The document discusses myths around condition monitoring of wind turbine drive trains. It presents data on common failures in gearboxes from different inspection techniques and discusses sensor locations that can detect these failures. Charts show examples of vibration data from the high speed section, planetary section, and generator bearing that indicate developing faults. The document argues that condition monitoring can detect planet section issues, is cost justified, and helps avoid unexpected breakdowns through trend analysis of key components.

1. Bachmann electronic GmbH
CONDITION MONITORING OF THE
DRIVE TRAIN MYTHS
end of warranty and permanent installations
- David Clark

2. Bachmann electronic GmbH
WHAT WILL FAIL? AVERAGE SIZE 1.5-2.5MW

3. Bachmann electronic GmbH
WHAT WILL FAIL AT EACH SENSOR
LOCATION?

4. Bachmann electronic GmbH
 TURBINE GEARBOX COMMON INSPECTION TECHNIQUES
Component detection percentages on a typical gearbox
 VISUAL INSPECTION BORESCOPE INSPECTION VIBRATION ANALYSIS

 High Speed Pinion 50% 50% 100%
 Intermediate Wheel & Pinion 100% n/a† 100%
 Low-Speed Wheel 100% n/a† 100%
 Sun Gear No 30%§ 100%
 Planetary Gears (3) 10% 30%§ 100%
 Ring Gear 20% 30% 100%
 High Speed Bearings (3) No 100% 100%
 Intermediate Bearings (2-3) No 50%‡ 100%
 Low Speed Bearings (2) No 50%‡ 100%
 Planetary Carrier Bearings (2) No 30%§ 100%
 Planetary Gear Bearings
 (6 drCRB) No 30%§ 100%
 † Clearly visible during visual inspection by removal of inspection cover
 ‡ Depends upon gearbox make/model, oil level and bearing configuration
 § Requires several rotations of rotor and to inspect 100%, adding several hours to inspection
 By Don Roberts and David Clark

5. Bachmann electronic GmbH
DIFFERENT TYPES OF VIBRATION UNITS- Velocity, acceleration,
displacement, demodulated/enveloped, time waveform, overall.
TIME WAVEFORM VIBRATION SPECTRUM
FFT

6. Bachmann electronic GmbH
CONDITION MONITORING MYTHS
. Need lots of data, lots of measurements, with a baseline
. Too difficult to understand the data
. Not cost justified
. Cannot detect planet section issues
…..All condition monitoring is the same

7. Bachmann electronic GmbH
FFT 1-30 - FFT 1 - Not specified - Acc Freq 1200 Hz
30/04/2004 2:14:30 p.m.
Hz
0 200 400 600 800 1,000 1,20
grms
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
O/All 0.991 g rms
30/04/2004 2:14:30 p.m. O/All 0.991 g rms <set RPM>
FFT 1-30 - FFT 1 - Not specified - Acc Freq 1200 Hz
7/07/2004 5:04:47 p.m.
Hz
0 200 400 600 800 1,000 1,20
grms
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
O/All 0.468 g rms
7/07/2004 5:04:47 p.m. O/All 0.468 g rms <set RPM>
RING GEAR

8. Bachmann electronic GmbH
FFT 1-30 - FFT 1 - Not specified - Acc Freq 1200 Hz
7/07/2004 5:04:47 p.m.
Hz
0 200 400 600 800 1,000 1,20
grms
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
O/All 0.468 g rms
7/07/2004 5:04:47 p.m. O/All 0.468 g rms <set RPM>
FFT 1-30 - FFT 1 - Not specified - Acc Freq 1200 Hz
30/04/2004 2:14:30 p.m.
Hz
0 200 400 600 800 1,000 1,20
grms
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
O/All 0.991 g rms
30/04/2004 2:14:30 p.m. O/All 0.991 g rms <set RPM>

9. Bachmann electronic GmbH
HIGH SPEED SECTION (HSS)

10. Bachmann electronic GmbH
HIGH SPEED SECTION (HSS)
secs
0 1 2 3 4 5 6 7 8
g
-0.8
-0.6
-0.4-0.4
-0.2
0
0.2
0.4
0.6
O/All 0.062 g RMS
Machine Note (3/8/2010 11:09:42 AM)
Changed to High RPM recording 3-8-10 RK
T03 Gbx HighSpeed Horizontal [Tach] Acc Wfm 8000 ms 6/23/2011 8:03:10 AM O/All 0.062 g RMS 1802.787 RPM
T04 Gbx HighSpeed Horizontal [Tach] Acc Wfm 8000 ms 3/14/2011 3:18:04 PM O/All 0.23 g RMS 1829.291 RPM

11. Bachmann electronic GmbH
PLANETARY SECTION
secs
0 10 20 30 40 50 60
g
-1
0
1
2
3
4
O/All 0.312 g RMS
Machine Note (3/8/2010 11:09:31 AM)
Changed to High RPM recording 3-8-10 RK
T04 Gbx Planetary Horizontal [Tach] Acc Wfm 64000 ms 3/14/2011 3:10:40 PM O/All 0.312 g RMS 20.484 RPM
T03 Gbx Planetary Horizontal [Tach] Acc Wfm 64000 ms 6/23/2011 8:10:43 AM O/All 0.035 g RMS 20.297 RPM

12. Bachmann electronic GmbH
CONDITION MONITORING MYTHS
. Need lots of data, lots of measurements,
with a baseline
. Too difficult to understand the data
. Not cost justified
. Cannot detect planet section issues
…..All condition monitoring is the same

13. Bachmann electronic GmbHWind FACTS V2.2
CPM
0 20,000 40,000 60,000 80,000 100,000 120,000
gRMS
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0.18
0.2
0.003 g37.687 orders48773.234 CPMCursor A:
O/All 0.243 g RMS
Turbine 18 HS Gbx Bearing Vertical [Tach] Demod Spec (2-10kHz) 120000 CPM 8/17/2009 8:09:43 AM O/All 0.243 g RMS
Turbine 19 high Speed Vertical Demod Spec (2-10kHz) 120000 CPM 8/17/2009 8:09:24 AM O/All 0.03 g RMS
QJ328BPFI
QJ328BPFI
QJ328BPFI
QJ328BPFI
HIGH SPEED SHAFT (HSS) $300,000 spectrum

14. Bachmann electronic GmbH
GENERATOR BEARING, $95k spectrum

15. Bachmann electronic GmbH
EPRI REPORT COST JUSTIFICATIONS

16. Bachmann electronic GmbH
CONDITION MONITORING MYTHS
. Need lots of data, lots of measurements,
with a baseline
. Too difficult to understand the data
. Not cost justified
. Cannot detect planet section issues
…..All condition monitoring is the same

17. Bachmann electronic GmbH
PLANET GEAR BEARING

18. Bachmann electronic GmbH
PLANET GEAR

19. Bachmann electronic GmbH
PLANET SECTION

20. Bachmann electronic GmbH
PLANET GEAR

21. Bachmann electronic GmbH
CONDITION MONITORING MYTHS
. Need lots of data, lots of measurements,
with a baseline
. Too difficult to understand the data
. Not cost justified
. Cannot detect planet section issues
…..All condition monitoring is the same

22. Bachmann electronic GmbH
+/- 20% ACCURACY

23. Bachmann electronic GmbH
60 RPM +
12 RPM +

24. Bachmann electronic GmbH
+/- 20% ACCURACY
BOTH ARE CURRENTLY BEING INSTALLED WITH OEM
CONDITION MONITORING SYSTEMS
WRONG SENSORS
+/- 20% ACCURACY
USING HIGH SPEED SENSOR IN LOW SPEED
LOCATION

25. Bachmann electronic GmbH
CONDITION MONITORING MYTHS
. Need lots of data, lots of measurements,
with a baseline
. Too difficult to understand the data
. Not cost justified
. Cannot detect planet section issues
…..All condition monitoring is the same

26. Bachmann electronic GmbH
TRENDING EXAMPLES

27. Bachmann electronic GmbH
6/11
warning
8/26
Replacement
of the gearbox
1/8
alarm
planetary stage

28. Bachmann electronic GmbH
2/3
warning
5/13
Replacement
of the bearing
2/17
alarm
HSS bearing

29. Bachmann electronic GmbH

30. DAVID CLARK
d.clark@bachmann.info