1. 1 2006 Wind Program Peer Review Drivetrain Development and Reliability Sandy Butterfield 5/10/2006 Need pictures

2. 2 2006 Wind Program Peer Review Design Evolution (Jason) History of designs. Why do they look like they do.  Variable speed – enabler for control of torque loads  High speed brakes gone  Noise (much reduced)  Integration ???  Design tools much improved  Margins much lower  Standards (assisted development of design practice now used for rest of the industry)  Size, lubrication, condition monitoring,

3. 3 2006 Wind Program Peer Review Drivetrain Evolution 1980198519901995 20002005 2010 Drivetrain rating increasing Lubrication additives and filtration High failure rates & noise Variable speed introduced High speed brakes eliminated Wind turbine standards development 40,000 hr. rebuilds required Condition monitoring

4. 4 2006 Wind Program Peer Review State of the art in drivetrain design Vestas, 4.5 MW Enercon, 6 MWMultibrid, 5 MWClipper, 2.5 MW

5. 5 2006 Wind Program Peer Review Design Problems Plaguing Industry  Gearbox failures have plagued the wind industry since early 80s.  Current life much less than 20 years, even using best practice  Reliability remains an issue throughout the drivetrain –Mainshaft and gearbox bearings—especially planetary spherical roller bearings –Housing deflections? –Power electronics IGBT failures –Others Planetary Bearing Inner Race and Roller Failure A. Toms - Gastops

6. 6 2006 Wind Program Peer Review Sample Wind Turbine Data Critical Mass Loss Critical Mass Rate Related to AFRL Prognostics

7. 7 2006 Wind Program Peer Review Program contributions (Walt) Dyno history of contributions (industry partnerships) understanding field problems qualifying production prototypes qualifying new braking controls, lubricants, gear tooth lead testing new concepts multi gen (clipper) NPS (DDG) (WindPact) GEC (mediuim speed gen) (WindPact) Standards support role in AGMA / IEC 61400-4 gearbox guideline by errichello WindPact drive train study Prototypes NPS DDG GEC hybrid

8. 8 2006 Wind Program Peer Review What should the DOE program be doing to foster High- Reliability Systems? High-Reliability Systems Appropriate Environmental Conditions Accurate Loads & Design Requirements Designed-in Reliability Condition Monitoring Reduced Failure Rates Improved O&M System Reliability Analysis Capability O&M Data Base Designed-in Maintainability Full-Scale Testing

9. 9 2006 Wind Program Peer Review Current Programs (Full Scale Dyno Tests)  NPS WindPact Direct Drive Gen prototype test  GEC WindPact medium speed drive prototype test NPS GEC

10. 10 2006 Wind Program Peer Review Current Program (Improved O&M)  Drive train R&D needs workshop (NREL 4/05) –Identified near term needs (failure data, industry collaborative root cause analysis, condition monitoring) –Loads validation –Greater integration between loads codes and internal stress codes –DDG appear to be heavier/more costly but hold promise for greater reliability and lower cost with R&D, especially for offshore  Predictive Maintenance Management workshop (NREL 4/20/06) –CM technology for gearing & bearings available but challenge to apply it economically to wind. –Other areas unique to wind turbines unexploited. (blades, automated fault diagnosis, model assisted load monitoring, poor performance diagnosis. –Need for integrated SCADA systems, O&M management systems and automated data interpretation tools.

11. 11 2006 Wind Program Peer Review Opportunities: (Reducing Failure Rates)  Reliability tools  Second generation WindPact drive train study under SeaCon and prototypes.  Loads Code/Gearbox internal stress code integration

12. 12 2006 Wind Program Peer Review Integrated Codes are Needed Component Level –Determine design integrity of individual components based on specified loads –Single-physics model –Not industry-specific –Commercial products available (ANSYS, etc.) Full System Level –Determine loads throughout full system for component level analysis –Multi-physics model –Wind industry-specific –Simple modeling of components Component Level –Single-physics model –Uncoupled loads do not capture housing flexure –Commercial products available (ANSYS, ADAMS, SimPack)? L. Mumper - SKF

13. 13 2006 Wind Program Peer Review Opportunities: Industry Collaboration  O&M database –Develop automated diagnostics –Identify R&D needs –Fuel reliability models  Predictive Maintenance Management (PdM) –Sandy will finish this.

14. 14 2006 Wind Program Peer Review Gearbox premature mortality investigation project (Walt)

15. 15 2006 Wind Program Peer Review Opportunities: Exploring new concepts SEACON extension of WindPACT drivetrain study 1.Survey existing concepts 2.Cost estimates 3.Reliability estimates 4.Better understand the direct drive / geared system reliability and cost tradeoff

16. 16 2006 Wind Program Peer Review Future Plans (Sandy)  More workshops planned –O&M Practices (SNL Sept 06) –Predictive Maintenance Management II (NREL March 07)  SeaCon Drivetrain concept studies  Attempt to organize industry collaboratives –Gearbox failure investigation –O&M data base –Condition monitoring opportunities