Expert en Acoustique et Vibration

Transcription

1 Expert en Acoustique et Vibration

2 The operator s assessment of Condition Monitoring Rémi Stein, Erelia, GDF Suez Group Frédéric Giordano,, AREVA EWEA 2011, March 17, 2011

3 Stakes and goals Operating 230 MW of wind turbines in France For wind turbines without OEM s maintenance contract : need to monitor the behavior of key components 2 wind farms with Condition Monitoring Systems: 33 wind turbines (1,5MW) 48MW Commissioned 2002 and 2004 CMS goals Reduce down time Plan repair Avoid heavier failures 3

4 CMS: making a choice 1 Vibration monitoring Best technology to determine accurately faulty components Allows to monitor gearbox and other components, whereas oil analysis is limited to the gearbox New vibration monitoring systems compare data measured under the same running conditions (wind speed, power, rpm ) designed to monitor low speed equipments 2 Oil and grease analysis, visual inspection as complements To confirm a diagnosis 4

5 Installation process 7 accelerometers 1 tachometer Cables 1. Install the sensors in the nacelle with turbine manufacturer 2. Connect with the controller to collect actual power and wind speed 3. Use the existing optic fibers network to reach the substation and the router 4. External communications made via a S or ADSL router Optic Fiber PLC Actual power Wind speed 230V~ About 2 days of down time per wind turbine 5

6 Installation process 7 accelerometers 1 tachometer A1 Wind A2 A3 A5 speed T1 A6 A7 A4 Power Cables Low speed Gearbox Generator PLC Actual power Wind speed 230V~ Optic Fiber 6

7 Identifying failures: a challenge Complex kinematics Gearboxes with planetary train Ratio = 100 (from 0.3 Hz to 30 Hz) Variable speed machine Repeatable Measurements are required: same moment (synchronous) & same condition (power, rotation speed, wind speed) Low and high rotation speeds... Depending on the type and location of a failure, the detection can be a challenging task. Specific Automatic processing are required to separate multiple vibration components

8 Condition Monitoring of WT Case Studies Overview Case study #1 Tooth breakage on sun gear Case study #2 Generator bearing Inner Ring defect Case study #3 Main Bearing Outer Ring defect

9 Case Study #1: A gear failure Typology of the defect : Abnormal periodic impacts with low amplitudes are generated by the broken tooth when meshing with the planet gears We used a filtered time wave. Specific automatic processing is required to detect and anticipate failures: ShockFinder tool Without CMS, the Gearbox would have been destroyed

10 Case Study #2: Generator bearing defect Typology of the defect : Repetitive impacts are generated by the rolling elements passing on the cracks of the defective inner race 1st step : Identify the degradation Inner Ring Frequency 2nd step : plan the bearing replacement Bearing replacement Without CMS, impossible to plan the replacement!

11 Case Study #3: Main bearing Typology of the defect : Repetitive impacts are generated by the rolling elements passing on the cracks of the defective outer race 1st step : Identify the degradation using a filtered time wave 2 nd step : monitor only, without any scheduled change, to optimize availability Outer Ring Frequency Without CMS, impossible to monitor the evolution of the degradation!

12 What are the gains? Hypotheses Parts supplied by manufacturer with short delivery time Costs are all inclusive: manpower, cranes, transportation, parts and eventually production losses Costs based on 1,5 MW wind turbines Examples: Cost for gearbox replacement (new component) = 300 to 350 k Cost for gearbox repair (high speed part) in the turbine : about 80 k

13 #1 Sun gear Failure confirmed by visual inspection on solar pinion No possible repair Detection allowed us to avoid larger damages. What are the gains? #3 Main Bearing No possible inspection Cost to repair: 5 days of downtime and main bearing replacement Cost avoided: 2-5 weeks of downtime and gearbox costs between 170 and 230 k #2 Generator Bearing Failure confirmed by increased signal level Cost to repair: 3 days of downtime and 35 k Cost avoided: generator replacement of 120 to 140 k

14 What financial impacts? Major components considered initially : main bearing, gearbox, generator The life time of major components will not be 20 years Impacts calculated on the 25 monitored wind turbines of La Haute Lys Early detection: Repair instead of replacing Early detection: Reduce down time to a few days 17% of gearbox failures detection to payback the CMS investment (17% of repairs instead of component changes) Gearboxes only: saving 1 replacement / WT on remaining lifetime saves 3,500 K WT remaining lifetime= 16 year Average Gearbox lifetime = 7 years 14

15 Getting your money s worth Total investment was about 450 to 500 k all inclusive for 25 wind turbines ROI (Return On Investment) within 2 to 4 years max, depending on failure rate, types of failure, and turbine age Start early: when CMS is installed on a new turbine, early detection is easier with historical data 15

16 Thank you for your attention Questions? Visit us in hall 12, booth