelle acceleration to tower bending moment High-pass filter to prevent drift Thrust estimator for low frequency compensation Gravity correction necessary The equivalent loads are underestimated by 8% with a standard deviation of 6% 6

25. Accelerating Wind Energy A Physical approach to monitor tower base fatigue loads using standard signals Thank you for your attention

26. Accelerating Wind Energy A Physical approach to monitor tower base fatigue loads using standard signals